6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017, 2019, 2020 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019, 2020 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 Nikita Gillmann@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019, 2020 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019 Guillaume Le Vaillant@*
72 Copyright @copyright{} 2020 Leo Prikler@*
73 Copyright @copyright{} 2019, 2020 Simon Tournier@*
74 Copyright @copyright{} 2020 Wiktor Żelazny@*
75 Copyright @copyright{} 2020 Damien Cassou@*
76 Copyright @copyright{} 2020 Jakub Kądziołka@*
77 Copyright @copyright{} 2020 Jack Hill@*
78 Copyright @copyright{} 2020 Naga Malleswari@*
79 Copyright @copyright{} 2020 Brice Waegeneire@*
80 Copyright @copyright{} 2020 R Veera Kumar@*
81 Copyright @copyright{} 2020 Pierre Langlois@*
82 Copyright @copyright{} 2020 pinoaffe@*
84 Permission is granted to copy, distribute and/or modify this document
85 under the terms of the GNU Free Documentation License, Version 1.3 or
86 any later version published by the Free Software Foundation; with no
87 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
88 copy of the license is included in the section entitled ``GNU Free
89 Documentation License''.
92 @dircategory System administration
94 * Guix: (guix). Manage installed software and system configuration.
95 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
96 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
97 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
98 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
99 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
102 @dircategory Software development
104 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
105 * guix build: (guix)Invoking guix build. Building packages.
106 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
110 @title GNU Guix Reference Manual
111 @subtitle Using the GNU Guix Functional Package Manager
112 @author The GNU Guix Developers
115 @vskip 0pt plus 1filll
116 Edition @value{EDITION} @*
124 @c *********************************************************************
128 This document describes GNU Guix version @value{VERSION}, a functional
129 package management tool written for the GNU system.
131 @c TRANSLATORS: You can replace the following paragraph with information on
132 @c how to join your own translation team and how to report issues with the
134 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
135 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
136 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
137 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
138 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
139 would like to translate it in your native language, consider joining the
140 @uref{https://translationproject.org/domain/guix-manual.html, Translation
144 * Introduction:: What is Guix about?
145 * Installation:: Installing Guix.
146 * System Installation:: Installing the whole operating system.
147 * Package Management:: Package installation, upgrade, etc.
148 * Development:: Guix-aided software development.
149 * Programming Interface:: Using Guix in Scheme.
150 * Utilities:: Package management commands.
151 * System Configuration:: Configuring the operating system.
152 * Documentation:: Browsing software user manuals.
153 * Installing Debugging Files:: Feeding the debugger.
154 * Security Updates:: Deploying security fixes quickly.
155 * Bootstrapping:: GNU/Linux built from scratch.
156 * Porting:: Targeting another platform or kernel.
157 * Contributing:: Your help needed!
159 * Acknowledgments:: Thanks!
160 * GNU Free Documentation License:: The license of this manual.
161 * Concept Index:: Concepts.
162 * Programming Index:: Data types, functions, and variables.
165 --- The Detailed Node Listing ---
169 * Managing Software the Guix Way:: What's special.
170 * GNU Distribution:: The packages and tools.
174 * Binary Installation:: Getting Guix running in no time!
175 * Requirements:: Software needed to build and run Guix.
176 * Running the Test Suite:: Testing Guix.
177 * Setting Up the Daemon:: Preparing the build daemon's environment.
178 * Invoking guix-daemon:: Running the build daemon.
179 * Application Setup:: Application-specific setup.
181 Setting Up the Daemon
183 * Build Environment Setup:: Preparing the isolated build environment.
184 * Daemon Offload Setup:: Offloading builds to remote machines.
185 * SELinux Support:: Using an SELinux policy for the daemon.
189 * Limitations:: What you can expect.
190 * Hardware Considerations:: Supported hardware.
191 * USB Stick and DVD Installation:: Preparing the installation medium.
192 * Preparing for Installation:: Networking, partitioning, etc.
193 * Guided Graphical Installation:: Easy graphical installation.
194 * Manual Installation:: Manual installation for wizards.
195 * After System Installation:: When installation succeeded.
196 * Installing Guix in a VM:: Guix System playground.
197 * Building the Installation Image:: How this comes to be.
201 * Keyboard Layout and Networking and Partitioning:: Initial setup.
202 * Proceeding with the Installation:: Installing.
206 * Features:: How Guix will make your life brighter.
207 * Invoking guix package:: Package installation, removal, etc.
208 * Substitutes:: Downloading pre-built binaries.
209 * Packages with Multiple Outputs:: Single source package, multiple outputs.
210 * Invoking guix gc:: Running the garbage collector.
211 * Invoking guix pull:: Fetching the latest Guix and distribution.
212 * Channels:: Customizing the package collection.
213 * Invoking guix time-machine:: Running an older revision of Guix.
214 * Inferiors:: Interacting with another revision of Guix.
215 * Invoking guix describe:: Display information about your Guix revision.
216 * Invoking guix archive:: Exporting and importing store files.
220 * Official Substitute Server:: One particular source of substitutes.
221 * Substitute Server Authorization:: How to enable or disable substitutes.
222 * Substitute Authentication:: How Guix verifies substitutes.
223 * Proxy Settings:: How to get substitutes via proxy.
224 * Substitution Failure:: What happens when substitution fails.
225 * On Trusting Binaries:: How can you trust that binary blob?
229 * Invoking guix environment:: Setting up development environments.
230 * Invoking guix pack:: Creating software bundles.
232 Programming Interface
234 * Package Modules:: Packages from the programmer's viewpoint.
235 * Defining Packages:: Defining new packages.
236 * Build Systems:: Specifying how packages are built.
237 * The Store:: Manipulating the package store.
238 * Derivations:: Low-level interface to package derivations.
239 * The Store Monad:: Purely functional interface to the store.
240 * G-Expressions:: Manipulating build expressions.
241 * Invoking guix repl:: Fiddling with Guix interactively.
245 * package Reference:: The package data type.
246 * origin Reference:: The origin data type.
250 * Invoking guix build:: Building packages from the command line.
251 * Invoking guix edit:: Editing package definitions.
252 * Invoking guix download:: Downloading a file and printing its hash.
253 * Invoking guix hash:: Computing the cryptographic hash of a file.
254 * Invoking guix import:: Importing package definitions.
255 * Invoking guix refresh:: Updating package definitions.
256 * Invoking guix lint:: Finding errors in package definitions.
257 * Invoking guix size:: Profiling disk usage.
258 * Invoking guix graph:: Visualizing the graph of packages.
259 * Invoking guix publish:: Sharing substitutes.
260 * Invoking guix challenge:: Challenging substitute servers.
261 * Invoking guix copy:: Copying to and from a remote store.
262 * Invoking guix container:: Process isolation.
263 * Invoking guix weather:: Assessing substitute availability.
264 * Invoking guix processes:: Listing client processes.
266 Invoking @command{guix build}
268 * Common Build Options:: Build options for most commands.
269 * Package Transformation Options:: Creating variants of packages.
270 * Additional Build Options:: Options specific to 'guix build'.
271 * Debugging Build Failures:: Real life packaging experience.
275 * Using the Configuration System:: Customizing your GNU system.
276 * operating-system Reference:: Detail of operating-system declarations.
277 * File Systems:: Configuring file system mounts.
278 * Mapped Devices:: Block device extra processing.
279 * User Accounts:: Specifying user accounts.
280 * Keyboard Layout:: How the system interprets key strokes.
281 * Locales:: Language and cultural convention settings.
282 * Services:: Specifying system services.
283 * Setuid Programs:: Programs running with root privileges.
284 * X.509 Certificates:: Authenticating HTTPS servers.
285 * Name Service Switch:: Configuring libc's name service switch.
286 * Initial RAM Disk:: Linux-Libre bootstrapping.
287 * Bootloader Configuration:: Configuring the boot loader.
288 * Invoking guix system:: Instantiating a system configuration.
289 * Invoking guix deploy:: Deploying a system configuration to a remote host.
290 * Running Guix in a VM:: How to run Guix System in a virtual machine.
291 * Defining Services:: Adding new service definitions.
295 * Base Services:: Essential system services.
296 * Scheduled Job Execution:: The mcron service.
297 * Log Rotation:: The rottlog service.
298 * Networking Services:: Network setup, SSH daemon, etc.
299 * X Window:: Graphical display.
300 * Printing Services:: Local and remote printer support.
301 * Desktop Services:: D-Bus and desktop services.
302 * Sound Services:: ALSA and Pulseaudio services.
303 * Database Services:: SQL databases, key-value stores, etc.
304 * Mail Services:: IMAP, POP3, SMTP, and all that.
305 * Messaging Services:: Messaging services.
306 * Telephony Services:: Telephony services.
307 * Monitoring Services:: Monitoring services.
308 * Kerberos Services:: Kerberos services.
309 * Web Services:: Web servers.
310 * Certificate Services:: TLS certificates via Let's Encrypt.
311 * DNS Services:: DNS daemons.
312 * VPN Services:: VPN daemons.
313 * Network File System:: NFS related services.
314 * Continuous Integration:: The Cuirass service.
315 * Power Management Services:: Extending battery life.
316 * Audio Services:: The MPD.
317 * Virtualization Services:: Virtualization services.
318 * Version Control Services:: Providing remote access to Git repositories.
319 * Game Services:: Game servers.
320 * PAM Mount Service:: Service to mount volumes when logging in.
321 * Linux Services:: Services tied to the Linux kernel.
322 * Miscellaneous Services:: Other services.
326 * Service Composition:: The model for composing services.
327 * Service Types and Services:: Types and services.
328 * Service Reference:: API reference.
329 * Shepherd Services:: A particular type of service.
334 @c *********************************************************************
336 @chapter Introduction
339 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
340 using the international phonetic alphabet (IPA).} is a package
341 management tool for and distribution of the GNU system.
342 Guix makes it easy for unprivileged
343 users to install, upgrade, or remove software packages, to roll back to a
344 previous package set, to build packages from source, and generally
345 assists with the creation and maintenance of software environments.
348 @cindex GuixSD, now Guix System
349 @cindex Guix System Distribution, now Guix System
350 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
351 complements the available tools without interference (@pxref{Installation}),
352 or you can use it as a standalone operating system distribution,
353 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
354 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
355 group everything under the ``Guix'' banner since, after all, Guix System is
356 readily available through the @command{guix system} command, even if you're
357 using a different distro underneath!}. @xref{GNU Distribution}.
360 * Managing Software the Guix Way:: What's special.
361 * GNU Distribution:: The packages and tools.
364 @node Managing Software the Guix Way
365 @section Managing Software the Guix Way
367 @cindex user interfaces
368 Guix provides a command-line package management interface
369 (@pxref{Package Management}), tools to help with software development
370 (@pxref{Development}), command-line utilities for more advanced usage,
371 (@pxref{Utilities}), as well as Scheme programming interfaces
372 (@pxref{Programming Interface}).
374 Its @dfn{build daemon} is responsible for building packages on behalf of
375 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
376 binaries from authorized sources (@pxref{Substitutes}).
378 @cindex extensibility of the distribution
379 @cindex customization, of packages
380 Guix includes package definitions for many GNU and non-GNU packages, all
381 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
382 user's computing freedom}. It is @emph{extensible}: users can write
383 their own package definitions (@pxref{Defining Packages}) and make them
384 available as independent package modules (@pxref{Package Modules}). It
385 is also @emph{customizable}: users can @emph{derive} specialized package
386 definitions from existing ones, including from the command line
387 (@pxref{Package Transformation Options}).
389 @cindex functional package management
391 Under the hood, Guix implements the @dfn{functional package management}
392 discipline pioneered by Nix (@pxref{Acknowledgments}).
393 In Guix, the package build and installation process is seen
394 as a @emph{function}, in the mathematical sense. That function takes inputs,
395 such as build scripts, a compiler, and libraries, and
396 returns an installed package. As a pure function, its result depends
397 solely on its inputs---for instance, it cannot refer to software or
398 scripts that were not explicitly passed as inputs. A build function
399 always produces the same result when passed a given set of inputs. It
400 cannot alter the environment of the running system in
401 any way; for instance, it cannot create, modify, or delete files outside
402 of its build and installation directories. This is achieved by running
403 build processes in isolated environments (or @dfn{containers}), where only their
404 explicit inputs are visible.
407 The result of package build functions is @dfn{cached} in the file
408 system, in a special directory called @dfn{the store} (@pxref{The
409 Store}). Each package is installed in a directory of its own in the
410 store---by default under @file{/gnu/store}. The directory name contains
411 a hash of all the inputs used to build that package; thus, changing an
412 input yields a different directory name.
414 This approach is the foundation for the salient features of Guix: support
415 for transactional package upgrade and rollback, per-user installation, and
416 garbage collection of packages (@pxref{Features}).
419 @node GNU Distribution
420 @section GNU Distribution
423 Guix comes with a distribution of the GNU system consisting entirely of
424 free software@footnote{The term ``free'' here refers to the
425 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
426 users of that software}.}. The
427 distribution can be installed on its own (@pxref{System Installation}),
428 but it is also possible to install Guix as a package manager on top of
429 an installed GNU/Linux system (@pxref{Installation}). When we need to
430 distinguish between the two, we refer to the standalone distribution as
433 The distribution provides core GNU packages such as GNU libc, GCC, and
434 Binutils, as well as many GNU and non-GNU applications. The complete
435 list of available packages can be browsed
436 @url{https://www.gnu.org/software/guix/packages,on-line} or by
437 running @command{guix package} (@pxref{Invoking guix package}):
440 guix package --list-available
443 Our goal is to provide a practical 100% free software distribution of
444 Linux-based and other variants of GNU, with a focus on the promotion and
445 tight integration of GNU components, and an emphasis on programs and
446 tools that help users exert that freedom.
448 Packages are currently available on the following platforms:
453 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
456 Intel 32-bit architecture (IA32), Linux-Libre kernel;
459 ARMv7-A architecture with hard float, Thumb-2 and NEON,
460 using the EABI hard-float application binary interface (ABI),
461 and Linux-Libre kernel.
464 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
467 little-endian 64-bit MIPS processors, specifically the Loongson series,
468 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
469 supported; in particular, the project's build farms no longer provide
470 substitutes for this architecture.
474 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
475 configuration and Guix takes care of instantiating the configuration in a
476 transactional, reproducible, and stateless fashion (@pxref{System
477 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
478 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
479 Manual}), the well-known GNU utilities and tool chain, as well as the
480 graphical environment or system services of your choice.
482 Guix System is available on all the above platforms except
483 @code{mips64el-linux}.
486 For information on porting to other architectures or kernels,
489 Building this distribution is a cooperative effort, and you are invited
490 to join! @xref{Contributing}, for information about how you can help.
493 @c *********************************************************************
495 @chapter Installation
497 @cindex installing Guix
500 We recommend the use of this
501 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
502 shell installer script} to install Guix on top of a running GNU/Linux system,
503 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
504 with the installation of the package manager, which can be done on top of a
505 running GNU/Linux system. If, instead, you want to install the complete GNU
506 operating system, @pxref{System Installation}.} The script automates the
507 download, installation, and initial configuration of Guix. It should be run
511 @cindex foreign distro
512 @cindex directories related to foreign distro
513 When installed on a foreign distro, GNU@tie{}Guix complements the available
514 tools without interference. Its data lives exclusively in two directories,
515 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
516 such as @file{/etc}, are left untouched.
518 Once installed, Guix can be updated by running @command{guix pull}
519 (@pxref{Invoking guix pull}).
521 If you prefer to perform the installation steps manually or want to tweak
522 them, you may find the following subsections useful. They describe the
523 software requirements of Guix, as well as how to install it manually and get
527 * Binary Installation:: Getting Guix running in no time!
528 * Requirements:: Software needed to build and run Guix.
529 * Running the Test Suite:: Testing Guix.
530 * Setting Up the Daemon:: Preparing the build daemon's environment.
531 * Invoking guix-daemon:: Running the build daemon.
532 * Application Setup:: Application-specific setup.
533 * Upgrading Guix:: Upgrading Guix and its build daemon.
536 @node Binary Installation
537 @section Binary Installation
539 @cindex installing Guix from binaries
540 @cindex installer script
541 This section describes how to install Guix on an arbitrary system from a
542 self-contained tarball providing binaries for Guix and for all its
543 dependencies. This is often quicker than installing from source, which
544 is described in the next sections. The only requirement is to have
547 @c Note duplicated from the ``Installation'' node.
549 We recommend the use of this
550 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
551 shell installer script}. The script automates the download, installation, and
552 initial configuration steps described below. It should be run as the root
553 user. As root, you can thus run this:
557 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
558 chmod +x guix-install.sh
563 Installing goes along these lines:
567 @cindex downloading Guix binary
568 Download the binary tarball from
569 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
570 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
571 already running the kernel Linux, and so on.
573 @c The following is somewhat duplicated in ``System Installation''.
574 Make sure to download the associated @file{.sig} file and to verify the
575 authenticity of the tarball against it, along these lines:
578 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
579 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
582 If that command fails because you do not have the required public key,
583 then run this command to import it:
586 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
587 -qO - | gpg --import -
591 and rerun the @code{gpg --verify} command.
593 Take note that a warning like ``This key is not certified with a trusted
594 signature!'' is normal.
596 @c end authentication part
599 Now, you need to become the @code{root} user. Depending on your distribution,
600 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
604 # tar --warning=no-timestamp -xf \
605 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
606 # mv var/guix /var/ && mv gnu /
609 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
610 The latter contains a ready-to-use profile for @code{root} (see next
613 Do @emph{not} unpack the tarball on a working Guix system since that
614 would overwrite its own essential files.
616 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
617 not emit warnings about ``implausibly old time stamps'' (such
618 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
620 They stem from the fact that all the
621 files in the archive have their modification time set to zero (which
622 means January 1st, 1970.) This is done on purpose to make sure the
623 archive content is independent of its creation time, thus making it
627 Make the profile available under @file{~root/.config/guix/current}, which is
628 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
631 # mkdir -p ~root/.config/guix
632 # ln -sf /var/guix/profiles/per-user/root/current-guix \
633 ~root/.config/guix/current
636 Source @file{etc/profile} to augment @env{PATH} and other relevant
637 environment variables:
640 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
641 source $GUIX_PROFILE/etc/profile
645 Create the group and user accounts for build users as explained below
646 (@pxref{Build Environment Setup}).
649 Run the daemon, and set it to automatically start on boot.
651 If your host distro uses the systemd init system, this can be achieved
654 @c Versions of systemd that supported symlinked service files are not
655 @c yet widely deployed, so we should suggest that users copy the service
658 @c See this thread for more information:
659 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
662 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
664 # systemctl enable --now guix-daemon
667 If your host distro uses the Upstart init system:
670 # initctl reload-configuration
671 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
676 Otherwise, you can still start the daemon manually with:
679 # ~root/.config/guix/current/bin/guix-daemon \
680 --build-users-group=guixbuild
684 Make the @command{guix} command available to other users on the machine,
688 # mkdir -p /usr/local/bin
690 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
693 It is also a good idea to make the Info version of this manual available
697 # mkdir -p /usr/local/share/info
698 # cd /usr/local/share/info
699 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
703 That way, assuming @file{/usr/local/share/info} is in the search path,
704 running @command{info guix} will open this manual (@pxref{Other Info
705 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
709 @cindex substitutes, authorization thereof
710 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
711 (@pxref{Substitutes}), authorize them:
714 # guix archive --authorize < \
715 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
719 Each user may need to perform a few additional steps to make their Guix
720 environment ready for use, @pxref{Application Setup}.
723 Voilà, the installation is complete!
725 You can confirm that Guix is working by installing a sample package into
732 The binary installation tarball can be (re)produced and verified simply
733 by running the following command in the Guix source tree:
736 make guix-binary.@var{system}.tar.xz
740 ...@: which, in turn, runs:
743 guix pack -s @var{system} --localstatedir \
744 --profile-name=current-guix guix
747 @xref{Invoking guix pack}, for more info on this handy tool.
750 @section Requirements
752 This section lists requirements when building Guix from source. The
753 build procedure for Guix is the same as for other GNU software, and is
754 not covered here. Please see the files @file{README} and @file{INSTALL}
755 in the Guix source tree for additional details.
757 @cindex official website
758 GNU Guix is available for download from its website at
759 @url{https://www.gnu.org/software/guix/}.
761 GNU Guix depends on the following packages:
764 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
766 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
769 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
770 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
771 Guile,, gnutls-guile, GnuTLS-Guile});
773 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
776 @c FIXME: Specify a version number once a release has been made.
777 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
779 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
780 @item @url{https://zlib.net, zlib};
781 @item @url{https://www.gnu.org/software/make/, GNU Make}.
784 The following dependencies are optional:
788 @c Note: We need at least 0.12.0 for 'userauth-gssapi!'.
789 Support for build offloading (@pxref{Daemon Offload Setup}) and
790 @command{guix copy} (@pxref{Invoking guix copy}) depends on
791 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
792 version 0.12.0 or later.
795 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
796 substitutes can be used and @command{guix publish} can compress substitutes
800 When @url{http://www.bzip.org, libbz2} is available,
801 @command{guix-daemon} can use it to compress build logs.
804 Unless @option{--disable-daemon} was passed to @command{configure}, the
805 following packages are also needed:
808 @item @url{https://gnupg.org/, GNU libgcrypt};
809 @item @url{https://sqlite.org, SQLite 3};
810 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
814 @cindex state directory
815 When configuring Guix on a system that already has a Guix installation,
816 be sure to specify the same state directory as the existing installation
817 using the @option{--localstatedir} option of the @command{configure}
818 script (@pxref{Directory Variables, @code{localstatedir},, standards,
819 GNU Coding Standards}). Usually, this @var{localstatedir} option is
820 set to the value @file{/var}. The @command{configure} script protects
821 against unintended misconfiguration of @var{localstatedir} so you do not
822 inadvertently corrupt your store (@pxref{The Store}).
824 @node Running the Test Suite
825 @section Running the Test Suite
828 After a successful @command{configure} and @code{make} run, it is a good
829 idea to run the test suite. It can help catch issues with the setup or
830 environment, or bugs in Guix itself---and really, reporting test
831 failures is a good way to help improve the software. To run the test
838 Test cases can run in parallel: you can use the @code{-j} option of
839 GNU@tie{}make to speed things up. The first run may take a few minutes
840 on a recent machine; subsequent runs will be faster because the store
841 that is created for test purposes will already have various things in
844 It is also possible to run a subset of the tests by defining the
845 @code{TESTS} makefile variable as in this example:
848 make check TESTS="tests/store.scm tests/cpio.scm"
851 By default, tests results are displayed at a file level. In order to
852 see the details of every individual test cases, it is possible to define
853 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
856 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
859 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
860 @file{test-suite.log} file. Please specify the Guix version being used
861 as well as version numbers of the dependencies (@pxref{Requirements}) in
864 Guix also comes with a whole-system test suite that tests complete
865 Guix System instances. It can only run on systems where
866 Guix is already installed, using:
873 or, again, by defining @code{TESTS} to select a subset of tests to run:
876 make check-system TESTS="basic mcron"
879 These system tests are defined in the @code{(gnu tests @dots{})}
880 modules. They work by running the operating systems under test with
881 lightweight instrumentation in a virtual machine (VM). They can be
882 computationally intensive or rather cheap, depending on whether
883 substitutes are available for their dependencies (@pxref{Substitutes}).
884 Some of them require a lot of storage space to hold VM images.
886 Again in case of test failures, please send @email{bug-guix@@gnu.org}
889 @node Setting Up the Daemon
890 @section Setting Up the Daemon
893 Operations such as building a package or running the garbage collector
894 are all performed by a specialized process, the @dfn{build daemon}, on
895 behalf of clients. Only the daemon may access the store and its
896 associated database. Thus, any operation that manipulates the store
897 goes through the daemon. For instance, command-line tools such as
898 @command{guix package} and @command{guix build} communicate with the
899 daemon (@i{via} remote procedure calls) to instruct it what to do.
901 The following sections explain how to prepare the build daemon's
902 environment. See also @ref{Substitutes}, for information on how to allow
903 the daemon to download pre-built binaries.
906 * Build Environment Setup:: Preparing the isolated build environment.
907 * Daemon Offload Setup:: Offloading builds to remote machines.
908 * SELinux Support:: Using an SELinux policy for the daemon.
911 @node Build Environment Setup
912 @subsection Build Environment Setup
914 @cindex build environment
915 In a standard multi-user setup, Guix and its daemon---the
916 @command{guix-daemon} program---are installed by the system
917 administrator; @file{/gnu/store} is owned by @code{root} and
918 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
919 Guix tools to build packages or otherwise access the store, and the
920 daemon will do it on their behalf, ensuring that the store is kept in a
921 consistent state, and allowing built packages to be shared among users.
924 When @command{guix-daemon} runs as @code{root}, you may not want package
925 build processes themselves to run as @code{root} too, for obvious
926 security reasons. To avoid that, a special pool of @dfn{build users}
927 should be created for use by build processes started by the daemon.
928 These build users need not have a shell and a home directory: they will
929 just be used when the daemon drops @code{root} privileges in build
930 processes. Having several such users allows the daemon to launch
931 distinct build processes under separate UIDs, which guarantees that they
932 do not interfere with each other---an essential feature since builds are
933 regarded as pure functions (@pxref{Introduction}).
935 On a GNU/Linux system, a build user pool may be created like this (using
936 Bash syntax and the @code{shadow} commands):
938 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
939 @c for why `-G' is needed.
941 # groupadd --system guixbuild
942 # for i in `seq -w 1 10`;
944 useradd -g guixbuild -G guixbuild \
945 -d /var/empty -s `which nologin` \
946 -c "Guix build user $i" --system \
952 The number of build users determines how many build jobs may run in
953 parallel, as specified by the @option{--max-jobs} option
954 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
955 @command{guix system vm} and related commands, you may need to add the
956 build users to the @code{kvm} group so they can access @file{/dev/kvm},
957 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
958 (@pxref{Invoking guix system}).
960 The @code{guix-daemon} program may then be run as @code{root} with the
961 following command@footnote{If your machine uses the systemd init system,
962 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
963 file in @file{/etc/systemd/system} will ensure that
964 @command{guix-daemon} is automatically started. Similarly, if your
965 machine uses the Upstart init system, drop the
966 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
967 file in @file{/etc/init}.}:
970 # guix-daemon --build-users-group=guixbuild
975 This way, the daemon starts build processes in a chroot, under one of
976 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
977 environment contains nothing but:
979 @c Keep this list in sync with libstore/build.cc! -----------------------
982 a minimal @code{/dev} directory, created mostly independently from the
983 host @code{/dev}@footnote{``Mostly'', because while the set of files
984 that appear in the chroot's @code{/dev} is fixed, most of these files
985 can only be created if the host has them.};
988 the @code{/proc} directory; it only shows the processes of the container
989 since a separate PID name space is used;
992 @file{/etc/passwd} with an entry for the current user and an entry for
996 @file{/etc/group} with an entry for the user's group;
999 @file{/etc/hosts} with an entry that maps @code{localhost} to
1003 a writable @file{/tmp} directory.
1006 You can influence the directory where the daemon stores build trees
1007 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1008 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1009 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1010 This way, the value of @env{TMPDIR} does not leak inside build
1011 environments, which avoids discrepancies in cases where build processes
1012 capture the name of their build tree.
1016 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1017 environment variables for HTTP and HTTPS downloads it performs, be it
1018 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1019 (@pxref{Substitutes}).
1021 If you are installing Guix as an unprivileged user, it is still possible
1022 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1023 However, build processes will not be isolated from one another, and not
1024 from the rest of the system. Thus, build processes may interfere with
1025 each other, and may access programs, libraries, and other files
1026 available on the system---making it much harder to view them as
1027 @emph{pure} functions.
1030 @node Daemon Offload Setup
1031 @subsection Using the Offload Facility
1035 When desired, the build daemon can @dfn{offload} derivation builds to
1036 other machines running Guix, using the @code{offload} @dfn{build
1037 hook}@footnote{This feature is available only when
1038 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1039 present.}. When that
1040 feature is enabled, a list of user-specified build machines is read from
1041 @file{/etc/guix/machines.scm}; every time a build is requested, for
1042 instance via @code{guix build}, the daemon attempts to offload it to one
1043 of the machines that satisfy the constraints of the derivation, in
1044 particular its system type---e.g., @file{x86_64-linux}. Missing
1045 prerequisites for the build are copied over SSH to the target machine,
1046 which then proceeds with the build; upon success the output(s) of the
1047 build are copied back to the initial machine.
1049 The @file{/etc/guix/machines.scm} file typically looks like this:
1052 (list (build-machine
1053 (name "eightysix.example.org")
1054 (system "x86_64-linux")
1055 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1057 (speed 2.)) ;incredibly fast!
1060 (name "meeps.example.org")
1061 (system "mips64el-linux")
1062 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1065 (string-append (getenv "HOME")
1066 "/.ssh/identity-for-guix"))))
1070 In the example above we specify a list of two build machines, one for
1071 the @code{x86_64} architecture and one for the @code{mips64el}
1074 In fact, this file is---not surprisingly!---a Scheme file that is
1075 evaluated when the @code{offload} hook is started. Its return value
1076 must be a list of @code{build-machine} objects. While this example
1077 shows a fixed list of build machines, one could imagine, say, using
1078 DNS-SD to return a list of potential build machines discovered in the
1079 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1080 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1083 @deftp {Data Type} build-machine
1084 This data type represents build machines to which the daemon may offload
1085 builds. The important fields are:
1090 The host name of the remote machine.
1093 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1096 The user account to use when connecting to the remote machine over SSH.
1097 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1098 allow non-interactive logins.
1101 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1102 This is used to authenticate the machine when we connect to it. It is a
1103 long string that looks like this:
1106 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1109 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1110 key can be found in a file such as
1111 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1113 If the machine is running the SSH daemon of GNU@tie{}lsh,
1114 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1115 similar file. It can be converted to the OpenSSH format using
1116 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1119 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1120 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1125 A number of optional fields may be specified:
1129 @item @code{port} (default: @code{22})
1130 Port number of SSH server on the machine.
1132 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1133 The SSH private key file to use when connecting to the machine, in
1134 OpenSSH format. This key must not be protected with a passphrase.
1136 Note that the default value is the private key @emph{of the root
1137 account}. Make sure it exists if you use the default.
1139 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1140 @itemx @code{compression-level} (default: @code{3})
1141 The SSH-level compression methods and compression level requested.
1143 Note that offloading relies on SSH compression to reduce bandwidth usage
1144 when transferring files to and from build machines.
1146 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1147 File name of the Unix-domain socket @command{guix-daemon} is listening
1150 @item @code{parallel-builds} (default: @code{1})
1151 The number of builds that may run in parallel on the machine.
1153 @item @code{speed} (default: @code{1.0})
1154 A ``relative speed factor''. The offload scheduler will tend to prefer
1155 machines with a higher speed factor.
1157 @item @code{features} (default: @code{'()})
1158 A list of strings denoting specific features supported by the machine.
1159 An example is @code{"kvm"} for machines that have the KVM Linux modules
1160 and corresponding hardware support. Derivations can request features by
1161 name, and they will be scheduled on matching build machines.
1166 The @command{guix} command must be in the search path on the build
1167 machines. You can check whether this is the case by running:
1170 ssh build-machine guix repl --version
1173 There is one last thing to do once @file{machines.scm} is in place. As
1174 explained above, when offloading, files are transferred back and forth
1175 between the machine stores. For this to work, you first need to
1176 generate a key pair on each machine to allow the daemon to export signed
1177 archives of files from the store (@pxref{Invoking guix archive}):
1180 # guix archive --generate-key
1184 Each build machine must authorize the key of the master machine so that
1185 it accepts store items it receives from the master:
1188 # guix archive --authorize < master-public-key.txt
1192 Likewise, the master machine must authorize the key of each build machine.
1194 All the fuss with keys is here to express pairwise mutual trust
1195 relations between the master and the build machines. Concretely, when
1196 the master receives files from a build machine (and @i{vice versa}), its
1197 build daemon can make sure they are genuine, have not been tampered
1198 with, and that they are signed by an authorized key.
1200 @cindex offload test
1201 To test whether your setup is operational, run this command on the
1208 This will attempt to connect to each of the build machines specified in
1209 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1210 available on each machine, attempt to export to the machine and import
1211 from it, and report any error in the process.
1213 If you want to test a different machine file, just specify it on the
1217 # guix offload test machines-qualif.scm
1220 Last, you can test the subset of the machines whose name matches a
1221 regular expression like this:
1224 # guix offload test machines.scm '\.gnu\.org$'
1227 @cindex offload status
1228 To display the current load of all build hosts, run this command on the
1232 # guix offload status
1236 @node SELinux Support
1237 @subsection SELinux Support
1239 @cindex SELinux, daemon policy
1240 @cindex mandatory access control, SELinux
1241 @cindex security, guix-daemon
1242 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1243 can be installed on a system where SELinux is enabled, in order to label
1244 Guix files and to specify the expected behavior of the daemon. Since
1245 Guix System does not provide an SELinux base policy, the daemon policy cannot
1246 be used on Guix System.
1248 @subsubsection Installing the SELinux policy
1249 @cindex SELinux, policy installation
1250 To install the policy run this command as root:
1253 semodule -i etc/guix-daemon.cil
1256 Then relabel the file system with @code{restorecon} or by a different
1257 mechanism provided by your system.
1259 Once the policy is installed, the file system has been relabeled, and
1260 the daemon has been restarted, it should be running in the
1261 @code{guix_daemon_t} context. You can confirm this with the following
1265 ps -Zax | grep guix-daemon
1268 Monitor the SELinux log files as you run a command like @code{guix build
1269 hello} to convince yourself that SELinux permits all necessary
1272 @subsubsection Limitations
1273 @cindex SELinux, limitations
1275 This policy is not perfect. Here is a list of limitations or quirks
1276 that should be considered when deploying the provided SELinux policy for
1281 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1282 operations involve contexts that have anything to do with
1283 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1284 but it would be preferrable to define socket rules for only this label.
1287 @code{guix gc} cannot access arbitrary links to profiles. By design,
1288 the file label of the destination of a symlink is independent of the
1289 file label of the link itself. Although all profiles under
1290 $localstatedir are labelled, the links to these profiles inherit the
1291 label of the directory they are in. For links in the user’s home
1292 directory this will be @code{user_home_t}. But for links from the root
1293 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1294 directory, etc, this won’t work. @code{guix gc} would be prevented from
1295 reading and following these links.
1298 The daemon’s feature to listen for TCP connections might no longer work.
1299 This might require extra rules, because SELinux treats network sockets
1300 differently from files.
1303 Currently all files with a name matching the regular expression
1304 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1305 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1306 that name in any profile would be permitted to run in the
1307 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1308 build a package that provides this executable and convince a user to
1309 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1310 At that point SELinux could not prevent it from accessing files that are
1311 allowed for processes in that domain.
1313 We could generate a much more restrictive policy at installation time,
1314 so that only the @emph{exact} file name of the currently installed
1315 @code{guix-daemon} executable would be labelled with
1316 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1317 The downside is that root would have to install or upgrade the policy at
1318 installation time whenever the Guix package that provides the
1319 effectively running @code{guix-daemon} executable is upgraded.
1322 @node Invoking guix-daemon
1323 @section Invoking @command{guix-daemon}
1325 The @command{guix-daemon} program implements all the functionality to
1326 access the store. This includes launching build processes, running the
1327 garbage collector, querying the availability of a build result, etc. It
1328 is normally run as @code{root} like this:
1331 # guix-daemon --build-users-group=guixbuild
1335 For details on how to set it up, @pxref{Setting Up the Daemon}.
1338 @cindex container, build environment
1339 @cindex build environment
1340 @cindex reproducible builds
1341 By default, @command{guix-daemon} launches build processes under
1342 different UIDs, taken from the build group specified with
1343 @option{--build-users-group}. In addition, each build process is run in a
1344 chroot environment that only contains the subset of the store that the
1345 build process depends on, as specified by its derivation
1346 (@pxref{Programming Interface, derivation}), plus a set of specific
1347 system directories. By default, the latter contains @file{/dev} and
1348 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1349 @dfn{container}: in addition to having its own file system tree, it has
1350 a separate mount name space, its own PID name space, network name space,
1351 etc. This helps achieve reproducible builds (@pxref{Features}).
1353 When the daemon performs a build on behalf of the user, it creates a
1354 build directory under @file{/tmp} or under the directory specified by
1355 its @env{TMPDIR} environment variable. This directory is shared with
1356 the container for the duration of the build, though within the container,
1357 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1359 The build directory is automatically deleted upon completion, unless the
1360 build failed and the client specified @option{--keep-failed}
1361 (@pxref{Invoking guix build, @option{--keep-failed}}).
1363 The daemon listens for connections and spawns one sub-process for each session
1364 started by a client (one of the @command{guix} sub-commands.) The
1365 @command{guix processes} command allows you to get an overview of the activity
1366 on your system by viewing each of the active sessions and clients.
1367 @xref{Invoking guix processes}, for more information.
1369 The following command-line options are supported:
1372 @item --build-users-group=@var{group}
1373 Take users from @var{group} to run build processes (@pxref{Setting Up
1374 the Daemon, build users}).
1376 @item --no-substitutes
1378 Do not use substitutes for build products. That is, always build things
1379 locally instead of allowing downloads of pre-built binaries
1380 (@pxref{Substitutes}).
1382 When the daemon runs with @option{--no-substitutes}, clients can still
1383 explicitly enable substitution @i{via} the @code{set-build-options}
1384 remote procedure call (@pxref{The Store}).
1386 @item --substitute-urls=@var{urls}
1387 @anchor{daemon-substitute-urls}
1388 Consider @var{urls} the default whitespace-separated list of substitute
1389 source URLs. When this option is omitted,
1390 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1392 This means that substitutes may be downloaded from @var{urls}, as long
1393 as they are signed by a trusted signature (@pxref{Substitutes}).
1397 Do not use offload builds to other machines (@pxref{Daemon Offload
1398 Setup}). That is, always build things locally instead of offloading
1399 builds to remote machines.
1401 @item --cache-failures
1402 Cache build failures. By default, only successful builds are cached.
1404 When this option is used, @command{guix gc --list-failures} can be used
1405 to query the set of store items marked as failed; @command{guix gc
1406 --clear-failures} removes store items from the set of cached failures.
1407 @xref{Invoking guix gc}.
1409 @item --cores=@var{n}
1411 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1414 The default value is @code{0}, but it may be overridden by clients, such
1415 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1418 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1419 in the build process, which can then use it to exploit internal
1420 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1422 @item --max-jobs=@var{n}
1424 Allow at most @var{n} build jobs in parallel. The default value is
1425 @code{1}. Setting it to @code{0} means that no builds will be performed
1426 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1427 Setup}), or simply fail.
1429 @item --max-silent-time=@var{seconds}
1430 When the build or substitution process remains silent for more than
1431 @var{seconds}, terminate it and report a build failure.
1433 The default value is @code{0}, which disables the timeout.
1435 The value specified here can be overridden by clients (@pxref{Common
1436 Build Options, @option{--max-silent-time}}).
1438 @item --timeout=@var{seconds}
1439 Likewise, when the build or substitution process lasts for more than
1440 @var{seconds}, terminate it and report a build failure.
1442 The default value is @code{0}, which disables the timeout.
1444 The value specified here can be overridden by clients (@pxref{Common
1445 Build Options, @option{--timeout}}).
1447 @item --rounds=@var{N}
1448 Build each derivation @var{n} times in a row, and raise an error if
1449 consecutive build results are not bit-for-bit identical. Note that this
1450 setting can be overridden by clients such as @command{guix build}
1451 (@pxref{Invoking guix build}).
1453 When used in conjunction with @option{--keep-failed}, the differing
1454 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1455 This makes it easy to look for differences between the two results.
1458 Produce debugging output.
1460 This is useful to debug daemon start-up issues, but then it may be
1461 overridden by clients, for example the @option{--verbosity} option of
1462 @command{guix build} (@pxref{Invoking guix build}).
1464 @item --chroot-directory=@var{dir}
1465 Add @var{dir} to the build chroot.
1467 Doing this may change the result of build processes---for instance if
1468 they use optional dependencies found in @var{dir} when it is available,
1469 and not otherwise. For that reason, it is not recommended to do so.
1470 Instead, make sure that each derivation declares all the inputs that it
1473 @item --disable-chroot
1474 Disable chroot builds.
1476 Using this option is not recommended since, again, it would allow build
1477 processes to gain access to undeclared dependencies. It is necessary,
1478 though, when @command{guix-daemon} is running under an unprivileged user
1481 @item --log-compression=@var{type}
1482 Compress build logs according to @var{type}, one of @code{gzip},
1483 @code{bzip2}, or @code{none}.
1485 Unless @option{--lose-logs} is used, all the build logs are kept in the
1486 @var{localstatedir}. To save space, the daemon automatically compresses
1487 them with Bzip2 by default.
1489 @item --disable-deduplication
1490 @cindex deduplication
1491 Disable automatic file ``deduplication'' in the store.
1493 By default, files added to the store are automatically ``deduplicated'':
1494 if a newly added file is identical to another one found in the store,
1495 the daemon makes the new file a hard link to the other file. This can
1496 noticeably reduce disk usage, at the expense of slightly increased
1497 input/output load at the end of a build process. This option disables
1500 @item --gc-keep-outputs[=yes|no]
1501 Tell whether the garbage collector (GC) must keep outputs of live
1505 @cindex garbage collector roots
1506 When set to @code{yes}, the GC will keep the outputs of any live
1507 derivation available in the store---the @file{.drv} files. The default
1508 is @code{no}, meaning that derivation outputs are kept only if they are
1509 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1512 @item --gc-keep-derivations[=yes|no]
1513 Tell whether the garbage collector (GC) must keep derivations
1514 corresponding to live outputs.
1516 When set to @code{yes}, as is the case by default, the GC keeps
1517 derivations---i.e., @file{.drv} files---as long as at least one of their
1518 outputs is live. This allows users to keep track of the origins of
1519 items in their store. Setting it to @code{no} saves a bit of disk
1522 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1523 liveness to flow from outputs to derivations, and setting
1524 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1525 derivations to outputs. When both are set to @code{yes}, the effect is
1526 to keep all the build prerequisites (the sources, compiler, libraries,
1527 and other build-time tools) of live objects in the store, regardless of
1528 whether these prerequisites are reachable from a GC root. This is
1529 convenient for developers since it saves rebuilds or downloads.
1531 @item --impersonate-linux-2.6
1532 On Linux-based systems, impersonate Linux 2.6. This means that the
1533 kernel's @command{uname} system call will report 2.6 as the release number.
1535 This might be helpful to build programs that (usually wrongfully) depend
1536 on the kernel version number.
1539 Do not keep build logs. By default they are kept under
1540 @file{@var{localstatedir}/guix/log}.
1542 @item --system=@var{system}
1543 Assume @var{system} as the current system type. By default it is the
1544 architecture/kernel pair found at configure time, such as
1545 @code{x86_64-linux}.
1547 @item --listen=@var{endpoint}
1548 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1549 as the file name of a Unix-domain socket if it starts with
1550 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1551 host name or host name and port to listen to. Here are a few examples:
1554 @item --listen=/gnu/var/daemon
1555 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1556 creating it if needed.
1558 @item --listen=localhost
1559 @cindex daemon, remote access
1560 @cindex remote access to the daemon
1561 @cindex daemon, cluster setup
1562 @cindex clusters, daemon setup
1563 Listen for TCP connections on the network interface corresponding to
1564 @code{localhost}, on port 44146.
1566 @item --listen=128.0.0.42:1234
1567 Listen for TCP connections on the network interface corresponding to
1568 @code{128.0.0.42}, on port 1234.
1571 This option can be repeated multiple times, in which case
1572 @command{guix-daemon} accepts connections on all the specified
1573 endpoints. Users can tell client commands what endpoint to connect to
1574 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1575 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1578 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1579 @option{--listen=@var{host}} is suitable on local networks, such as
1580 clusters, where only trusted nodes may connect to the build daemon. In
1581 other cases where remote access to the daemon is needed, we recommend
1582 using Unix-domain sockets along with SSH.
1585 When @option{--listen} is omitted, @command{guix-daemon} listens for
1586 connections on the Unix-domain socket located at
1587 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1591 @node Application Setup
1592 @section Application Setup
1594 @cindex foreign distro
1595 When using Guix on top of GNU/Linux distribution other than Guix System---a
1596 so-called @dfn{foreign distro}---a few additional steps are needed to
1597 get everything in place. Here are some of them.
1601 @anchor{locales-and-locpath}
1602 @cindex locales, when not on Guix System
1604 @vindex GUIX_LOCPATH
1605 Packages installed @i{via} Guix will not use the locale data of the
1606 host system. Instead, you must first install one of the locale packages
1607 available with Guix and then define the @env{GUIX_LOCPATH} environment
1611 $ guix install glibc-locales
1612 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1615 Note that the @code{glibc-locales} package contains data for all the
1616 locales supported by the GNU@tie{}libc and weighs in at around
1617 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1618 limited to a few UTF-8 locales.
1620 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1621 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1622 Manual}). There are two important differences though:
1626 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1627 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1628 to make sure the programs of the foreign distro will not end up loading
1629 incompatible locale data.
1632 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1633 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1634 should your Guix profile contain a mixture of programs linked against
1635 different libc version, each libc version will only try to load locale
1636 data in the right format.
1639 This is important because the locale data format used by different libc
1640 versions may be incompatible.
1642 @subsection Name Service Switch
1644 @cindex name service switch, glibc
1645 @cindex NSS (name service switch), glibc
1646 @cindex nscd (name service caching daemon)
1647 @cindex name service caching daemon (nscd)
1648 When using Guix on a foreign distro, we @emph{strongly recommend} that
1649 the system run the GNU C library's @dfn{name service cache daemon},
1650 @command{nscd}, which should be listening on the
1651 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1652 installed with Guix may fail to look up host names or user accounts, or
1653 may even crash. The next paragraphs explain why.
1655 @cindex @file{nsswitch.conf}
1656 The GNU C library implements a @dfn{name service switch} (NSS), which is
1657 an extensible mechanism for ``name lookups'' in general: host name
1658 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1659 The GNU C Library Reference Manual}).
1661 @cindex Network information service (NIS)
1662 @cindex NIS (Network information service)
1663 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1664 lookup implementations: for example, the @code{nss-mdns} plugin allow
1665 resolution of @code{.local} host names, the @code{nis} plugin allows
1666 user account lookup using the Network information service (NIS), and so
1667 on. These extra ``lookup services'' are configured system-wide in
1668 @file{/etc/nsswitch.conf}, and all the programs running on the system
1669 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1672 When they perform a name lookup---for instance by calling the
1673 @code{getaddrinfo} function in C---applications first try to connect to
1674 the nscd; on success, nscd performs name lookups on their behalf. If
1675 the nscd is not running, then they perform the name lookup by
1676 themselves, by loading the name lookup services into their own address
1677 space and running it. These name lookup services---the
1678 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1679 the host system's C library, rather than from the C library the
1680 application is linked against (the C library coming from Guix).
1682 And this is where the problem is: if your application is linked against
1683 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1684 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1685 likely crash or have its name lookups fail unexpectedly.
1687 Running @command{nscd} on the system, among other advantages, eliminates
1688 this binary incompatibility problem because those @code{libnss_*.so}
1689 files are loaded in the @command{nscd} process, not in applications
1692 @subsection X11 Fonts
1695 The majority of graphical applications use Fontconfig to locate and
1696 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1697 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1698 by default. Thus, to allow graphical applications installed with Guix
1699 to display fonts, you have to install fonts with Guix as well.
1700 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1701 @code{font-gnu-freefont}.
1703 @cindex @code{fc-cache}
1705 Once you have installed or removed fonts, or when you notice an
1706 application that does not find fonts, you may need to install Fontconfig
1707 and to force an update of its font cache by running:
1710 guix install fontconfig
1714 To display text written in Chinese languages, Japanese, or Korean in
1715 graphical applications, consider installing
1716 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1717 has multiple outputs, one per language family (@pxref{Packages with
1718 Multiple Outputs}). For instance, the following command installs fonts
1719 for Chinese languages:
1722 guix install font-adobe-source-han-sans:cn
1725 @cindex @code{xterm}
1726 Older programs such as @command{xterm} do not use Fontconfig and instead
1727 rely on server-side font rendering. Such programs require to specify a
1728 full name of a font using XLFD (X Logical Font Description), like this:
1731 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1734 To be able to use such full names for the TrueType fonts installed in
1735 your Guix profile, you need to extend the font path of the X server:
1737 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1738 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1740 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1743 @cindex @code{xlsfonts}
1744 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1745 to make sure your TrueType fonts are listed there.
1748 @subsection X.509 Certificates
1750 @cindex @code{nss-certs}
1751 The @code{nss-certs} package provides X.509 certificates, which allow
1752 programs to authenticate Web servers accessed over HTTPS.
1754 When using Guix on a foreign distro, you can install this package and
1755 define the relevant environment variables so that packages know where to
1756 look for certificates. @xref{X.509 Certificates}, for detailed
1759 @subsection Emacs Packages
1761 @cindex @code{emacs}
1762 When you install Emacs packages with Guix, the Elisp files are placed
1763 under the @file{share/emacs/site-lisp/} directory of the profile in
1764 which they are installed. The Elisp libraries are made available to
1765 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1766 set when installing Emacs itself.
1768 Additionally, autoload definitions are automatically evaluated at the
1769 initialization of Emacs, by the Guix-specific
1770 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1771 want to avoid auto-loading the Emacs packages installed with Guix, you
1772 can do so by running Emacs with the @option{--no-site-file} option
1773 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1775 @subsection The GCC toolchain
1777 @c XXX: The contents of this section were moved under
1778 @c ``Development'', since it makes more sense there and is not specific
1779 @c foreign distros. Remove it from here eventually?
1780 @xref{Packages for C Development}, for information on packages for C/C++
1783 @node Upgrading Guix
1784 @section Upgrading Guix
1786 @cindex Upgrading Guix, on a foreign distro
1788 To upgrade Guix, run:
1794 @xref{Invoking guix pull}, for more information.
1796 @cindex upgrading Guix for the root user, on a foreign distro
1797 @cindex upgrading the Guix daemon, on a foreign distro
1798 @cindex @command{guix pull} for the root user, on a foreign distro
1800 On a foreign distro, you can upgrade the build daemon by running:
1807 followed by (assuming your distro uses the systemd service management
1811 systemctl restart guix-daemon.service
1814 On Guix System, upgrading the daemon is achieved by reconfiguring the
1815 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1819 @c *********************************************************************
1820 @node System Installation
1821 @chapter System Installation
1823 @cindex installing Guix System
1824 @cindex Guix System, installation
1825 This section explains how to install Guix System
1826 on a machine. Guix, as a package manager, can
1827 also be installed on top of a running GNU/Linux system,
1828 @pxref{Installation}.
1832 @c This paragraph is for people reading this from tty2 of the
1833 @c installation image.
1834 You are reading this documentation with an Info reader. For details on
1835 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1836 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1837 Info}. Hit @kbd{l} afterwards to come back here.
1839 Alternately, run @command{info info} in another tty to keep the manual
1845 * Limitations:: What you can expect.
1846 * Hardware Considerations:: Supported hardware.
1847 * USB Stick and DVD Installation:: Preparing the installation medium.
1848 * Preparing for Installation:: Networking, partitioning, etc.
1849 * Guided Graphical Installation:: Easy graphical installation.
1850 * Manual Installation:: Manual installation for wizards.
1851 * After System Installation:: When installation succeeded.
1852 * Installing Guix in a VM:: Guix System playground.
1853 * Building the Installation Image:: How this comes to be.
1857 @section Limitations
1859 We consider Guix System to be ready for a wide range of ``desktop'' and server
1860 use cases. The reliability guarantees it provides---transactional upgrades
1861 and rollbacks, reproducibility---make it a solid foundation.
1863 Nevertheless, before you proceed with the installation, be aware of the
1864 following noteworthy limitations applicable to version @value{VERSION}:
1868 Support for the Logical Volume Manager (LVM) is missing.
1871 More and more system services are provided (@pxref{Services}), but some
1875 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1876 as well as a number of X11 window managers. However, KDE is currently
1880 More than a disclaimer, this is an invitation to report issues (and success
1881 stories!), and to join us in improving it. @xref{Contributing}, for more
1885 @node Hardware Considerations
1886 @section Hardware Considerations
1888 @cindex hardware support on Guix System
1889 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1890 builds around the kernel Linux-libre, which means that only hardware for
1891 which free software drivers and firmware exist is supported. Nowadays,
1892 a wide range of off-the-shelf hardware is supported on
1893 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1894 Ethernet controllers. Unfortunately, there are still areas where
1895 hardware vendors deny users control over their own computing, and such
1896 hardware is not supported on Guix System.
1898 @cindex WiFi, hardware support
1899 One of the main areas where free drivers or firmware are lacking is WiFi
1900 devices. WiFi devices known to work include those using Atheros chips
1901 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1902 driver, and those using Broadcom/AirForce chips (BCM43xx with
1903 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1904 Linux-libre driver. Free firmware exists for both and is available
1905 out-of-the-box on Guix System, as part of @code{%base-firmware}
1906 (@pxref{operating-system Reference, @code{firmware}}).
1908 @cindex RYF, Respects Your Freedom
1909 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1910 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1911 certification program for hardware products that respect your freedom
1912 and your privacy and ensure that you have control over your device. We
1913 encourage you to check the list of RYF-certified devices.
1915 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1916 web site. It contains a catalog of hardware devices with information
1917 about their support in GNU/Linux.
1920 @node USB Stick and DVD Installation
1921 @section USB Stick and DVD Installation
1923 An ISO-9660 installation image that can be written to a USB stick or
1924 burnt to a DVD can be downloaded from
1925 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1926 where @var{system} is one of:
1930 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1933 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1936 @c start duplication of authentication part from ``Binary Installation''
1937 Make sure to download the associated @file{.sig} file and to verify the
1938 authenticity of the image against it, along these lines:
1941 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1942 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1945 If that command fails because you do not have the required public key,
1946 then run this command to import it:
1949 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1950 -qO - | gpg --import -
1954 and rerun the @code{gpg --verify} command.
1956 Take note that a warning like ``This key is not certified with a trusted
1957 signature!'' is normal.
1961 This image contains the tools necessary for an installation.
1962 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1964 @unnumberedsubsec Copying to a USB Stick
1966 To copy the image to a USB stick, follow these steps:
1970 Decompress the image using the @command{xz} command:
1973 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1977 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1978 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1979 copy the image with:
1982 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1986 Access to @file{/dev/sdX} usually requires root privileges.
1989 @unnumberedsubsec Burning on a DVD
1991 To copy the image to a DVD, follow these steps:
1995 Decompress the image using the @command{xz} command:
1998 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
2002 Insert a blank DVD into your machine, and determine
2003 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2004 copy the image with:
2007 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
2010 Access to @file{/dev/srX} usually requires root privileges.
2013 @unnumberedsubsec Booting
2015 Once this is done, you should be able to reboot the system and boot from
2016 the USB stick or DVD. The latter usually requires you to get in the
2017 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2018 In order to boot from Libreboot, switch to the command mode by pressing
2019 the @kbd{c} key and type @command{search_grub usb}.
2021 @xref{Installing Guix in a VM}, if, instead, you would like to install
2022 Guix System in a virtual machine (VM).
2025 @node Preparing for Installation
2026 @section Preparing for Installation
2028 Once you have booted, you can use the guided graphical installer, which makes
2029 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2030 if you are already familiar with GNU/Linux and if you want more control than
2031 what the graphical installer provides, you can choose the ``manual''
2032 installation process (@pxref{Manual Installation}).
2034 The graphical installer is available on TTY1. You can obtain root shells on
2035 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2036 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2037 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2038 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2039 which allows you to select text with the left mouse button and to paste it
2040 with the middle button.
2043 Installation requires access to the Internet so that any missing
2044 dependencies of your system configuration can be downloaded. See the
2045 ``Networking'' section below.
2048 @node Guided Graphical Installation
2049 @section Guided Graphical Installation
2051 The graphical installer is a text-based user interface. It will guide you,
2052 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2054 The first dialog boxes allow you to set up the system as you use it during the
2055 installation: you can choose the language, keyboard layout, and set up
2056 networking, which will be used during the installation. The image below shows
2057 the networking dialog.
2059 @image{images/installer-network,5in,, networking setup with the graphical installer}
2061 Later steps allow you to partition your hard disk, as shown in the image
2062 below, to choose whether or not to use encrypted file systems, to enter the
2063 host name and root password, and to create an additional account, among other
2066 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2068 Note that, at any time, the installer allows you to exit the current
2069 installation step and resume at a previous step, as show in the image below.
2071 @image{images/installer-resume,5in,, resuming the installation process}
2073 Once you're done, the installer produces an operating system configuration and
2074 displays it (@pxref{Using the Configuration System}). At that point you can
2075 hit ``OK'' and installation will proceed. On success, you can reboot into the
2076 new system and enjoy. @xref{After System Installation}, for what's next!
2079 @node Manual Installation
2080 @section Manual Installation
2082 This section describes how you would ``manually'' install GNU@tie{}Guix System
2083 on your machine. This option requires familiarity with GNU/Linux, with the
2084 shell, and with common administration tools. If you think this is not for
2085 you, consider using the guided graphical installer (@pxref{Guided Graphical
2088 The installation system provides root shells on TTYs 3 to 6; press
2089 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2090 many common tools needed to install the system. But it is also a full-blown
2091 Guix System, which means that you can install additional packages, should you
2092 need it, using @command{guix package} (@pxref{Invoking guix package}).
2095 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2096 * Proceeding with the Installation:: Installing.
2099 @node Keyboard Layout and Networking and Partitioning
2100 @subsection Keyboard Layout, Networking, and Partitioning
2102 Before you can install the system, you may want to adjust the keyboard layout,
2103 set up networking, and partition your target hard disk. This section will
2104 guide you through this.
2106 @subsubsection Keyboard Layout
2108 @cindex keyboard layout
2109 The installation image uses the US qwerty keyboard layout. If you want
2110 to change it, you can use the @command{loadkeys} command. For example,
2111 the following command selects the Dvorak keyboard layout:
2117 See the files under @file{/run/current-system/profile/share/keymaps} for
2118 a list of available keyboard layouts. Run @command{man loadkeys} for
2121 @subsubsection Networking
2123 Run the following command to see what your network interfaces are called:
2130 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2136 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2137 Wired interfaces have a name starting with @samp{e}; for example, the
2138 interface corresponding to the first on-board Ethernet controller is
2139 called @samp{eno1}. Wireless interfaces have a name starting with
2140 @samp{w}, like @samp{w1p2s0}.
2143 @item Wired connection
2144 To configure a wired network run the following command, substituting
2145 @var{interface} with the name of the wired interface you want to use.
2148 ifconfig @var{interface} up
2152 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2155 ip link set @var{interface} up
2158 @item Wireless connection
2161 To configure wireless networking, you can create a configuration file
2162 for the @command{wpa_supplicant} configuration tool (its location is not
2163 important) using one of the available text editors such as
2167 nano wpa_supplicant.conf
2170 As an example, the following stanza can go to this file and will work
2171 for many wireless networks, provided you give the actual SSID and
2172 passphrase for the network you are connecting to:
2176 ssid="@var{my-ssid}"
2178 psk="the network's secret passphrase"
2182 Start the wireless service and run it in the background with the
2183 following command (substitute @var{interface} with the name of the
2184 network interface you want to use):
2187 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2190 Run @command{man wpa_supplicant} for more information.
2194 At this point, you need to acquire an IP address. On a network where IP
2195 addresses are automatically assigned @i{via} DHCP, you can run:
2198 dhclient -v @var{interface}
2201 Try to ping a server to see if networking is up and running:
2207 Setting up network access is almost always a requirement because the
2208 image does not contain all the software and tools that may be needed.
2210 @cindex proxy, during system installation
2211 If you need HTTP and HTTPS access to go through a proxy, run the
2215 herd set-http-proxy guix-daemon @var{URL}
2219 where @var{URL} is the proxy URL, for example
2220 @code{http://example.org:8118}.
2222 @cindex installing over SSH
2223 If you want to, you can continue the installation remotely by starting
2227 herd start ssh-daemon
2230 Make sure to either set a password with @command{passwd}, or configure
2231 OpenSSH public key authentication before logging in.
2233 @subsubsection Disk Partitioning
2235 Unless this has already been done, the next step is to partition, and
2236 then format the target partition(s).
2238 The installation image includes several partitioning tools, including
2239 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2240 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2241 the partition layout you want:
2247 If your disk uses the GUID Partition Table (GPT) format and you plan to
2248 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2249 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2252 @cindex EFI, installation
2253 @cindex UEFI, installation
2254 @cindex ESP, EFI system partition
2255 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2256 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2257 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2260 parted /dev/sda set 1 esp on
2264 @vindex grub-bootloader
2265 @vindex grub-efi-bootloader
2266 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2267 @file{/sys/firmware/efi} exists in the installation image, then you should
2268 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2269 Otherwise you should use the BIOS-based GRUB, known as
2270 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2274 Once you are done partitioning the target hard disk drive, you have to
2275 create a file system on the relevant partition(s)@footnote{Currently
2276 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2277 code that reads file system UUIDs and labels only works for these file system
2278 types.}. For the ESP, if you have one and assuming it is
2279 @file{/dev/sda1}, run:
2282 mkfs.fat -F32 /dev/sda1
2285 Preferably, assign file systems a label so that you can easily and
2286 reliably refer to them in @code{file-system} declarations (@pxref{File
2287 Systems}). This is typically done using the @code{-L} option of
2288 @command{mkfs.ext4} and related commands. So, assuming the target root
2289 partition lives at @file{/dev/sda2}, a file system with the label
2290 @code{my-root} can be created with:
2293 mkfs.ext4 -L my-root /dev/sda2
2296 @cindex encrypted disk
2297 If you are instead planning to encrypt the root partition, you can use
2298 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2299 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2300 @code{man cryptsetup}} for more information.) Assuming you want to
2301 store the root partition on @file{/dev/sda2}, the command sequence would
2302 be along these lines:
2305 cryptsetup luksFormat /dev/sda2
2306 cryptsetup open --type luks /dev/sda2 my-partition
2307 mkfs.ext4 -L my-root /dev/mapper/my-partition
2310 Once that is done, mount the target file system under @file{/mnt}
2311 with a command like (again, assuming @code{my-root} is the label of the
2315 mount LABEL=my-root /mnt
2318 Also mount any other file systems you would like to use on the target
2319 system relative to this path. If you have opted for @file{/boot/efi} as an
2320 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2321 found by @code{guix system init} afterwards.
2323 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2324 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2325 sure to initialize them with @command{mkswap}. Assuming you have one
2326 swap partition on @file{/dev/sda3}, you would run:
2333 Alternatively, you may use a swap file. For example, assuming that in
2334 the new system you want to use the file @file{/swapfile} as a swap file,
2335 you would run@footnote{This example will work for many types of file
2336 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2337 btrfs), the required steps may be different. For details, see the
2338 manual pages for @command{mkswap} and @command{swapon}.}:
2341 # This is 10 GiB of swap space. Adjust "count" to change the size.
2342 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2343 # For security, make the file readable and writable only by root.
2344 chmod 600 /mnt/swapfile
2345 mkswap /mnt/swapfile
2346 swapon /mnt/swapfile
2349 Note that if you have encrypted the root partition and created a swap
2350 file in its file system as described above, then the encryption also
2351 protects the swap file, just like any other file in that file system.
2353 @node Proceeding with the Installation
2354 @subsection Proceeding with the Installation
2356 With the target partitions ready and the target root mounted on
2357 @file{/mnt}, we're ready to go. First, run:
2360 herd start cow-store /mnt
2363 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2364 during the installation phase are written to the target disk on @file{/mnt}
2365 rather than kept in memory. This is necessary because the first phase of
2366 the @command{guix system init} command (see below) entails downloads or
2367 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2369 Next, you have to edit a file and
2370 provide the declaration of the operating system to be installed. To
2371 that end, the installation system comes with three text editors. We
2372 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2373 supports syntax highlighting and parentheses matching; other editors
2374 include GNU Zile (an Emacs clone), and
2375 nvi (a clone of the original BSD @command{vi} editor).
2376 We strongly recommend storing that file on the target root file system, say,
2377 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2378 configuration file once you have rebooted into the newly-installed system.
2380 @xref{Using the Configuration System}, for an overview of the
2381 configuration file. The example configurations discussed in that
2382 section are available under @file{/etc/configuration} in the
2383 installation image. Thus, to get started with a system configuration
2384 providing a graphical display server (a ``desktop'' system), you can run
2385 something along these lines:
2389 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2390 # nano /mnt/etc/config.scm
2393 You should pay attention to what your configuration file contains, and
2398 Make sure the @code{bootloader-configuration} form refers to the target
2399 you want to install GRUB on. It should mention @code{grub-bootloader} if
2400 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2401 for newer UEFI systems. For legacy systems, the @code{target} field
2402 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2403 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2404 currently mounted and a @code{file-system} entry is specified in your
2408 Be sure that your file system labels match the value of their respective
2409 @code{device} fields in your @code{file-system} configuration, assuming
2410 your @code{file-system} configuration uses the @code{file-system-label}
2411 procedure in its @code{device} field.
2414 If there are encrypted or RAID partitions, make sure to add a
2415 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2418 Once you are done preparing the configuration file, the new system must
2419 be initialized (remember that the target root file system is mounted
2423 guix system init /mnt/etc/config.scm /mnt
2427 This copies all the necessary files and installs GRUB on
2428 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2429 more information, @pxref{Invoking guix system}. This command may trigger
2430 downloads or builds of missing packages, which can take some time.
2432 Once that command has completed---and hopefully succeeded!---you can run
2433 @command{reboot} and boot into the new system. The @code{root} password
2434 in the new system is initially empty; other users' passwords need to be
2435 initialized by running the @command{passwd} command as @code{root},
2436 unless your configuration specifies otherwise
2437 (@pxref{user-account-password, user account passwords}).
2438 @xref{After System Installation}, for what's next!
2441 @node After System Installation
2442 @section After System Installation
2444 Success, you've now booted into Guix System! From then on, you can update the
2445 system whenever you want by running, say:
2449 sudo guix system reconfigure /etc/config.scm
2453 This builds a new system generation with the latest packages and services
2454 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2455 your system includes the latest security updates (@pxref{Security Updates}).
2457 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2459 @cindex sudo vs. @command{guix pull}
2460 Note that @command{sudo guix} runs your user's @command{guix} command and
2461 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2462 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2464 The difference matters here, because @command{guix pull} updates
2465 the @command{guix} command and package definitions only for the user it is ran
2466 as. This means that if you choose to use @command{guix system reconfigure} in
2467 root's login shell, you'll need to @command{guix pull} separately.
2470 Join us on @code{#guix} on the Freenode IRC network or on
2471 @email{guix-devel@@gnu.org} to share your experience!
2474 @node Installing Guix in a VM
2475 @section Installing Guix in a Virtual Machine
2477 @cindex virtual machine, Guix System installation
2478 @cindex virtual private server (VPS)
2479 @cindex VPS (virtual private server)
2480 If you'd like to install Guix System in a virtual machine (VM) or on a
2481 virtual private server (VPS) rather than on your beloved machine, this
2484 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2485 disk image, follow these steps:
2489 First, retrieve and decompress the Guix system installation image as
2490 described previously (@pxref{USB Stick and DVD Installation}).
2493 Create a disk image that will hold the installed system. To make a
2494 qcow2-formatted disk image, use the @command{qemu-img} command:
2497 qemu-img create -f qcow2 guix-system.img 50G
2500 The resulting file will be much smaller than 50 GB (typically less than
2501 1 MB), but it will grow as the virtualized storage device is filled up.
2504 Boot the USB installation image in an VM:
2507 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2508 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2509 -drive file=guix-system.img \
2510 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2513 @code{-enable-kvm} is optional, but significantly improves performance,
2514 @pxref{Running Guix in a VM}.
2517 You're now root in the VM, proceed with the installation process.
2518 @xref{Preparing for Installation}, and follow the instructions.
2521 Once installation is complete, you can boot the system that's on your
2522 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2525 @node Building the Installation Image
2526 @section Building the Installation Image
2528 @cindex installation image
2529 The installation image described above was built using the @command{guix
2530 system} command, specifically:
2533 guix system disk-image --file-system-type=iso9660 \
2534 gnu/system/install.scm
2537 Have a look at @file{gnu/system/install.scm} in the source tree,
2538 and see also @ref{Invoking guix system} for more information
2539 about the installation image.
2541 @section Building the Installation Image for ARM Boards
2543 Many ARM boards require a specific variant of the
2544 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2546 If you build a disk image and the bootloader is not available otherwise
2547 (on another boot drive etc), it's advisable to build an image that
2548 includes the bootloader, specifically:
2551 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2554 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2555 board, a list of possible boards will be printed.
2557 @c *********************************************************************
2558 @node Package Management
2559 @chapter Package Management
2562 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2563 remove software packages, without having to know about their build
2564 procedures or dependencies. Guix also goes beyond this obvious set of
2567 This chapter describes the main features of Guix, as well as the
2568 package management tools it provides. Along with the command-line
2569 interface described below (@pxref{Invoking guix package, @code{guix
2570 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2571 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2572 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2576 guix install emacs-guix
2580 * Features:: How Guix will make your life brighter.
2581 * Invoking guix package:: Package installation, removal, etc.
2582 * Substitutes:: Downloading pre-built binaries.
2583 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2584 * Invoking guix gc:: Running the garbage collector.
2585 * Invoking guix pull:: Fetching the latest Guix and distribution.
2586 * Channels:: Customizing the package collection.
2587 * Invoking guix time-machine:: Running an older revision of Guix.
2588 * Inferiors:: Interacting with another revision of Guix.
2589 * Invoking guix describe:: Display information about your Guix revision.
2590 * Invoking guix archive:: Exporting and importing store files.
2596 When using Guix, each package ends up in the @dfn{package store}, in its
2597 own directory---something that resembles
2598 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2600 Instead of referring to these directories, users have their own
2601 @dfn{profile}, which points to the packages that they actually want to
2602 use. These profiles are stored within each user's home directory, at
2603 @code{$HOME/.guix-profile}.
2605 For example, @code{alice} installs GCC 4.7.2. As a result,
2606 @file{/home/alice/.guix-profile/bin/gcc} points to
2607 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2608 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2609 simply continues to point to
2610 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2611 coexist on the same system without any interference.
2613 The @command{guix package} command is the central tool to manage
2614 packages (@pxref{Invoking guix package}). It operates on the per-user
2615 profiles, and can be used @emph{with normal user privileges}.
2617 @cindex transactions
2618 The command provides the obvious install, remove, and upgrade
2619 operations. Each invocation is actually a @emph{transaction}: either
2620 the specified operation succeeds, or nothing happens. Thus, if the
2621 @command{guix package} process is terminated during the transaction,
2622 or if a power outage occurs during the transaction, then the user's
2623 profile remains in its previous state, and remains usable.
2625 In addition, any package transaction may be @emph{rolled back}. So, if,
2626 for example, an upgrade installs a new version of a package that turns
2627 out to have a serious bug, users may roll back to the previous instance
2628 of their profile, which was known to work well. Similarly, the global
2629 system configuration on Guix is subject to
2630 transactional upgrades and roll-back
2631 (@pxref{Using the Configuration System}).
2633 All packages in the package store may be @emph{garbage-collected}.
2634 Guix can determine which packages are still referenced by user
2635 profiles, and remove those that are provably no longer referenced
2636 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2637 generations of their profile so that the packages they refer to can be
2640 @cindex reproducibility
2641 @cindex reproducible builds
2642 Guix takes a @dfn{purely functional} approach to package
2643 management, as described in the introduction (@pxref{Introduction}).
2644 Each @file{/gnu/store} package directory name contains a hash of all the
2645 inputs that were used to build that package---compiler, libraries, build
2646 scripts, etc. This direct correspondence allows users to make sure a
2647 given package installation matches the current state of their
2648 distribution. It also helps maximize @dfn{build reproducibility}:
2649 thanks to the isolated build environments that are used, a given build
2650 is likely to yield bit-identical files when performed on different
2651 machines (@pxref{Invoking guix-daemon, container}).
2654 This foundation allows Guix to support @dfn{transparent binary/source
2655 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2656 available from an external source---a @dfn{substitute}, Guix just
2657 downloads it and unpacks it;
2658 otherwise, it builds the package from source, locally
2659 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2660 reproducible, users do not have to trust servers that provide
2661 substitutes: they can force a local build and @emph{challenge} providers
2662 (@pxref{Invoking guix challenge}).
2664 Control over the build environment is a feature that is also useful for
2665 developers. The @command{guix environment} command allows developers of
2666 a package to quickly set up the right development environment for their
2667 package, without having to manually install the dependencies of the
2668 package into their profile (@pxref{Invoking guix environment}).
2670 @cindex replication, of software environments
2671 @cindex provenance tracking, of software artifacts
2672 All of Guix and its package definitions is version-controlled, and
2673 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2674 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2675 Guix instance on a different machine or at a later point in time, which in
2676 turn allows you to @emph{replicate complete software environments}, while
2677 retaining precise @dfn{provenance tracking} of the software.
2679 @node Invoking guix package
2680 @section Invoking @command{guix package}
2682 @cindex installing packages
2683 @cindex removing packages
2684 @cindex package installation
2685 @cindex package removal
2686 The @command{guix package} command is the tool that allows users to
2687 install, upgrade, and remove packages, as well as rolling back to
2688 previous configurations. It operates only on the user's own profile,
2689 and works with normal user privileges (@pxref{Features}). Its syntax
2693 guix package @var{options}
2696 @cindex transactions
2697 Primarily, @var{options} specifies the operations to be performed during
2698 the transaction. Upon completion, a new profile is created, but
2699 previous @dfn{generations} of the profile remain available, should the user
2702 For example, to remove @code{lua} and install @code{guile} and
2703 @code{guile-cairo} in a single transaction:
2706 guix package -r lua -i guile guile-cairo
2709 @cindex aliases, for @command{guix package}
2710 For your convenience, we also provide the following aliases:
2714 @command{guix search} is an alias for @command{guix package -s},
2716 @command{guix install} is an alias for @command{guix package -i},
2718 @command{guix remove} is an alias for @command{guix package -r},
2720 @command{guix upgrade} is an alias for @command{guix package -u},
2722 and @command{guix show} is an alias for @command{guix package --show=}.
2725 These aliases are less expressive than @command{guix package} and provide
2726 fewer options, so in some cases you'll probably want to use @command{guix
2729 @command{guix package} also supports a @dfn{declarative approach}
2730 whereby the user specifies the exact set of packages to be available and
2731 passes it @i{via} the @option{--manifest} option
2732 (@pxref{profile-manifest, @option{--manifest}}).
2735 For each user, a symlink to the user's default profile is automatically
2736 created in @file{$HOME/.guix-profile}. This symlink always points to the
2737 current generation of the user's default profile. Thus, users can add
2738 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
2739 variable, and so on.
2740 @cindex search paths
2741 If you are not using Guix System, consider adding the
2742 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2743 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2744 shells get all the right environment variable definitions:
2747 GUIX_PROFILE="$HOME/.guix-profile" ; \
2748 source "$HOME/.guix-profile/etc/profile"
2751 In a multi-user setup, user profiles are stored in a place registered as
2752 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2753 to (@pxref{Invoking guix gc}). That directory is normally
2754 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2755 @var{localstatedir} is the value passed to @code{configure} as
2756 @option{--localstatedir}, and @var{user} is the user name. The
2757 @file{per-user} directory is created when @command{guix-daemon} is
2758 started, and the @var{user} sub-directory is created by @command{guix
2761 The @var{options} can be among the following:
2765 @item --install=@var{package} @dots{}
2766 @itemx -i @var{package} @dots{}
2767 Install the specified @var{package}s.
2769 Each @var{package} may specify either a simple package name, such as
2770 @code{guile}, or a package name followed by an at-sign and version number,
2771 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2772 case, the newest version prefixed by @code{1.8} is selected.)
2774 If no version number is specified, the
2775 newest available version will be selected. In addition, @var{package}
2776 may contain a colon, followed by the name of one of the outputs of the
2777 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2778 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2779 name (and optionally version) are searched for among the GNU
2780 distribution modules (@pxref{Package Modules}).
2782 @cindex propagated inputs
2783 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2784 that automatically get installed along with the required package
2785 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2786 @code{package} objects}, for information about propagated inputs in
2787 package definitions).
2789 @anchor{package-cmd-propagated-inputs}
2790 An example is the GNU MPC library: its C header files refer to those of
2791 the GNU MPFR library, which in turn refer to those of the GMP library.
2792 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2793 in the profile; removing MPC also removes MPFR and GMP---unless they had
2794 also been explicitly installed by the user.
2796 Besides, packages sometimes rely on the definition of environment
2797 variables for their search paths (see explanation of
2798 @option{--search-paths} below). Any missing or possibly incorrect
2799 environment variable definitions are reported here.
2801 @item --install-from-expression=@var{exp}
2803 Install the package @var{exp} evaluates to.
2805 @var{exp} must be a Scheme expression that evaluates to a
2806 @code{<package>} object. This option is notably useful to disambiguate
2807 between same-named variants of a package, with expressions such as
2808 @code{(@@ (gnu packages base) guile-final)}.
2810 Note that this option installs the first output of the specified
2811 package, which may be insufficient when needing a specific output of a
2812 multiple-output package.
2814 @item --install-from-file=@var{file}
2815 @itemx -f @var{file}
2816 Install the package that the code within @var{file} evaluates to.
2818 As an example, @var{file} might contain a definition like this
2819 (@pxref{Defining Packages}):
2822 @include package-hello.scm
2825 Developers may find it useful to include such a @file{guix.scm} file
2826 in the root of their project source tree that can be used to test
2827 development snapshots and create reproducible development environments
2828 (@pxref{Invoking guix environment}).
2830 The @var{file} may also contain a JSON representation of one or more
2831 package definitions. Running @code{guix package -f} on
2832 @file{hello.json} with the following contents would result in installing
2833 the package @code{greeter} after building @code{myhello}:
2836 @verbatiminclude package-hello.json
2839 @item --remove=@var{package} @dots{}
2840 @itemx -r @var{package} @dots{}
2841 Remove the specified @var{package}s.
2843 As for @option{--install}, each @var{package} may specify a version number
2844 and/or output name in addition to the package name. For instance,
2845 @samp{-r glibc:debug} would remove the @code{debug} output of
2848 @item --upgrade[=@var{regexp} @dots{}]
2849 @itemx -u [@var{regexp} @dots{}]
2850 @cindex upgrading packages
2851 Upgrade all the installed packages. If one or more @var{regexp}s are
2852 specified, upgrade only installed packages whose name matches a
2853 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
2855 Note that this upgrades package to the latest version of packages found
2856 in the distribution currently installed. To update your distribution,
2857 you should regularly run @command{guix pull} (@pxref{Invoking guix
2860 @item --do-not-upgrade[=@var{regexp} @dots{}]
2861 When used together with the @option{--upgrade} option, do @emph{not}
2862 upgrade any packages whose name matches a @var{regexp}. For example, to
2863 upgrade all packages in the current profile except those containing the
2864 substring ``emacs'':
2867 $ guix package --upgrade . --do-not-upgrade emacs
2870 @item @anchor{profile-manifest}--manifest=@var{file}
2871 @itemx -m @var{file}
2872 @cindex profile declaration
2873 @cindex profile manifest
2874 Create a new generation of the profile from the manifest object
2875 returned by the Scheme code in @var{file}. This option can be repeated
2876 several times, in which case the manifests are concatenated.
2878 This allows you to @emph{declare} the profile's contents rather than
2879 constructing it through a sequence of @option{--install} and similar
2880 commands. The advantage is that @var{file} can be put under version
2881 control, copied to different machines to reproduce the same profile, and
2884 @c FIXME: Add reference to (guix profile) documentation when available.
2885 @var{file} must return a @dfn{manifest} object, which is roughly a list
2888 @findex packages->manifest
2890 (use-package-modules guile emacs)
2895 ;; Use a specific package output.
2896 (list guile-2.0 "debug")))
2899 @findex specifications->manifest
2900 In this example we have to know which modules define the @code{emacs}
2901 and @code{guile-2.0} variables to provide the right
2902 @code{use-package-modules} line, which can be cumbersome. We can
2903 instead provide regular package specifications and let
2904 @code{specifications->manifest} look up the corresponding package
2908 (specifications->manifest
2909 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2913 @cindex rolling back
2914 @cindex undoing transactions
2915 @cindex transactions, undoing
2916 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2917 the last transaction.
2919 When combined with options such as @option{--install}, roll back occurs
2920 before any other actions.
2922 When rolling back from the first generation that actually contains
2923 installed packages, the profile is made to point to the @dfn{zeroth
2924 generation}, which contains no files apart from its own metadata.
2926 After having rolled back, installing, removing, or upgrading packages
2927 overwrites previous future generations. Thus, the history of the
2928 generations in a profile is always linear.
2930 @item --switch-generation=@var{pattern}
2931 @itemx -S @var{pattern}
2933 Switch to a particular generation defined by @var{pattern}.
2935 @var{pattern} may be either a generation number or a number prefixed
2936 with ``+'' or ``-''. The latter means: move forward/backward by a
2937 specified number of generations. For example, if you want to return to
2938 the latest generation after @option{--roll-back}, use
2939 @option{--switch-generation=+1}.
2941 The difference between @option{--roll-back} and
2942 @option{--switch-generation=-1} is that @option{--switch-generation} will
2943 not make a zeroth generation, so if a specified generation does not
2944 exist, the current generation will not be changed.
2946 @item --search-paths[=@var{kind}]
2947 @cindex search paths
2948 Report environment variable definitions, in Bash syntax, that may be
2949 needed in order to use the set of installed packages. These environment
2950 variables are used to specify @dfn{search paths} for files used by some
2951 of the installed packages.
2953 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
2954 environment variables to be defined so it can look for headers and
2955 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2956 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2957 library are installed in the profile, then @option{--search-paths} will
2958 suggest setting these variables to @file{@var{profile}/include} and
2959 @file{@var{profile}/lib}, respectively.
2961 The typical use case is to define these environment variables in the
2965 $ eval `guix package --search-paths`
2968 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2969 meaning that the returned environment variable definitions will either
2970 be exact settings, or prefixes or suffixes of the current value of these
2971 variables. When omitted, @var{kind} defaults to @code{exact}.
2973 This option can also be used to compute the @emph{combined} search paths
2974 of several profiles. Consider this example:
2977 $ guix package -p foo -i guile
2978 $ guix package -p bar -i guile-json
2979 $ guix package -p foo -p bar --search-paths
2982 The last command above reports about the @env{GUILE_LOAD_PATH}
2983 variable, even though, taken individually, neither @file{foo} nor
2984 @file{bar} would lead to that recommendation.
2987 @item --profile=@var{profile}
2988 @itemx -p @var{profile}
2989 Use @var{profile} instead of the user's default profile.
2991 @var{profile} must be the name of a file that will be created upon
2992 completion. Concretely, @var{profile} will be a mere symbolic link
2993 (``symlink'') pointing to the actual profile where packages are
2997 $ guix install hello -p ~/code/my-profile
2999 $ ~/code/my-profile/bin/hello
3003 All it takes to get rid of the profile is to remove this symlink and its
3004 siblings that point to specific generations:
3007 $ rm ~/code/my-profile ~/code/my-profile-*-link
3010 @item --list-profiles
3011 List all the user's profiles:
3014 $ guix package --list-profiles
3015 /home/charlie/.guix-profile
3016 /home/charlie/code/my-profile
3017 /home/charlie/code/devel-profile
3018 /home/charlie/tmp/test
3021 When running as root, list all the profiles of all the users.
3023 @cindex collisions, in a profile
3024 @cindex colliding packages in profiles
3025 @cindex profile collisions
3026 @item --allow-collisions
3027 Allow colliding packages in the new profile. Use at your own risk!
3029 By default, @command{guix package} reports as an error @dfn{collisions}
3030 in the profile. Collisions happen when two or more different versions
3031 or variants of a given package end up in the profile.
3034 Use the bootstrap Guile to build the profile. This option is only
3035 useful to distribution developers.
3039 In addition to these actions, @command{guix package} supports the
3040 following options to query the current state of a profile, or the
3041 availability of packages:
3045 @item --search=@var{regexp}
3046 @itemx -s @var{regexp}
3047 @cindex searching for packages
3048 List the available packages whose name, synopsis, or description matches
3049 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3050 Print all the metadata of matching packages in
3051 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3052 GNU recutils manual}).
3054 This allows specific fields to be extracted using the @command{recsel}
3055 command, for instance:
3058 $ guix package -s malloc | recsel -p name,version,relevance
3072 Similarly, to show the name of all the packages available under the
3073 terms of the GNU@tie{}LGPL version 3:
3076 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3083 It is also possible to refine search results using several @code{-s} flags to
3084 @command{guix package}, or several arguments to @command{guix search}. For
3085 example, the following command returns a list of board games (this time using
3086 the @command{guix search} alias):
3089 $ guix search '\<board\>' game | recsel -p name
3094 If we were to omit @code{-s game}, we would also get software packages
3095 that deal with printed circuit boards; removing the angle brackets
3096 around @code{board} would further add packages that have to do with
3099 And now for a more elaborate example. The following command searches
3100 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3101 libraries, and prints the name and synopsis of the matching packages:
3104 $ guix search crypto library | \
3105 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3109 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3110 information on @dfn{selection expressions} for @code{recsel -e}.
3112 @item --show=@var{package}
3113 Show details about @var{package}, taken from the list of available packages, in
3114 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3118 $ guix package --show=python | recsel -p name,version
3126 You may also specify the full name of a package to only get details about a
3127 specific version of it (this time using the @command{guix show} alias):
3129 $ guix show python@@3.4 | recsel -p name,version
3136 @item --list-installed[=@var{regexp}]
3137 @itemx -I [@var{regexp}]
3138 List the currently installed packages in the specified profile, with the
3139 most recently installed packages shown last. When @var{regexp} is
3140 specified, list only installed packages whose name matches @var{regexp}.
3142 For each installed package, print the following items, separated by
3143 tabs: the package name, its version string, the part of the package that
3144 is installed (for instance, @code{out} for the default output,
3145 @code{include} for its headers, etc.), and the path of this package in
3148 @item --list-available[=@var{regexp}]
3149 @itemx -A [@var{regexp}]
3150 List packages currently available in the distribution for this system
3151 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3152 available packages whose name matches @var{regexp}.
3154 For each package, print the following items separated by tabs: its name,
3155 its version string, the parts of the package (@pxref{Packages with
3156 Multiple Outputs}), and the source location of its definition.
3158 @item --list-generations[=@var{pattern}]
3159 @itemx -l [@var{pattern}]
3161 Return a list of generations along with their creation dates; for each
3162 generation, show the installed packages, with the most recently
3163 installed packages shown last. Note that the zeroth generation is never
3166 For each installed package, print the following items, separated by
3167 tabs: the name of a package, its version string, the part of the package
3168 that is installed (@pxref{Packages with Multiple Outputs}), and the
3169 location of this package in the store.
3171 When @var{pattern} is used, the command returns only matching
3172 generations. Valid patterns include:
3175 @item @emph{Integers and comma-separated integers}. Both patterns denote
3176 generation numbers. For instance, @option{--list-generations=1} returns
3179 And @option{--list-generations=1,8,2} outputs three generations in the
3180 specified order. Neither spaces nor trailing commas are allowed.
3182 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3183 specified generations and everything in between. Note that the start of
3184 a range must be smaller than its end.
3186 It is also possible to omit the endpoint. For example,
3187 @option{--list-generations=2..}, returns all generations starting from the
3190 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3191 or months by passing an integer along with the first letter of the
3192 duration. For example, @option{--list-generations=20d} lists generations
3193 that are up to 20 days old.
3196 @item --delete-generations[=@var{pattern}]
3197 @itemx -d [@var{pattern}]
3198 When @var{pattern} is omitted, delete all generations except the current
3201 This command accepts the same patterns as @option{--list-generations}.
3202 When @var{pattern} is specified, delete the matching generations. When
3203 @var{pattern} specifies a duration, generations @emph{older} than the
3204 specified duration match. For instance, @option{--delete-generations=1m}
3205 deletes generations that are more than one month old.
3207 If the current generation matches, it is @emph{not} deleted. Also, the
3208 zeroth generation is never deleted.
3210 Note that deleting generations prevents rolling back to them.
3211 Consequently, this command must be used with care.
3215 Finally, since @command{guix package} may actually start build
3216 processes, it supports all the common build options (@pxref{Common Build
3217 Options}). It also supports package transformation options, such as
3218 @option{--with-source} (@pxref{Package Transformation Options}).
3219 However, note that package transformations are lost when upgrading; to
3220 preserve transformations across upgrades, you should define your own
3221 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3222 (@pxref{Defining Packages}).
3225 @section Substitutes
3228 @cindex pre-built binaries
3229 Guix supports transparent source/binary deployment, which means that it
3230 can either build things locally, or download pre-built items from a
3231 server, or both. We call these pre-built items @dfn{substitutes}---they
3232 are substitutes for local build results. In many cases, downloading a
3233 substitute is much faster than building things locally.
3235 Substitutes can be anything resulting from a derivation build
3236 (@pxref{Derivations}). Of course, in the common case, they are
3237 pre-built package binaries, but source tarballs, for instance, which
3238 also result from derivation builds, can be available as substitutes.
3241 * Official Substitute Server:: One particular source of substitutes.
3242 * Substitute Server Authorization:: How to enable or disable substitutes.
3243 * Substitute Authentication:: How Guix verifies substitutes.
3244 * Proxy Settings:: How to get substitutes via proxy.
3245 * Substitution Failure:: What happens when substitution fails.
3246 * On Trusting Binaries:: How can you trust that binary blob?
3249 @node Official Substitute Server
3250 @subsection Official Substitute Server
3253 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3254 that builds packages from Guix continuously for some
3255 architectures, and makes them available as substitutes. This is the
3256 default source of substitutes; it can be overridden by passing the
3257 @option{--substitute-urls} option either to @command{guix-daemon}
3258 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3259 or to client tools such as @command{guix package}
3260 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3263 Substitute URLs can be either HTTP or HTTPS.
3264 HTTPS is recommended because communications are encrypted; conversely,
3265 using HTTP makes all communications visible to an eavesdropper, who
3266 could use the information gathered to determine, for instance, whether
3267 your system has unpatched security vulnerabilities.
3269 Substitutes from the official build farm are enabled by default when
3270 using Guix System (@pxref{GNU Distribution}). However,
3271 they are disabled by default when using Guix on a foreign distribution,
3272 unless you have explicitly enabled them via one of the recommended
3273 installation steps (@pxref{Installation}). The following paragraphs
3274 describe how to enable or disable substitutes for the official build
3275 farm; the same procedure can also be used to enable substitutes for any
3276 other substitute server.
3278 @node Substitute Server Authorization
3279 @subsection Substitute Server Authorization
3282 @cindex substitutes, authorization thereof
3283 @cindex access control list (ACL), for substitutes
3284 @cindex ACL (access control list), for substitutes
3285 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3287 must add its public key to the access control list (ACL) of archive
3288 imports, using the @command{guix archive} command (@pxref{Invoking guix
3289 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3290 be compromised and to serve genuine substitutes.
3292 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3293 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3294 the installation prefix of Guix. If you installed Guix from source,
3295 make sure you checked the GPG signature of
3296 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3297 Then, you can run something like this:
3300 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3303 Once this is in place, the output of a command like @code{guix build}
3304 should change from something like:
3307 $ guix build emacs --dry-run
3308 The following derivations would be built:
3309 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3310 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3311 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3312 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3320 $ guix build emacs --dry-run
3321 112.3 MB would be downloaded:
3322 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3323 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3324 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3325 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3330 The text changed from ``The following derivations would be built'' to
3331 ``112.3 MB would be downloaded''. This indicates that substitutes from
3332 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3333 possible, for future builds.
3335 @cindex substitutes, how to disable
3336 The substitute mechanism can be disabled globally by running
3337 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3338 guix-daemon}). It can also be disabled temporarily by passing the
3339 @option{--no-substitutes} option to @command{guix package},
3340 @command{guix build}, and other command-line tools.
3342 @node Substitute Authentication
3343 @subsection Substitute Authentication
3345 @cindex digital signatures
3346 Guix detects and raises an error when attempting to use a substitute
3347 that has been tampered with. Likewise, it ignores substitutes that are
3348 not signed, or that are not signed by one of the keys listed in the ACL.
3350 There is one exception though: if an unauthorized server provides
3351 substitutes that are @emph{bit-for-bit identical} to those provided by
3352 an authorized server, then the unauthorized server becomes eligible for
3353 downloads. For example, assume we have chosen two substitute servers
3357 --substitute-urls="https://a.example.org https://b.example.org"
3361 @cindex reproducible builds
3362 If the ACL contains only the key for @samp{b.example.org}, and if
3363 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3364 then Guix will download substitutes from @samp{a.example.org} because it
3365 comes first in the list and can be considered a mirror of
3366 @samp{b.example.org}. In practice, independent build machines usually
3367 produce the same binaries, thanks to bit-reproducible builds (see
3370 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3371 (in other words, the server is not authenticated), contrary to what
3372 HTTPS clients such as Web browsers usually do. This is because Guix
3373 authenticates substitute information itself, as explained above, which
3374 is what we care about (whereas X.509 certificates are about
3375 authenticating bindings between domain names and public keys.)
3377 @node Proxy Settings
3378 @subsection Proxy Settings
3382 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3383 @env{https_proxy} environment variables can be set in the environment of
3384 @command{guix-daemon} and are honored for downloads of substitutes.
3385 Note that the value of those environment variables in the environment
3386 where @command{guix build}, @command{guix package}, and other client
3387 commands are run has @emph{absolutely no effect}.
3389 @node Substitution Failure
3390 @subsection Substitution Failure
3392 Even when a substitute for a derivation is available, sometimes the
3393 substitution attempt will fail. This can happen for a variety of
3394 reasons: the substitute server might be offline, the substitute may
3395 recently have been deleted, the connection might have been interrupted,
3398 When substitutes are enabled and a substitute for a derivation is
3399 available, but the substitution attempt fails, Guix will attempt to
3400 build the derivation locally depending on whether or not
3401 @option{--fallback} was given (@pxref{fallback-option,, common build
3402 option @option{--fallback}}). Specifically, if @option{--fallback} was
3403 omitted, then no local build will be performed, and the derivation is
3404 considered to have failed. However, if @option{--fallback} was given,
3405 then Guix will attempt to build the derivation locally, and the success
3406 or failure of the derivation depends on the success or failure of the
3407 local build. Note that when substitutes are disabled or no substitute
3408 is available for the derivation in question, a local build will
3409 @emph{always} be performed, regardless of whether or not
3410 @option{--fallback} was given.
3412 To get an idea of how many substitutes are available right now, you can
3413 try running the @command{guix weather} command (@pxref{Invoking guix
3414 weather}). This command provides statistics on the substitutes provided
3417 @node On Trusting Binaries
3418 @subsection On Trusting Binaries
3420 @cindex trust, of pre-built binaries
3421 Today, each individual's control over their own computing is at the
3422 mercy of institutions, corporations, and groups with enough power and
3423 determination to subvert the computing infrastructure and exploit its
3424 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3425 convenient, we encourage users to also build on their own, or even run
3426 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3427 interesting target. One way to help is by publishing the software you
3428 build using @command{guix publish} so that others have one more choice
3429 of server to download substitutes from (@pxref{Invoking guix publish}).
3431 Guix has the foundations to maximize build reproducibility
3432 (@pxref{Features}). In most cases, independent builds of a given
3433 package or derivation should yield bit-identical results. Thus, through
3434 a diverse set of independent package builds, we can strengthen the
3435 integrity of our systems. The @command{guix challenge} command aims to
3436 help users assess substitute servers, and to assist developers in
3437 finding out about non-deterministic package builds (@pxref{Invoking guix
3438 challenge}). Similarly, the @option{--check} option of @command{guix
3439 build} allows users to check whether previously-installed substitutes
3440 are genuine by rebuilding them locally (@pxref{build-check,
3441 @command{guix build --check}}).
3443 In the future, we want Guix to have support to publish and retrieve
3444 binaries to/from other users, in a peer-to-peer fashion. If you would
3445 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3447 @node Packages with Multiple Outputs
3448 @section Packages with Multiple Outputs
3450 @cindex multiple-output packages
3451 @cindex package outputs
3454 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3455 source package leads to exactly one directory in the store. When running
3456 @command{guix install glibc}, one installs the default output of the
3457 GNU libc package; the default output is called @code{out}, but its name
3458 can be omitted as shown in this command. In this particular case, the
3459 default output of @code{glibc} contains all the C header files, shared
3460 libraries, static libraries, Info documentation, and other supporting
3463 Sometimes it is more appropriate to separate the various types of files
3464 produced from a single source package into separate outputs. For
3465 instance, the GLib C library (used by GTK+ and related packages)
3466 installs more than 20 MiB of reference documentation as HTML pages.
3467 To save space for users who do not need it, the documentation goes to a
3468 separate output, called @code{doc}. To install the main GLib output,
3469 which contains everything but the documentation, one would run:
3475 @cindex documentation
3476 The command to install its documentation is:
3479 guix install glib:doc
3482 Some packages install programs with different ``dependency footprints''.
3483 For instance, the WordNet package installs both command-line tools and
3484 graphical user interfaces (GUIs). The former depend solely on the C
3485 library, whereas the latter depend on Tcl/Tk and the underlying X
3486 libraries. In this case, we leave the command-line tools in the default
3487 output, whereas the GUIs are in a separate output. This allows users
3488 who do not need the GUIs to save space. The @command{guix size} command
3489 can help find out about such situations (@pxref{Invoking guix size}).
3490 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3492 There are several such multiple-output packages in the GNU distribution.
3493 Other conventional output names include @code{lib} for libraries and
3494 possibly header files, @code{bin} for stand-alone programs, and
3495 @code{debug} for debugging information (@pxref{Installing Debugging
3496 Files}). The outputs of a packages are listed in the third column of
3497 the output of @command{guix package --list-available} (@pxref{Invoking
3501 @node Invoking guix gc
3502 @section Invoking @command{guix gc}
3504 @cindex garbage collector
3506 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3507 The @command{guix gc} command allows users to explicitly run the garbage
3508 collector to reclaim space from the @file{/gnu/store} directory. It is
3509 the @emph{only} way to remove files from @file{/gnu/store}---removing
3510 files or directories manually may break it beyond repair!
3513 @cindex garbage collector roots
3514 The garbage collector has a set of known @dfn{roots}: any file under
3515 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3516 cannot be deleted; any other file is considered @dfn{dead} and may be
3517 deleted. The set of garbage collector roots (``GC roots'' for short)
3518 includes default user profiles; by default, the symlinks under
3519 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3520 added with @command{guix build --root}, for example (@pxref{Invoking
3521 guix build}). The @command{guix gc --list-roots} command lists them.
3523 Prior to running @code{guix gc --collect-garbage} to make space, it is
3524 often useful to remove old generations from user profiles; that way, old
3525 package builds referenced by those generations can be reclaimed. This
3526 is achieved by running @code{guix package --delete-generations}
3527 (@pxref{Invoking guix package}).
3529 Our recommendation is to run a garbage collection periodically, or when
3530 you are short on disk space. For instance, to guarantee that at least
3531 5@tie{}GB are available on your disk, simply run:
3537 It is perfectly safe to run as a non-interactive periodic job
3538 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3539 Running @command{guix gc} with no arguments will collect as
3540 much garbage as it can, but that is often inconvenient: you may find
3541 yourself having to rebuild or re-download software that is ``dead'' from
3542 the GC viewpoint but that is necessary to build other pieces of
3543 software---e.g., the compiler tool chain.
3545 The @command{guix gc} command has three modes of operation: it can be
3546 used to garbage-collect any dead files (the default), to delete specific
3547 files (the @option{--delete} option), to print garbage-collector
3548 information, or for more advanced queries. The garbage collection
3549 options are as follows:
3552 @item --collect-garbage[=@var{min}]
3553 @itemx -C [@var{min}]
3554 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3555 sub-directories. This is the default operation when no option is
3558 When @var{min} is given, stop once @var{min} bytes have been collected.
3559 @var{min} may be a number of bytes, or it may include a unit as a
3560 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3561 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3563 When @var{min} is omitted, collect all the garbage.
3565 @item --free-space=@var{free}
3566 @itemx -F @var{free}
3567 Collect garbage until @var{free} space is available under
3568 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3569 as @code{500MiB}, as described above.
3571 When @var{free} or more is already available in @file{/gnu/store}, do
3572 nothing and exit immediately.
3574 @item --delete-generations[=@var{duration}]
3575 @itemx -d [@var{duration}]
3576 Before starting the garbage collection process, delete all the generations
3577 older than @var{duration}, for all the user profiles; when run as root, this
3578 applies to all the profiles @emph{of all the users}.
3580 For example, this command deletes all the generations of all your profiles
3581 that are older than 2 months (except generations that are current), and then
3582 proceeds to free space until at least 10 GiB are available:
3585 guix gc -d 2m -F 10G
3590 Attempt to delete all the store files and directories specified as
3591 arguments. This fails if some of the files are not in the store, or if
3592 they are still live.
3594 @item --list-failures
3595 List store items corresponding to cached build failures.
3597 This prints nothing unless the daemon was started with
3598 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3599 @option{--cache-failures}}).
3602 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3606 List store items in use by currently running processes. These store
3607 items are effectively considered GC roots: they cannot be deleted.
3609 @item --clear-failures
3610 Remove the specified store items from the failed-build cache.
3612 Again, this option only makes sense when the daemon is started with
3613 @option{--cache-failures}. Otherwise, it does nothing.
3616 Show the list of dead files and directories still present in the
3617 store---i.e., files and directories no longer reachable from any root.
3620 Show the list of live store files and directories.
3624 In addition, the references among existing store files can be queried:
3630 @cindex package dependencies
3631 List the references (respectively, the referrers) of store files given
3637 List the requisites of the store files passed as arguments. Requisites
3638 include the store files themselves, their references, and the references
3639 of these, recursively. In other words, the returned list is the
3640 @dfn{transitive closure} of the store files.
3642 @xref{Invoking guix size}, for a tool to profile the size of the closure
3643 of an element. @xref{Invoking guix graph}, for a tool to visualize
3644 the graph of references.
3648 Return the derivation(s) leading to the given store items
3649 (@pxref{Derivations}).
3651 For example, this command:
3654 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3658 returns the @file{.drv} file(s) leading to the @code{emacs} package
3659 installed in your profile.
3661 Note that there may be zero matching @file{.drv} files, for instance
3662 because these files have been garbage-collected. There can also be more
3663 than one matching @file{.drv} due to fixed-output derivations.
3666 Lastly, the following options allow you to check the integrity of the
3667 store and to control disk usage.
3671 @item --verify[=@var{options}]
3672 @cindex integrity, of the store
3673 @cindex integrity checking
3674 Verify the integrity of the store.
3676 By default, make sure that all the store items marked as valid in the
3677 database of the daemon actually exist in @file{/gnu/store}.
3679 When provided, @var{options} must be a comma-separated list containing one
3680 or more of @code{contents} and @code{repair}.
3682 When passing @option{--verify=contents}, the daemon computes the
3683 content hash of each store item and compares it against its hash in the
3684 database. Hash mismatches are reported as data corruptions. Because it
3685 traverses @emph{all the files in the store}, this command can take a
3686 long time, especially on systems with a slow disk drive.
3688 @cindex repairing the store
3689 @cindex corruption, recovering from
3690 Using @option{--verify=repair} or @option{--verify=contents,repair}
3691 causes the daemon to try to repair corrupt store items by fetching
3692 substitutes for them (@pxref{Substitutes}). Because repairing is not
3693 atomic, and thus potentially dangerous, it is available only to the
3694 system administrator. A lightweight alternative, when you know exactly
3695 which items in the store are corrupt, is @command{guix build --repair}
3696 (@pxref{Invoking guix build}).
3699 @cindex deduplication
3700 Optimize the store by hard-linking identical files---this is
3701 @dfn{deduplication}.
3703 The daemon performs deduplication after each successful build or archive
3704 import, unless it was started with @option{--disable-deduplication}
3705 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
3706 this option is primarily useful when the daemon was running with
3707 @option{--disable-deduplication}.
3711 @node Invoking guix pull
3712 @section Invoking @command{guix pull}
3714 @cindex upgrading Guix
3715 @cindex updating Guix
3716 @cindex @command{guix pull}
3718 Packages are installed or upgraded to the latest version available in
3719 the distribution currently available on your local machine. To update
3720 that distribution, along with the Guix tools, you must run @command{guix
3721 pull}: the command downloads the latest Guix source code and package
3722 descriptions, and deploys it. Source code is downloaded from a
3723 @uref{https://git-scm.com, Git} repository, by default the official
3724 GNU@tie{}Guix repository, though this can be customized.
3726 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3727 (@pxref{Channels}) specified by one of the followings, in this order:
3731 the @option{--channels} option;
3733 the user's @file{~/.config/guix/channels.scm} file;
3735 the system-wide @file{/etc/guix/channels.scm} file;
3737 the built-in default channels specified in the @code{%default-channels}
3741 On completion, @command{guix package} will use packages and package
3742 versions from this just-retrieved copy of Guix. Not only that, but all
3743 the Guix commands and Scheme modules will also be taken from that latest
3744 version. New @command{guix} sub-commands added by the update also
3747 Any user can update their Guix copy using @command{guix pull}, and the
3748 effect is limited to the user who ran @command{guix pull}. For
3749 instance, when user @code{root} runs @command{guix pull}, this has no
3750 effect on the version of Guix that user @code{alice} sees, and vice
3753 The result of running @command{guix pull} is a @dfn{profile} available
3754 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3755 make sure to add it to the beginning of your search path so that you use
3756 the latest version, and similarly for the Info manual
3757 (@pxref{Documentation}):
3760 export PATH="$HOME/.config/guix/current/bin:$PATH"
3761 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3764 The @option{--list-generations} or @option{-l} option lists past generations
3765 produced by @command{guix pull}, along with details about their provenance:
3769 Generation 1 Jun 10 2018 00:18:18
3771 repository URL: https://git.savannah.gnu.org/git/guix.git
3772 branch: origin/master
3773 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3775 Generation 2 Jun 11 2018 11:02:49
3777 repository URL: https://git.savannah.gnu.org/git/guix.git
3778 branch: origin/master
3779 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3780 2 new packages: keepalived, libnfnetlink
3781 6 packages upgraded: emacs-nix-mode@@2.0.4,
3782 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3783 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3785 Generation 3 Jun 13 2018 23:31:07 (current)
3787 repository URL: https://git.savannah.gnu.org/git/guix.git
3788 branch: origin/master
3789 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3790 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3791 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3794 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3795 describe the current status of Guix.
3797 This @code{~/.config/guix/current} profile works exactly like the profiles
3798 created by @command{guix package} (@pxref{Invoking guix package}). That
3799 is, you can list generations, roll back to the previous
3800 generation---i.e., the previous Guix---and so on:
3803 $ guix pull --roll-back
3804 switched from generation 3 to 2
3805 $ guix pull --delete-generations=1
3806 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3809 You can also use @command{guix package} (@pxref{Invoking guix package})
3810 to manage the profile by naming it explicitly:
3812 $ guix package -p ~/.config/guix/current --roll-back
3813 switched from generation 3 to 2
3814 $ guix package -p ~/.config/guix/current --delete-generations=1
3815 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3818 The @command{guix pull} command is usually invoked with no arguments,
3819 but it supports the following options:
3822 @item --url=@var{url}
3823 @itemx --commit=@var{commit}
3824 @itemx --branch=@var{branch}
3825 Download code for the @code{guix} channel from the specified @var{url}, at the
3826 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3827 string), or @var{branch}.
3829 @cindex @file{channels.scm}, configuration file
3830 @cindex configuration file for channels
3831 These options are provided for convenience, but you can also specify your
3832 configuration in the @file{~/.config/guix/channels.scm} file or using the
3833 @option{--channels} option (see below).
3835 @item --channels=@var{file}
3836 @itemx -C @var{file}
3837 Read the list of channels from @var{file} instead of
3838 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3839 @var{file} must contain Scheme code that
3840 evaluates to a list of channel objects. @xref{Channels}, for more
3843 @cindex channel news
3846 Display the list of packages added or upgraded since the previous
3847 generation, as well as, occasionally, news written by channel authors
3848 for their users (@pxref{Channels, Writing Channel News}).
3850 The package information is the same as displayed upon @command{guix
3851 pull} completion, but without ellipses; it is also similar to the output
3852 of @command{guix pull -l} for the last generation (see below).
3854 @item --list-generations[=@var{pattern}]
3855 @itemx -l [@var{pattern}]
3856 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3857 is provided, the subset of generations that match @var{pattern}.
3858 The syntax of @var{pattern} is the same as with @code{guix package
3859 --list-generations} (@pxref{Invoking guix package}).
3862 @cindex rolling back
3863 @cindex undoing transactions
3864 @cindex transactions, undoing
3865 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3866 undo the last transaction.
3868 @item --switch-generation=@var{pattern}
3869 @itemx -S @var{pattern}
3871 Switch to a particular generation defined by @var{pattern}.
3873 @var{pattern} may be either a generation number or a number prefixed
3874 with ``+'' or ``-''. The latter means: move forward/backward by a
3875 specified number of generations. For example, if you want to return to
3876 the latest generation after @option{--roll-back}, use
3877 @option{--switch-generation=+1}.
3879 @item --delete-generations[=@var{pattern}]
3880 @itemx -d [@var{pattern}]
3881 When @var{pattern} is omitted, delete all generations except the current
3884 This command accepts the same patterns as @option{--list-generations}.
3885 When @var{pattern} is specified, delete the matching generations. When
3886 @var{pattern} specifies a duration, generations @emph{older} than the
3887 specified duration match. For instance, @option{--delete-generations=1m}
3888 deletes generations that are more than one month old.
3890 If the current generation matches, it is @emph{not} deleted.
3892 Note that deleting generations prevents rolling back to them.
3893 Consequently, this command must be used with care.
3895 @xref{Invoking guix describe}, for a way to display information about the
3896 current generation only.
3898 @item --profile=@var{profile}
3899 @itemx -p @var{profile}
3900 Use @var{profile} instead of @file{~/.config/guix/current}.
3904 Show which channel commit(s) would be used and what would be built or
3905 substituted but do not actually do it.
3907 @item --system=@var{system}
3908 @itemx -s @var{system}
3909 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3910 the system type of the build host.
3913 Produce verbose output, writing build logs to the standard error output.
3916 Use the bootstrap Guile to build the latest Guix. This option is only
3917 useful to Guix developers.
3920 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3921 repository and branch to pull from, as well as @emph{additional} repositories
3922 containing package modules that should be deployed. @xref{Channels}, for more
3925 In addition, @command{guix pull} supports all the common build options
3926 (@pxref{Common Build Options}).
3932 @cindex @file{channels.scm}, configuration file
3933 @cindex configuration file for channels
3934 @cindex @command{guix pull}, configuration file
3935 @cindex configuration of @command{guix pull}
3936 Guix and its package collection are updated by running @command{guix pull}
3937 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3938 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3939 customized by defining @dfn{channels} in the
3940 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3941 of a Git repository to be deployed, and @command{guix pull} can be instructed
3942 to pull from one or more channels. In other words, channels can be used to
3943 @emph{customize} and to @emph{extend} Guix, as we will see below.
3945 @subsection Using a Custom Guix Channel
3947 The channel called @code{guix} specifies where Guix itself---its command-line
3948 tools as well as its package collection---should be downloaded. For instance,
3949 suppose you want to update from your own copy of the Guix repository at
3950 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3951 write in @code{~/.config/guix/channels.scm} this specification:
3954 ;; Tell 'guix pull' to use my own repo.
3957 (url "https://example.org/my-guix.git")
3958 (branch "super-hacks")))
3962 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3963 branch of the repository at @code{example.org}.
3965 @subsection Specifying Additional Channels
3967 @cindex extending the package collection (channels)
3968 @cindex personal packages (channels)
3969 @cindex channels, for personal packages
3970 You can also specify @emph{additional channels} to pull from. Let's say you
3971 have a bunch of custom package variants or personal packages that you think
3972 would make little sense to contribute to the Guix project, but would like to
3973 have these packages transparently available to you at the command line. You
3974 would first write modules containing those package definitions (@pxref{Package
3975 Modules}), maintain them in a Git repository, and then you and anyone else can
3976 use it as an additional channel to get packages from. Neat, no?
3978 @c What follows stems from discussions at
3979 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3980 @c earlier discussions on guix-devel@gnu.org.
3982 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3983 publish your personal channel to the world, we would like to share a few words
3988 Before publishing a channel, please consider contributing your package
3989 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3990 to free software of all sorts, and packages in Guix proper are readily
3991 available to all Guix users and benefit from the project's quality assurance
3995 When you maintain package definitions outside Guix, we, Guix developers,
3996 consider that @emph{the compatibility burden is on you}. Remember that
3997 package modules and package definitions are just Scheme code that uses various
3998 programming interfaces (APIs). We want to remain free to change these APIs to
3999 keep improving Guix, possibly in ways that break your channel. We never
4000 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
4004 Corollary: if you're using an external channel and that channel breaks, please
4005 @emph{report the issue to the channel authors}, not to the Guix project.
4008 You've been warned! Having said this, we believe external channels are a
4009 practical way to exert your freedom to augment Guix' package collection and to
4010 share your improvements, which are basic tenets of
4011 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4012 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4015 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4016 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4019 @vindex %default-channels
4021 ;; Add my personal packages to those Guix provides.
4023 (name 'my-personal-packages)
4024 (url "https://example.org/personal-packages.git"))
4029 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4030 add a channel the list of channels that the variable @code{%default-channels}
4031 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4032 Manual}). With this file in place, @command{guix pull} builds not only Guix
4033 but also the package modules from your own repository. The result in
4034 @file{~/.config/guix/current} is the union of Guix with your own package
4038 $ guix pull --list-generations
4040 Generation 19 Aug 27 2018 16:20:48
4042 repository URL: https://git.savannah.gnu.org/git/guix.git
4044 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4045 my-personal-packages dd3df5e
4046 repository URL: https://example.org/personal-packages.git
4048 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4049 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4050 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4054 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4055 both Guix and packages from the @code{my-personal-packages} channel. Among
4056 the new and upgraded packages that are listed, some like @code{my-gimp} and
4057 @code{my-emacs-with-cool-features} might come from
4058 @code{my-personal-packages}, while others come from the Guix default channel.
4060 To create a channel, create a Git repository containing your own package
4061 modules and make it available. The repository can contain anything, but a
4062 useful channel will contain Guile modules that export packages. Once you
4063 start using a channel, Guix will behave as if the root directory of that
4064 channel's Git repository has been added to the Guile load path (@pxref{Load
4065 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4066 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4067 module, then the module will be available under the name @code{(my-packages
4068 my-tools)}, and you will be able to use it like any other module
4069 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4071 @cindex dependencies, channels
4072 @cindex meta-data, channels
4073 @subsection Declaring Channel Dependencies
4075 Channel authors may decide to augment a package collection provided by other
4076 channels. They can declare their channel to be dependent on other channels in
4077 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4078 the channel repository.
4080 The meta-data file should contain a simple S-expression like this:
4087 (name some-collection)
4088 (url "https://example.org/first-collection.git"))
4090 (name some-other-collection)
4091 (url "https://example.org/second-collection.git")
4092 (branch "testing"))))
4095 In the above example this channel is declared to depend on two other channels,
4096 which will both be fetched automatically. The modules provided by the channel
4097 will be compiled in an environment where the modules of all these declared
4098 channels are available.
4100 For the sake of reliability and maintainability, you should avoid dependencies
4101 on channels that you don't control, and you should aim to keep the number of
4102 dependencies to a minimum.
4104 @cindex subdirectory, channels
4105 @subsection Package Modules in a Sub-directory
4107 As a channel author, you may want to keep your channel modules in a
4108 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4109 add a meta-data file @file{.guix-channel} that contains:
4117 @cindex news, for channels
4118 @subsection Writing Channel News
4120 Channel authors may occasionally want to communicate to their users
4121 information about important changes in the channel. You'd send them all
4122 an email, but that's not convenient.
4124 Instead, channels can provide a @dfn{news file}; when the channel users
4125 run @command{guix pull}, that news file is automatically read and
4126 @command{guix pull --news} can display the announcements that correspond
4127 to the new commits that have been pulled, if any.
4129 To do that, channel authors must first declare the name of the news file
4130 in their @file{.guix-channel} file:
4135 (news-file "etc/news.txt"))
4138 The news file itself, @file{etc/news.txt} in this example, must look
4139 something like this:
4144 (entry (tag "the-bug-fix")
4145 (title (en "Fixed terrible bug")
4147 (body (en "@@emph@{Good news@}! It's fixed!")
4148 (eo "Certe ĝi pli bone funkcias nun!")))
4149 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4150 (title (en "Added a great package")
4151 (ca "Què vol dir guix?"))
4152 (body (en "Don't miss the @@code@{hello@} package!"))))
4155 The file consists of a list of @dfn{news entries}. Each entry is
4156 associated with a commit or tag: it describes changes made in this
4157 commit, possibly in preceding commits as well. Users see entries only
4158 the first time they obtain the commit the entry refers to.
4160 The @code{title} field should be a one-line summary while @code{body}
4161 can be arbitrarily long, and both can contain Texinfo markup
4162 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4163 a list of language tag/message tuples, which allows @command{guix pull}
4164 to display news in the language that corresponds to the user's locale.
4166 If you want to translate news using a gettext-based workflow, you can
4167 extract translatable strings with @command{xgettext} (@pxref{xgettext
4168 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4169 you write news entries in English first, the command below creates a PO
4170 file containing the strings to translate:
4173 xgettext -o news.po -l scheme -ken etc/news.scm
4176 To sum up, yes, you could use your channel as a blog. But beware, this
4177 is @emph{not quite} what your users might expect.
4179 @subsection Replicating Guix
4181 @cindex pinning, channels
4182 @cindex replicating Guix
4183 @cindex reproducibility, of Guix
4184 The @command{guix pull --list-generations} output above shows precisely which
4185 commits were used to build this instance of Guix. We can thus replicate it,
4186 say, on another machine, by providing a channel specification in
4187 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4190 ;; Deploy specific commits of my channels of interest.
4193 (url "https://git.savannah.gnu.org/git/guix.git")
4194 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4196 (name 'my-personal-packages)
4197 (url "https://example.org/personal-packages.git")
4198 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4201 The @command{guix describe --format=channels} command can even generate this
4202 list of channels directly (@pxref{Invoking guix describe}). The resulting
4203 file can be used with the -C options of @command{guix pull}
4204 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4205 (@pxref{Invoking guix time-machine}).
4207 At this point the two machines run the @emph{exact same Guix}, with access to
4208 the @emph{exact same packages}. The output of @command{guix build gimp} on
4209 one machine will be exactly the same, bit for bit, as the output of the same
4210 command on the other machine. It also means both machines have access to all
4211 the source code of Guix and, transitively, to all the source code of every
4214 This gives you super powers, allowing you to track the provenance of binary
4215 artifacts with very fine grain, and to reproduce software environments at
4216 will---some sort of ``meta reproducibility'' capabilities, if you will.
4217 @xref{Inferiors}, for another way to take advantage of these super powers.
4219 @node Invoking guix time-machine
4220 @section Invoking @command{guix time-machine}
4222 @cindex @command{guix time-machine}
4223 @cindex pinning, channels
4224 @cindex replicating Guix
4225 @cindex reproducibility, of Guix
4227 The @command{guix time-machine} command provides access to other
4228 revisions of Guix, for example to install older versions of packages,
4229 or to reproduce a computation in an identical environment. The revision
4230 of Guix to be used is defined by a commit or by a channel
4231 description file created by @command{guix describe}
4232 (@pxref{Invoking guix describe}).
4234 The general syntax is:
4237 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4240 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4241 @command{guix} command of the specified revision. The @var{options} that define
4242 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4245 @item --url=@var{url}
4246 @itemx --commit=@var{commit}
4247 @itemx --branch=@var{branch}
4248 Use the @code{guix} channel from the specified @var{url}, at the
4249 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4250 string), or @var{branch}.
4252 @item --channels=@var{file}
4253 @itemx -C @var{file}
4254 Read the list of channels from @var{file}. @var{file} must contain
4255 Scheme code that evaluates to a list of channel objects.
4256 @xref{Channels} for more information.
4259 As for @command{guix pull}, the absence of any options means that the
4260 the latest commit on the master branch will be used. The command
4263 guix time-machine -- build hello
4266 will thus build the package @code{hello} as defined in the master branch,
4267 which is in general a newer revision of Guix than you have installed.
4268 Time travel works in both directions!
4270 Note that @command{guix time-machine} can trigger builds of channels and
4271 their dependencies, and these are controlled by the standard build
4272 options (@pxref{Common Build Options}).
4277 @c TODO: Remove this once we're more confident about API stability.
4279 The functionality described here is a ``technology preview'' as of version
4280 @value{VERSION}. As such, the interface is subject to change.
4284 @cindex composition of Guix revisions
4285 Sometimes you might need to mix packages from the revision of Guix you're
4286 currently running with packages available in a different revision of Guix.
4287 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4288 revisions in arbitrary ways.
4290 @cindex inferior packages
4291 Technically, an ``inferior'' is essentially a separate Guix process connected
4292 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4293 @code{(guix inferior)} module allows you to create inferiors and to
4294 communicate with them. It also provides a high-level interface to browse and
4295 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4297 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4298 to interact with a separate revision of Guix. For example, let's assume you
4299 want to install in your profile the current @code{guile} package, along with
4300 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4301 because the newer @code{guile-json} has an incompatible API and you want to
4302 run your code against the old API@. To do that, you could write a manifest for
4303 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4304 manifest, you would create an inferior for that old Guix revision you care
4305 about, and you would look up the @code{guile-json} package in the inferior:
4308 (use-modules (guix inferior) (guix channels)
4309 (srfi srfi-1)) ;for 'first'
4312 ;; This is the old revision from which we want to
4313 ;; extract guile-json.
4316 (url "https://git.savannah.gnu.org/git/guix.git")
4318 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4321 ;; An inferior representing the above revision.
4322 (inferior-for-channels channels))
4324 ;; Now create a manifest with the current "guile" package
4325 ;; and the old "guile-json" package.
4327 (list (first (lookup-inferior-packages inferior "guile-json"))
4328 (specification->package "guile")))
4331 On its first run, @command{guix package --manifest} might have to build the
4332 channel you specified before it can create the inferior; subsequent runs will
4333 be much faster because the Guix revision will be cached.
4335 The @code{(guix inferior)} module provides the following procedures to open an
4338 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4339 [#:cache-directory] [#:ttl]
4340 Return an inferior for @var{channels}, a list of channels. Use the cache at
4341 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4342 This procedure opens a new connection to the build daemon.
4344 As a side effect, this procedure may build or substitute binaries for
4345 @var{channels}, which can take time.
4348 @deffn {Scheme Procedure} open-inferior @var{directory} @
4349 [#:command "bin/guix"]
4350 Open the inferior Guix in @var{directory}, running
4351 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4352 the inferior could not be launched.
4355 @cindex inferior packages
4356 The procedures listed below allow you to obtain and manipulate inferior
4359 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4360 Return the list of packages known to @var{inferior}.
4363 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4365 Return the sorted list of inferior packages matching @var{name} in
4366 @var{inferior}, with highest version numbers first. If @var{version} is true,
4367 return only packages with a version number prefixed by @var{version}.
4370 @deffn {Scheme Procedure} inferior-package? @var{obj}
4371 Return true if @var{obj} is an inferior package.
4374 @deffn {Scheme Procedure} inferior-package-name @var{package}
4375 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4376 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4377 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4378 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4379 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4380 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4381 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4382 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4383 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4384 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4385 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4386 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4387 These procedures are the counterpart of package record accessors
4388 (@pxref{package Reference}). Most of them work by querying the inferior
4389 @var{package} comes from, so the inferior must still be live when you call
4393 Inferior packages can be used transparently like any other package or
4394 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4395 transparently handled by the @code{packages->manifest} procedure, which is
4396 commonly use in manifests (@pxref{Invoking guix package, the
4397 @option{--manifest} option of @command{guix package}}). Thus you can insert
4398 an inferior package pretty much anywhere you would insert a regular package:
4399 in manifests, in the @code{packages} field of your @code{operating-system}
4400 declaration, and so on.
4402 @node Invoking guix describe
4403 @section Invoking @command{guix describe}
4405 @cindex reproducibility
4406 @cindex replicating Guix
4407 Often you may want to answer questions like: ``Which revision of Guix am I
4408 using?'' or ``Which channels am I using?'' This is useful information in many
4409 situations: if you want to @emph{replicate} an environment on a different
4410 machine or user account, if you want to report a bug or to determine what
4411 change in the channels you are using caused it, or if you want to record your
4412 system state for reproducibility purposes. The @command{guix describe}
4413 command answers these questions.
4415 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4416 displays the channel(s) that it was built from, including their repository URL
4417 and commit IDs (@pxref{Channels}):
4421 Generation 10 Sep 03 2018 17:32:44 (current)
4423 repository URL: https://git.savannah.gnu.org/git/guix.git
4425 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4428 If you're familiar with the Git version control system, this is similar in
4429 spirit to @command{git describe}; the output is also similar to that of
4430 @command{guix pull --list-generations}, but limited to the current generation
4431 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4432 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4433 information is all it takes to describe the revision of Guix you're using, and
4434 also to replicate it.
4436 To make it easier to replicate Guix, @command{guix describe} can also be asked
4437 to return a list of channels instead of the human-readable description above:
4440 $ guix describe -f channels
4443 (url "https://git.savannah.gnu.org/git/guix.git")
4445 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4449 You can save this to a file and feed it to @command{guix pull -C} on some
4450 other machine or at a later point in time, which will instantiate @emph{this
4451 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4452 From there on, since you're able to deploy the same revision of Guix, you can
4453 just as well @emph{replicate a complete software environment}. We humbly
4454 think that this is @emph{awesome}, and we hope you'll like it too!
4456 The details of the options supported by @command{guix describe} are as
4460 @item --format=@var{format}
4461 @itemx -f @var{format}
4462 Produce output in the specified @var{format}, one of:
4466 produce human-readable output;
4468 produce a list of channel specifications that can be passed to @command{guix
4469 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4473 produce a list of channel specifications in JSON format;
4475 produce a list of channel specifications in Recutils format.
4478 @item --profile=@var{profile}
4479 @itemx -p @var{profile}
4480 Display information about @var{profile}.
4483 @node Invoking guix archive
4484 @section Invoking @command{guix archive}
4486 @cindex @command{guix archive}
4488 The @command{guix archive} command allows users to @dfn{export} files
4489 from the store into a single archive, and to later @dfn{import} them on
4490 a machine that runs Guix.
4491 In particular, it allows store files to be transferred from one machine
4492 to the store on another machine.
4495 If you're looking for a way to produce archives in a format suitable for
4496 tools other than Guix, @pxref{Invoking guix pack}.
4499 @cindex exporting store items
4500 To export store files as an archive to standard output, run:
4503 guix archive --export @var{options} @var{specifications}...
4506 @var{specifications} may be either store file names or package
4507 specifications, as for @command{guix package} (@pxref{Invoking guix
4508 package}). For instance, the following command creates an archive
4509 containing the @code{gui} output of the @code{git} package and the main
4510 output of @code{emacs}:
4513 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4516 If the specified packages are not built yet, @command{guix archive}
4517 automatically builds them. The build process may be controlled with the
4518 common build options (@pxref{Common Build Options}).
4520 To transfer the @code{emacs} package to a machine connected over SSH,
4524 guix archive --export -r emacs | ssh the-machine guix archive --import
4528 Similarly, a complete user profile may be transferred from one machine
4529 to another like this:
4532 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4533 ssh the-machine guix archive --import
4537 However, note that, in both examples, all of @code{emacs} and the
4538 profile as well as all of their dependencies are transferred (due to
4539 @option{-r}), regardless of what is already available in the store on
4540 the target machine. The @option{--missing} option can help figure out
4541 which items are missing from the target store. The @command{guix copy}
4542 command simplifies and optimizes this whole process, so this is probably
4543 what you should use in this case (@pxref{Invoking guix copy}).
4545 @cindex nar, archive format
4546 @cindex normalized archive (nar)
4547 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4548 comparable in spirit to `tar', but with differences
4549 that make it more appropriate for our purposes. First, rather than
4550 recording all Unix metadata for each file, the nar format only mentions
4551 the file type (regular, directory, or symbolic link); Unix permissions
4552 and owner/group are dismissed. Second, the order in which directory
4553 entries are stored always follows the order of file names according to
4554 the C locale collation order. This makes archive production fully
4557 When exporting, the daemon digitally signs the contents of the archive,
4558 and that digital signature is appended. When importing, the daemon
4559 verifies the signature and rejects the import in case of an invalid
4560 signature or if the signing key is not authorized.
4561 @c FIXME: Add xref to daemon doc about signatures.
4563 The main options are:
4567 Export the specified store files or packages (see below.) Write the
4568 resulting archive to the standard output.
4570 Dependencies are @emph{not} included in the output, unless
4571 @option{--recursive} is passed.
4575 When combined with @option{--export}, this instructs @command{guix archive}
4576 to include dependencies of the given items in the archive. Thus, the
4577 resulting archive is self-contained: it contains the closure of the
4578 exported store items.
4581 Read an archive from the standard input, and import the files listed
4582 therein into the store. Abort if the archive has an invalid digital
4583 signature, or if it is signed by a public key not among the authorized
4584 keys (see @option{--authorize} below.)
4587 Read a list of store file names from the standard input, one per line,
4588 and write on the standard output the subset of these files missing from
4591 @item --generate-key[=@var{parameters}]
4592 @cindex signing, archives
4593 Generate a new key pair for the daemon. This is a prerequisite before
4594 archives can be exported with @option{--export}. Note that this
4595 operation usually takes time, because it needs to gather enough entropy
4596 to generate the key pair.
4598 The generated key pair is typically stored under @file{/etc/guix}, in
4599 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4600 key, which must be kept secret.) When @var{parameters} is omitted,
4601 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4602 versions before 1.6.0, it is a 4096-bit RSA key.
4603 Alternatively, @var{parameters} can specify
4604 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4605 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4606 Libgcrypt Reference Manual}).
4609 @cindex authorizing, archives
4610 Authorize imports signed by the public key passed on standard input.
4611 The public key must be in ``s-expression advanced format''---i.e., the
4612 same format as the @file{signing-key.pub} file.
4614 The list of authorized keys is kept in the human-editable file
4615 @file{/etc/guix/acl}. The file contains
4616 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4617 s-expressions''} and is structured as an access-control list in the
4618 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4621 @item --extract=@var{directory}
4622 @itemx -x @var{directory}
4623 Read a single-item archive as served by substitute servers
4624 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4625 low-level operation needed in only very narrow use cases; see below.
4627 For example, the following command extracts the substitute for Emacs
4628 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4632 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4633 | gunzip | guix archive -x /tmp/emacs
4636 Single-item archives are different from multiple-item archives produced
4637 by @command{guix archive --export}; they contain a single store item,
4638 and they do @emph{not} embed a signature. Thus this operation does
4639 @emph{no} signature verification and its output should be considered
4642 The primary purpose of this operation is to facilitate inspection of
4643 archive contents coming from possibly untrusted substitute servers
4644 (@pxref{Invoking guix challenge}).
4648 Read a single-item archive as served by substitute servers
4649 (@pxref{Substitutes}) and print the list of files it contains, as in
4654 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4655 | lzip -d | guix archive -t
4661 @c *********************************************************************
4663 @chapter Development
4665 @cindex software development
4666 If you are a software developer, Guix provides tools that you should find
4667 helpful---independently of the language you're developing in. This is what
4668 this chapter is about.
4670 The @command{guix environment} command provides a convenient way to set up
4671 @dfn{development environments} containing all the dependencies and tools
4672 necessary to work on the software package of your choice. The @command{guix
4673 pack} command allows you to create @dfn{application bundles} that can be
4674 easily distributed to users who do not run Guix.
4677 * Invoking guix environment:: Setting up development environments.
4678 * Invoking guix pack:: Creating software bundles.
4679 * Packages for C Development:: Working with C code with Guix.
4682 @node Invoking guix environment
4683 @section Invoking @command{guix environment}
4685 @cindex reproducible build environments
4686 @cindex development environments
4687 @cindex @command{guix environment}
4688 @cindex environment, package build environment
4689 The purpose of @command{guix environment} is to assist hackers in
4690 creating reproducible development environments without polluting their
4691 package profile. The @command{guix environment} tool takes one or more
4692 packages, builds all of their inputs, and creates a shell
4693 environment to use them.
4695 The general syntax is:
4698 guix environment @var{options} @var{package}@dots{}
4701 The following example spawns a new shell set up for the development of
4705 guix environment guile
4708 If the needed dependencies are not built yet, @command{guix environment}
4709 automatically builds them. The environment of the new shell is an
4710 augmented version of the environment that @command{guix environment} was
4711 run in. It contains the necessary search paths for building the given
4712 package added to the existing environment variables. To create
4713 a ``pure'' environment, in which the original environment variables have
4714 been unset, use the @option{--pure} option@footnote{Users sometimes
4715 wrongfully augment environment variables such as @env{PATH} in their
4716 @file{~/.bashrc} file. As a consequence, when @command{guix
4717 environment} launches it, Bash may read @file{~/.bashrc}, thereby
4718 introducing ``impurities'' in these environment variables. It is an
4719 error to define such environment variables in @file{.bashrc}; instead,
4720 they should be defined in @file{.bash_profile}, which is sourced only by
4721 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
4722 Manual}, for details on Bash start-up files.}.
4724 @vindex GUIX_ENVIRONMENT
4725 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
4726 variable in the shell it spawns; its value is the file name of the
4727 profile of this environment. This allows users to, say, define a
4728 specific prompt for development environments in their @file{.bashrc}
4729 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4732 if [ -n "$GUIX_ENVIRONMENT" ]
4734 export PS1="\u@@\h \w [dev]\$ "
4739 ...@: or to browse the profile:
4742 $ ls "$GUIX_ENVIRONMENT/bin"
4745 Additionally, more than one package may be specified, in which case the
4746 union of the inputs for the given packages are used. For example, the
4747 command below spawns a shell where all of the dependencies of both Guile
4748 and Emacs are available:
4751 guix environment guile emacs
4754 Sometimes an interactive shell session is not desired. An arbitrary
4755 command may be invoked by placing the @code{--} token to separate the
4756 command from the rest of the arguments:
4759 guix environment guile -- make -j4
4762 In other situations, it is more convenient to specify the list of
4763 packages needed in the environment. For example, the following command
4764 runs @command{python} from an environment containing Python@tie{}2.7 and
4768 guix environment --ad-hoc python2-numpy python-2.7 -- python
4771 Furthermore, one might want the dependencies of a package and also some
4772 additional packages that are not build-time or runtime dependencies, but
4773 are useful when developing nonetheless. Because of this, the
4774 @option{--ad-hoc} flag is positional. Packages appearing before
4775 @option{--ad-hoc} are interpreted as packages whose dependencies will be
4776 added to the environment. Packages appearing after are interpreted as
4777 packages that will be added to the environment directly. For example,
4778 the following command creates a Guix development environment that
4779 additionally includes Git and strace:
4782 guix environment --pure guix --ad-hoc git strace
4786 Sometimes it is desirable to isolate the environment as much as
4787 possible, for maximal purity and reproducibility. In particular, when
4788 using Guix on a host distro that is not Guix System, it is desirable to
4789 prevent access to @file{/usr/bin} and other system-wide resources from
4790 the development environment. For example, the following command spawns
4791 a Guile REPL in a ``container'' where only the store and the current
4792 working directory are mounted:
4795 guix environment --ad-hoc --container guile -- guile
4799 The @option{--container} option requires Linux-libre 3.19 or newer.
4802 @cindex certificates
4803 Another typical use case for containers is to run security-sensitive
4804 applications such as a web browser. To run Eolie, we must expose and
4805 share some files and directories; we include @code{nss-certs} and expose
4806 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
4807 the @env{DISPLAY} environment variable since containerized graphical
4808 applications won't display without it.
4811 guix environment --preserve='^DISPLAY$' --container --network \
4812 --expose=/etc/machine-id \
4813 --expose=/etc/ssl/certs/ \
4814 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
4815 --ad-hoc eolie nss-certs dbus -- eolie
4818 The available options are summarized below.
4821 @item --root=@var{file}
4822 @itemx -r @var{file}
4823 @cindex persistent environment
4824 @cindex garbage collector root, for environments
4825 Make @var{file} a symlink to the profile for this environment, and
4826 register it as a garbage collector root.
4828 This is useful if you want to protect your environment from garbage
4829 collection, to make it ``persistent''.
4831 When this option is omitted, the environment is protected from garbage
4832 collection only for the duration of the @command{guix environment}
4833 session. This means that next time you recreate the same environment,
4834 you could have to rebuild or re-download packages. @xref{Invoking guix
4835 gc}, for more on GC roots.
4837 @item --expression=@var{expr}
4838 @itemx -e @var{expr}
4839 Create an environment for the package or list of packages that
4840 @var{expr} evaluates to.
4842 For example, running:
4845 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4848 starts a shell with the environment for this specific variant of the
4854 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4857 starts a shell with all the base system packages available.
4859 The above commands only use the default output of the given packages.
4860 To select other outputs, two element tuples can be specified:
4863 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4866 @item --load=@var{file}
4867 @itemx -l @var{file}
4868 Create an environment for the package or list of packages that the code
4869 within @var{file} evaluates to.
4871 As an example, @var{file} might contain a definition like this
4872 (@pxref{Defining Packages}):
4875 @verbatiminclude environment-gdb.scm
4878 @item --manifest=@var{file}
4879 @itemx -m @var{file}
4880 Create an environment for the packages contained in the manifest object
4881 returned by the Scheme code in @var{file}. This option can be repeated
4882 several times, in which case the manifests are concatenated.
4884 This is similar to the same-named option in @command{guix package}
4885 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4889 Include all specified packages in the resulting environment, as if an
4890 @i{ad hoc} package were defined with them as inputs. This option is
4891 useful for quickly creating an environment without having to write a
4892 package expression to contain the desired inputs.
4894 For instance, the command:
4897 guix environment --ad-hoc guile guile-sdl -- guile
4900 runs @command{guile} in an environment where Guile and Guile-SDL are
4903 Note that this example implicitly asks for the default output of
4904 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4905 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4906 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4908 This option may be composed with the default behavior of @command{guix
4909 environment}. Packages appearing before @option{--ad-hoc} are
4910 interpreted as packages whose dependencies will be added to the
4911 environment, the default behavior. Packages appearing after are
4912 interpreted as packages that will be added to the environment directly.
4915 Unset existing environment variables when building the new environment, except
4916 those specified with @option{--preserve} (see below.) This has the effect of
4917 creating an environment in which search paths only contain package inputs.
4919 @item --preserve=@var{regexp}
4920 @itemx -E @var{regexp}
4921 When used alongside @option{--pure}, preserve the environment variables
4922 matching @var{regexp}---in other words, put them on a ``white list'' of
4923 environment variables that must be preserved. This option can be repeated
4927 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4931 This example runs @command{mpirun} in a context where the only environment
4932 variables defined are @env{PATH}, environment variables whose name starts
4933 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
4936 @item --search-paths
4937 Display the environment variable definitions that make up the
4940 @item --system=@var{system}
4941 @itemx -s @var{system}
4942 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4947 Run @var{command} within an isolated container. The current working
4948 directory outside the container is mapped inside the container.
4949 Additionally, unless overridden with @option{--user}, a dummy home
4950 directory is created that matches the current user's home directory, and
4951 @file{/etc/passwd} is configured accordingly.
4953 The spawned process runs as the current user outside the container. Inside
4954 the container, it has the same UID and GID as the current user, unless
4955 @option{--user} is passed (see below.)
4959 For containers, share the network namespace with the host system.
4960 Containers created without this flag only have access to the loopback
4963 @item --link-profile
4965 For containers, link the environment profile to @file{~/.guix-profile}
4966 within the container. This is equivalent to running the command
4967 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
4968 Linking will fail and abort the environment if the directory already
4969 exists, which will certainly be the case if @command{guix environment}
4970 was invoked in the user's home directory.
4972 Certain packages are configured to look in @file{~/.guix-profile} for
4973 configuration files and data;@footnote{For example, the
4974 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
4975 for additional fonts.} @option{--link-profile} allows these programs to
4976 behave as expected within the environment.
4978 @item --user=@var{user}
4979 @itemx -u @var{user}
4980 For containers, use the username @var{user} in place of the current
4981 user. The generated @file{/etc/passwd} entry within the container will
4982 contain the name @var{user}, the home directory will be
4983 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4984 the UID and GID inside the container are 1000. @var{user}
4985 need not exist on the system.
4987 Additionally, any shared or exposed path (see @option{--share} and
4988 @option{--expose} respectively) whose target is within the current user's
4989 home directory will be remapped relative to @file{/home/USER}; this
4990 includes the automatic mapping of the current working directory.
4993 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4995 guix environment --container --user=foo \
4996 --expose=$HOME/test \
4997 --expose=/tmp/target=$HOME/target
5000 While this will limit the leaking of user identity through home paths
5001 and each of the user fields, this is only one useful component of a
5002 broader privacy/anonymity solution---not one in and of itself.
5005 For containers, the default behavior is to share the current working
5006 directory with the isolated container and immediately change to that
5007 directory within the container. If this is undesirable,
5008 @option{--no-cwd} will cause the current working directory to @emph{not}
5009 be automatically shared and will change to the user's home directory
5010 within the container instead. See also @option{--user}.
5012 @item --expose=@var{source}[=@var{target}]
5013 @itemx --share=@var{source}[=@var{target}]
5014 For containers, @option{--expose} (resp. @option{--share}) exposes the
5015 file system @var{source} from the host system as the read-only
5016 (resp. writable) file system @var{target} within the container. If
5017 @var{target} is not specified, @var{source} is used as the target mount
5018 point in the container.
5020 The example below spawns a Guile REPL in a container in which the user's
5021 home directory is accessible read-only via the @file{/exchange}
5025 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5030 @command{guix environment}
5031 also supports all of the common build options that @command{guix
5032 build} supports (@pxref{Common Build Options}) as well as package
5033 transformation options (@pxref{Package Transformation Options}).
5035 @node Invoking guix pack
5036 @section Invoking @command{guix pack}
5038 Occasionally you want to pass software to people who are not (yet!)
5039 lucky enough to be using Guix. You'd tell them to run @command{guix
5040 package -i @var{something}}, but that's not possible in this case. This
5041 is where @command{guix pack} comes in.
5044 If you are looking for ways to exchange binaries among machines that
5045 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5046 publish}, and @ref{Invoking guix archive}.
5051 @cindex application bundle
5052 @cindex software bundle
5053 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5054 @dfn{software bundle}: it creates a tarball or some other archive
5055 containing the binaries of the software you're interested in, and all
5056 its dependencies. The resulting archive can be used on any machine that
5057 does not have Guix, and people can run the exact same binaries as those
5058 you have with Guix. The pack itself is created in a bit-reproducible
5059 fashion, so anyone can verify that it really contains the build results
5060 that you pretend to be shipping.
5062 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5063 their dependencies, you can run:
5066 $ guix pack guile emacs geiser
5068 /gnu/store/@dots{}-pack.tar.gz
5071 The result here is a tarball containing a @file{/gnu/store} directory
5072 with all the relevant packages. The resulting tarball contains a
5073 @dfn{profile} with the three packages of interest; the profile is the
5074 same as would be created by @command{guix package -i}. It is this
5075 mechanism that is used to create Guix's own standalone binary tarball
5076 (@pxref{Binary Installation}).
5078 Users of this pack would have to run
5079 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5080 find inconvenient. To work around it, you can create, say, a
5081 @file{/opt/gnu/bin} symlink to the profile:
5084 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5088 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5090 @cindex relocatable binaries, with @command{guix pack}
5091 What if the recipient of your pack does not have root privileges on
5092 their machine, and thus cannot unpack it in the root file system? In
5093 that case, you will want to use the @option{--relocatable} option (see
5094 below). This option produces @dfn{relocatable binaries}, meaning they
5095 they can be placed anywhere in the file system hierarchy: in the example
5096 above, users can unpack your tarball in their home directory and
5097 directly run @file{./opt/gnu/bin/guile}.
5099 @cindex Docker, build an image with guix pack
5100 Alternatively, you can produce a pack in the Docker image format using
5101 the following command:
5104 guix pack -f docker -S /bin=bin guile guile-readline
5108 The result is a tarball that can be passed to the @command{docker load}
5109 command, followed by @code{docker run}:
5112 docker load < @var{file}
5113 docker run -ti guile-guile-readline /bin/guile
5117 where @var{file} is the image returned by @var{guix pack}, and
5118 @code{guile-guile-readline} is its ``image tag''. See the
5119 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5120 documentation} for more information.
5122 @cindex Singularity, build an image with guix pack
5123 @cindex SquashFS, build an image with guix pack
5124 Yet another option is to produce a SquashFS image with the following
5128 guix pack -f squashfs bash guile emacs geiser
5132 The result is a SquashFS file system image that can either be mounted or
5133 directly be used as a file system container image with the
5134 @uref{https://www.sylabs.io/docs/, Singularity container execution
5135 environment}, using commands like @command{singularity shell} or
5136 @command{singularity exec}.
5138 Several command-line options allow you to customize your pack:
5141 @item --format=@var{format}
5142 @itemx -f @var{format}
5143 Produce a pack in the given @var{format}.
5145 The available formats are:
5149 This is the default format. It produces a tarball containing all the
5150 specified binaries and symlinks.
5153 This produces a tarball that follows the
5154 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5155 Docker Image Specification}. The ``repository name'' as it appears in
5156 the output of the @command{docker images} command is computed from
5157 package names passed on the command line or in the manifest file.
5160 This produces a SquashFS image containing all the specified binaries and
5161 symlinks, as well as empty mount points for virtual file systems like
5165 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5166 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5167 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5168 with something like:
5171 guix pack -f squashfs bash @dots{}
5174 If you forget the @code{bash} (or similar) package, @command{singularity
5175 run} and @command{singularity exec} will fail with an unhelpful ``no
5176 such file or directory'' message.
5180 @cindex relocatable binaries
5183 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5184 anywhere in the file system hierarchy and run from there.
5186 When this option is passed once, the resulting binaries require support for
5187 @dfn{user namespaces} in the kernel Linux; when passed
5188 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5189 PRoot support, can be thought of as the abbreviation of ``Really
5190 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5191 other techniques if user namespaces are unavailable, and essentially
5192 work anywhere---see below for the implications.
5194 For example, if you create a pack containing Bash with:
5197 guix pack -RR -S /mybin=bin bash
5201 ...@: you can copy that pack to a machine that lacks Guix, and from your
5202 home directory as a normal user, run:
5210 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5211 @file{/gnu/store} shows up and contains all the dependencies of
5212 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5213 altogether! That is probably the simplest way to deploy Guix-built
5214 software on a non-Guix machine.
5217 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5218 the kernel Linux, which allows unprivileged users to mount or change root.
5219 Old versions of Linux did not support it, and some GNU/Linux distributions
5222 To produce relocatable binaries that work even in the absence of user
5223 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5224 case, binaries will try user namespace support and fall back to another
5225 @dfn{execution engine} if user namespaces are not supported. The
5226 following execution engines are supported:
5230 Try user namespaces and fall back to PRoot if user namespaces are not
5231 supported (see below).
5234 Try user namespaces and fall back to Fakechroot if user namespaces are
5235 not supported (see below).
5238 Run the program through user namespaces and abort if they are not
5242 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5243 provides the necessary
5244 support for file system virtualization. It achieves that by using the
5245 @code{ptrace} system call on the running program. This approach has the
5246 advantage to work without requiring special kernel support, but it incurs
5247 run-time overhead every time a system call is made.
5250 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5251 Fakechroot} virtualizes file system accesses by intercepting calls to C
5252 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5253 on. Unlike PRoot, it incurs very little overhead. However, it does not
5254 always work: for example, some file system accesses made from within the
5255 C library are not intercepted, and file system accesses made @i{via}
5256 direct syscalls are not intercepted either, leading to erratic behavior.
5259 @vindex GUIX_EXECUTION_ENGINE
5260 When running a wrapped program, you can explicitly request one of the
5261 execution engines listed above by setting the
5262 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5265 @cindex entry point, for Docker images
5266 @item --entry-point=@var{command}
5267 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5268 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5269 support it. @var{command} must be relative to the profile contained in the
5272 The entry point specifies the command that tools like @code{docker run} or
5273 @code{singularity run} automatically start by default. For example, you can
5277 guix pack -f docker --entry-point=bin/guile guile
5280 The resulting pack can easily be loaded and @code{docker run} with no extra
5281 arguments will spawn @code{bin/guile}:
5284 docker load -i pack.tar.gz
5285 docker run @var{image-id}
5288 @item --expression=@var{expr}
5289 @itemx -e @var{expr}
5290 Consider the package @var{expr} evaluates to.
5292 This has the same purpose as the same-named option in @command{guix
5293 build} (@pxref{Additional Build Options, @option{--expression} in
5294 @command{guix build}}).
5296 @item --manifest=@var{file}
5297 @itemx -m @var{file}
5298 Use the packages contained in the manifest object returned by the Scheme
5299 code in @var{file}. This option can be repeated several times, in which
5300 case the manifests are concatenated.
5302 This has a similar purpose as the same-named option in @command{guix
5303 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5304 same manifest files. It allows you to define a collection of packages
5305 once and use it both for creating profiles and for creating archives
5306 for use on machines that do not have Guix installed. Note that you can
5307 specify @emph{either} a manifest file @emph{or} a list of packages,
5310 @item --system=@var{system}
5311 @itemx -s @var{system}
5312 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5313 the system type of the build host.
5315 @item --target=@var{triplet}
5316 @cindex cross-compilation
5317 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5318 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5319 configuration triplets,, autoconf, Autoconf}).
5321 @item --compression=@var{tool}
5322 @itemx -C @var{tool}
5323 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5324 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5326 @item --symlink=@var{spec}
5327 @itemx -S @var{spec}
5328 Add the symlinks specified by @var{spec} to the pack. This option can
5329 appear several times.
5331 @var{spec} has the form @code{@var{source}=@var{target}}, where
5332 @var{source} is the symlink that will be created and @var{target} is the
5335 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5336 symlink pointing to the @file{bin} sub-directory of the profile.
5338 @item --save-provenance
5339 Save provenance information for the packages passed on the command line.
5340 Provenance information includes the URL and commit of the channels in use
5343 Provenance information is saved in the
5344 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5345 usual package metadata---the name and version of each package, their
5346 propagated inputs, and so on. It is useful information to the recipient of
5347 the pack, who then knows how the pack was (supposedly) obtained.
5349 This option is not enabled by default because, like timestamps, provenance
5350 information contributes nothing to the build process. In other words, there
5351 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5352 Recording such ``silent'' metadata in the output thus potentially breaks the
5353 source-to-binary bitwise reproducibility property.
5355 @item --root=@var{file}
5356 @itemx -r @var{file}
5357 @cindex garbage collector root, for packs
5358 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5361 @item --localstatedir
5362 @itemx --profile-name=@var{name}
5363 Include the ``local state directory'', @file{/var/guix}, in the resulting
5364 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5365 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5366 @file{~root/.guix-profile}.
5368 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5369 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5370 the pack means that the store is ``complete'' and manageable by Guix;
5371 not providing it pack means that the store is ``dead'': items cannot be
5372 added to it or removed from it after extraction of the pack.
5374 One use case for this is the Guix self-contained binary tarball
5375 (@pxref{Binary Installation}).
5379 Print the name of the derivation that builds the pack.
5382 Use the bootstrap binaries to build the pack. This option is only
5383 useful to Guix developers.
5386 In addition, @command{guix pack} supports all the common build options
5387 (@pxref{Common Build Options}) and all the package transformation
5388 options (@pxref{Package Transformation Options}).
5390 @node Packages for C Development
5391 @section Packages for C Development
5395 @cindex linker wrapper
5396 @cindex toolchain, for C development
5398 If you need a complete toolchain for compiling and linking C or C++
5399 source code, use the @code{gcc-toolchain} package. This package
5400 provides a complete GCC toolchain for C/C++ development, including GCC
5401 itself, the GNU C Library (headers and binaries, plus debugging symbols
5402 in the @code{debug} output), Binutils, and a linker wrapper.
5404 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5405 passed to the linker, add corresponding @code{-rpath} arguments, and
5406 invoke the actual linker with this new set of arguments. You can instruct the
5407 wrapper to refuse to link against libraries not in the store by setting the
5408 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5412 @c *********************************************************************
5413 @node Programming Interface
5414 @chapter Programming Interface
5416 GNU Guix provides several Scheme programming interfaces (APIs) to
5417 define, build, and query packages. The first interface allows users to
5418 write high-level package definitions. These definitions refer to
5419 familiar packaging concepts, such as the name and version of a package,
5420 its build system, and its dependencies. These definitions can then be
5421 turned into concrete build actions.
5423 Build actions are performed by the Guix daemon, on behalf of users. In a
5424 standard setup, the daemon has write access to the store---the
5425 @file{/gnu/store} directory---whereas users do not. The recommended
5426 setup also has the daemon perform builds in chroots, under a specific
5427 build users, to minimize interference with the rest of the system.
5430 Lower-level APIs are available to interact with the daemon and the
5431 store. To instruct the daemon to perform a build action, users actually
5432 provide it with a @dfn{derivation}. A derivation is a low-level
5433 representation of the build actions to be taken, and the environment in
5434 which they should occur---derivations are to package definitions what
5435 assembly is to C programs. The term ``derivation'' comes from the fact
5436 that build results @emph{derive} from them.
5438 This chapter describes all these APIs in turn, starting from high-level
5439 package definitions.
5442 * Package Modules:: Packages from the programmer's viewpoint.
5443 * Defining Packages:: Defining new packages.
5444 * Build Systems:: Specifying how packages are built.
5445 * The Store:: Manipulating the package store.
5446 * Derivations:: Low-level interface to package derivations.
5447 * The Store Monad:: Purely functional interface to the store.
5448 * G-Expressions:: Manipulating build expressions.
5449 * Invoking guix repl:: Fiddling with Guix interactively.
5452 @node Package Modules
5453 @section Package Modules
5455 From a programming viewpoint, the package definitions of the
5456 GNU distribution are provided by Guile modules in the @code{(gnu packages
5457 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5458 packages @dots{})} module name space are not necessarily ``GNU
5459 packages''. This module naming scheme follows the usual Guile module
5460 naming convention: @code{gnu} means that these modules are distributed
5461 as part of the GNU system, and @code{packages} identifies modules that
5462 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5463 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5464 module exports a variable named @code{emacs}, which is bound to a
5465 @code{<package>} object (@pxref{Defining Packages}).
5467 The @code{(gnu packages @dots{})} module name space is
5468 automatically scanned for packages by the command-line tools. For
5469 instance, when running @code{guix install emacs}, all the @code{(gnu
5470 packages @dots{})} modules are scanned until one that exports a package
5471 object whose name is @code{emacs} is found. This package search
5472 facility is implemented in the @code{(gnu packages)} module.
5474 @cindex customization, of packages
5475 @cindex package module search path
5476 Users can store package definitions in modules with different
5477 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5478 name and module name must match. For instance, the @code{(my-packages
5479 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5480 relative to the load path specified with @option{--load-path} or
5481 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5482 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5483 these package definitions visible to the user interfaces:
5487 By adding the directory containing your package modules to the search path
5488 with the @code{-L} flag of @command{guix package} and other commands
5489 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
5490 environment variable described below.
5493 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5494 pulls from it. A channel is essentially a Git repository containing package
5495 modules. @xref{Channels}, for more information on how to define and use
5499 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5501 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5502 This is a colon-separated list of directories to search for additional
5503 package modules. Directories listed in this variable take precedence
5504 over the own modules of the distribution.
5507 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5508 each package is built based solely on other packages in the
5509 distribution. The root of this dependency graph is a small set of
5510 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5511 bootstrap)} module. For more information on bootstrapping,
5512 @pxref{Bootstrapping}.
5514 @node Defining Packages
5515 @section Defining Packages
5517 The high-level interface to package definitions is implemented in the
5518 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5519 example, the package definition, or @dfn{recipe}, for the GNU Hello
5520 package looks like this:
5523 (define-module (gnu packages hello)
5524 #:use-module (guix packages)
5525 #:use-module (guix download)
5526 #:use-module (guix build-system gnu)
5527 #:use-module (guix licenses)
5528 #:use-module (gnu packages gawk))
5530 (define-public hello
5536 (uri (string-append "mirror://gnu/hello/hello-" version
5540 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5541 (build-system gnu-build-system)
5542 (arguments '(#:configure-flags '("--enable-silent-rules")))
5543 (inputs `(("gawk" ,gawk)))
5544 (synopsis "Hello, GNU world: An example GNU package")
5545 (description "Guess what GNU Hello prints!")
5546 (home-page "https://www.gnu.org/software/hello/")
5551 Without being a Scheme expert, the reader may have guessed the meaning
5552 of the various fields here. This expression binds the variable
5553 @code{hello} to a @code{<package>} object, which is essentially a record
5554 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5555 This package object can be inspected using procedures found in the
5556 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5557 returns---surprise!---@code{"hello"}.
5559 With luck, you may be able to import part or all of the definition of
5560 the package you are interested in from another repository, using the
5561 @code{guix import} command (@pxref{Invoking guix import}).
5563 In the example above, @var{hello} is defined in a module of its own,
5564 @code{(gnu packages hello)}. Technically, this is not strictly
5565 necessary, but it is convenient to do so: all the packages defined in
5566 modules under @code{(gnu packages @dots{})} are automatically known to
5567 the command-line tools (@pxref{Package Modules}).
5569 There are a few points worth noting in the above package definition:
5573 The @code{source} field of the package is an @code{<origin>} object
5574 (@pxref{origin Reference}, for the complete reference).
5575 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5576 meaning that the source is a file to be downloaded over FTP or HTTP.
5578 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5579 the GNU mirrors defined in @code{(guix download)}.
5581 The @code{sha256} field specifies the expected SHA256 hash of the file
5582 being downloaded. It is mandatory, and allows Guix to check the
5583 integrity of the file. The @code{(base32 @dots{})} form introduces the
5584 base32 representation of the hash. You can obtain this information with
5585 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5586 hash} (@pxref{Invoking guix hash}).
5589 When needed, the @code{origin} form can also have a @code{patches} field
5590 listing patches to be applied, and a @code{snippet} field giving a
5591 Scheme expression to modify the source code.
5594 @cindex GNU Build System
5595 The @code{build-system} field specifies the procedure to build the
5596 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5597 represents the familiar GNU Build System, where packages may be
5598 configured, built, and installed with the usual @code{./configure &&
5599 make && make check && make install} command sequence.
5602 The @code{arguments} field specifies options for the build system
5603 (@pxref{Build Systems}). Here it is interpreted by
5604 @var{gnu-build-system} as a request run @file{configure} with the
5605 @option{--enable-silent-rules} flag.
5611 What about these quote (@code{'}) characters? They are Scheme syntax to
5612 introduce a literal list; @code{'} is synonymous with @code{quote}.
5613 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5614 for details. Here the value of the @code{arguments} field is a list of
5615 arguments passed to the build system down the road, as with @code{apply}
5616 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5619 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5620 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5621 @code{#:configure-flags} is a keyword used to pass a keyword argument
5622 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5626 The @code{inputs} field specifies inputs to the build process---i.e.,
5627 build-time or run-time dependencies of the package. Here, we define an
5628 input called @code{"gawk"} whose value is that of the @var{gawk}
5629 variable; @var{gawk} is itself bound to a @code{<package>} object.
5631 @cindex backquote (quasiquote)
5634 @cindex comma (unquote)
5638 @findex unquote-splicing
5639 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5640 us to introduce a literal list in the @code{inputs} field, while
5641 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5642 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5645 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5646 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5647 of ensuring that they are present (@pxref{Build Systems}).
5649 However, any other dependencies need to be specified in the
5650 @code{inputs} field. Any dependency not specified here will simply be
5651 unavailable to the build process, possibly leading to a build failure.
5654 @xref{package Reference}, for a full description of possible fields.
5656 Once a package definition is in place, the
5657 package may actually be built using the @code{guix build} command-line
5658 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5659 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5660 package definition using the @command{guix edit} command
5661 (@pxref{Invoking guix edit}).
5662 @xref{Packaging Guidelines}, for
5663 more information on how to test package definitions, and
5664 @ref{Invoking guix lint}, for information on how to check a definition
5665 for style conformance.
5666 @vindex GUIX_PACKAGE_PATH
5667 Lastly, @pxref{Channels}, for information
5668 on how to extend the distribution by adding your own package definitions
5671 Finally, updating the package definition to a new upstream version
5672 can be partly automated by the @command{guix refresh} command
5673 (@pxref{Invoking guix refresh}).
5675 Behind the scenes, a derivation corresponding to the @code{<package>}
5676 object is first computed by the @code{package-derivation} procedure.
5677 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
5678 The build actions it prescribes may then be realized by using the
5679 @code{build-derivations} procedure (@pxref{The Store}).
5681 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5682 Return the @code{<derivation>} object of @var{package} for @var{system}
5683 (@pxref{Derivations}).
5685 @var{package} must be a valid @code{<package>} object, and @var{system}
5686 must be a string denoting the target system type---e.g.,
5687 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5688 must be a connection to the daemon, which operates on the store
5689 (@pxref{The Store}).
5693 @cindex cross-compilation
5694 Similarly, it is possible to compute a derivation that cross-builds a
5695 package for some other system:
5697 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5698 @var{package} @var{target} [@var{system}]
5699 Return the @code{<derivation>} object of @var{package} cross-built from
5700 @var{system} to @var{target}.
5702 @var{target} must be a valid GNU triplet denoting the target hardware
5703 and operating system, such as @code{"mips64el-linux-gnu"}
5704 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5707 @cindex package transformations
5708 @cindex input rewriting
5709 @cindex dependency tree rewriting
5710 Packages can be manipulated in arbitrary ways. An example of a useful
5711 transformation is @dfn{input rewriting}, whereby the dependency tree of
5712 a package is rewritten by replacing specific inputs by others:
5714 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5715 [@var{rewrite-name}]
5716 Return a procedure that, when passed a package, replaces its direct and
5717 indirect dependencies (but not its implicit inputs) according to
5718 @var{replacements}. @var{replacements} is a list of package pairs; the
5719 first element of each pair is the package to replace, and the second one
5722 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5723 the name of a package and returns its new name after rewrite.
5727 Consider this example:
5730 (define libressl-instead-of-openssl
5731 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5733 (package-input-rewriting `((,openssl . ,libressl))))
5735 (define git-with-libressl
5736 (libressl-instead-of-openssl git))
5740 Here we first define a rewriting procedure that replaces @var{openssl}
5741 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5742 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5743 This is exactly what the @option{--with-input} command-line option does
5744 (@pxref{Package Transformation Options, @option{--with-input}}).
5746 The following variant of @code{package-input-rewriting} can match packages to
5747 be replaced by name rather than by identity.
5749 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5750 Return a procedure that, given a package, applies the given @var{replacements} to
5751 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5752 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5753 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5754 replacement for that package.
5757 The example above could be rewritten this way:
5760 (define libressl-instead-of-openssl
5761 ;; Replace all the packages called "openssl" with LibreSSL.
5762 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5765 The key difference here is that, this time, packages are matched by spec and
5766 not by identity. In other words, any package in the graph that is called
5767 @code{openssl} will be replaced.
5769 A more generic procedure to rewrite a package dependency graph is
5770 @code{package-mapping}: it supports arbitrary changes to nodes in the
5773 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5774 Return a procedure that, given a package, applies @var{proc} to all the packages
5775 depended on and returns the resulting package. The procedure stops recursion
5776 when @var{cut?} returns true for a given package.
5780 * package Reference:: The package data type.
5781 * origin Reference:: The origin data type.
5785 @node package Reference
5786 @subsection @code{package} Reference
5788 This section summarizes all the options available in @code{package}
5789 declarations (@pxref{Defining Packages}).
5791 @deftp {Data Type} package
5792 This is the data type representing a package recipe.
5796 The name of the package, as a string.
5798 @item @code{version}
5799 The version of the package, as a string.
5802 An object telling how the source code for the package should be
5803 acquired. Most of the time, this is an @code{origin} object, which
5804 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5805 can also be any other ``file-like'' object such as a @code{local-file},
5806 which denotes a file from the local file system (@pxref{G-Expressions,
5807 @code{local-file}}).
5809 @item @code{build-system}
5810 The build system that should be used to build the package (@pxref{Build
5813 @item @code{arguments} (default: @code{'()})
5814 The arguments that should be passed to the build system. This is a
5815 list, typically containing sequential keyword-value pairs.
5817 @item @code{inputs} (default: @code{'()})
5818 @itemx @code{native-inputs} (default: @code{'()})
5819 @itemx @code{propagated-inputs} (default: @code{'()})
5820 @cindex inputs, of packages
5821 These fields list dependencies of the package. Each one is a list of
5822 tuples, where each tuple has a label for the input (a string) as its
5823 first element, a package, origin, or derivation as its second element,
5824 and optionally the name of the output thereof that should be used, which
5825 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5826 more on package outputs). For example, the list below specifies three
5830 `(("libffi" ,libffi)
5831 ("libunistring" ,libunistring)
5832 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5835 @cindex cross compilation, package dependencies
5836 The distinction between @code{native-inputs} and @code{inputs} is
5837 necessary when considering cross-compilation. When cross-compiling,
5838 dependencies listed in @code{inputs} are built for the @emph{target}
5839 architecture; conversely, dependencies listed in @code{native-inputs}
5840 are built for the architecture of the @emph{build} machine.
5842 @code{native-inputs} is typically used to list tools needed at
5843 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5844 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5845 this area (@pxref{Invoking guix lint}).
5847 @anchor{package-propagated-inputs}
5848 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5849 specified packages will be automatically installed alongside the package
5850 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5851 package}}, for information on how @command{guix package} deals with
5854 For example this is necessary when a C/C++ library needs headers of
5855 another library to compile, or when a pkg-config file refers to another
5856 one @i{via} its @code{Requires} field.
5858 Another example where @code{propagated-inputs} is useful is for languages
5859 that lack a facility to record the run-time search path akin to the
5860 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5861 more. To ensure that libraries written in those languages can find
5862 library code they depend on at run time, run-time dependencies must be
5863 listed in @code{propagated-inputs} rather than @code{inputs}.
5865 @item @code{outputs} (default: @code{'("out")})
5866 The list of output names of the package. @xref{Packages with Multiple
5867 Outputs}, for typical uses of additional outputs.
5869 @item @code{native-search-paths} (default: @code{'()})
5870 @itemx @code{search-paths} (default: @code{'()})
5871 A list of @code{search-path-specification} objects describing
5872 search-path environment variables honored by the package.
5874 @item @code{replacement} (default: @code{#f})
5875 This must be either @code{#f} or a package object that will be used as a
5876 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5879 @item @code{synopsis}
5880 A one-line description of the package.
5882 @item @code{description}
5883 A more elaborate description of the package.
5885 @item @code{license}
5886 @cindex license, of packages
5887 The license of the package; a value from @code{(guix licenses)},
5888 or a list of such values.
5890 @item @code{home-page}
5891 The URL to the home-page of the package, as a string.
5893 @item @code{supported-systems} (default: @code{%supported-systems})
5894 The list of systems supported by the package, as strings of the form
5895 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5897 @item @code{location} (default: source location of the @code{package} form)
5898 The source location of the package. It is useful to override this when
5899 inheriting from another package, in which case this field is not
5900 automatically corrected.
5904 @deffn {Scheme Syntax} this-package
5905 When used in the @emph{lexical scope} of a package field definition, this
5906 identifier resolves to the package being defined.
5908 The example below shows how to add a package as a native input of itself when
5916 ;; When cross-compiled, Guile, for example, depends on
5917 ;; a native version of itself. Add it here.
5918 (native-inputs (if (%current-target-system)
5919 `(("self" ,this-package))
5923 It is an error to refer to @code{this-package} outside a package definition.
5926 @node origin Reference
5927 @subsection @code{origin} Reference
5929 This section summarizes all the options available in @code{origin}
5930 declarations (@pxref{Defining Packages}).
5932 @deftp {Data Type} origin
5933 This is the data type representing a source code origin.
5937 An object containing the URI of the source. The object type depends on
5938 the @code{method} (see below). For example, when using the
5939 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5940 values are: a URL represented as a string, or a list thereof.
5943 A procedure that handles the URI.
5948 @item @var{url-fetch} from @code{(guix download)}
5949 download a file from the HTTP, HTTPS, or FTP URL specified in the
5953 @item @var{git-fetch} from @code{(guix git-download)}
5954 clone the Git version control repository, and check out the revision
5955 specified in the @code{uri} field as a @code{git-reference} object; a
5956 @code{git-reference} looks like this:
5960 (url "https://git.savannah.gnu.org/git/hello.git")
5966 A bytevector containing the SHA-256 hash of the source. Typically the
5967 @code{base32} form is used here to generate the bytevector from a
5970 You can obtain this information using @code{guix download}
5971 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5974 @item @code{file-name} (default: @code{#f})
5975 The file name under which the source code should be saved. When this is
5976 @code{#f}, a sensible default value will be used in most cases. In case
5977 the source is fetched from a URL, the file name from the URL will be
5978 used. For version control checkouts, it is recommended to provide the
5979 file name explicitly because the default is not very descriptive.
5981 @item @code{patches} (default: @code{'()})
5982 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5983 file-like objects}) pointing to patches to be applied to the source.
5985 This list of patches must be unconditional. In particular, it cannot
5986 depend on the value of @code{%current-system} or
5987 @code{%current-target-system}.
5989 @item @code{snippet} (default: @code{#f})
5990 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5991 in the source directory. This is a convenient way to modify the source,
5992 sometimes more convenient than a patch.
5994 @item @code{patch-flags} (default: @code{'("-p1")})
5995 A list of command-line flags that should be passed to the @code{patch}
5998 @item @code{patch-inputs} (default: @code{#f})
5999 Input packages or derivations to the patching process. When this is
6000 @code{#f}, the usual set of inputs necessary for patching are provided,
6001 such as GNU@tie{}Patch.
6003 @item @code{modules} (default: @code{'()})
6004 A list of Guile modules that should be loaded during the patching
6005 process and while running the code in the @code{snippet} field.
6007 @item @code{patch-guile} (default: @code{#f})
6008 The Guile package that should be used in the patching process. When
6009 this is @code{#f}, a sensible default is used.
6015 @section Build Systems
6017 @cindex build system
6018 Each package definition specifies a @dfn{build system} and arguments for
6019 that build system (@pxref{Defining Packages}). This @code{build-system}
6020 field represents the build procedure of the package, as well as implicit
6021 dependencies of that build procedure.
6023 Build systems are @code{<build-system>} objects. The interface to
6024 create and manipulate them is provided by the @code{(guix build-system)}
6025 module, and actual build systems are exported by specific modules.
6027 @cindex bag (low-level package representation)
6028 Under the hood, build systems first compile package objects to
6029 @dfn{bags}. A @dfn{bag} is like a package, but with less
6030 ornamentation---in other words, a bag is a lower-level representation of
6031 a package, which includes all the inputs of that package, including some
6032 that were implicitly added by the build system. This intermediate
6033 representation is then compiled to a derivation (@pxref{Derivations}).
6035 Build systems accept an optional list of @dfn{arguments}. In package
6036 definitions, these are passed @i{via} the @code{arguments} field
6037 (@pxref{Defining Packages}). They are typically keyword arguments
6038 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6039 Guile Reference Manual}). The value of these arguments is usually
6040 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6041 by the daemon (@pxref{Derivations}).
6043 The main build system is @code{gnu-build-system}, which implements the
6044 standard build procedure for GNU and many other packages. It
6045 is provided by the @code{(guix build-system gnu)} module.
6047 @defvr {Scheme Variable} gnu-build-system
6048 @code{gnu-build-system} represents the GNU Build System, and variants
6049 thereof (@pxref{Configuration, configuration and makefile conventions,,
6050 standards, GNU Coding Standards}).
6052 @cindex build phases
6053 In a nutshell, packages using it are configured, built, and installed with
6054 the usual @code{./configure && make && make check && make install}
6055 command sequence. In practice, a few additional steps are often needed.
6056 All these steps are split up in separate @dfn{phases},
6057 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6058 modules for more details about the build phases.}:
6062 Unpack the source tarball, and change the current directory to the
6063 extracted source tree. If the source is actually a directory, copy it
6064 to the build tree, and enter that directory.
6066 @item patch-source-shebangs
6067 Patch shebangs encountered in source files so they refer to the right
6068 store file names. For instance, this changes @code{#!/bin/sh} to
6069 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6072 Run the @file{configure} script with a number of default options, such
6073 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6074 by the @code{#:configure-flags} argument.
6077 Run @code{make} with the list of flags specified with
6078 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6079 (the default), build with @code{make -j}.
6082 Run @code{make check}, or some other target specified with
6083 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6084 @code{#:parallel-tests?} argument is true (the default), run @code{make
6088 Run @code{make install} with the flags listed in @code{#:make-flags}.
6090 @item patch-shebangs
6091 Patch shebangs on the installed executable files.
6094 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6095 is false), copying them to the @code{debug} output when available
6096 (@pxref{Installing Debugging Files}).
6099 @vindex %standard-phases
6100 The build-side module @code{(guix build gnu-build-system)} defines
6101 @code{%standard-phases} as the default list of build phases.
6102 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6103 procedure implements the actual phase.
6105 The list of phases used for a particular package can be changed with the
6106 @code{#:phases} parameter. For instance, passing:
6109 #:phases (modify-phases %standard-phases (delete 'configure))
6112 means that all the phases described above will be used, except the
6113 @code{configure} phase.
6115 In addition, this build system ensures that the ``standard'' environment
6116 for GNU packages is available. This includes tools such as GCC, libc,
6117 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6118 build-system gnu)} module for a complete list). We call these the
6119 @dfn{implicit inputs} of a package, because package definitions do not
6120 have to mention them.
6123 Other @code{<build-system>} objects are defined to support other
6124 conventions and tools used by free software packages. They inherit most
6125 of @code{gnu-build-system}, and differ mainly in the set of inputs
6126 implicitly added to the build process, and in the list of phases
6127 executed. Some of these build systems are listed below.
6129 @defvr {Scheme Variable} ant-build-system
6130 This variable is exported by @code{(guix build-system ant)}. It
6131 implements the build procedure for Java packages that can be built with
6132 @url{https://ant.apache.org/, Ant build tool}.
6134 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6135 provided by the @code{icedtea} package to the set of inputs. Different
6136 packages can be specified with the @code{#:ant} and @code{#:jdk}
6137 parameters, respectively.
6139 When the original package does not provide a suitable Ant build file,
6140 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6141 build file @file{build.xml} with tasks to build the specified jar
6142 archive. In this case the parameter @code{#:source-dir} can be used to
6143 specify the source sub-directory, defaulting to ``src''.
6145 The @code{#:main-class} parameter can be used with the minimal ant
6146 buildfile to specify the main class of the resulting jar. This makes the
6147 jar file executable. The @code{#:test-include} parameter can be used to
6148 specify the list of junit tests to run. It defaults to
6149 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6150 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6151 because abstract classes cannot be run as tests.
6153 The parameter @code{#:build-target} can be used to specify the Ant task
6154 that should be run during the @code{build} phase. By default the
6155 ``jar'' task will be run.
6159 @defvr {Scheme Variable} android-ndk-build-system
6160 @cindex Android distribution
6161 @cindex Android NDK build system
6162 This variable is exported by @code{(guix build-system android-ndk)}. It
6163 implements a build procedure for Android NDK (native development kit)
6164 packages using a Guix-specific build process.
6166 The build system assumes that packages install their public interface
6167 (header) files to the subdirectory @file{include} of the @code{out} output and
6168 their libraries to the subdirectory @file{lib} the @code{out} output.
6170 It's also assumed that the union of all the dependencies of a package
6171 has no conflicting files.
6173 For the time being, cross-compilation is not supported - so right now
6174 the libraries and header files are assumed to be host tools.
6178 @defvr {Scheme Variable} asdf-build-system/source
6179 @defvrx {Scheme Variable} asdf-build-system/sbcl
6180 @defvrx {Scheme Variable} asdf-build-system/ecl
6182 These variables, exported by @code{(guix build-system asdf)}, implement
6183 build procedures for Common Lisp packages using
6184 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6185 definition facility for Common Lisp programs and libraries.
6187 The @code{asdf-build-system/source} system installs the packages in
6188 source form, and can be loaded using any common lisp implementation, via
6189 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6190 systems in the format which a particular implementation understands.
6191 These build systems can also be used to produce executable programs, or
6192 lisp images which contain a set of packages pre-loaded.
6194 The build system uses naming conventions. For binary packages, the
6195 package name should be prefixed with the lisp implementation, such as
6196 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6198 Additionally, the corresponding source package should be labeled using
6199 the same convention as python packages (see @ref{Python Modules}), using
6200 the @code{cl-} prefix.
6202 For binary packages, each system should be defined as a Guix package.
6203 If one package @code{origin} contains several systems, package variants
6204 can be created in order to build all the systems. Source packages,
6205 which use @code{asdf-build-system/source}, may contain several systems.
6207 In order to create executable programs and images, the build-side
6208 procedures @code{build-program} and @code{build-image} can be used.
6209 They should be called in a build phase after the @code{create-symlinks}
6210 phase, so that the system which was just built can be used within the
6211 resulting image. @code{build-program} requires a list of Common Lisp
6212 expressions to be passed as the @code{#:entry-program} argument.
6214 If the system is not defined within its own @file{.asd} file of the same
6215 name, then the @code{#:asd-file} parameter should be used to specify
6216 which file the system is defined in. Furthermore, if the package
6217 defines a system for its tests in a separate file, it will be loaded
6218 before the tests are run if it is specified by the
6219 @code{#:test-asd-file} parameter. If it is not set, the files
6220 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6221 and @code{test.asd} will be tried if they exist.
6223 If for some reason the package must be named in a different way than the
6224 naming conventions suggest, the @code{#:asd-system-name} parameter can
6225 be used to specify the name of the system.
6229 @defvr {Scheme Variable} cargo-build-system
6230 @cindex Rust programming language
6231 @cindex Cargo (Rust build system)
6232 This variable is exported by @code{(guix build-system cargo)}. It
6233 supports builds of packages using Cargo, the build tool of the
6234 @uref{https://www.rust-lang.org, Rust programming language}.
6236 It adds @code{rustc} and @code{cargo} to the set of inputs.
6237 A different Rust package can be specified with the @code{#:rust} parameter.
6239 Regular cargo dependencies should be added to the package definition via the
6240 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6241 spec can be a package or a source definition. Note that the spec must
6242 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6243 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6244 should be added to the package definition via the
6245 @code{#:cargo-development-inputs} parameter.
6247 In its @code{configure} phase, this build system will make any source inputs
6248 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6249 parameters available to cargo. It will also remove an included
6250 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6251 @code{build} phase. The @code{install} phase installs any crate the binaries
6252 if they are defined by the crate.
6256 @defvr {Scheme Variable} copy-build-system
6257 This variable is exported by @code{(guix build-system copy)}. It
6258 supports builds of simple packages that don't require much compiling,
6259 mostly just moving files around.
6261 It adds much of the @code{gnu-build-system} packages to the set of
6262 inputs. Because of this, the @code{copy-build-system} does not require
6263 all the boilerplate code often needed for the
6264 @code{trivial-build-system}.
6266 To further simplify the file installation process, an
6267 @code{#:install-plan} argument is exposed to let the packager specify
6268 which files go where. The install plan is a list of @code{(@var{source}
6269 @var{target} [@var{filters}])}. @var{filters} are optional.
6272 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6274 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6275 @item Otherwise install @var{source} as @var{target}.
6278 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6279 the trailing slash of @var{target} is implied with the same meaning
6282 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6283 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6284 @code{#:exclude-regexp}, only select files are installed depending on
6285 the filters. Each filters is specified by a list of strings.
6287 @item With @code{#:include}, install all the files which the path suffix matches
6288 at least one of the elements in the given list.
6289 @item With @code{#:include-regexp}, install all the files which the
6290 subpaths match at least one of the regular expressions in the given
6292 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6293 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6294 install all files but those matching the exclusion filters.
6295 If both inclusions and exclusions are specified, the exclusions are done
6296 on top of the inclusions.
6299 In all cases, the paths relative to @var{source} are preserved within
6306 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6307 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6308 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6309 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6310 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6311 @file{share/my-app/sub/file}.
6312 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6313 @file{share/my-app/file}.
6318 @cindex Clojure (programming language)
6319 @cindex simple Clojure build system
6320 @defvr {Scheme Variable} clojure-build-system
6321 This variable is exported by @code{(guix build-system clojure)}. It implements
6322 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6323 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6326 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6327 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6328 @code{#:zip} parameters, respectively.
6330 A list of source directories, test directories and jar names can be specified
6331 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6332 parameters, respectively. Compile directory and main class can be specified
6333 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6334 Other parameters are documented below.
6336 This build system is an extension of @code{ant-build-system}, but with the
6337 following phases changed:
6342 This phase calls @code{compile} in Clojure to compile source files and runs
6343 @command{jar} to create jars from both source files and compiled files
6344 according to the include list and exclude list specified in
6345 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6346 has priority over the include list. These lists consist of symbols
6347 representing Clojure libraries or the special keyword @code{#:all} representing
6348 all Clojure libraries found under the source directories. The parameter
6349 @code{#:omit-source?} decides if source should be included into the jars.
6352 This phase runs tests according to the include list and exclude list specified
6353 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6354 meanings are analogous to that of @code{#:aot-include} and
6355 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6356 stands for all Clojure libraries found under the test directories. The
6357 parameter @code{#:tests?} decides if tests should be run.
6360 This phase installs all jars built previously.
6363 Apart from the above, this build system also contains an additional phase:
6368 This phase installs all top-level files with base name matching
6369 @code{%doc-regex}. A different regex can be specified with the
6370 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6371 directories specified in @code{#:doc-dirs} are installed as well.
6375 @defvr {Scheme Variable} cmake-build-system
6376 This variable is exported by @code{(guix build-system cmake)}. It
6377 implements the build procedure for packages using the
6378 @url{https://www.cmake.org, CMake build tool}.
6380 It automatically adds the @code{cmake} package to the set of inputs.
6381 Which package is used can be specified with the @code{#:cmake}
6384 The @code{#:configure-flags} parameter is taken as a list of flags
6385 passed to the @command{cmake} command. The @code{#:build-type}
6386 parameter specifies in abstract terms the flags passed to the compiler;
6387 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6388 debugging information''), which roughly means that code is compiled with
6389 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6392 @defvr {Scheme Variable} dune-build-system
6393 This variable is exported by @code{(guix build-system dune)}. It
6394 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6395 tool for the OCaml programming language. It is implemented as an extension
6396 of the @code{ocaml-build-system} which is described below. As such, the
6397 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6400 It automatically adds the @code{dune} package to the set of inputs.
6401 Which package is used can be specified with the @code{#:dune}
6404 There is no @code{configure} phase because dune packages typically don't
6405 need to be configured. The @code{#:build-flags} parameter is taken as a
6406 list of flags passed to the @code{dune} command during the build.
6408 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6409 command instead of the more recent @code{dune} command while building
6410 a package. Its default value is @code{#f}.
6412 The @code{#:package} parameter can be passed to specify a package name, which
6413 is useful when a package contains multiple packages and you want to build
6414 only one of them. This is equivalent to passing the @code{-p} argument to
6418 @defvr {Scheme Variable} go-build-system
6419 This variable is exported by @code{(guix build-system go)}. It
6420 implements a build procedure for Go packages using the standard
6421 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6422 Go build mechanisms}.
6424 The user is expected to provide a value for the key @code{#:import-path}
6425 and, in some cases, @code{#:unpack-path}. The
6426 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6427 corresponds to the file system path expected by the package's build
6428 scripts and any referring packages, and provides a unique way to
6429 refer to a Go package. It is typically based on a combination of the
6430 package source code's remote URI and file system hierarchy structure. In
6431 some cases, you will need to unpack the package's source code to a
6432 different directory structure than the one indicated by the import path,
6433 and @code{#:unpack-path} should be used in such cases.
6435 Packages that provide Go libraries should install their source code into
6436 the built output. The key @code{#:install-source?}, which defaults to
6437 @code{#t}, controls whether or not the source code is installed. It can
6438 be set to @code{#f} for packages that only provide executable files.
6441 @defvr {Scheme Variable} glib-or-gtk-build-system
6442 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6443 is intended for use with packages making use of GLib or GTK+.
6445 This build system adds the following two phases to the ones defined by
6446 @code{gnu-build-system}:
6449 @item glib-or-gtk-wrap
6450 The phase @code{glib-or-gtk-wrap} ensures that programs in
6451 @file{bin/} are able to find GLib ``schemas'' and
6452 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6453 modules}. This is achieved by wrapping the programs in launch scripts
6454 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
6455 environment variables.
6457 It is possible to exclude specific package outputs from that wrapping
6458 process by listing their names in the
6459 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6460 when an output is known not to contain any GLib or GTK+ binaries, and
6461 where wrapping would gratuitously add a dependency of that output on
6464 @item glib-or-gtk-compile-schemas
6465 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6466 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6467 GSettings schemas} of GLib are compiled. Compilation is performed by the
6468 @command{glib-compile-schemas} program. It is provided by the package
6469 @code{glib:bin} which is automatically imported by the build system.
6470 The @code{glib} package providing @command{glib-compile-schemas} can be
6471 specified with the @code{#:glib} parameter.
6474 Both phases are executed after the @code{install} phase.
6477 @defvr {Scheme Variable} guile-build-system
6478 This build system is for Guile packages that consist exclusively of Scheme
6479 code and that are so lean that they don't even have a makefile, let alone a
6480 @file{configure} script. It compiles Scheme code using @command{guild
6481 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6482 installs the @file{.scm} and @file{.go} files in the right place. It also
6483 installs documentation.
6485 This build system supports cross-compilation by using the
6486 @option{--target} option of @samp{guild compile}.
6488 Packages built with @code{guile-build-system} must provide a Guile package in
6489 their @code{native-inputs} field.
6492 @defvr {Scheme Variable} julia-build-system
6493 This variable is exported by @code{(guix build-system julia)}. It
6494 implements the build procedure used by @uref{https://julialang.org/,
6495 julia} packages, which essentially is similar to running @samp{julia -e
6496 'using Pkg; Pkg.add(package)'} in an environment where
6497 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
6498 Tests are run not run.
6500 Julia packages require the source @code{file-name} to be the real name of the
6501 package, correctly capitalized.
6503 For packages requiring shared library dependencies, you may need to write the
6504 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6505 variable = /gnu/store/library.so} for each dependency, plus a void function
6506 @code{check_deps() = nothing}.
6508 Some older packages that aren't using @file{Package.toml} yet, will require
6509 this file to be created, too. The function @code{julia-create-package-toml}
6510 helps creating the file. You need to pass the outputs and the source of the
6511 package, it's name (the same as the @code{file-name} parameter), the package
6512 uuid, the package version, and a list of dependencies specified by their name
6516 @defvr {Scheme Variable} minify-build-system
6517 This variable is exported by @code{(guix build-system minify)}. It
6518 implements a minification procedure for simple JavaScript packages.
6520 It adds @code{uglify-js} to the set of inputs and uses it to compress
6521 all JavaScript files in the @file{src} directory. A different minifier
6522 package can be specified with the @code{#:uglify-js} parameter, but it
6523 is expected that the package writes the minified code to the standard
6526 When the input JavaScript files are not all located in the @file{src}
6527 directory, the parameter @code{#:javascript-files} can be used to
6528 specify a list of file names to feed to the minifier.
6531 @defvr {Scheme Variable} ocaml-build-system
6532 This variable is exported by @code{(guix build-system ocaml)}. It implements
6533 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6534 of choosing the correct set of commands to run for each package. OCaml
6535 packages can expect many different commands to be run. This build system will
6538 When the package has a @file{setup.ml} file present at the top-level, it will
6539 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6540 @code{ocaml setup.ml -install}. The build system will assume that this file
6541 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6542 care of setting the prefix and enabling tests if they are not disabled. You
6543 can pass configure and build flags with the @code{#:configure-flags} and
6544 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6545 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6546 bypass this system in the build and install phases.
6548 When the package has a @file{configure} file, it is assumed that it is a
6549 hand-made configure script that requires a different argument format than
6550 in the @code{gnu-build-system}. You can add more flags with the
6551 @code{#:configure-flags} key.
6553 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6554 @code{#t}), it will be used and more flags can be passed to the build and
6555 install phases with the @code{#:make-flags} key.
6557 Finally, some packages do not have these files and use a somewhat standard
6558 location for its build system. In that case, the build system will run
6559 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6560 providing the path to the required findlib module. Additional flags can
6561 be passed via the @code{#:build-flags} key. Install is taken care of by
6562 @command{opam-installer}. In this case, the @code{opam} package must
6563 be added to the @code{native-inputs} field of the package definition.
6565 Note that most OCaml packages assume they will be installed in the same
6566 directory as OCaml, which is not what we want in guix. In particular, they
6567 will install @file{.so} files in their module's directory, which is usually
6568 fine because it is in the OCaml compiler directory. In guix though, these
6569 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
6570 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6571 @file{.so} libraries should be installed.
6574 @defvr {Scheme Variable} python-build-system
6575 This variable is exported by @code{(guix build-system python)}. It
6576 implements the more or less standard build procedure used by Python
6577 packages, which consists in running @code{python setup.py build} and
6578 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6580 For packages that install stand-alone Python programs under @code{bin/},
6581 it takes care of wrapping these programs so that their @env{PYTHONPATH}
6582 environment variable points to all the Python libraries they depend on.
6584 Which Python package is used to perform the build can be specified with
6585 the @code{#:python} parameter. This is a useful way to force a package
6586 to be built for a specific version of the Python interpreter, which
6587 might be necessary if the package is only compatible with a single
6588 interpreter version.
6590 By default guix calls @code{setup.py} under control of
6591 @code{setuptools}, much like @command{pip} does. Some packages are not
6592 compatible with setuptools (and pip), thus you can disable this by
6593 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6596 @defvr {Scheme Variable} perl-build-system
6597 This variable is exported by @code{(guix build-system perl)}. It
6598 implements the standard build procedure for Perl packages, which either
6599 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6600 followed by @code{Build} and @code{Build install}; or in running
6601 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6602 @code{make} and @code{make install}, depending on which of
6603 @code{Build.PL} or @code{Makefile.PL} is present in the package
6604 distribution. Preference is given to the former if both @code{Build.PL}
6605 and @code{Makefile.PL} exist in the package distribution. This
6606 preference can be reversed by specifying @code{#t} for the
6607 @code{#:make-maker?} parameter.
6609 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6610 passes flags specified by the @code{#:make-maker-flags} or
6611 @code{#:module-build-flags} parameter, respectively.
6613 Which Perl package is used can be specified with @code{#:perl}.
6616 @defvr {Scheme Variable} qt-build-system
6617 This variable is exported by @code{(guix build-system qt)}. It
6618 is intended for use with applications using Qt or KDE.
6620 This build system adds the following two phases to the ones defined by
6621 @code{cmake-build-system}:
6625 The phase @code{check-setup} prepares the environment for running
6626 the checks as commonly used by Qt test programs.
6627 For now this only sets some environment variables:
6628 @code{QT_QPA_PLATFORM=offscreen},
6629 @code{DBUS_FATAL_WARNINGS=0} and
6630 @code{CTEST_OUTPUT_ON_FAILURE=1}.
6632 This phase is added before the @code{check} phase.
6633 It's a separate phase to ease adjusting if necessary.
6636 The phase @code{qt-wrap}
6637 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6638 and output. In case some path is found, all programs in the output's
6639 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6640 are wrapped in scripts defining the necessary environment variables.
6642 It is possible to exclude specific package outputs from that wrapping process
6643 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6644 This is useful when an output is known not to contain any Qt binaries, and
6645 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6648 This phase is added after the @code{install} phase.
6652 @defvr {Scheme Variable} r-build-system
6653 This variable is exported by @code{(guix build-system r)}. It
6654 implements the build procedure used by @uref{https://r-project.org, R}
6655 packages, which essentially is little more than running @samp{R CMD
6656 INSTALL --library=/gnu/store/@dots{}} in an environment where
6657 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
6658 run after installation using the R function
6659 @code{tools::testInstalledPackage}.
6662 @defvr {Scheme Variable} rakudo-build-system
6663 This variable is exported by @code{(guix build-system rakudo)}. It
6664 implements the build procedure used by @uref{https://rakudo.org/,
6665 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6666 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6667 installs the binaries, library files and the resources, as well as wrap
6668 the files under the @code{bin/} directory. Tests can be skipped by
6669 passing @code{#f} to the @code{tests?} parameter.
6671 Which rakudo package is used can be specified with @code{rakudo}.
6672 Which perl6-tap-harness package used for the tests can be specified with
6673 @code{#:prove6} or removed by passing @code{#f} to the
6674 @code{with-prove6?} parameter.
6675 Which perl6-zef package used for tests and installing can be specified
6676 with @code{#:zef} or removed by passing @code{#f} to the
6677 @code{with-zef?} parameter.
6680 @defvr {Scheme Variable} texlive-build-system
6681 This variable is exported by @code{(guix build-system texlive)}. It is
6682 used to build TeX packages in batch mode with a specified engine. The
6683 build system sets the @env{TEXINPUTS} variable to find all TeX source
6684 files in the inputs.
6686 By default it runs @code{luatex} on all files ending on @code{ins}. A
6687 different engine and format can be specified with the
6688 @code{#:tex-format} argument. Different build targets can be specified
6689 with the @code{#:build-targets} argument, which expects a list of file
6690 names. The build system adds only @code{texlive-bin} and
6691 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6692 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6693 and @code{#:texlive-latex-base}, respectively.
6695 The @code{#:tex-directory} parameter tells the build system where to
6696 install the built files under the texmf tree.
6699 @defvr {Scheme Variable} ruby-build-system
6700 This variable is exported by @code{(guix build-system ruby)}. It
6701 implements the RubyGems build procedure used by Ruby packages, which
6702 involves running @code{gem build} followed by @code{gem install}.
6704 The @code{source} field of a package that uses this build system
6705 typically references a gem archive, since this is the format that Ruby
6706 developers use when releasing their software. The build system unpacks
6707 the gem archive, potentially patches the source, runs the test suite,
6708 repackages the gem, and installs it. Additionally, directories and
6709 tarballs may be referenced to allow building unreleased gems from Git or
6710 a traditional source release tarball.
6712 Which Ruby package is used can be specified with the @code{#:ruby}
6713 parameter. A list of additional flags to be passed to the @command{gem}
6714 command can be specified with the @code{#:gem-flags} parameter.
6717 @defvr {Scheme Variable} waf-build-system
6718 This variable is exported by @code{(guix build-system waf)}. It
6719 implements a build procedure around the @code{waf} script. The common
6720 phases---@code{configure}, @code{build}, and @code{install}---are
6721 implemented by passing their names as arguments to the @code{waf}
6724 The @code{waf} script is executed by the Python interpreter. Which
6725 Python package is used to run the script can be specified with the
6726 @code{#:python} parameter.
6729 @defvr {Scheme Variable} scons-build-system
6730 This variable is exported by @code{(guix build-system scons)}. It
6731 implements the build procedure used by the SCons software construction
6732 tool. This build system runs @code{scons} to build the package,
6733 @code{scons test} to run tests, and then @code{scons install} to install
6736 Additional flags to be passed to @code{scons} can be specified with the
6737 @code{#:scons-flags} parameter. The default build and install targets
6738 can be overridden with @code{#:build-targets} and
6739 @code{#:install-targets} respectively. The version of Python used to
6740 run SCons can be specified by selecting the appropriate SCons package
6741 with the @code{#:scons} parameter.
6744 @defvr {Scheme Variable} haskell-build-system
6745 This variable is exported by @code{(guix build-system haskell)}. It
6746 implements the Cabal build procedure used by Haskell packages, which
6747 involves running @code{runhaskell Setup.hs configure
6748 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6749 Instead of installing the package by running @code{runhaskell Setup.hs
6750 install}, to avoid trying to register libraries in the read-only
6751 compiler store directory, the build system uses @code{runhaskell
6752 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6753 addition, the build system generates the package documentation by
6754 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6755 is passed. Optional Haddock parameters can be passed with the help of
6756 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6757 not found, the build system looks for @code{Setup.lhs} instead.
6759 Which Haskell compiler is used can be specified with the @code{#:haskell}
6760 parameter which defaults to @code{ghc}.
6763 @defvr {Scheme Variable} dub-build-system
6764 This variable is exported by @code{(guix build-system dub)}. It
6765 implements the Dub build procedure used by D packages, which
6766 involves running @code{dub build} and @code{dub run}.
6767 Installation is done by copying the files manually.
6769 Which D compiler is used can be specified with the @code{#:ldc}
6770 parameter which defaults to @code{ldc}.
6773 @defvr {Scheme Variable} emacs-build-system
6774 This variable is exported by @code{(guix build-system emacs)}. It
6775 implements an installation procedure similar to the packaging system
6776 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6778 It first creates the @code{@code{package}-autoloads.el} file, then it
6779 byte compiles all Emacs Lisp files. Differently from the Emacs
6780 packaging system, the Info documentation files are moved to the standard
6781 documentation directory and the @file{dir} file is deleted. The Elisp
6782 package files are installed directly under @file{share/emacs/site-lisp}.
6785 @defvr {Scheme Variable} font-build-system
6786 This variable is exported by @code{(guix build-system font)}. It
6787 implements an installation procedure for font packages where upstream
6788 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6789 need to be copied into place. It copies font files to standard
6790 locations in the output directory.
6793 @defvr {Scheme Variable} meson-build-system
6794 This variable is exported by @code{(guix build-system meson)}. It
6795 implements the build procedure for packages that use
6796 @url{https://mesonbuild.com, Meson} as their build system.
6798 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6799 of inputs, and they can be changed with the parameters @code{#:meson}
6800 and @code{#:ninja} if needed. The default Meson is
6801 @code{meson-for-build}, which is special because it doesn't clear the
6802 @code{RUNPATH} of binaries and libraries when they are installed.
6804 This build system is an extension of @code{gnu-build-system}, but with the
6805 following phases changed to some specific for Meson:
6810 The phase runs @code{meson} with the flags specified in
6811 @code{#:configure-flags}. The flag @option{--build-type} is always set to
6812 @code{plain} unless something else is specified in @code{#:build-type}.
6815 The phase runs @code{ninja} to build the package in parallel by default, but
6816 this can be changed with @code{#:parallel-build?}.
6819 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6820 which is @code{"test"} by default.
6823 The phase runs @code{ninja install} and can not be changed.
6826 Apart from that, the build system also adds the following phases:
6831 This phase ensures that all binaries can find the libraries they need.
6832 It searches for required libraries in subdirectories of the package being
6833 built, and adds those to @code{RUNPATH} where needed. It also removes
6834 references to libraries left over from the build phase by
6835 @code{meson-for-build}, such as test dependencies, that aren't actually
6836 required for the program to run.
6838 @item glib-or-gtk-wrap
6839 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6840 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6842 @item glib-or-gtk-compile-schemas
6843 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6844 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6848 @defvr {Scheme Variable} linux-module-build-system
6849 @code{linux-module-build-system} allows building Linux kernel modules.
6851 @cindex build phases
6852 This build system is an extension of @code{gnu-build-system}, but with the
6853 following phases changed:
6858 This phase configures the environment so that the Linux kernel's Makefile
6859 can be used to build the external kernel module.
6862 This phase uses the Linux kernel's Makefile in order to build the external
6866 This phase uses the Linux kernel's Makefile in order to install the external
6870 It is possible and useful to specify the Linux kernel to use for building
6871 the module (in the @code{arguments} form of a package using the
6872 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
6875 @defvr {Scheme Variable} node-build-system
6876 This variable is exported by @code{(guix build-system node)}. It
6877 implements the build procedure used by @uref{https://nodejs.org,
6878 Node.js}, which implements an approximation of the @code{npm install}
6879 command, followed by an @code{npm test} command.
6881 Which Node.js package is used to interpret the @code{npm} commands can
6882 be specified with the @code{#:node} parameter which defaults to
6886 Lastly, for packages that do not need anything as sophisticated, a
6887 ``trivial'' build system is provided. It is trivial in the sense that
6888 it provides basically no support: it does not pull any implicit inputs,
6889 and does not have a notion of build phases.
6891 @defvr {Scheme Variable} trivial-build-system
6892 This variable is exported by @code{(guix build-system trivial)}.
6894 This build system requires a @code{#:builder} argument. This argument
6895 must be a Scheme expression that builds the package output(s)---as
6896 with @code{build-expression->derivation} (@pxref{Derivations,
6897 @code{build-expression->derivation}}).
6907 Conceptually, the @dfn{store} is the place where derivations that have
6908 been built successfully are stored---by default, @file{/gnu/store}.
6909 Sub-directories in the store are referred to as @dfn{store items} or
6910 sometimes @dfn{store paths}. The store has an associated database that
6911 contains information such as the store paths referred to by each store
6912 path, and the list of @emph{valid} store items---results of successful
6913 builds. This database resides in @file{@var{localstatedir}/guix/db},
6914 where @var{localstatedir} is the state directory specified @i{via}
6915 @option{--localstatedir} at configure time, usually @file{/var}.
6917 The store is @emph{always} accessed by the daemon on behalf of its clients
6918 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6919 connect to the daemon over a Unix-domain socket, send requests to it,
6920 and read the result---these are remote procedure calls, or RPCs.
6923 Users must @emph{never} modify files under @file{/gnu/store} directly.
6924 This would lead to inconsistencies and break the immutability
6925 assumptions of Guix's functional model (@pxref{Introduction}).
6927 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6928 how to check the integrity of the store and attempt recovery from
6929 accidental modifications.
6932 The @code{(guix store)} module provides procedures to connect to the
6933 daemon, and to perform RPCs. These are described below. By default,
6934 @code{open-connection}, and thus all the @command{guix} commands,
6935 connect to the local daemon or to the URI specified by the
6936 @env{GUIX_DAEMON_SOCKET} environment variable.
6938 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6939 When set, the value of this variable should be a file name or a URI
6940 designating the daemon endpoint. When it is a file name, it denotes a
6941 Unix-domain socket to connect to. In addition to file names, the
6942 supported URI schemes are:
6947 These are for Unix-domain sockets.
6948 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6949 @file{/var/guix/daemon-socket/socket}.
6952 @cindex daemon, remote access
6953 @cindex remote access to the daemon
6954 @cindex daemon, cluster setup
6955 @cindex clusters, daemon setup
6956 These URIs denote connections over TCP/IP, without encryption nor
6957 authentication of the remote host. The URI must specify the host name
6958 and optionally a port number (by default port 44146 is used):
6961 guix://master.guix.example.org:1234
6964 This setup is suitable on local networks, such as clusters, where only
6965 trusted nodes may connect to the build daemon at
6966 @code{master.guix.example.org}.
6968 The @option{--listen} option of @command{guix-daemon} can be used to
6969 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6970 @option{--listen}}).
6973 @cindex SSH access to build daemons
6974 These URIs allow you to connect to a remote daemon over SSH. This
6975 feature requires Guile-SSH (@pxref{Requirements}) and a working
6976 @command{guile} binary in @env{PATH} on the destination machine. It
6977 supports public key and GSSAPI authentication. A typical URL might look
6981 ssh://charlie@@guix.example.org:22
6984 As for @command{guix copy}, the usual OpenSSH client configuration files
6985 are honored (@pxref{Invoking guix copy}).
6988 Additional URI schemes may be supported in the future.
6990 @c XXX: Remove this note when the protocol incurs fewer round trips
6991 @c and when (guix derivations) no longer relies on file system access.
6993 The ability to connect to remote build daemons is considered
6994 experimental as of @value{VERSION}. Please get in touch with us to
6995 share any problems or suggestions you may have (@pxref{Contributing}).
6999 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7000 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7001 @var{reserve-space?} is true, instruct it to reserve a little bit of
7002 extra space on the file system so that the garbage collector can still
7003 operate should the disk become full. Return a server object.
7005 @var{file} defaults to @code{%default-socket-path}, which is the normal
7006 location given the options that were passed to @command{configure}.
7009 @deffn {Scheme Procedure} close-connection @var{server}
7010 Close the connection to @var{server}.
7013 @defvr {Scheme Variable} current-build-output-port
7014 This variable is bound to a SRFI-39 parameter, which refers to the port
7015 where build and error logs sent by the daemon should be written.
7018 Procedures that make RPCs all take a server object as their first
7021 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7022 @cindex invalid store items
7023 Return @code{#t} when @var{path} designates a valid store item and
7024 @code{#f} otherwise (an invalid item may exist on disk but still be
7025 invalid, for instance because it is the result of an aborted or failed
7028 A @code{&store-protocol-error} condition is raised if @var{path} is not
7029 prefixed by the store directory (@file{/gnu/store}).
7032 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7033 Add @var{text} under file @var{name} in the store, and return its store
7034 path. @var{references} is the list of store paths referred to by the
7035 resulting store path.
7038 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7040 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7041 file names, or derivation/output pairs, using the specified
7042 @var{mode}---@code{(build-mode normal)} by default.
7045 Note that the @code{(guix monads)} module provides a monad as well as
7046 monadic versions of the above procedures, with the goal of making it
7047 more convenient to work with code that accesses the store (@pxref{The
7051 @i{This section is currently incomplete.}
7054 @section Derivations
7057 Low-level build actions and the environment in which they are performed
7058 are represented by @dfn{derivations}. A derivation contains the
7059 following pieces of information:
7063 The outputs of the derivation---derivations produce at least one file or
7064 directory in the store, but may produce more.
7067 @cindex build-time dependencies
7068 @cindex dependencies, build-time
7069 The inputs of the derivations---i.e., its build-time dependencies---which may
7070 be other derivations or plain files in the store (patches, build scripts,
7074 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7077 The file name of a build script in the store, along with the arguments
7081 A list of environment variables to be defined.
7085 @cindex derivation path
7086 Derivations allow clients of the daemon to communicate build actions to
7087 the store. They exist in two forms: as an in-memory representation,
7088 both on the client- and daemon-side, and as files in the store whose
7089 name end in @file{.drv}---these files are referred to as @dfn{derivation
7090 paths}. Derivations paths can be passed to the @code{build-derivations}
7091 procedure to perform the build actions they prescribe (@pxref{The
7094 @cindex fixed-output derivations
7095 Operations such as file downloads and version-control checkouts for
7096 which the expected content hash is known in advance are modeled as
7097 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7098 of a fixed-output derivation are independent of its inputs---e.g., a
7099 source code download produces the same result regardless of the download
7100 method and tools being used.
7103 @cindex run-time dependencies
7104 @cindex dependencies, run-time
7105 The outputs of derivations---i.e., the build results---have a set of
7106 @dfn{references}, as reported by the @code{references} RPC or the
7107 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7108 are the set of run-time dependencies of the build results. References are a
7109 subset of the inputs of the derivation; this subset is automatically computed
7110 by the build daemon by scanning all the files in the outputs.
7112 The @code{(guix derivations)} module provides a representation of
7113 derivations as Scheme objects, along with procedures to create and
7114 otherwise manipulate derivations. The lowest-level primitive to create
7115 a derivation is the @code{derivation} procedure:
7117 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7118 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7119 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7120 [#:system (%current-system)] [#:references-graphs #f] @
7121 [#:allowed-references #f] [#:disallowed-references #f] @
7122 [#:leaked-env-vars #f] [#:local-build? #f] @
7123 [#:substitutable? #t] [#:properties '()]
7124 Build a derivation with the given arguments, and return the resulting
7125 @code{<derivation>} object.
7127 When @var{hash} and @var{hash-algo} are given, a
7128 @dfn{fixed-output derivation} is created---i.e., one whose result is
7129 known in advance, such as a file download. If, in addition,
7130 @var{recursive?} is true, then that fixed output may be an executable
7131 file or a directory and @var{hash} must be the hash of an archive
7132 containing this output.
7134 When @var{references-graphs} is true, it must be a list of file
7135 name/store path pairs. In that case, the reference graph of each store
7136 path is exported in the build environment in the corresponding file, in
7137 a simple text format.
7139 When @var{allowed-references} is true, it must be a list of store items
7140 or outputs that the derivation's output may refer to. Likewise,
7141 @var{disallowed-references}, if true, must be a list of things the
7142 outputs may @emph{not} refer to.
7144 When @var{leaked-env-vars} is true, it must be a list of strings
7145 denoting environment variables that are allowed to ``leak'' from the
7146 daemon's environment to the build environment. This is only applicable
7147 to fixed-output derivations---i.e., when @var{hash} is true. The main
7148 use is to allow variables such as @code{http_proxy} to be passed to
7149 derivations that download files.
7151 When @var{local-build?} is true, declare that the derivation is not a
7152 good candidate for offloading and should rather be built locally
7153 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7154 where the costs of data transfers would outweigh the benefits.
7156 When @var{substitutable?} is false, declare that substitutes of the
7157 derivation's output should not be used (@pxref{Substitutes}). This is
7158 useful, for instance, when building packages that capture details of the
7159 host CPU instruction set.
7161 @var{properties} must be an association list describing ``properties'' of the
7162 derivation. It is kept as-is, uninterpreted, in the derivation.
7166 Here's an example with a shell script as its builder, assuming
7167 @var{store} is an open connection to the daemon, and @var{bash} points
7168 to a Bash executable in the store:
7171 (use-modules (guix utils)
7175 (let ((builder ; add the Bash script to the store
7176 (add-text-to-store store "my-builder.sh"
7177 "echo hello world > $out\n" '())))
7178 (derivation store "foo"
7179 bash `("-e" ,builder)
7180 #:inputs `((,bash) (,builder))
7181 #:env-vars '(("HOME" . "/homeless"))))
7182 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7185 As can be guessed, this primitive is cumbersome to use directly. A
7186 better approach is to write build scripts in Scheme, of course! The
7187 best course of action for that is to write the build code as a
7188 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7189 information, @pxref{G-Expressions}.
7191 Once upon a time, @code{gexp->derivation} did not exist and constructing
7192 derivations with build code written in Scheme was achieved with
7193 @code{build-expression->derivation}, documented below. This procedure
7194 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7196 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7197 @var{name} @var{exp} @
7198 [#:system (%current-system)] [#:inputs '()] @
7199 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7200 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7201 [#:references-graphs #f] [#:allowed-references #f] @
7202 [#:disallowed-references #f] @
7203 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7204 Return a derivation that executes Scheme expression @var{exp} as a
7205 builder for derivation @var{name}. @var{inputs} must be a list of
7206 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7207 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7208 modules from the current search path to be copied in the store,
7209 compiled, and made available in the load path during the execution of
7210 @var{exp}---e.g., @code{((guix build utils) (guix build
7211 gnu-build-system))}.
7213 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7214 to a list of output/path pairs, and where @code{%build-inputs} is bound
7215 to a list of string/output-path pairs made from @var{inputs}.
7216 Optionally, @var{env-vars} is a list of string pairs specifying the name
7217 and value of environment variables visible to the builder. The builder
7218 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7219 @var{exp} returns @code{#f}, the build is considered to have failed.
7221 @var{exp} is built using @var{guile-for-build} (a derivation). When
7222 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7223 @code{%guile-for-build} fluid is used instead.
7225 See the @code{derivation} procedure for the meaning of
7226 @var{references-graphs}, @var{allowed-references},
7227 @var{disallowed-references}, @var{local-build?}, and
7228 @var{substitutable?}.
7232 Here's an example of a single-output derivation that creates a directory
7233 containing one file:
7236 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7237 (mkdir out) ; create /gnu/store/@dots{}-goo
7238 (call-with-output-file (string-append out "/test")
7240 (display '(hello guix) p))))))
7241 (build-expression->derivation store "goo" builder))
7243 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7247 @node The Store Monad
7248 @section The Store Monad
7252 The procedures that operate on the store described in the previous
7253 sections all take an open connection to the build daemon as their first
7254 argument. Although the underlying model is functional, they either have
7255 side effects or depend on the current state of the store.
7257 The former is inconvenient: the connection to the build daemon has to be
7258 carried around in all those functions, making it impossible to compose
7259 functions that do not take that parameter with functions that do. The
7260 latter can be problematic: since store operations have side effects
7261 and/or depend on external state, they have to be properly sequenced.
7263 @cindex monadic values
7264 @cindex monadic functions
7265 This is where the @code{(guix monads)} module comes in. This module
7266 provides a framework for working with @dfn{monads}, and a particularly
7267 useful monad for our uses, the @dfn{store monad}. Monads are a
7268 construct that allows two things: associating ``context'' with values
7269 (in our case, the context is the store), and building sequences of
7270 computations (here computations include accesses to the store). Values
7271 in a monad---values that carry this additional context---are called
7272 @dfn{monadic values}; procedures that return such values are called
7273 @dfn{monadic procedures}.
7275 Consider this ``normal'' procedure:
7278 (define (sh-symlink store)
7279 ;; Return a derivation that symlinks the 'bash' executable.
7280 (let* ((drv (package-derivation store bash))
7281 (out (derivation->output-path drv))
7282 (sh (string-append out "/bin/bash")))
7283 (build-expression->derivation store "sh"
7284 `(symlink ,sh %output))))
7287 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7288 as a monadic function:
7291 (define (sh-symlink)
7292 ;; Same, but return a monadic value.
7293 (mlet %store-monad ((drv (package->derivation bash)))
7294 (gexp->derivation "sh"
7295 #~(symlink (string-append #$drv "/bin/bash")
7299 There are several things to note in the second version: the @code{store}
7300 parameter is now implicit and is ``threaded'' in the calls to the
7301 @code{package->derivation} and @code{gexp->derivation} monadic
7302 procedures, and the monadic value returned by @code{package->derivation}
7303 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7305 As it turns out, the call to @code{package->derivation} can even be
7306 omitted since it will take place implicitly, as we will see later
7307 (@pxref{G-Expressions}):
7310 (define (sh-symlink)
7311 (gexp->derivation "sh"
7312 #~(symlink (string-append #$bash "/bin/bash")
7317 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7318 @c for the funny quote.
7319 Calling the monadic @code{sh-symlink} has no effect. As someone once
7320 said, ``you exit a monad like you exit a building on fire: by running''.
7321 So, to exit the monad and get the desired effect, one must use
7322 @code{run-with-store}:
7325 (run-with-store (open-connection) (sh-symlink))
7326 @result{} /gnu/store/...-sh-symlink
7329 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7330 new ``meta-commands'' to make it easier to deal with monadic procedures:
7331 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7332 to ``run'' a single monadic value through the store:
7335 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7336 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7339 The latter enters a recursive REPL, where all the return values are
7340 automatically run through the store:
7343 scheme@@(guile-user)> ,enter-store-monad
7344 store-monad@@(guile-user) [1]> (package->derivation hello)
7345 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7346 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7347 $3 = "/gnu/store/@dots{}-foo"
7348 store-monad@@(guile-user) [1]> ,q
7349 scheme@@(guile-user)>
7353 Note that non-monadic values cannot be returned in the
7354 @code{store-monad} REPL.
7356 The main syntactic forms to deal with monads in general are provided by
7357 the @code{(guix monads)} module and are described below.
7359 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7360 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7364 @deffn {Scheme Syntax} return @var{val}
7365 Return a monadic value that encapsulates @var{val}.
7368 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7369 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7370 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7371 referred to as ``bind'', but that name denotes an unrelated procedure in
7372 Guile. Thus we use this somewhat cryptic symbol inherited from the
7373 Haskell language.}. There can be one @var{mproc} or several of them, as
7378 (with-monad %state-monad
7380 (lambda (x) (return (+ 1 x)))
7381 (lambda (x) (return (* 2 x)))))
7385 @result{} some-state
7389 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7391 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7393 Bind the variables @var{var} to the monadic values @var{mval} in
7394 @var{body}, which is a sequence of expressions. As with the bind
7395 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7396 value ``contained'' in @var{mval} and making @var{var} refer to that
7397 raw, non-monadic value within the scope of the @var{body}. The form
7398 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7399 @var{val}, as per @code{let}. The binding operations occur in sequence
7400 from left to right. The last expression of @var{body} must be a monadic
7401 expression, and its result will become the result of the @code{mlet} or
7402 @code{mlet*} when run in the @var{monad}.
7404 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7405 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7408 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7409 Bind @var{mexp} and the following monadic expressions in sequence,
7410 returning the result of the last expression. Every expression in the
7411 sequence must be a monadic expression.
7413 This is akin to @code{mlet}, except that the return values of the
7414 monadic expressions are ignored. In that sense, it is analogous to
7415 @code{begin}, but applied to monadic expressions.
7418 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7419 When @var{condition} is true, evaluate the sequence of monadic
7420 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7421 @var{condition} is false, return @code{*unspecified*} in the current
7422 monad. Every expression in the sequence must be a monadic expression.
7425 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7426 When @var{condition} is false, evaluate the sequence of monadic
7427 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7428 @var{condition} is true, return @code{*unspecified*} in the current
7429 monad. Every expression in the sequence must be a monadic expression.
7433 The @code{(guix monads)} module provides the @dfn{state monad}, which
7434 allows an additional value---the state---to be @emph{threaded} through
7435 monadic procedure calls.
7437 @defvr {Scheme Variable} %state-monad
7438 The state monad. Procedures in the state monad can access and change
7439 the state that is threaded.
7441 Consider the example below. The @code{square} procedure returns a value
7442 in the state monad. It returns the square of its argument, but also
7443 increments the current state value:
7447 (mlet %state-monad ((count (current-state)))
7448 (mbegin %state-monad
7449 (set-current-state (+ 1 count))
7452 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7457 When ``run'' through @code{%state-monad}, we obtain that additional state
7458 value, which is the number of @code{square} calls.
7461 @deffn {Monadic Procedure} current-state
7462 Return the current state as a monadic value.
7465 @deffn {Monadic Procedure} set-current-state @var{value}
7466 Set the current state to @var{value} and return the previous state as a
7470 @deffn {Monadic Procedure} state-push @var{value}
7471 Push @var{value} to the current state, which is assumed to be a list,
7472 and return the previous state as a monadic value.
7475 @deffn {Monadic Procedure} state-pop
7476 Pop a value from the current state and return it as a monadic value.
7477 The state is assumed to be a list.
7480 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7481 Run monadic value @var{mval} starting with @var{state} as the initial
7482 state. Return two values: the resulting value, and the resulting state.
7485 The main interface to the store monad, provided by the @code{(guix
7486 store)} module, is as follows.
7488 @defvr {Scheme Variable} %store-monad
7489 The store monad---an alias for @code{%state-monad}.
7491 Values in the store monad encapsulate accesses to the store. When its
7492 effect is needed, a value of the store monad must be ``evaluated'' by
7493 passing it to the @code{run-with-store} procedure (see below.)
7496 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7497 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7498 open store connection.
7501 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7502 Return as a monadic value the absolute file name in the store of the file
7503 containing @var{text}, a string. @var{references} is a list of store items that the
7504 resulting text file refers to; it defaults to the empty list.
7507 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7508 Return as a monadic value the absolute file name in the store of the file
7509 containing @var{data}, a bytevector. @var{references} is a list of store
7510 items that the resulting binary file refers to; it defaults to the empty list.
7513 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7514 [#:recursive? #t] [#:select? (const #t)]
7515 Return the name of @var{file} once interned in the store. Use
7516 @var{name} as its store name, or the basename of @var{file} if
7517 @var{name} is omitted.
7519 When @var{recursive?} is true, the contents of @var{file} are added
7520 recursively; if @var{file} designates a flat file and @var{recursive?}
7521 is true, its contents are added, and its permission bits are kept.
7523 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7524 @var{stat})} for each directory entry, where @var{file} is the entry's
7525 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7526 entries for which @var{select?} does not return true.
7528 The example below adds a file to the store, under two different names:
7531 (run-with-store (open-connection)
7532 (mlet %store-monad ((a (interned-file "README"))
7533 (b (interned-file "README" "LEGU-MIN")))
7534 (return (list a b))))
7536 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7541 The @code{(guix packages)} module exports the following package-related
7544 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7545 [#:system (%current-system)] [#:target #f] @
7548 value in the absolute file name of @var{file} within the @var{output}
7549 directory of @var{package}. When @var{file} is omitted, return the name
7550 of the @var{output} directory of @var{package}. When @var{target} is
7551 true, use it as a cross-compilation target triplet.
7553 Note that this procedure does @emph{not} build @var{package}. Thus, the
7554 result might or might not designate an existing file. We recommend not
7555 using this procedure unless you know what you are doing.
7558 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7559 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7560 @var{target} [@var{system}]
7561 Monadic version of @code{package-derivation} and
7562 @code{package-cross-derivation} (@pxref{Defining Packages}).
7567 @section G-Expressions
7569 @cindex G-expression
7570 @cindex build code quoting
7571 So we have ``derivations'', which represent a sequence of build actions
7572 to be performed to produce an item in the store (@pxref{Derivations}).
7573 These build actions are performed when asking the daemon to actually
7574 build the derivations; they are run by the daemon in a container
7575 (@pxref{Invoking guix-daemon}).
7577 @cindex strata of code
7578 It should come as no surprise that we like to write these build actions
7579 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7580 code@footnote{The term @dfn{stratum} in this context was coined by
7581 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7582 Kiselyov, who has written insightful
7583 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7584 on this topic}, refers to this kind of code generation as
7585 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7586 to the daemon, etc.---and the ``build code''---code that actually
7587 performs build actions, such as making directories, invoking
7588 @command{make}, etc.
7590 To describe a derivation and its build actions, one typically needs to
7591 embed build code inside host code. It boils down to manipulating build
7592 code as data, and the homoiconicity of Scheme---code has a direct
7593 representation as data---comes in handy for that. But we need more than
7594 the normal @code{quasiquote} mechanism in Scheme to construct build
7597 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7598 S-expressions adapted to build expressions. G-expressions, or
7599 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7600 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7601 @code{#$}, and @code{#$@@}), which are comparable to
7602 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7603 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7604 GNU Guile Reference Manual}). However, there are major differences:
7608 Gexps are meant to be written to a file and run or manipulated by other
7612 When a high-level object such as a package or derivation is unquoted
7613 inside a gexp, the result is as if its output file name had been
7617 Gexps carry information about the packages or derivations they refer to,
7618 and these dependencies are automatically added as inputs to the build
7619 processes that use them.
7622 @cindex lowering, of high-level objects in gexps
7623 This mechanism is not limited to package and derivation
7624 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7625 derivations or files in the store can be defined,
7626 such that these objects can also be inserted
7627 into gexps. For example, a useful type of high-level objects that can be
7628 inserted in a gexp is ``file-like objects'', which make it easy to
7629 add files to the store and to refer to them in
7630 derivations and such (see @code{local-file} and @code{plain-file}
7633 To illustrate the idea, here is an example of a gexp:
7640 (symlink (string-append #$coreutils "/bin/ls")
7644 This gexp can be passed to @code{gexp->derivation}; we obtain a
7645 derivation that builds a directory containing exactly one symlink to
7646 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7649 (gexp->derivation "the-thing" build-exp)
7652 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7653 substituted to the reference to the @var{coreutils} package in the
7654 actual build code, and @var{coreutils} is automatically made an input to
7655 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7656 output)}) is replaced by a string containing the directory name of the
7657 output of the derivation.
7659 @cindex cross compilation
7660 In a cross-compilation context, it is useful to distinguish between
7661 references to the @emph{native} build of a package---that can run on the
7662 host---versus references to cross builds of a package. To that end, the
7663 @code{#+} plays the same role as @code{#$}, but is a reference to a
7664 native package build:
7667 (gexp->derivation "vi"
7670 (mkdir (string-append #$output "/bin"))
7671 (system* (string-append #+coreutils "/bin/ln")
7673 (string-append #$emacs "/bin/emacs")
7674 (string-append #$output "/bin/vi")))
7675 #:target "mips64el-linux-gnu")
7679 In the example above, the native build of @var{coreutils} is used, so
7680 that @command{ln} can actually run on the host; but then the
7681 cross-compiled build of @var{emacs} is referenced.
7683 @cindex imported modules, for gexps
7684 @findex with-imported-modules
7685 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7686 able to use certain Guile modules from the ``host environment'' in the
7687 gexp, so those modules should be imported in the ``build environment''.
7688 The @code{with-imported-modules} form allows you to express that:
7691 (let ((build (with-imported-modules '((guix build utils))
7693 (use-modules (guix build utils))
7694 (mkdir-p (string-append #$output "/bin"))))))
7695 (gexp->derivation "empty-dir"
7698 (display "success!\n")
7703 In this example, the @code{(guix build utils)} module is automatically
7704 pulled into the isolated build environment of our gexp, such that
7705 @code{(use-modules (guix build utils))} works as expected.
7707 @cindex module closure
7708 @findex source-module-closure
7709 Usually you want the @emph{closure} of the module to be imported---i.e.,
7710 the module itself and all the modules it depends on---rather than just
7711 the module; failing to do that, attempts to use the module will fail
7712 because of missing dependent modules. The @code{source-module-closure}
7713 procedure computes the closure of a module by looking at its source file
7714 headers, which comes in handy in this case:
7717 (use-modules (guix modules)) ;for 'source-module-closure'
7719 (with-imported-modules (source-module-closure
7720 '((guix build utils)
7722 (gexp->derivation "something-with-vms"
7724 (use-modules (guix build utils)
7729 @cindex extensions, for gexps
7730 @findex with-extensions
7731 In the same vein, sometimes you want to import not just pure-Scheme
7732 modules, but also ``extensions'' such as Guile bindings to C libraries
7733 or other ``full-blown'' packages. Say you need the @code{guile-json}
7734 package available on the build side, here's how you would do it:
7737 (use-modules (gnu packages guile)) ;for 'guile-json'
7739 (with-extensions (list guile-json)
7740 (gexp->derivation "something-with-json"
7742 (use-modules (json))
7746 The syntactic form to construct gexps is summarized below.
7748 @deffn {Scheme Syntax} #~@var{exp}
7749 @deffnx {Scheme Syntax} (gexp @var{exp})
7750 Return a G-expression containing @var{exp}. @var{exp} may contain one
7751 or more of the following forms:
7755 @itemx (ungexp @var{obj})
7756 Introduce a reference to @var{obj}. @var{obj} may have one of the
7757 supported types, for example a package or a
7758 derivation, in which case the @code{ungexp} form is replaced by its
7759 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7761 If @var{obj} is a list, it is traversed and references to supported
7762 objects are substituted similarly.
7764 If @var{obj} is another gexp, its contents are inserted and its
7765 dependencies are added to those of the containing gexp.
7767 If @var{obj} is another kind of object, it is inserted as is.
7769 @item #$@var{obj}:@var{output}
7770 @itemx (ungexp @var{obj} @var{output})
7771 This is like the form above, but referring explicitly to the
7772 @var{output} of @var{obj}---this is useful when @var{obj} produces
7773 multiple outputs (@pxref{Packages with Multiple Outputs}).
7776 @itemx #+@var{obj}:output
7777 @itemx (ungexp-native @var{obj})
7778 @itemx (ungexp-native @var{obj} @var{output})
7779 Same as @code{ungexp}, but produces a reference to the @emph{native}
7780 build of @var{obj} when used in a cross compilation context.
7782 @item #$output[:@var{output}]
7783 @itemx (ungexp output [@var{output}])
7784 Insert a reference to derivation output @var{output}, or to the main
7785 output when @var{output} is omitted.
7787 This only makes sense for gexps passed to @code{gexp->derivation}.
7790 @itemx (ungexp-splicing @var{lst})
7791 Like the above, but splices the contents of @var{lst} inside the
7795 @itemx (ungexp-native-splicing @var{lst})
7796 Like the above, but refers to native builds of the objects listed in
7801 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7802 of the @code{gexp?} type (see below.)
7805 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7806 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7807 in their execution environment.
7809 Each item in @var{modules} can be the name of a module, such as
7810 @code{(guix build utils)}, or it can be a module name, followed by an
7811 arrow, followed by a file-like object:
7814 `((guix build utils)
7816 ((guix config) => ,(scheme-file "config.scm"
7817 #~(define-module @dots{}))))
7821 In the example above, the first two modules are taken from the search
7822 path, and the last one is created from the given file-like object.
7824 This form has @emph{lexical} scope: it has an effect on the gexps
7825 directly defined in @var{body}@dots{}, but not on those defined, say, in
7826 procedures called from @var{body}@dots{}.
7829 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7830 Mark the gexps defined in @var{body}@dots{} as requiring
7831 @var{extensions} in their build and execution environment.
7832 @var{extensions} is typically a list of package objects such as those
7833 defined in the @code{(gnu packages guile)} module.
7835 Concretely, the packages listed in @var{extensions} are added to the
7836 load path while compiling imported modules in @var{body}@dots{}; they
7837 are also added to the load path of the gexp returned by
7841 @deffn {Scheme Procedure} gexp? @var{obj}
7842 Return @code{#t} if @var{obj} is a G-expression.
7845 G-expressions are meant to be written to disk, either as code building
7846 some derivation, or as plain files in the store. The monadic procedures
7847 below allow you to do that (@pxref{The Store Monad}, for more
7848 information about monads.)
7850 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7851 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7852 [#:hash #f] [#:hash-algo #f] @
7853 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7854 [#:module-path @code{%load-path}] @
7855 [#:effective-version "2.2"] @
7856 [#:references-graphs #f] [#:allowed-references #f] @
7857 [#:disallowed-references #f] @
7858 [#:leaked-env-vars #f] @
7859 [#:script-name (string-append @var{name} "-builder")] @
7860 [#:deprecation-warnings #f] @
7861 [#:local-build? #f] [#:substitutable? #t] @
7862 [#:properties '()] [#:guile-for-build #f]
7863 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7864 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7865 stored in a file called @var{script-name}. When @var{target} is true,
7866 it is used as the cross-compilation target triplet for packages referred
7869 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7871 make @var{modules} available in the evaluation context of @var{exp};
7872 @var{modules} is a list of names of Guile modules searched in
7873 @var{module-path} to be copied in the store, compiled, and made available in
7874 the load path during the execution of @var{exp}---e.g., @code{((guix
7875 build utils) (guix build gnu-build-system))}.
7877 @var{effective-version} determines the string to use when adding extensions of
7878 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7880 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7883 When @var{references-graphs} is true, it must be a list of tuples of one of the
7887 (@var{file-name} @var{package})
7888 (@var{file-name} @var{package} @var{output})
7889 (@var{file-name} @var{derivation})
7890 (@var{file-name} @var{derivation} @var{output})
7891 (@var{file-name} @var{store-item})
7894 The right-hand-side of each element of @var{references-graphs} is automatically made
7895 an input of the build process of @var{exp}. In the build environment, each
7896 @var{file-name} contains the reference graph of the corresponding item, in a simple
7899 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7900 In the latter case, the list denotes store items that the result is allowed to
7901 refer to. Any reference to another store item will lead to a build error.
7902 Similarly for @var{disallowed-references}, which can list items that must not be
7903 referenced by the outputs.
7905 @var{deprecation-warnings} determines whether to show deprecation warnings while
7906 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7908 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7911 @cindex file-like objects
7912 The @code{local-file}, @code{plain-file}, @code{computed-file},
7913 @code{program-file}, and @code{scheme-file} procedures below return
7914 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7915 these objects lead to a file in the store. Consider this G-expression:
7918 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7919 #$(local-file "/tmp/my-nscd.conf"))
7922 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7923 to the store. Once expanded, for instance @i{via}
7924 @code{gexp->derivation}, the G-expression refers to that copy under
7925 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7926 does not have any effect on what the G-expression does.
7927 @code{plain-file} can be used similarly; it differs in that the file
7928 content is directly passed as a string.
7930 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7931 [#:recursive? #f] [#:select? (const #t)]
7932 Return an object representing local file @var{file} to add to the store;
7933 this object can be used in a gexp. If @var{file} is a literal string
7934 denoting a relative file name, it is looked up relative to the source
7935 file where it appears; if @var{file} is not a literal string, it is
7936 looked up relative to the current working directory at run time.
7937 @var{file} will be added to the store under @var{name}--by default the
7938 base name of @var{file}.
7940 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7941 designates a flat file and @var{recursive?} is true, its contents are added, and its
7942 permission bits are kept.
7944 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7945 @var{stat})} for each directory entry, where @var{file} is the entry's
7946 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7947 entries for which @var{select?} does not return true.
7949 This is the declarative counterpart of the @code{interned-file} monadic
7950 procedure (@pxref{The Store Monad, @code{interned-file}}).
7953 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7954 Return an object representing a text file called @var{name} with the given
7955 @var{content} (a string or a bytevector) to be added to the store.
7957 This is the declarative counterpart of @code{text-file}.
7960 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7961 [#:options '(#:local-build? #t)]
7962 Return an object representing the store item @var{name}, a file or
7963 directory computed by @var{gexp}. @var{options}
7964 is a list of additional arguments to pass to @code{gexp->derivation}.
7966 This is the declarative counterpart of @code{gexp->derivation}.
7969 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7970 [#:guile (default-guile)] [#:module-path %load-path] @
7971 [#:system (%current-system)] [#:target #f]
7972 Return an executable script @var{name} that runs @var{exp} using
7973 @var{guile}, with @var{exp}'s imported modules in its search path.
7974 Look up @var{exp}'s modules in @var{module-path}.
7976 The example below builds a script that simply invokes the @command{ls}
7980 (use-modules (guix gexp) (gnu packages base))
7982 (gexp->script "list-files"
7983 #~(execl #$(file-append coreutils "/bin/ls")
7987 When ``running'' it through the store (@pxref{The Store Monad,
7988 @code{run-with-store}}), we obtain a derivation that produces an
7989 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7992 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7994 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7998 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7999 [#:guile #f] [#:module-path %load-path]
8000 Return an object representing the executable store item @var{name} that
8001 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8002 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8004 This is the declarative counterpart of @code{gexp->script}.
8007 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8008 [#:set-load-path? #t] [#:module-path %load-path] @
8010 [#:guile (default-guile)]
8011 Return a derivation that builds a file @var{name} containing @var{exp}.
8012 When @var{splice?} is true, @var{exp} is considered to be a list of
8013 expressions that will be spliced in the resulting file.
8015 When @var{set-load-path?} is true, emit code in the resulting file to
8016 set @code{%load-path} and @code{%load-compiled-path} to honor
8017 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8020 The resulting file holds references to all the dependencies of @var{exp}
8021 or a subset thereof.
8024 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8025 [#:splice? #f] [#:set-load-path? #t]
8026 Return an object representing the Scheme file @var{name} that contains
8029 This is the declarative counterpart of @code{gexp->file}.
8032 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8033 Return as a monadic value a derivation that builds a text file
8034 containing all of @var{text}. @var{text} may list, in addition to
8035 strings, objects of any type that can be used in a gexp: packages,
8036 derivations, local file objects, etc. The resulting store file holds
8037 references to all these.
8039 This variant should be preferred over @code{text-file} anytime the file
8040 to create will reference items from the store. This is typically the
8041 case when building a configuration file that embeds store file names,
8045 (define (profile.sh)
8046 ;; Return the name of a shell script in the store that
8047 ;; initializes the 'PATH' environment variable.
8048 (text-file* "profile.sh"
8049 "export PATH=" coreutils "/bin:"
8050 grep "/bin:" sed "/bin\n"))
8053 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8054 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8055 preventing them from being garbage-collected during its lifetime.
8058 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8059 Return an object representing store file @var{name} containing
8060 @var{text}. @var{text} is a sequence of strings and file-like objects,
8064 (mixed-text-file "profile"
8065 "export PATH=" coreutils "/bin:" grep "/bin")
8068 This is the declarative counterpart of @code{text-file*}.
8071 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8072 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8073 Each item in @var{files} must be a two-element list where the first element is the
8074 file name to use in the new directory, and the second element is a gexp
8075 denoting the target file. Here's an example:
8079 `(("hosts" ,(plain-file "hosts"
8080 "127.0.0.1 localhost"))
8081 ("bashrc" ,(plain-file "bashrc"
8082 "alias ls='ls --color=auto'"))))
8085 This yields an @code{etc} directory containing these two files.
8088 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8089 Return a directory that is the union of @var{things}, where @var{things} is a list of
8090 file-like objects denoting directories. For example:
8093 (directory-union "guile+emacs" (list guile emacs))
8096 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8099 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8100 Return a file-like object that expands to the concatenation of @var{obj}
8101 and @var{suffix}, where @var{obj} is a lowerable object and each
8102 @var{suffix} is a string.
8104 As an example, consider this gexp:
8107 (gexp->script "run-uname"
8108 #~(system* #$(file-append coreutils
8112 The same effect could be achieved with:
8115 (gexp->script "run-uname"
8116 #~(system* (string-append #$coreutils
8120 There is one difference though: in the @code{file-append} case, the
8121 resulting script contains the absolute file name as a string, whereas in
8122 the second case, the resulting script contains a @code{(string-append
8123 @dots{})} expression to construct the file name @emph{at run time}.
8126 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8127 This macro is similar to the @code{parameterize} form for
8128 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8129 Guile Reference Manual}). The key difference is that it takes effect
8130 when the file-like object returned by @var{exp} is lowered to a
8131 derivation or store item.
8133 A typical use of @code{with-parameters} is to force the system in effect
8137 (with-parameters ((%current-system "i686-linux"))
8141 The example above returns an object that corresponds to the i686 build
8142 of Coreutils, regardless of the current value of @code{%current-system}.
8146 Of course, in addition to gexps embedded in ``host'' code, there are
8147 also modules containing build tools. To make it clear that they are
8148 meant to be used in the build stratum, these modules are kept in the
8149 @code{(guix build @dots{})} name space.
8151 @cindex lowering, of high-level objects in gexps
8152 Internally, high-level objects are @dfn{lowered}, using their compiler,
8153 to either derivations or store items. For instance, lowering a package
8154 yields a derivation, and lowering a @code{plain-file} yields a store
8155 item. This is achieved using the @code{lower-object} monadic procedure.
8157 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8159 Return as a value in @code{%store-monad} the derivation or store item
8160 corresponding to @var{obj} for @var{system}, cross-compiling for
8161 @var{target} if @var{target} is true. @var{obj} must be an object that
8162 has an associated gexp compiler, such as a @code{<package>}.
8165 @node Invoking guix repl
8166 @section Invoking @command{guix repl}
8168 @cindex REPL, read-eval-print loop
8169 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
8170 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
8171 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
8172 command, @command{guix repl} guarantees that all the Guix modules and all its
8173 dependencies are available in the search path. You can use it this way:
8177 scheme@@(guile-user)> ,use (gnu packages base)
8178 scheme@@(guile-user)> coreutils
8179 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8183 In addition, @command{guix repl} implements a simple machine-readable REPL
8184 protocol for use by @code{(guix inferior)}, a facility to interact with
8185 @dfn{inferiors}, separate processes running a potentially different revision
8188 The available options are as follows:
8191 @item --type=@var{type}
8192 @itemx -t @var{type}
8193 Start a REPL of the given @var{TYPE}, which can be one of the following:
8197 This is default, and it spawns a standard full-featured Guile REPL.
8199 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8200 that the @code{(guix inferior)} module speaks.
8203 @item --listen=@var{endpoint}
8204 By default, @command{guix repl} reads from standard input and writes to
8205 standard output. When this option is passed, it will instead listen for
8206 connections on @var{endpoint}. Here are examples of valid options:
8209 @item --listen=tcp:37146
8210 Accept connections on localhost on port 37146.
8212 @item --listen=unix:/tmp/socket
8213 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8216 @item --load-path=@var{directory}
8217 @itemx -L @var{directory}
8218 Add @var{directory} to the front of the package module search path
8219 (@pxref{Package Modules}).
8221 This allows users to define their own packages and make them visible to
8222 the command-line tool.
8225 Inhibit loading of the @file{~/.guile} file. By default, that
8226 configuration file is loaded when spawning a @code{guile} REPL.
8229 @c *********************************************************************
8233 This section describes Guix command-line utilities. Some of them are
8234 primarily targeted at developers and users who write new package
8235 definitions, while others are more generally useful. They complement
8236 the Scheme programming interface of Guix in a convenient way.
8239 * Invoking guix build:: Building packages from the command line.
8240 * Invoking guix edit:: Editing package definitions.
8241 * Invoking guix download:: Downloading a file and printing its hash.
8242 * Invoking guix hash:: Computing the cryptographic hash of a file.
8243 * Invoking guix import:: Importing package definitions.
8244 * Invoking guix refresh:: Updating package definitions.
8245 * Invoking guix lint:: Finding errors in package definitions.
8246 * Invoking guix size:: Profiling disk usage.
8247 * Invoking guix graph:: Visualizing the graph of packages.
8248 * Invoking guix publish:: Sharing substitutes.
8249 * Invoking guix challenge:: Challenging substitute servers.
8250 * Invoking guix copy:: Copying to and from a remote store.
8251 * Invoking guix container:: Process isolation.
8252 * Invoking guix weather:: Assessing substitute availability.
8253 * Invoking guix processes:: Listing client processes.
8256 @node Invoking guix build
8257 @section Invoking @command{guix build}
8259 @cindex package building
8260 @cindex @command{guix build}
8261 The @command{guix build} command builds packages or derivations and
8262 their dependencies, and prints the resulting store paths. Note that it
8263 does not modify the user's profile---this is the job of the
8264 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8265 it is mainly useful for distribution developers.
8267 The general syntax is:
8270 guix build @var{options} @var{package-or-derivation}@dots{}
8273 As an example, the following command builds the latest versions of Emacs
8274 and of Guile, displays their build logs, and finally displays the
8275 resulting directories:
8278 guix build emacs guile
8281 Similarly, the following command builds all the available packages:
8284 guix build --quiet --keep-going \
8285 `guix package -A | cut -f1,2 --output-delimiter=@@`
8288 @var{package-or-derivation} may be either the name of a package found in
8289 the software distribution such as @code{coreutils} or
8290 @code{coreutils@@8.20}, or a derivation such as
8291 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8292 package with the corresponding name (and optionally version) is searched
8293 for among the GNU distribution modules (@pxref{Package Modules}).
8295 Alternatively, the @option{--expression} option may be used to specify a
8296 Scheme expression that evaluates to a package; this is useful when
8297 disambiguating among several same-named packages or package variants is
8300 There may be zero or more @var{options}. The available options are
8301 described in the subsections below.
8304 * Common Build Options:: Build options for most commands.
8305 * Package Transformation Options:: Creating variants of packages.
8306 * Additional Build Options:: Options specific to 'guix build'.
8307 * Debugging Build Failures:: Real life packaging experience.
8310 @node Common Build Options
8311 @subsection Common Build Options
8313 A number of options that control the build process are common to
8314 @command{guix build} and other commands that can spawn builds, such as
8315 @command{guix package} or @command{guix archive}. These are the
8320 @item --load-path=@var{directory}
8321 @itemx -L @var{directory}
8322 Add @var{directory} to the front of the package module search path
8323 (@pxref{Package Modules}).
8325 This allows users to define their own packages and make them visible to
8326 the command-line tools.
8330 Keep the build tree of failed builds. Thus, if a build fails, its build
8331 tree is kept under @file{/tmp}, in a directory whose name is shown at
8332 the end of the build log. This is useful when debugging build issues.
8333 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8336 This option implies @option{--no-offload}, and it has no effect when
8337 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8338 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
8342 Keep going when some of the derivations fail to build; return only once
8343 all the builds have either completed or failed.
8345 The default behavior is to stop as soon as one of the specified
8346 derivations has failed.
8350 Do not build the derivations.
8352 @anchor{fallback-option}
8354 When substituting a pre-built binary fails, fall back to building
8355 packages locally (@pxref{Substitution Failure}).
8357 @item --substitute-urls=@var{urls}
8358 @anchor{client-substitute-urls}
8359 Consider @var{urls} the whitespace-separated list of substitute source
8360 URLs, overriding the default list of URLs of @command{guix-daemon}
8361 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8363 This means that substitutes may be downloaded from @var{urls}, provided
8364 they are signed by a key authorized by the system administrator
8365 (@pxref{Substitutes}).
8367 When @var{urls} is the empty string, substitutes are effectively
8370 @item --no-substitutes
8371 Do not use substitutes for build products. That is, always build things
8372 locally instead of allowing downloads of pre-built binaries
8373 (@pxref{Substitutes}).
8376 Do not ``graft'' packages. In practice, this means that package updates
8377 available as grafts are not applied. @xref{Security Updates}, for more
8378 information on grafts.
8380 @item --rounds=@var{n}
8381 Build each derivation @var{n} times in a row, and raise an error if
8382 consecutive build results are not bit-for-bit identical.
8384 This is a useful way to detect non-deterministic builds processes.
8385 Non-deterministic build processes are a problem because they make it
8386 practically impossible for users to @emph{verify} whether third-party
8387 binaries are genuine. @xref{Invoking guix challenge}, for more.
8389 Note that, currently, the differing build results are not kept around,
8390 so you will have to manually investigate in case of an error---e.g., by
8391 stashing one of the build results with @code{guix archive --export}
8392 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8396 Do not use offload builds to other machines (@pxref{Daemon Offload
8397 Setup}). That is, always build things locally instead of offloading
8398 builds to remote machines.
8400 @item --max-silent-time=@var{seconds}
8401 When the build or substitution process remains silent for more than
8402 @var{seconds}, terminate it and report a build failure.
8404 By default, the daemon's setting is honored (@pxref{Invoking
8405 guix-daemon, @option{--max-silent-time}}).
8407 @item --timeout=@var{seconds}
8408 Likewise, when the build or substitution process lasts for more than
8409 @var{seconds}, terminate it and report a build failure.
8411 By default, the daemon's setting is honored (@pxref{Invoking
8412 guix-daemon, @option{--timeout}}).
8414 @c Note: This option is actually not part of %standard-build-options but
8415 @c most programs honor it.
8416 @cindex verbosity, of the command-line tools
8417 @cindex build logs, verbosity
8418 @item -v @var{level}
8419 @itemx --verbosity=@var{level}
8420 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8421 output is produced, 1 is for quiet output, and 2 shows all the build log
8422 output on standard error.
8424 @item --cores=@var{n}
8426 Allow the use of up to @var{n} CPU cores for the build. The special
8427 value @code{0} means to use as many CPU cores as available.
8429 @item --max-jobs=@var{n}
8431 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8432 guix-daemon, @option{--max-jobs}}, for details about this option and the
8433 equivalent @command{guix-daemon} option.
8435 @item --debug=@var{level}
8436 Produce debugging output coming from the build daemon. @var{level} must be an
8437 integer between 0 and 5; higher means more verbose output. Setting a level of
8438 4 or more may be helpful when debugging setup issues with the build daemon.
8442 Behind the scenes, @command{guix build} is essentially an interface to
8443 the @code{package-derivation} procedure of the @code{(guix packages)}
8444 module, and to the @code{build-derivations} procedure of the @code{(guix
8445 derivations)} module.
8447 In addition to options explicitly passed on the command line,
8448 @command{guix build} and other @command{guix} commands that support
8449 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
8451 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8452 Users can define this variable to a list of command line options that
8453 will automatically be used by @command{guix build} and other
8454 @command{guix} commands that can perform builds, as in the example
8458 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8461 These options are parsed independently, and the result is appended to
8462 the parsed command-line options.
8466 @node Package Transformation Options
8467 @subsection Package Transformation Options
8469 @cindex package variants
8470 Another set of command-line options supported by @command{guix build}
8471 and also @command{guix package} are @dfn{package transformation
8472 options}. These are options that make it possible to define @dfn{package
8473 variants}---for instance, packages built from different source code.
8474 This is a convenient way to create customized packages on the fly
8475 without having to type in the definitions of package variants
8476 (@pxref{Defining Packages}).
8480 @item --with-source=@var{source}
8481 @itemx --with-source=@var{package}=@var{source}
8482 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8483 Use @var{source} as the source of @var{package}, and @var{version} as
8485 @var{source} must be a file name or a URL, as for @command{guix
8486 download} (@pxref{Invoking guix download}).
8488 When @var{package} is omitted,
8489 it is taken to be the package name specified on the
8490 command line that matches the base of @var{source}---e.g.,
8491 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8492 package is @code{guile}.
8494 Likewise, when @var{version} is omitted, the version string is inferred from
8495 @var{source}; in the previous example, it is @code{2.0.10}.
8497 This option allows users to try out versions of packages other than the
8498 one provided by the distribution. The example below downloads
8499 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8500 the @code{ed} package:
8503 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8506 As a developer, @option{--with-source} makes it easy to test release
8510 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8513 @dots{} or to build from a checkout in a pristine environment:
8516 $ git clone git://git.sv.gnu.org/guix.git
8517 $ guix build guix --with-source=guix@@1.0=./guix
8520 @item --with-input=@var{package}=@var{replacement}
8521 Replace dependency on @var{package} by a dependency on
8522 @var{replacement}. @var{package} must be a package name, and
8523 @var{replacement} must be a package specification such as @code{guile}
8524 or @code{guile@@1.8}.
8526 For instance, the following command builds Guix, but replaces its
8527 dependency on the current stable version of Guile with a dependency on
8528 the legacy version of Guile, @code{guile@@2.0}:
8531 guix build --with-input=guile=guile@@2.0 guix
8534 This is a recursive, deep replacement. So in this example, both
8535 @code{guix} and its dependency @code{guile-json} (which also depends on
8536 @code{guile}) get rebuilt against @code{guile@@2.0}.
8538 This is implemented using the @code{package-input-rewriting} Scheme
8539 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8541 @item --with-graft=@var{package}=@var{replacement}
8542 This is similar to @option{--with-input} but with an important difference:
8543 instead of rebuilding the whole dependency chain, @var{replacement} is
8544 built and then @dfn{grafted} onto the binaries that were initially
8545 referring to @var{package}. @xref{Security Updates}, for more
8546 information on grafts.
8548 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8549 and all its dependencies, replacing references to the version of GnuTLS
8550 they currently refer to:
8553 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8556 This has the advantage of being much faster than rebuilding everything.
8557 But there is a caveat: it works if and only if @var{package} and
8558 @var{replacement} are strictly compatible---for example, if they provide
8559 a library, the application binary interface (ABI) of those libraries
8560 must be compatible. If @var{replacement} is somehow incompatible with
8561 @var{package}, then the resulting package may be unusable. Use with
8564 @item --with-git-url=@var{package}=@var{url}
8565 @cindex Git, using the latest commit
8566 @cindex latest commit, building
8567 Build @var{package} from the latest commit of the @code{master} branch of the
8568 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8571 For example, the following command builds the NumPy Python library against the
8572 latest commit of the master branch of Python itself:
8575 guix build python-numpy \
8576 --with-git-url=python=https://github.com/python/cpython
8579 This option can also be combined with @option{--with-branch} or
8580 @option{--with-commit} (see below).
8582 @cindex continuous integration
8583 Obviously, since it uses the latest commit of the given branch, the result of
8584 such a command varies over time. Nevertheless it is a convenient way to
8585 rebuild entire software stacks against the latest commit of one or more
8586 packages. This is particularly useful in the context of continuous
8589 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8590 consecutive accesses to the same repository. You may want to clean it up once
8591 in a while to save disk space.
8593 @item --with-branch=@var{package}=@var{branch}
8594 Build @var{package} from the latest commit of @var{branch}. If the
8595 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8596 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8597 repository URL is taken from that @code{source}. Otherwise you have to use
8598 @option{--with-git-url} to specify the URL of the Git repository.
8600 For instance, the following command builds @code{guile-sqlite3} from the
8601 latest commit of its @code{master} branch, and then builds @code{guix} (which
8602 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8603 specific @code{guile-sqlite3} build:
8606 guix build --with-branch=guile-sqlite3=master cuirass
8609 @item --with-commit=@var{package}=@var{commit}
8610 This is similar to @option{--with-branch}, except that it builds from
8611 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8612 Git commit SHA1 identifier or a tag.
8615 @node Additional Build Options
8616 @subsection Additional Build Options
8618 The command-line options presented below are specific to @command{guix
8625 Build quietly, without displaying the build log; this is equivalent to
8626 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8627 (or similar) and can always be retrieved using the @option{--log-file} option.
8629 @item --file=@var{file}
8630 @itemx -f @var{file}
8631 Build the package, derivation, or other file-like object that the code within
8632 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8634 As an example, @var{file} might contain a package definition like this
8635 (@pxref{Defining Packages}):
8638 @include package-hello.scm
8641 The @var{file} may also contain a JSON representation of one or more
8642 package definitions. Running @code{guix build -f} on @file{hello.json}
8643 with the following contents would result in building the packages
8644 @code{myhello} and @code{greeter}:
8647 @verbatiminclude package-hello.json
8650 @item --manifest=@var{manifest}
8651 @itemx -m @var{manifest}
8652 Build all packages listed in the given @var{manifest}
8653 (@pxref{profile-manifest, @option{--manifest}}).
8655 @item --expression=@var{expr}
8656 @itemx -e @var{expr}
8657 Build the package or derivation @var{expr} evaluates to.
8659 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8660 guile-1.8)}, which unambiguously designates this specific variant of
8661 version 1.8 of Guile.
8663 Alternatively, @var{expr} may be a G-expression, in which case it is used
8664 as a build program passed to @code{gexp->derivation}
8665 (@pxref{G-Expressions}).
8667 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8668 (@pxref{The Store Monad}). The procedure must return a derivation as a
8669 monadic value, which is then passed through @code{run-with-store}.
8673 Build the source derivations of the packages, rather than the packages
8676 For instance, @code{guix build -S gcc} returns something like
8677 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8680 The returned source tarball is the result of applying any patches and
8681 code snippets specified in the package @code{origin} (@pxref{Defining
8684 Note that @command{guix build -S} compiles the sources only of the
8685 specified packages. They do not include the sources of statically
8686 linked dependencies and by themselves are insufficient for reproducing
8690 Fetch and return the source of @var{package-or-derivation} and all their
8691 dependencies, recursively. This is a handy way to obtain a local copy
8692 of all the source code needed to build @var{packages}, allowing you to
8693 eventually build them even without network access. It is an extension
8694 of the @option{--source} option and can accept one of the following
8695 optional argument values:
8699 This value causes the @option{--sources} option to behave in the same way
8700 as the @option{--source} option.
8703 Build the source derivations of all packages, including any source that
8704 might be listed as @code{inputs}. This is the default value.
8707 $ guix build --sources tzdata
8708 The following derivations will be built:
8709 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8710 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8714 Build the source derivations of all packages, as well of all transitive
8715 inputs to the packages. This can be used e.g.@: to
8716 prefetch package source for later offline building.
8719 $ guix build --sources=transitive tzdata
8720 The following derivations will be built:
8721 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8722 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8723 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8724 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8725 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8726 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8732 @item --system=@var{system}
8733 @itemx -s @var{system}
8734 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8735 the system type of the build host. The @command{guix build} command allows
8736 you to repeat this option several times, in which case it builds for all the
8737 specified systems; other commands ignore extraneous @option{-s} options.
8740 The @option{--system} flag is for @emph{native} compilation and must not
8741 be confused with cross-compilation. See @option{--target} below for
8742 information on cross-compilation.
8745 An example use of this is on Linux-based systems, which can emulate
8746 different personalities. For instance, passing
8747 @option{--system=i686-linux} on an @code{x86_64-linux} system or
8748 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
8749 you to build packages in a complete 32-bit environment.
8752 Building for an @code{armhf-linux} system is unconditionally enabled on
8753 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8754 allow for this functionality, notably the ThunderX.
8757 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8758 is enabled (@pxref{Virtualization Services,
8759 @code{qemu-binfmt-service-type}}), you can build for any system for
8760 which a QEMU @code{binfmt_misc} handler is installed.
8762 Builds for a system other than that of the machine you are using can
8763 also be offloaded to a remote machine of the right architecture.
8764 @xref{Daemon Offload Setup}, for more information on offloading.
8766 @item --target=@var{triplet}
8767 @cindex cross-compilation
8768 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8769 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8770 configuration triplets,, autoconf, Autoconf}).
8772 @anchor{build-check}
8774 @cindex determinism, checking
8775 @cindex reproducibility, checking
8776 Rebuild @var{package-or-derivation}, which are already available in the
8777 store, and raise an error if the build results are not bit-for-bit
8780 This mechanism allows you to check whether previously installed
8781 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8782 of a package is deterministic. @xref{Invoking guix challenge}, for more
8783 background information and tools.
8785 When used in conjunction with @option{--keep-failed}, the differing
8786 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8787 This makes it easy to look for differences between the two results.
8790 @cindex repairing store items
8791 @cindex corruption, recovering from
8792 Attempt to repair the specified store items, if they are corrupt, by
8793 re-downloading or rebuilding them.
8795 This operation is not atomic and thus restricted to @code{root}.
8799 Return the derivation paths, not the output paths, of the given
8802 @item --root=@var{file}
8803 @itemx -r @var{file}
8804 @cindex GC roots, adding
8805 @cindex garbage collector roots, adding
8806 Make @var{file} a symlink to the result, and register it as a garbage
8809 Consequently, the results of this @command{guix build} invocation are
8810 protected from garbage collection until @var{file} is removed. When
8811 that option is omitted, build results are eligible for garbage
8812 collection as soon as the build completes. @xref{Invoking guix gc}, for
8816 @cindex build logs, access
8817 Return the build log file names or URLs for the given
8818 @var{package-or-derivation}, or raise an error if build logs are
8821 This works regardless of how packages or derivations are specified. For
8822 instance, the following invocations are equivalent:
8825 guix build --log-file `guix build -d guile`
8826 guix build --log-file `guix build guile`
8827 guix build --log-file guile
8828 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8831 If a log is unavailable locally, and unless @option{--no-substitutes} is
8832 passed, the command looks for a corresponding log on one of the
8833 substitute servers (as specified with @option{--substitute-urls}.)
8835 So for instance, imagine you want to see the build log of GDB on MIPS,
8836 but you are actually on an @code{x86_64} machine:
8839 $ guix build --log-file gdb -s mips64el-linux
8840 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8843 You can freely access a huge library of build logs!
8846 @node Debugging Build Failures
8847 @subsection Debugging Build Failures
8849 @cindex build failures, debugging
8850 When defining a new package (@pxref{Defining Packages}), you will
8851 probably find yourself spending some time debugging and tweaking the
8852 build until it succeeds. To do that, you need to operate the build
8853 commands yourself in an environment as close as possible to the one the
8856 To that end, the first thing to do is to use the @option{--keep-failed}
8857 or @option{-K} option of @command{guix build}, which will keep the
8858 failed build tree in @file{/tmp} or whatever directory you specified as
8859 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
8861 From there on, you can @command{cd} to the failed build tree and source
8862 the @file{environment-variables} file, which contains all the
8863 environment variable definitions that were in place when the build
8864 failed. So let's say you're debugging a build failure in package
8865 @code{foo}; a typical session would look like this:
8869 @dots{} @i{build fails}
8870 $ cd /tmp/guix-build-foo.drv-0
8871 $ source ./environment-variables
8875 Now, you can invoke commands as if you were the daemon (almost) and
8876 troubleshoot your build process.
8878 Sometimes it happens that, for example, a package's tests pass when you
8879 run them manually but they fail when the daemon runs them. This can
8880 happen because the daemon runs builds in containers where, unlike in our
8881 environment above, network access is missing, @file{/bin/sh} does not
8882 exist, etc. (@pxref{Build Environment Setup}).
8884 In such cases, you may need to run inspect the build process from within
8885 a container similar to the one the build daemon creates:
8890 $ cd /tmp/guix-build-foo.drv-0
8891 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8892 [env]# source ./environment-variables
8896 Here, @command{guix environment -C} creates a container and spawns a new
8897 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8898 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8899 the container, which you may find handy while debugging. The
8900 @option{--no-grafts} option makes sure we get the exact same
8901 environment, with ungrafted packages (@pxref{Security Updates}, for more
8904 To get closer to a container like that used by the build daemon, we can
8905 remove @file{/bin/sh}:
8911 (Don't worry, this is harmless: this is all happening in the throw-away
8912 container created by @command{guix environment}.)
8914 The @command{strace} command is probably not in the search path, but we
8918 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8921 In this way, not only you will have reproduced the environment variables
8922 the daemon uses, you will also be running the build process in a container
8923 similar to the one the daemon uses.
8926 @node Invoking guix edit
8927 @section Invoking @command{guix edit}
8929 @cindex @command{guix edit}
8930 @cindex package definition, editing
8931 So many packages, so many source files! The @command{guix edit} command
8932 facilitates the life of users and packagers by pointing their editor at
8933 the source file containing the definition of the specified packages.
8937 guix edit gcc@@4.9 vim
8941 launches the program specified in the @env{VISUAL} or in the
8942 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8945 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8946 have created your own packages on @env{GUIX_PACKAGE_PATH}
8947 (@pxref{Package Modules}), you will be able to edit the package
8948 recipes. In other cases, you will be able to examine the read-only recipes
8949 for packages currently in the store.
8951 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
8952 @option{--load-path=@var{directory}} (or in short @option{-L
8953 @var{directory}}) allows you to add @var{directory} to the front of the
8954 package module search path and so make your own packages visible.
8956 @node Invoking guix download
8957 @section Invoking @command{guix download}
8959 @cindex @command{guix download}
8960 @cindex downloading package sources
8961 When writing a package definition, developers typically need to download
8962 a source tarball, compute its SHA256 hash, and write that
8963 hash in the package definition (@pxref{Defining Packages}). The
8964 @command{guix download} tool helps with this task: it downloads a file
8965 from the given URI, adds it to the store, and prints both its file name
8966 in the store and its SHA256 hash.
8968 The fact that the downloaded file is added to the store saves bandwidth:
8969 when the developer eventually tries to build the newly defined package
8970 with @command{guix build}, the source tarball will not have to be
8971 downloaded again because it is already in the store. It is also a
8972 convenient way to temporarily stash files, which may be deleted
8973 eventually (@pxref{Invoking guix gc}).
8975 The @command{guix download} command supports the same URIs as used in
8976 package definitions. In particular, it supports @code{mirror://} URIs.
8977 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8978 Guile bindings for GnuTLS are available in the user's environment; when
8979 they are not available, an error is raised. @xref{Guile Preparations,
8980 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8981 GnuTLS-Guile}, for more information.
8983 @command{guix download} verifies HTTPS server certificates by loading
8984 the certificates of X.509 authorities from the directory pointed to by
8985 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
8986 Certificates}), unless @option{--no-check-certificate} is used.
8988 The following options are available:
8991 @item --format=@var{fmt}
8993 Write the hash in the format specified by @var{fmt}. For more
8994 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8996 @item --no-check-certificate
8997 Do not validate the X.509 certificates of HTTPS servers.
8999 When using this option, you have @emph{absolutely no guarantee} that you
9000 are communicating with the authentic server responsible for the given
9001 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9003 @item --output=@var{file}
9004 @itemx -o @var{file}
9005 Save the downloaded file to @var{file} instead of adding it to the
9009 @node Invoking guix hash
9010 @section Invoking @command{guix hash}
9012 @cindex @command{guix hash}
9013 The @command{guix hash} command computes the SHA256 hash of a file.
9014 It is primarily a convenience tool for anyone contributing to the
9015 distribution: it computes the cryptographic hash of a file, which can be
9016 used in the definition of a package (@pxref{Defining Packages}).
9018 The general syntax is:
9021 guix hash @var{option} @var{file}
9024 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9025 hash of data read from standard input. @command{guix hash} has the
9030 @item --format=@var{fmt}
9032 Write the hash in the format specified by @var{fmt}.
9034 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
9035 (@code{hex} and @code{hexadecimal} can be used as well).
9037 If the @option{--format} option is not specified, @command{guix hash}
9038 will output the hash in @code{nix-base32}. This representation is used
9039 in the definitions of packages.
9043 Compute the hash on @var{file} recursively.
9045 In this case, the hash is computed on an archive containing @var{file},
9046 including its children if it is a directory. Some of the metadata of
9047 @var{file} is part of the archive; for instance, when @var{file} is a
9048 regular file, the hash is different depending on whether @var{file} is
9049 executable or not. Metadata such as time stamps has no impact on the
9050 hash (@pxref{Invoking guix archive}).
9051 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9056 When combined with @option{--recursive}, exclude version control system
9057 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
9060 As an example, here is how you would compute the hash of a Git checkout,
9061 which is useful when using the @code{git-fetch} method (@pxref{origin
9065 $ git clone http://example.org/foo.git
9071 @node Invoking guix import
9072 @section Invoking @command{guix import}
9074 @cindex importing packages
9075 @cindex package import
9076 @cindex package conversion
9077 @cindex Invoking @command{guix import}
9078 The @command{guix import} command is useful for people who would like to
9079 add a package to the distribution with as little work as
9080 possible---a legitimate demand. The command knows of a few
9081 repositories from which it can ``import'' package metadata. The result
9082 is a package definition, or a template thereof, in the format we know
9083 (@pxref{Defining Packages}).
9085 The general syntax is:
9088 guix import @var{importer} @var{options}@dots{}
9091 @var{importer} specifies the source from which to import package
9092 metadata, and @var{options} specifies a package identifier and other
9093 options specific to @var{importer}.
9095 Some of the importers rely on the ability to run the @command{gpgv} command.
9096 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9099 Currently, the available ``importers'' are:
9103 Import metadata for the given GNU package. This provides a template
9104 for the latest version of that GNU package, including the hash of its
9105 source tarball, and its canonical synopsis and description.
9107 Additional information such as the package dependencies and its
9108 license needs to be figured out manually.
9110 For example, the following command returns a package definition for
9114 guix import gnu hello
9117 Specific command-line options are:
9120 @item --key-download=@var{policy}
9121 As for @command{guix refresh}, specify the policy to handle missing
9122 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9123 refresh, @option{--key-download}}.
9128 Import metadata from the @uref{https://pypi.python.org/, Python Package
9129 Index}. Information is taken from the JSON-formatted description
9130 available at @code{pypi.python.org} and usually includes all the relevant
9131 information, including package dependencies. For maximum efficiency, it
9132 is recommended to install the @command{unzip} utility, so that the
9133 importer can unzip Python wheels and gather data from them.
9135 The command below imports metadata for the @code{itsdangerous} Python
9139 guix import pypi itsdangerous
9145 Traverse the dependency graph of the given upstream package recursively
9146 and generate package expressions for all those packages that are not yet
9152 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9153 is taken from the JSON-formatted description available at
9154 @code{rubygems.org} and includes most relevant information, including
9155 runtime dependencies. There are some caveats, however. The metadata
9156 doesn't distinguish between synopses and descriptions, so the same string
9157 is used for both fields. Additionally, the details of non-Ruby
9158 dependencies required to build native extensions is unavailable and left
9159 as an exercise to the packager.
9161 The command below imports metadata for the @code{rails} Ruby package:
9164 guix import gem rails
9170 Traverse the dependency graph of the given upstream package recursively
9171 and generate package expressions for all those packages that are not yet
9177 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9178 Information is taken from the JSON-formatted metadata provided through
9179 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9180 relevant information, such as module dependencies. License information
9181 should be checked closely. If Perl is available in the store, then the
9182 @code{corelist} utility will be used to filter core modules out of the
9183 list of dependencies.
9185 The command command below imports metadata for the Acme::Boolean Perl
9189 guix import cpan Acme::Boolean
9194 @cindex Bioconductor
9195 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9196 central repository for the @uref{https://r-project.org, GNU@tie{}R
9197 statistical and graphical environment}.
9199 Information is extracted from the @file{DESCRIPTION} file of the package.
9201 The command command below imports metadata for the Cairo R package:
9204 guix import cran Cairo
9207 When @option{--recursive} is added, the importer will traverse the
9208 dependency graph of the given upstream package recursively and generate
9209 package expressions for all those packages that are not yet in Guix.
9211 When @option{--archive=bioconductor} is added, metadata is imported from
9212 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9213 packages for for the analysis and comprehension of high-throughput
9214 genomic data in bioinformatics.
9216 Information is extracted from the @file{DESCRIPTION} file contained in the
9219 The command below imports metadata for the GenomicRanges R package:
9222 guix import cran --archive=bioconductor GenomicRanges
9225 Finally, you can also import R packages that have not yet been published on
9226 CRAN or Bioconductor as long as they are in a git repository. Use
9227 @option{--archive=git} followed by the URL of the git repository:
9230 guix import cran --archive=git https://github.com/immunogenomics/harmony
9236 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9237 comprehensive TeX archive network for TeX packages that are part of the
9238 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9240 Information about the package is obtained through the XML API provided
9241 by CTAN, while the source code is downloaded from the SVN repository of
9242 the Tex Live project. This is done because the CTAN does not keep
9245 The command command below imports metadata for the @code{fontspec}
9249 guix import texlive fontspec
9252 When @option{--archive=@var{directory}} is added, the source code is
9253 downloaded not from the @file{latex} sub-directory of the
9254 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9255 the specified sibling @var{directory} under the same root.
9257 The command below imports metadata for the @code{ifxetex} package from
9258 CTAN while fetching the sources from the directory
9259 @file{texmf/source/generic}:
9262 guix import texlive --archive=generic ifxetex
9266 @cindex JSON, import
9267 Import package metadata from a local JSON file. Consider the following
9268 example package definition in JSON format:
9274 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9275 "build-system": "gnu",
9276 "home-page": "https://www.gnu.org/software/hello/",
9277 "synopsis": "Hello, GNU world: An example GNU package",
9278 "description": "GNU Hello prints a greeting.",
9279 "license": "GPL-3.0+",
9280 "native-inputs": ["gettext"]
9284 The field names are the same as for the @code{<package>} record
9285 (@xref{Defining Packages}). References to other packages are provided
9286 as JSON lists of quoted package specification strings such as
9287 @code{guile} or @code{guile@@2.0}.
9289 The importer also supports a more explicit source definition using the
9290 common fields for @code{<origin>} records:
9296 "method": "url-fetch",
9297 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9299 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9306 The command below reads metadata from the JSON file @code{hello.json}
9307 and outputs a package expression:
9310 guix import json hello.json
9314 Import metadata from a local copy of the source of the
9315 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9316 relies on the @command{nix-instantiate} command of
9317 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9318 typically written in a mixture of Nix-language and Bash code. This
9319 command only imports the high-level package structure that is written in
9320 the Nix language. It normally includes all the basic fields of a
9323 When importing a GNU package, the synopsis and descriptions are replaced
9324 by their canonical upstream variant.
9326 Usually, you will first need to do:
9329 export NIX_REMOTE=daemon
9333 so that @command{nix-instantiate} does not try to open the Nix database.
9335 As an example, the command below imports the package definition of
9336 LibreOffice (more precisely, it imports the definition of the package
9337 bound to the @code{libreoffice} top-level attribute):
9340 guix import nix ~/path/to/nixpkgs libreoffice
9345 Import metadata from the Haskell community's central package archive
9346 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9347 Cabal files and includes all the relevant information, including package
9350 Specific command-line options are:
9355 Read a Cabal file from standard input.
9356 @item --no-test-dependencies
9358 Do not include dependencies required only by the test suites.
9359 @item --cabal-environment=@var{alist}
9360 @itemx -e @var{alist}
9361 @var{alist} is a Scheme alist defining the environment in which the
9362 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9363 @code{arch}, @code{impl} and a string representing the name of a flag.
9364 The value associated with a flag has to be either the symbol
9365 @code{true} or @code{false}. The value associated with other keys
9366 has to conform to the Cabal file format definition. The default value
9367 associated with the keys @code{os}, @code{arch} and @code{impl} is
9368 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9371 Traverse the dependency graph of the given upstream package recursively
9372 and generate package expressions for all those packages that are not yet
9376 The command below imports metadata for the latest version of the
9377 HTTP Haskell package without including test dependencies and
9378 specifying the value of the flag @samp{network-uri} as @code{false}:
9381 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9384 A specific package version may optionally be specified by following the
9385 package name by an at-sign and a version number as in the following example:
9388 guix import hackage mtl@@2.1.3.1
9393 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9394 It takes a package name, looks up the package version included in a
9395 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9396 release and uses the @code{hackage} importer to retrieve its metadata.
9397 Note that it is up to you to select an LTS release compatible with the
9398 GHC compiler used by Guix.
9400 Specific command-line options are:
9403 @item --no-test-dependencies
9405 Do not include dependencies required only by the test suites.
9406 @item --lts-version=@var{version}
9407 @itemx -l @var{version}
9408 @var{version} is the desired LTS release version. If omitted the latest
9412 Traverse the dependency graph of the given upstream package recursively
9413 and generate package expressions for all those packages that are not yet
9417 The command below imports metadata for the HTTP Haskell package
9418 included in the LTS Stackage release version 7.18:
9421 guix import stackage --lts-version=7.18 HTTP
9426 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9427 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9429 Specific command-line options are:
9432 @item --archive=@var{repo}
9433 @itemx -a @var{repo}
9434 @var{repo} identifies the archive repository from which to retrieve the
9435 information. Currently the supported repositories and their identifiers
9439 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9440 identifier. This is the default.
9442 Packages from @code{elpa.gnu.org} are signed with one of the keys
9443 contained in the GnuPG keyring at
9444 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9445 @code{emacs} package (@pxref{Package Installation, ELPA package
9446 signatures,, emacs, The GNU Emacs Manual}).
9449 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9450 @code{melpa-stable} identifier.
9453 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9459 Traverse the dependency graph of the given upstream package recursively
9460 and generate package expressions for all those packages that are not yet
9466 Import metadata from the crates.io Rust package repository
9467 @uref{https://crates.io, crates.io}, as in this example:
9470 guix import crate blake2-rfc
9473 The crate importer also allows you to specify a version string:
9476 guix import crate constant-time-eq@@0.1.0
9479 Additional options include:
9484 Traverse the dependency graph of the given upstream package recursively
9485 and generate package expressions for all those packages that are not yet
9492 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9493 repository used by the OCaml community.
9496 The structure of the @command{guix import} code is modular. It would be
9497 useful to have more importers for other package formats, and your help
9498 is welcome here (@pxref{Contributing}).
9500 @node Invoking guix refresh
9501 @section Invoking @command{guix refresh}
9503 @cindex @command {guix refresh}
9504 The primary audience of the @command{guix refresh} command is developers
9505 of the GNU software distribution. By default, it reports any packages
9506 provided by the distribution that are outdated compared to the latest
9507 upstream version, like this:
9511 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9512 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9515 Alternately, one can specify packages to consider, in which case a
9516 warning is emitted for packages that lack an updater:
9519 $ guix refresh coreutils guile guile-ssh
9520 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9521 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9524 @command{guix refresh} browses the upstream repository of each package and determines
9525 the highest version number of the releases therein. The command
9526 knows how to update specific types of packages: GNU packages, ELPA
9527 packages, etc.---see the documentation for @option{--type} below. There
9528 are many packages, though, for which it lacks a method to determine
9529 whether a new upstream release is available. However, the mechanism is
9530 extensible, so feel free to get in touch with us to add a new method!
9535 Consider the packages specified, and all the packages upon which they depend.
9538 $ guix refresh --recursive coreutils
9539 gnu/packages/acl.scm:35:2: warning: no updater for acl
9540 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9541 gnu/packages/xml.scm:68:2: warning: no updater for expat
9542 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9548 Sometimes the upstream name differs from the package name used in Guix,
9549 and @command{guix refresh} needs a little help. Most updaters honor the
9550 @code{upstream-name} property in package definitions, which can be used
9554 (define-public network-manager
9556 (name "network-manager")
9558 (properties '((upstream-name . "NetworkManager")))))
9561 When passed @option{--update}, it modifies distribution source files to
9562 update the version numbers and source tarball hashes of those package
9563 recipes (@pxref{Defining Packages}). This is achieved by downloading
9564 each package's latest source tarball and its associated OpenPGP
9565 signature, authenticating the downloaded tarball against its signature
9566 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9567 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9570 key used to sign the tarball is missing from the user's keyring, an
9571 attempt is made to automatically retrieve it from a public key server;
9572 when this is successful, the key is added to the user's keyring; otherwise,
9573 @command{guix refresh} reports an error.
9575 The following options are supported:
9579 @item --expression=@var{expr}
9580 @itemx -e @var{expr}
9581 Consider the package @var{expr} evaluates to.
9583 This is useful to precisely refer to a package, as in this example:
9586 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9589 This command lists the dependents of the ``final'' libc (essentially all
9594 Update distribution source files (package recipes) in place. This is
9595 usually run from a checkout of the Guix source tree (@pxref{Running
9596 Guix Before It Is Installed}):
9599 $ ./pre-inst-env guix refresh -s non-core -u
9602 @xref{Defining Packages}, for more information on package definitions.
9604 @item --select=[@var{subset}]
9605 @itemx -s @var{subset}
9606 Select all the packages in @var{subset}, one of @code{core} or
9609 The @code{core} subset refers to all the packages at the core of the
9610 distribution---i.e., packages that are used to build ``everything
9611 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9612 changing one of these packages in the distribution entails a rebuild of
9613 all the others. Thus, such updates are an inconvenience to users in
9614 terms of build time or bandwidth used to achieve the upgrade.
9616 The @code{non-core} subset refers to the remaining packages. It is
9617 typically useful in cases where an update of the core packages would be
9620 @item --manifest=@var{file}
9621 @itemx -m @var{file}
9622 Select all the packages from the manifest in @var{file}. This is useful to
9623 check if any packages of the user manifest can be updated.
9625 @item --type=@var{updater}
9626 @itemx -t @var{updater}
9627 Select only packages handled by @var{updater} (may be a comma-separated
9628 list of updaters). Currently, @var{updater} may be one of:
9632 the updater for GNU packages;
9634 the updater for GNOME packages;
9636 the updater for KDE packages;
9638 the updater for X.org packages;
9640 the updater for packages hosted on kernel.org;
9642 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9644 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9646 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9648 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9650 the updater for @uref{https://pypi.python.org, PyPI} packages.
9652 the updater for @uref{https://rubygems.org, RubyGems} packages.
9654 the updater for @uref{https://github.com, GitHub} packages.
9656 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9658 the updater for @uref{https://www.stackage.org, Stackage} packages.
9660 the updater for @uref{https://crates.io, Crates} packages.
9662 the updater for @uref{https://launchpad.net, Launchpad} packages.
9665 For instance, the following command only checks for updates of Emacs
9666 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9669 $ guix refresh --type=elpa,cran
9670 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9671 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9676 In addition, @command{guix refresh} can be passed one or more package
9677 names, as in this example:
9680 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9684 The command above specifically updates the @code{emacs} and
9685 @code{idutils} packages. The @option{--select} option would have no
9686 effect in this case.
9688 When considering whether to upgrade a package, it is sometimes
9689 convenient to know which packages would be affected by the upgrade and
9690 should be checked for compatibility. For this the following option may
9691 be used when passing @command{guix refresh} one or more package names:
9695 @item --list-updaters
9697 List available updaters and exit (see @option{--type} above.)
9699 For each updater, display the fraction of packages it covers; at the
9700 end, display the fraction of packages covered by all these updaters.
9702 @item --list-dependent
9704 List top-level dependent packages that would need to be rebuilt as a
9705 result of upgrading one or more packages.
9707 @xref{Invoking guix graph, the @code{reverse-package} type of
9708 @command{guix graph}}, for information on how to visualize the list of
9709 dependents of a package.
9713 Be aware that the @option{--list-dependent} option only
9714 @emph{approximates} the rebuilds that would be required as a result of
9715 an upgrade. More rebuilds might be required under some circumstances.
9718 $ guix refresh --list-dependent flex
9719 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9720 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9723 The command above lists a set of packages that could be built to check
9724 for compatibility with an upgraded @code{flex} package.
9728 @item --list-transitive
9729 List all the packages which one or more packages depend upon.
9732 $ guix refresh --list-transitive flex
9733 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9734 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{}
9739 The command above lists a set of packages which, when changed, would cause
9740 @code{flex} to be rebuilt.
9742 The following options can be used to customize GnuPG operation:
9746 @item --gpg=@var{command}
9747 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9748 for in @code{$PATH}.
9750 @item --keyring=@var{file}
9751 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9752 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9753 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9754 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9755 information on a tool to manipulate keybox files).
9757 When this option is omitted, @command{guix refresh} uses
9758 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9759 signing keys. OpenPGP signatures are checked against keys from this keyring;
9760 missing keys are downloaded to this keyring as well (see
9761 @option{--key-download} below.)
9763 You can export keys from your default GPG keyring into a keybox file using
9764 commands like this one:
9767 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9770 Likewise, you can fetch keys to a specific keybox file like this:
9773 gpg --no-default-keyring --keyring mykeyring.kbx \
9774 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9777 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9778 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9780 @item --key-download=@var{policy}
9781 Handle missing OpenPGP keys according to @var{policy}, which may be one
9786 Always download missing OpenPGP keys from the key server, and add them
9787 to the user's GnuPG keyring.
9790 Never try to download missing OpenPGP keys. Instead just bail out.
9793 When a package signed with an unknown OpenPGP key is encountered, ask
9794 the user whether to download it or not. This is the default behavior.
9797 @item --key-server=@var{host}
9798 Use @var{host} as the OpenPGP key server when importing a public key.
9800 @item --load-path=@var{directory}
9801 Add @var{directory} to the front of the package module search path
9802 (@pxref{Package Modules}).
9804 This allows users to define their own packages and make them visible to
9805 the command-line tools.
9809 The @code{github} updater uses the
9810 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9811 releases. When used repeatedly e.g.@: when refreshing all packages,
9812 GitHub will eventually refuse to answer any further API requests. By
9813 default 60 API requests per hour are allowed, and a full refresh on all
9814 GitHub packages in Guix requires more than this. Authentication with
9815 GitHub through the use of an API token alleviates these limits. To use
9816 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
9817 token procured from @uref{https://github.com/settings/tokens} or
9821 @node Invoking guix lint
9822 @section Invoking @command{guix lint}
9824 @cindex @command{guix lint}
9825 @cindex package, checking for errors
9826 The @command{guix lint} command is meant to help package developers avoid
9827 common errors and use a consistent style. It runs a number of checks on
9828 a given set of packages in order to find common mistakes in their
9829 definitions. Available @dfn{checkers} include (see
9830 @option{--list-checkers} for a complete list):
9835 Validate certain typographical and stylistic rules about package
9836 descriptions and synopses.
9838 @item inputs-should-be-native
9839 Identify inputs that should most likely be native inputs.
9845 @itemx source-file-name
9846 Probe @code{home-page} and @code{source} URLs and report those that are
9847 invalid. Suggest a @code{mirror://} URL when applicable. If the
9848 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9849 URL. Check that the source file name is meaningful, e.g.@: is not just a
9850 version number or ``git-checkout'', without a declared @code{file-name}
9851 (@pxref{origin Reference}).
9853 @item source-unstable-tarball
9854 Parse the @code{source} URL to determine if a tarball from GitHub is
9855 autogenerated or if it is a release tarball. Unfortunately GitHub's
9856 autogenerated tarballs are sometimes regenerated.
9859 @cindex Software Heritage, source code archive
9860 @cindex archival of source code, Software Heritage
9861 Checks whether the package's source code is archived at
9862 @uref{https://www.softwareheritage.org, Software Heritage}.
9864 When the source code that is not archived comes from a version-control system
9865 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9866 ``save'' request so that it eventually archives it. This ensures that the
9867 source will remain available in the long term, and that Guix can fall back to
9868 Software Heritage should the source code disappear from its original host.
9869 The status of recent ``save'' requests can be
9870 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9872 When source code is a tarball obtained with @code{url-fetch}, simply print a
9873 message when it is not archived. As of this writing, Software Heritage does
9874 not allow requests to save arbitrary tarballs; we are working on ways to
9875 ensure that non-VCS source code is also archived.
9878 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9879 request rate per IP address}. When the limit is reached, @command{guix lint}
9880 prints a message and the @code{archival} checker stops doing anything until
9881 that limit has been reset.
9884 @cindex security vulnerabilities
9885 @cindex CVE, Common Vulnerabilities and Exposures
9886 Report known vulnerabilities found in the Common Vulnerabilities and
9887 Exposures (CVE) databases of the current and past year
9888 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9891 To view information about a particular vulnerability, visit pages such as:
9895 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9897 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9901 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9902 @code{CVE-2015-7554}.
9904 Package developers can specify in package recipes the
9905 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9906 name and version of the package when they differ from the name or version
9907 that Guix uses, as in this example:
9913 ;; CPE calls this package "grub2".
9914 (properties '((cpe-name . "grub2")
9915 (cpe-version . "2.3"))))
9918 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9919 Some entries in the CVE database do not specify which version of a
9920 package they apply to, and would thus ``stick around'' forever. Package
9921 developers who found CVE alerts and verified they can be ignored can
9922 declare them as in this example:
9928 ;; These CVEs no longer apply and can be safely ignored.
9929 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9932 "CVE-2011-5244")))))
9936 Warn about obvious source code formatting issues: trailing white space,
9937 use of tabulations, etc.
9940 The general syntax is:
9943 guix lint @var{options} @var{package}@dots{}
9946 If no package is given on the command line, then all packages are checked.
9947 The @var{options} may be zero or more of the following:
9950 @item --list-checkers
9952 List and describe all the available checkers that will be run on packages
9957 Only enable the checkers specified in a comma-separated list using the
9958 names returned by @option{--list-checkers}.
9960 @item --load-path=@var{directory}
9961 @itemx -L @var{directory}
9962 Add @var{directory} to the front of the package module search path
9963 (@pxref{Package Modules}).
9965 This allows users to define their own packages and make them visible to
9966 the command-line tools.
9970 @node Invoking guix size
9971 @section Invoking @command{guix size}
9974 @cindex package size
9976 @cindex @command{guix size}
9977 The @command{guix size} command helps package developers profile the
9978 disk usage of packages. It is easy to overlook the impact of an
9979 additional dependency added to a package, or the impact of using a
9980 single output for a package that could easily be split (@pxref{Packages
9981 with Multiple Outputs}). Such are the typical issues that
9982 @command{guix size} can highlight.
9984 The command can be passed one or more package specifications
9985 such as @code{gcc@@4.8}
9986 or @code{guile:debug}, or a file name in the store. Consider this
9990 $ guix size coreutils
9991 store item total self
9992 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9993 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9994 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9995 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9996 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9997 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9998 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9999 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10004 The store items listed here constitute the @dfn{transitive closure} of
10005 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10006 would be returned by:
10009 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10012 Here the output shows three columns next to store items. The first column,
10013 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10014 the store item---that is, its own size plus the size of all its
10015 dependencies. The next column, labeled ``self'', shows the size of the
10016 item itself. The last column shows the ratio of the size of the item
10017 itself to the space occupied by all the items listed here.
10019 In this example, we see that the closure of Coreutils weighs in at
10020 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10021 libraries. (That libc and GCC's libraries represent a large fraction of
10022 the closure is not a problem @i{per se} because they are always available
10023 on the system anyway.)
10025 When the package(s) passed to @command{guix size} are available in the
10026 store@footnote{More precisely, @command{guix size} looks for the
10027 @emph{ungrafted} variant of the given package(s), as returned by
10028 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10029 for information on grafts.}, @command{guix size} queries the daemon to determine its
10030 dependencies, and measures its size in the store, similar to @command{du
10031 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10034 When the given packages are @emph{not} in the store, @command{guix size}
10035 reports information based on the available substitutes
10036 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10037 store items that are not even on disk, only available remotely.
10039 You can also specify several package names:
10042 $ guix size coreutils grep sed bash
10043 store item total self
10044 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10045 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10046 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10047 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10053 In this example we see that the combination of the four packages takes
10054 102.3@tie{}MiB in total, which is much less than the sum of each closure
10055 since they have a lot of dependencies in common.
10057 When looking at the profile returned by @command{guix size}, you may
10058 find yourself wondering why a given package shows up in the profile at
10059 all. To understand it, you can use @command{guix graph --path -t
10060 references} to display the shortest path between the two packages
10061 (@pxref{Invoking guix graph}).
10063 The available options are:
10067 @item --substitute-urls=@var{urls}
10068 Use substitute information from @var{urls}.
10069 @xref{client-substitute-urls, the same option for @code{guix build}}.
10071 @item --sort=@var{key}
10072 Sort lines according to @var{key}, one of the following options:
10076 the size of each item (the default);
10078 the total size of the item's closure.
10081 @item --map-file=@var{file}
10082 Write a graphical map of disk usage in PNG format to @var{file}.
10084 For the example above, the map looks like this:
10086 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10087 produced by @command{guix size}}
10089 This option requires that
10090 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10091 installed and visible in Guile's module search path. When that is not
10092 the case, @command{guix size} fails as it tries to load it.
10094 @item --system=@var{system}
10095 @itemx -s @var{system}
10096 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10098 @item --load-path=@var{directory}
10099 @itemx -L @var{directory}
10100 Add @var{directory} to the front of the package module search path
10101 (@pxref{Package Modules}).
10103 This allows users to define their own packages and make them visible to
10104 the command-line tools.
10107 @node Invoking guix graph
10108 @section Invoking @command{guix graph}
10111 @cindex @command{guix graph}
10112 @cindex package dependencies
10113 Packages and their dependencies form a @dfn{graph}, specifically a
10114 directed acyclic graph (DAG). It can quickly become difficult to have a
10115 mental model of the package DAG, so the @command{guix graph} command
10116 provides a visual representation of the DAG. By default,
10117 @command{guix graph} emits a DAG representation in the input format of
10118 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10119 directly to the @command{dot} command of Graphviz. It can also emit an
10120 HTML page with embedded JavaScript code to display a ``chord diagram''
10121 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10122 emit Cypher queries to construct a graph in a graph database supporting
10123 the @uref{https://www.opencypher.org/, openCypher} query language. With
10124 @option{--path}, it simply displays the shortest path between two
10125 packages. The general syntax is:
10128 guix graph @var{options} @var{package}@dots{}
10131 For example, the following command generates a PDF file representing the
10132 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10136 guix graph coreutils | dot -Tpdf > dag.pdf
10139 The output looks like this:
10141 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10143 Nice little graph, no?
10145 You may find it more pleasant to navigate the graph interactively with
10146 @command{xdot} (from the @code{xdot} package):
10149 guix graph coreutils | xdot -
10152 But there is more than one graph! The one above is concise: it is the
10153 graph of package objects, omitting implicit inputs such as GCC, libc,
10154 grep, etc. It is often useful to have such a concise graph, but
10155 sometimes one may want to see more details. @command{guix graph} supports
10156 several types of graphs, allowing you to choose the level of detail:
10160 This is the default type used in the example above. It shows the DAG of
10161 package objects, excluding implicit dependencies. It is concise, but
10162 filters out many details.
10164 @item reverse-package
10165 This shows the @emph{reverse} DAG of packages. For example:
10168 guix graph --type=reverse-package ocaml
10171 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10172 you are also interested in cases where OCaml is an implicit dependency, see
10173 @code{reverse-bag} below.)
10175 Note that for core packages this can yield huge graphs. If all you want
10176 is to know the number of packages that depend on a given package, use
10177 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10178 @option{--list-dependent}}).
10181 This is the package DAG, @emph{including} implicit inputs.
10183 For instance, the following command:
10186 guix graph --type=bag-emerged coreutils
10189 ...@: yields this bigger graph:
10191 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10193 At the bottom of the graph, we see all the implicit inputs of
10194 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10196 Now, note that the dependencies of these implicit inputs---that is, the
10197 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10198 here, for conciseness.
10201 Similar to @code{bag-emerged}, but this time including all the bootstrap
10204 @item bag-with-origins
10205 Similar to @code{bag}, but also showing origins and their dependencies.
10208 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10209 it also takes implicit dependencies into account. For example:
10212 guix graph -t reverse-bag dune
10216 ...@: yields the graph of all packages that depend on Dune, directly or
10217 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10218 @i{via} @code{dune-build-system}, this shows a large number of packages,
10219 whereas @code{reverse-package} would show very few if any.
10222 This is the most detailed representation: It shows the DAG of
10223 derivations (@pxref{Derivations}) and plain store items. Compared to
10224 the above representation, many additional nodes are visible, including
10225 build scripts, patches, Guile modules, etc.
10227 For this type of graph, it is also possible to pass a @file{.drv} file
10228 name instead of a package name, as in:
10231 guix graph -t derivation `guix system build -d my-config.scm`
10235 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10236 For example, the following command shows the graph for the package
10237 module that defines the @code{guile} package:
10240 guix graph -t module guile | xdot -
10244 All the types above correspond to @emph{build-time dependencies}. The
10245 following graph type represents the @emph{run-time dependencies}:
10249 This is the graph of @dfn{references} of a package output, as returned
10250 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10252 If the given package output is not available in the store, @command{guix
10253 graph} attempts to obtain dependency information from substitutes.
10255 Here you can also pass a store file name instead of a package name. For
10256 example, the command below produces the reference graph of your profile
10257 (which can be big!):
10260 guix graph -t references `readlink -f ~/.guix-profile`
10264 This is the graph of the @dfn{referrers} of a store item, as returned by
10265 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10267 This relies exclusively on local information from your store. For
10268 instance, let us suppose that the current Inkscape is available in 10
10269 profiles on your machine; @command{guix graph -t referrers inkscape}
10270 will show a graph rooted at Inkscape and with those 10 profiles linked
10273 It can help determine what is preventing a store item from being garbage
10278 @cindex shortest path, between packages
10279 Often, the graph of the package you are interested in does not fit on
10280 your screen, and anyway all you want to know is @emph{why} that package
10281 actually depends on some seemingly unrelated package. The
10282 @option{--path} option instructs @command{guix graph} to display the
10283 shortest path between two packages (or derivations, or store items,
10287 $ guix graph --path emacs libunistring
10290 libunistring@@0.9.10
10291 $ guix graph --path -t derivation emacs libunistring
10292 /gnu/store/@dots{}-emacs-26.3.drv
10293 /gnu/store/@dots{}-mailutils-3.9.drv
10294 /gnu/store/@dots{}-libunistring-0.9.10.drv
10295 $ guix graph --path -t references emacs libunistring
10296 /gnu/store/@dots{}-emacs-26.3
10297 /gnu/store/@dots{}-libidn2-2.2.0
10298 /gnu/store/@dots{}-libunistring-0.9.10
10301 The available options are the following:
10304 @item --type=@var{type}
10305 @itemx -t @var{type}
10306 Produce a graph output of @var{type}, where @var{type} must be one of
10307 the values listed above.
10310 List the supported graph types.
10312 @item --backend=@var{backend}
10313 @itemx -b @var{backend}
10314 Produce a graph using the selected @var{backend}.
10316 @item --list-backends
10317 List the supported graph backends.
10319 Currently, the available backends are Graphviz and d3.js.
10322 Display the shortest path between two nodes of the type specified by
10323 @option{--type}. The example below shows the shortest path between
10324 @code{libreoffice} and @code{llvm} according to the references of
10325 @code{libreoffice}:
10328 $ guix graph --path -t references libreoffice llvm
10329 /gnu/store/@dots{}-libreoffice-6.4.2.2
10330 /gnu/store/@dots{}-libepoxy-1.5.4
10331 /gnu/store/@dots{}-mesa-19.3.4
10332 /gnu/store/@dots{}-llvm-9.0.1
10335 @item --expression=@var{expr}
10336 @itemx -e @var{expr}
10337 Consider the package @var{expr} evaluates to.
10339 This is useful to precisely refer to a package, as in this example:
10342 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10345 @item --system=@var{system}
10346 @itemx -s @var{system}
10347 Display the graph for @var{system}---e.g., @code{i686-linux}.
10349 The package dependency graph is largely architecture-independent, but there
10350 are some architecture-dependent bits that this option allows you to visualize.
10352 @item --load-path=@var{directory}
10353 @itemx -L @var{directory}
10354 Add @var{directory} to the front of the package module search path
10355 (@pxref{Package Modules}).
10357 This allows users to define their own packages and make them visible to
10358 the command-line tools.
10361 On top of that, @command{guix graph} supports all the usual package
10362 transformation options (@pxref{Package Transformation Options}). This
10363 makes it easy to view the effect of a graph-rewriting transformation
10364 such as @option{--with-input}. For example, the command below outputs
10365 the graph of @code{git} once @code{openssl} has been replaced by
10366 @code{libressl} everywhere in the graph:
10369 guix graph git --with-input=openssl=libressl
10372 So many possibilities, so much fun!
10374 @node Invoking guix publish
10375 @section Invoking @command{guix publish}
10377 @cindex @command{guix publish}
10378 The purpose of @command{guix publish} is to enable users to easily share
10379 their store with others, who can then use it as a substitute server
10380 (@pxref{Substitutes}).
10382 When @command{guix publish} runs, it spawns an HTTP server which allows
10383 anyone with network access to obtain substitutes from it. This means
10384 that any machine running Guix can also act as if it were a build farm,
10385 since the HTTP interface is compatible with Cuirass, the software behind
10386 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10388 For security, each substitute is signed, allowing recipients to check
10389 their authenticity and integrity (@pxref{Substitutes}). Because
10390 @command{guix publish} uses the signing key of the system, which is only
10391 readable by the system administrator, it must be started as root; the
10392 @option{--user} option makes it drop root privileges early on.
10394 The signing key pair must be generated before @command{guix publish} is
10395 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10398 The general syntax is:
10401 guix publish @var{options}@dots{}
10404 Running @command{guix publish} without any additional arguments will
10405 spawn an HTTP server on port 8080:
10411 Once a publishing server has been authorized (@pxref{Invoking guix
10412 archive}), the daemon may download substitutes from it:
10415 guix-daemon --substitute-urls=http://example.org:8080
10418 By default, @command{guix publish} compresses archives on the fly as it
10419 serves them. This ``on-the-fly'' mode is convenient in that it requires
10420 no setup and is immediately available. However, when serving lots of
10421 clients, we recommend using the @option{--cache} option, which enables
10422 caching of the archives before they are sent to clients---see below for
10423 details. The @command{guix weather} command provides a handy way to
10424 check what a server provides (@pxref{Invoking guix weather}).
10426 As a bonus, @command{guix publish} also serves as a content-addressed
10427 mirror for source files referenced in @code{origin} records
10428 (@pxref{origin Reference}). For instance, assuming @command{guix
10429 publish} is running on @code{example.org}, the following URL returns the
10430 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10431 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10434 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10437 Obviously, these URLs only work for files that are in the store; in
10438 other cases, they return 404 (``Not Found'').
10440 @cindex build logs, publication
10441 Build logs are available from @code{/log} URLs like:
10444 http://example.org/log/gwspk@dots{}-guile-2.2.3
10448 When @command{guix-daemon} is configured to save compressed build logs,
10449 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10450 URLs return the compressed log as-is, with an appropriate
10451 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10452 running @command{guix-daemon} with @option{--log-compression=gzip} since
10453 Web browsers can automatically decompress it, which is not the case with
10456 The following options are available:
10459 @item --port=@var{port}
10460 @itemx -p @var{port}
10461 Listen for HTTP requests on @var{port}.
10463 @item --listen=@var{host}
10464 Listen on the network interface for @var{host}. The default is to
10465 accept connections from any interface.
10467 @item --user=@var{user}
10468 @itemx -u @var{user}
10469 Change privileges to @var{user} as soon as possible---i.e., once the
10470 server socket is open and the signing key has been read.
10472 @item --compression[=@var{method}[:@var{level}]]
10473 @itemx -C [@var{method}[:@var{level}]]
10474 Compress data using the given @var{method} and @var{level}. @var{method} is
10475 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10478 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10479 to different compression levels: 1 is the fastest, and 9 is the best
10480 (CPU-intensive). The default is 3.
10482 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10483 increase in CPU usage; see
10484 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10487 Unless @option{--cache} is used, compression occurs on the fly and
10488 the compressed streams are not
10489 cached. Thus, to reduce load on the machine that runs @command{guix
10490 publish}, it may be a good idea to choose a low compression level, to
10491 run @command{guix publish} behind a caching proxy, or to use
10492 @option{--cache}. Using @option{--cache} has the advantage that it
10493 allows @command{guix publish} to add @code{Content-Length} HTTP header
10496 This option can be repeated, in which case every substitute gets compressed
10497 using all the selected methods, and all of them are advertised. This is
10498 useful when users may not support all the compression methods: they can select
10499 the one they support.
10501 @item --cache=@var{directory}
10502 @itemx -c @var{directory}
10503 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10504 and only serve archives that are in cache.
10506 When this option is omitted, archives and meta-data are created
10507 on-the-fly. This can reduce the available bandwidth, especially when
10508 compression is enabled, since this may become CPU-bound. Another
10509 drawback of the default mode is that the length of archives is not known
10510 in advance, so @command{guix publish} does not add a
10511 @code{Content-Length} HTTP header to its responses, which in turn
10512 prevents clients from knowing the amount of data being downloaded.
10514 Conversely, when @option{--cache} is used, the first request for a store
10515 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10516 background process to @dfn{bake} the archive---computing its
10517 @code{.narinfo} and compressing the archive, if needed. Once the
10518 archive is cached in @var{directory}, subsequent requests succeed and
10519 are served directly from the cache, which guarantees that clients get
10520 the best possible bandwidth.
10522 The ``baking'' process is performed by worker threads. By default, one
10523 thread per CPU core is created, but this can be customized. See
10524 @option{--workers} below.
10526 When @option{--ttl} is used, cached entries are automatically deleted
10527 when they have expired.
10529 @item --workers=@var{N}
10530 When @option{--cache} is used, request the allocation of @var{N} worker
10531 threads to ``bake'' archives.
10533 @item --ttl=@var{ttl}
10534 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10535 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10536 days, @code{1m} means 1 month, and so on.
10538 This allows the user's Guix to keep substitute information in cache for
10539 @var{ttl}. However, note that @code{guix publish} does not itself
10540 guarantee that the store items it provides will indeed remain available
10541 for as long as @var{ttl}.
10543 Additionally, when @option{--cache} is used, cached entries that have
10544 not been accessed for @var{ttl} and that no longer have a corresponding
10545 item in the store, may be deleted.
10547 @item --nar-path=@var{path}
10548 Use @var{path} as the prefix for the URLs of ``nar'' files
10549 (@pxref{Invoking guix archive, normalized archives}).
10551 By default, nars are served at a URL such as
10552 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10553 change the @code{/nar} part to @var{path}.
10555 @item --public-key=@var{file}
10556 @itemx --private-key=@var{file}
10557 Use the specific @var{file}s as the public/private key pair used to sign
10558 the store items being published.
10560 The files must correspond to the same key pair (the private key is used
10561 for signing and the public key is merely advertised in the signature
10562 metadata). They must contain keys in the canonical s-expression format
10563 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10564 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10565 @file{/etc/guix/signing-key.sec} are used.
10567 @item --repl[=@var{port}]
10568 @itemx -r [@var{port}]
10569 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10570 Reference Manual}) on @var{port} (37146 by default). This is used
10571 primarily for debugging a running @command{guix publish} server.
10574 Enabling @command{guix publish} on Guix System is a one-liner: just
10575 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10576 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10577 @code{guix-publish-service-type}}).
10579 If you are instead running Guix on a ``foreign distro'', follow these
10584 If your host distro uses the systemd init system:
10587 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10588 /etc/systemd/system/
10589 # systemctl start guix-publish && systemctl enable guix-publish
10593 If your host distro uses the Upstart init system:
10596 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10597 # start guix-publish
10601 Otherwise, proceed similarly with your distro's init system.
10604 @node Invoking guix challenge
10605 @section Invoking @command{guix challenge}
10607 @cindex reproducible builds
10608 @cindex verifiable builds
10609 @cindex @command{guix challenge}
10611 Do the binaries provided by this server really correspond to the source
10612 code it claims to build? Is a package build process deterministic?
10613 These are the questions the @command{guix challenge} command attempts to
10616 The former is obviously an important question: Before using a substitute
10617 server (@pxref{Substitutes}), one had better @emph{verify} that it
10618 provides the right binaries, and thus @emph{challenge} it. The latter
10619 is what enables the former: If package builds are deterministic, then
10620 independent builds of the package should yield the exact same result,
10621 bit for bit; if a server provides a binary different from the one
10622 obtained locally, it may be either corrupt or malicious.
10624 We know that the hash that shows up in @file{/gnu/store} file names is
10625 the hash of all the inputs of the process that built the file or
10626 directory---compilers, libraries, build scripts,
10627 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10628 one store file name should map to exactly one build output.
10629 @command{guix challenge} checks whether there is, indeed, a single
10630 mapping by comparing the build outputs of several independent builds of
10631 any given store item.
10633 The command output looks like this:
10636 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10637 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10638 updating list of substitutes from 'https://guix.example.org'... 100.0%
10639 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10640 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10641 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10642 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10644 /lib/libcrypto.so.1.1
10647 /gnu/store/@dots{}-git-2.5.0 contents differ:
10648 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10649 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10650 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10652 /libexec/git-core/git-fsck
10654 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10655 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10656 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10657 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10659 /share/man/man1/pius.1.gz
10663 6,406 store items were analyzed:
10664 - 4,749 (74.1%) were identical
10665 - 525 (8.2%) differed
10666 - 1,132 (17.7%) were inconclusive
10670 In this example, @command{guix challenge} first scans the store to
10671 determine the set of locally-built derivations---as opposed to store
10672 items that were downloaded from a substitute server---and then queries
10673 all the substitute servers. It then reports those store items for which
10674 the servers obtained a result different from the local build.
10676 @cindex non-determinism, in package builds
10677 As an example, @code{guix.example.org} always gets a different answer.
10678 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10679 case of Git. This might indicate that the build process of Git is
10680 non-deterministic, meaning that its output varies as a function of
10681 various things that Guix does not fully control, in spite of building
10682 packages in isolated environments (@pxref{Features}). Most common
10683 sources of non-determinism include the addition of timestamps in build
10684 results, the inclusion of random numbers, and directory listings sorted
10685 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10688 To find out what is wrong with this Git binary, the easiest approach is
10692 guix challenge git \
10693 --diff=diffoscope \
10694 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10697 This automatically invokes @command{diffoscope}, which displays detailed
10698 information about files that differ.
10700 Alternately, we can do something along these lines (@pxref{Invoking guix
10704 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
10705 | lzip -d | guix archive -x /tmp/git
10706 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10709 This command shows the difference between the files resulting from the
10710 local build, and the files resulting from the build on
10711 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10712 diffutils, Comparing and Merging Files}). The @command{diff} command
10713 works great for text files. When binary files differ, a better option
10714 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10715 visualize differences for all kinds of files.
10717 Once you have done that work, you can tell whether the differences are due
10718 to a non-deterministic build process or to a malicious server. We try
10719 hard to remove sources of non-determinism in packages to make it easier
10720 to verify substitutes, but of course, this is a process that
10721 involves not just Guix, but a large part of the free software community.
10722 In the meantime, @command{guix challenge} is one tool to help address
10725 If you are writing packages for Guix, you are encouraged to check
10726 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10727 same build result as you did with:
10730 $ guix challenge @var{package}
10734 where @var{package} is a package specification such as
10735 @code{guile@@2.0} or @code{glibc:debug}.
10737 The general syntax is:
10740 guix challenge @var{options} [@var{packages}@dots{}]
10743 When a difference is found between the hash of a locally-built item and
10744 that of a server-provided substitute, or among substitutes provided by
10745 different servers, the command displays it as in the example above and
10746 its exit code is 2 (other non-zero exit codes denote other kinds of
10749 The one option that matters is:
10753 @item --substitute-urls=@var{urls}
10754 Consider @var{urls} the whitespace-separated list of substitute source
10755 URLs to compare to.
10757 @item --diff=@var{mode}
10758 Upon mismatches, show differences according to @var{mode}, one of:
10761 @item @code{simple} (the default)
10762 Show the list of files that differ.
10764 @item @code{diffoscope}
10765 @itemx @var{command}
10766 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
10767 two directories whose contents do not match.
10769 When @var{command} is an absolute file name, run @var{command} instead
10773 Do not show further details about the differences.
10776 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
10777 downloads the store items from the given substitute servers so that it
10782 Show details about matches (identical contents) in addition to
10783 information about mismatches.
10787 @node Invoking guix copy
10788 @section Invoking @command{guix copy}
10790 @cindex copy, of store items, over SSH
10791 @cindex SSH, copy of store items
10792 @cindex sharing store items across machines
10793 @cindex transferring store items across machines
10794 The @command{guix copy} command copies items from the store of one
10795 machine to that of another machine over a secure shell (SSH)
10796 connection@footnote{This command is available only when Guile-SSH was
10797 found. @xref{Requirements}, for details.}. For example, the following
10798 command copies the @code{coreutils} package, the user's profile, and all
10799 their dependencies over to @var{host}, logged in as @var{user}:
10802 guix copy --to=@var{user}@@@var{host} \
10803 coreutils `readlink -f ~/.guix-profile`
10806 If some of the items to be copied are already present on @var{host},
10807 they are not actually sent.
10809 The command below retrieves @code{libreoffice} and @code{gimp} from
10810 @var{host}, assuming they are available there:
10813 guix copy --from=@var{host} libreoffice gimp
10816 The SSH connection is established using the Guile-SSH client, which is
10817 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10818 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10820 The key used to sign items that are sent must be accepted by the remote
10821 machine. Likewise, the key used by the remote machine to sign items you
10822 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10823 own daemon. @xref{Invoking guix archive}, for more information about
10824 store item authentication.
10826 The general syntax is:
10829 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10832 You must always specify one of the following options:
10835 @item --to=@var{spec}
10836 @itemx --from=@var{spec}
10837 Specify the host to send to or receive from. @var{spec} must be an SSH
10838 spec such as @code{example.org}, @code{charlie@@example.org}, or
10839 @code{charlie@@example.org:2222}.
10842 The @var{items} can be either package names, such as @code{gimp}, or
10843 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10845 When specifying the name of a package to send, it is first built if
10846 needed, unless @option{--dry-run} was specified. Common build options
10847 are supported (@pxref{Common Build Options}).
10850 @node Invoking guix container
10851 @section Invoking @command{guix container}
10853 @cindex @command{guix container}
10855 As of version @value{VERSION}, this tool is experimental. The interface
10856 is subject to radical change in the future.
10859 The purpose of @command{guix container} is to manipulate processes
10860 running within an isolated environment, commonly known as a
10861 ``container'', typically created by the @command{guix environment}
10862 (@pxref{Invoking guix environment}) and @command{guix system container}
10863 (@pxref{Invoking guix system}) commands.
10865 The general syntax is:
10868 guix container @var{action} @var{options}@dots{}
10871 @var{action} specifies the operation to perform with a container, and
10872 @var{options} specifies the context-specific arguments for the action.
10874 The following actions are available:
10878 Execute a command within the context of a running container.
10883 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10886 @var{pid} specifies the process ID of the running container.
10887 @var{program} specifies an executable file name within the root file
10888 system of the container. @var{arguments} are the additional options that
10889 will be passed to @var{program}.
10891 The following command launches an interactive login shell inside a
10892 Guix system container, started by @command{guix system container}, and whose
10893 process ID is 9001:
10896 guix container exec 9001 /run/current-system/profile/bin/bash --login
10899 Note that the @var{pid} cannot be the parent process of a container. It
10900 must be PID 1 of the container or one of its child processes.
10904 @node Invoking guix weather
10905 @section Invoking @command{guix weather}
10907 Occasionally you're grumpy because substitutes are lacking and you end
10908 up building packages by yourself (@pxref{Substitutes}). The
10909 @command{guix weather} command reports on substitute availability on the
10910 specified servers so you can have an idea of whether you'll be grumpy
10911 today. It can sometimes be useful info as a user, but it is primarily
10912 useful to people running @command{guix publish} (@pxref{Invoking guix
10915 @cindex statistics, for substitutes
10916 @cindex availability of substitutes
10917 @cindex substitute availability
10918 @cindex weather, substitute availability
10919 Here's a sample run:
10922 $ guix weather --substitute-urls=https://guix.example.org
10923 computing 5,872 package derivations for x86_64-linux...
10924 looking for 6,128 store items on https://guix.example.org..
10925 updating list of substitutes from 'https://guix.example.org'... 100.0%
10926 https://guix.example.org
10927 43.4% substitutes available (2,658 out of 6,128)
10928 7,032.5 MiB of nars (compressed)
10929 19,824.2 MiB on disk (uncompressed)
10930 0.030 seconds per request (182.9 seconds in total)
10931 33.5 requests per second
10933 9.8% (342 out of 3,470) of the missing items are queued
10935 x86_64-linux: 518 (59.7%)
10936 i686-linux: 221 (25.5%)
10937 aarch64-linux: 128 (14.8%)
10938 build rate: 23.41 builds per hour
10939 x86_64-linux: 11.16 builds per hour
10940 i686-linux: 6.03 builds per hour
10941 aarch64-linux: 6.41 builds per hour
10944 @cindex continuous integration, statistics
10945 As you can see, it reports the fraction of all the packages for which
10946 substitutes are available on the server---regardless of whether
10947 substitutes are enabled, and regardless of whether this server's signing
10948 key is authorized. It also reports the size of the compressed archives
10949 (``nars'') provided by the server, the size the corresponding store
10950 items occupy in the store (assuming deduplication is turned off), and
10951 the server's throughput. The second part gives continuous integration
10952 (CI) statistics, if the server supports it. In addition, using the
10953 @option{--coverage} option, @command{guix weather} can list ``important''
10954 package substitutes missing on the server (see below).
10956 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10957 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10958 challenge}, it ignores signatures on those substitutes, which is
10959 innocuous since the command only gathers statistics and cannot install
10962 The general syntax is:
10965 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10968 When @var{packages} is omitted, @command{guix weather} checks the availability
10969 of substitutes for @emph{all} the packages, or for those specified with
10970 @option{--manifest}; otherwise it only considers the specified packages. It
10971 is also possible to query specific system types with @option{--system}.
10972 @command{guix weather} exits with a non-zero code when the fraction of
10973 available substitutes is below 100%.
10975 The available options are listed below.
10978 @item --substitute-urls=@var{urls}
10979 @var{urls} is the space-separated list of substitute server URLs to
10980 query. When this option is omitted, the default set of substitute
10981 servers is queried.
10983 @item --system=@var{system}
10984 @itemx -s @var{system}
10985 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10986 option can be repeated, in which case @command{guix weather} will query
10987 substitutes for several system types.
10989 @item --manifest=@var{file}
10990 Instead of querying substitutes for all the packages, only ask for those
10991 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10992 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10995 This option can be repeated several times, in which case the manifests
10998 @item --coverage[=@var{count}]
10999 @itemx -c [@var{count}]
11000 Report on substitute coverage for packages: list packages with at least
11001 @var{count} dependents (zero by default) for which substitutes are
11002 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11003 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11004 @var{b} usually lacks substitutes as well. The result looks like this:
11007 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11008 computing 8,983 package derivations for x86_64-linux...
11009 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11010 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11011 @value{SUBSTITUTE-URL}
11012 64.7% substitutes available (6,047 out of 9,343)
11014 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11015 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11016 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11017 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11021 What this example shows is that @code{kcoreaddons} and presumably the 58
11022 packages that depend on it have no substitutes at @code{ci.guix.info};
11023 likewise for @code{qgpgme} and the 46 packages that depend on it.
11025 If you are a Guix developer, or if you are taking care of this build farm,
11026 you'll probably want to have a closer look at these packages: they may simply
11029 @item --display-missing
11030 Display the list of store items for which substitutes are missing.
11033 @node Invoking guix processes
11034 @section Invoking @command{guix processes}
11036 The @command{guix processes} command can be useful to developers and system
11037 administrators, especially on multi-user machines and on build farms: it lists
11038 the current sessions (connections to the daemon), as well as information about
11039 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11040 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11041 listed.}. Here's an example of the information it returns:
11044 $ sudo guix processes
11047 ClientCommand: guix environment --ad-hoc python
11051 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11055 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11056 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11057 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11058 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11059 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11060 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11061 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11064 In this example we see that @command{guix-daemon} has three clients:
11065 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11066 integration tool; their process identifier (PID) is given by the
11067 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11068 @command{guix-daemon} sub-process of this particular session.
11070 The @code{LockHeld} fields show which store items are currently locked by this
11071 session, which corresponds to store items being built or substituted (the
11072 @code{LockHeld} field is not displayed when @command{guix processes} is not
11073 running as root.) Last, by looking at the @code{ChildProcess} field, we
11074 understand that these three builds are being offloaded (@pxref{Daemon Offload
11077 The output is in Recutils format so we can use the handy @command{recsel}
11078 command to select sessions of interest (@pxref{Selection Expressions,,,
11079 recutils, GNU recutils manual}). As an example, the command shows the command
11080 line and PID of the client that triggered the build of a Perl package:
11083 $ sudo guix processes | \
11084 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11086 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11089 @node System Configuration
11090 @chapter System Configuration
11092 @cindex system configuration
11093 Guix System supports a consistent whole-system configuration
11094 mechanism. By that we mean that all aspects of the global system
11095 configuration---such as the available system services, timezone and
11096 locale settings, user accounts---are declared in a single place. Such
11097 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11099 One of the advantages of putting all the system configuration under the
11100 control of Guix is that it supports transactional system upgrades, and
11101 makes it possible to roll back to a previous system instantiation,
11102 should something go wrong with the new one (@pxref{Features}). Another
11103 advantage is that it makes it easy to replicate the exact same configuration
11104 across different machines, or at different points in time, without
11105 having to resort to additional administration tools layered on top of
11106 the own tools of the system.
11107 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11109 This section describes this mechanism. First we focus on the system
11110 administrator's viewpoint---explaining how the system is configured and
11111 instantiated. Then we show how this mechanism can be extended, for
11112 instance to support new system services.
11115 * Using the Configuration System:: Customizing your GNU system.
11116 * operating-system Reference:: Detail of operating-system declarations.
11117 * File Systems:: Configuring file system mounts.
11118 * Mapped Devices:: Block device extra processing.
11119 * User Accounts:: Specifying user accounts.
11120 * Keyboard Layout:: How the system interprets key strokes.
11121 * Locales:: Language and cultural convention settings.
11122 * Services:: Specifying system services.
11123 * Setuid Programs:: Programs running with root privileges.
11124 * X.509 Certificates:: Authenticating HTTPS servers.
11125 * Name Service Switch:: Configuring libc's name service switch.
11126 * Initial RAM Disk:: Linux-Libre bootstrapping.
11127 * Bootloader Configuration:: Configuring the boot loader.
11128 * Invoking guix system:: Instantiating a system configuration.
11129 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11130 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11131 * Defining Services:: Adding new service definitions.
11134 @node Using the Configuration System
11135 @section Using the Configuration System
11137 The operating system is configured by providing an
11138 @code{operating-system} declaration in a file that can then be passed to
11139 the @command{guix system} command (@pxref{Invoking guix system}). A
11140 simple setup, with the default system services, the default Linux-Libre
11141 kernel, initial RAM disk, and boot loader looks like this:
11143 @findex operating-system
11145 @include os-config-bare-bones.texi
11148 This example should be self-describing. Some of the fields defined
11149 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11150 Others, such as @code{packages} and @code{services}, can be omitted, in
11151 which case they get a default value.
11153 Below we discuss the effect of some of the most important fields
11154 (@pxref{operating-system Reference}, for details about all the available
11155 fields), and how to @dfn{instantiate} the operating system using
11156 @command{guix system}.
11158 @unnumberedsubsec Bootloader
11160 @cindex legacy boot, on Intel machines
11161 @cindex BIOS boot, on Intel machines
11164 The @code{bootloader} field describes the method that will be used to boot
11165 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11166 mode, as in the example above. However, more recent machines rely instead on
11167 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11168 the @code{bootloader} field should contain something along these lines:
11171 (bootloader-configuration
11172 (bootloader grub-efi-bootloader)
11173 (target "/boot/efi"))
11176 @xref{Bootloader Configuration}, for more information on the available
11177 configuration options.
11179 @unnumberedsubsec Globally-Visible Packages
11181 @vindex %base-packages
11182 The @code{packages} field lists packages that will be globally visible
11183 on the system, for all user accounts---i.e., in every user's @env{PATH}
11184 environment variable---in addition to the per-user profiles
11185 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11186 provides all the tools one would expect for basic user and administrator
11187 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11188 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11189 etc. The example above adds GNU@tie{}Screen to those,
11190 taken from the @code{(gnu packages screen)}
11191 module (@pxref{Package Modules}). The
11192 @code{(list package output)} syntax can be used to add a specific output
11196 (use-modules (gnu packages))
11197 (use-modules (gnu packages dns))
11201 (packages (cons (list bind "utils")
11205 @findex specification->package
11206 Referring to packages by variable name, like @code{bind} above, has
11207 the advantage of being unambiguous; it also allows typos and such to be
11208 diagnosed right away as ``unbound variables''. The downside is that one
11209 needs to know which module defines which package, and to augment the
11210 @code{use-package-modules} line accordingly. To avoid that, one can use
11211 the @code{specification->package} procedure of the @code{(gnu packages)}
11212 module, which returns the best package for a given name or name and
11216 (use-modules (gnu packages))
11220 (packages (append (map specification->package
11221 '("tcpdump" "htop" "gnupg@@2.0"))
11225 @unnumberedsubsec System Services
11228 @vindex %base-services
11229 The @code{services} field lists @dfn{system services} to be made
11230 available when the system starts (@pxref{Services}).
11231 The @code{operating-system} declaration above specifies that, in
11232 addition to the basic services, we want the OpenSSH secure shell
11233 daemon listening on port 2222 (@pxref{Networking Services,
11234 @code{openssh-service-type}}). Under the hood,
11235 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11236 right command-line options, possibly with supporting configuration files
11237 generated as needed (@pxref{Defining Services}).
11239 @cindex customization, of services
11240 @findex modify-services
11241 Occasionally, instead of using the base services as is, you will want to
11242 customize them. To do this, use @code{modify-services} (@pxref{Service
11243 Reference, @code{modify-services}}) to modify the list.
11245 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11246 (the console log-in) in the @code{%base-services} list (@pxref{Base
11247 Services, @code{%base-services}}). To do that, you can write the
11248 following in your operating system declaration:
11251 (define %my-services
11252 ;; My very own list of services.
11253 (modify-services %base-services
11254 (guix-service-type config =>
11255 (guix-configuration
11257 (use-substitutes? #f)
11258 (extra-options '("--gc-keep-derivations"))))
11259 (mingetty-service-type config =>
11260 (mingetty-configuration
11261 (inherit config)))))
11265 (services %my-services))
11268 This changes the configuration---i.e., the service parameters---of the
11269 @code{guix-service-type} instance, and that of all the
11270 @code{mingetty-service-type} instances in the @code{%base-services} list.
11271 Observe how this is accomplished: first, we arrange for the original
11272 configuration to be bound to the identifier @code{config} in the
11273 @var{body}, and then we write the @var{body} so that it evaluates to the
11274 desired configuration. In particular, notice how we use @code{inherit}
11275 to create a new configuration which has the same values as the old
11276 configuration, but with a few modifications.
11278 @cindex encrypted disk
11279 The configuration for a typical ``desktop'' usage, with an encrypted
11280 root partition, the X11 display
11281 server, GNOME and Xfce (users can choose which of these desktop
11282 environments to use at the log-in screen by pressing @kbd{F1}), network
11283 management, power management, and more, would look like this:
11286 @include os-config-desktop.texi
11289 A graphical system with a choice of lightweight window managers
11290 instead of full-blown desktop environments would look like this:
11293 @include os-config-lightweight-desktop.texi
11296 This example refers to the @file{/boot/efi} file system by its UUID,
11297 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11298 as returned by the @command{blkid} command.
11300 @xref{Desktop Services}, for the exact list of services provided by
11301 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11302 information about the @code{nss-certs} package that is used here.
11304 Again, @code{%desktop-services} is just a list of service objects. If
11305 you want to remove services from there, you can do so using the
11306 procedures for list filtering (@pxref{SRFI-1 Filtering and
11307 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11308 following expression returns a list that contains all the services in
11309 @code{%desktop-services} minus the Avahi service:
11312 (remove (lambda (service)
11313 (eq? (service-kind service) avahi-service-type))
11317 @unnumberedsubsec Instantiating the System
11319 Assuming the @code{operating-system} declaration
11320 is stored in the @file{my-system-config.scm}
11321 file, the @command{guix system reconfigure my-system-config.scm} command
11322 instantiates that configuration, and makes it the default GRUB boot
11323 entry (@pxref{Invoking guix system}).
11325 The normal way to change the system configuration is by updating this
11326 file and re-running @command{guix system reconfigure}. One should never
11327 have to touch files in @file{/etc} or to run commands that modify the
11328 system state such as @command{useradd} or @command{grub-install}. In
11329 fact, you must avoid that since that would not only void your warranty
11330 but also prevent you from rolling back to previous versions of your
11331 system, should you ever need to.
11333 @cindex roll-back, of the operating system
11334 Speaking of roll-back, each time you run @command{guix system
11335 reconfigure}, a new @dfn{generation} of the system is created---without
11336 modifying or deleting previous generations. Old system generations get
11337 an entry in the bootloader boot menu, allowing you to boot them in case
11338 something went wrong with the latest generation. Reassuring, no? The
11339 @command{guix system list-generations} command lists the system
11340 generations available on disk. It is also possible to roll back the
11341 system via the commands @command{guix system roll-back} and
11342 @command{guix system switch-generation}.
11344 Although the @command{guix system reconfigure} command will not modify
11345 previous generations, you must take care when the current generation is not
11346 the latest (e.g., after invoking @command{guix system roll-back}), since
11347 the operation might overwrite a later generation (@pxref{Invoking guix
11350 @unnumberedsubsec The Programming Interface
11352 At the Scheme level, the bulk of an @code{operating-system} declaration
11353 is instantiated with the following monadic procedure (@pxref{The Store
11356 @deffn {Monadic Procedure} operating-system-derivation os
11357 Return a derivation that builds @var{os}, an @code{operating-system}
11358 object (@pxref{Derivations}).
11360 The output of the derivation is a single directory that refers to all
11361 the packages, configuration files, and other supporting files needed to
11362 instantiate @var{os}.
11365 This procedure is provided by the @code{(gnu system)} module. Along
11366 with @code{(gnu services)} (@pxref{Services}), this module contains the
11367 guts of Guix System. Make sure to visit it!
11370 @node operating-system Reference
11371 @section @code{operating-system} Reference
11373 This section summarizes all the options available in
11374 @code{operating-system} declarations (@pxref{Using the Configuration
11377 @deftp {Data Type} operating-system
11378 This is the data type representing an operating system configuration.
11379 By that, we mean all the global system configuration, not per-user
11380 configuration (@pxref{Using the Configuration System}).
11383 @item @code{kernel} (default: @code{linux-libre})
11384 The package object of the operating system kernel to use@footnote{Currently
11385 only the Linux-libre kernel is supported. In the future, it will be
11386 possible to use the GNU@tie{}Hurd.}.
11388 @item @code{kernel-loadable-modules} (default: '())
11389 A list of objects (usually packages) to collect loadable kernel modules
11390 from--e.g. @code{(list ddcci-driver-linux)}.
11392 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
11393 List of strings or gexps representing additional arguments to pass on
11394 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11396 @item @code{bootloader}
11397 The system bootloader configuration object. @xref{Bootloader Configuration}.
11400 This is the label (a string) as it appears in the bootloader's menu entry.
11401 The default label includes the kernel name and version.
11403 @item @code{keyboard-layout} (default: @code{#f})
11404 This field specifies the keyboard layout to use in the console. It can be
11405 either @code{#f}, in which case the default keyboard layout is used (usually
11406 US English), or a @code{<keyboard-layout>} record.
11408 This keyboard layout is in effect as soon as the kernel has booted. For
11409 instance, it is the keyboard layout in effect when you type a passphrase if
11410 your root file system is on a @code{luks-device-mapping} mapped device
11411 (@pxref{Mapped Devices}).
11414 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11415 that used by the graphical display server. @xref{Bootloader Configuration},
11416 for information on how to specify the bootloader's keyboard layout. @xref{X
11417 Window}, for information on how to specify the keyboard layout used by the X
11421 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11423 @cindex initial RAM disk
11424 The list of Linux kernel modules that need to be available in the
11425 initial RAM disk. @xref{Initial RAM Disk}.
11427 @item @code{initrd} (default: @code{base-initrd})
11428 A procedure that returns an initial RAM disk for the Linux
11429 kernel. This field is provided to support low-level customization and
11430 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11432 @item @code{firmware} (default: @code{%base-firmware})
11434 List of firmware packages loadable by the operating system kernel.
11436 The default includes firmware needed for Atheros- and Broadcom-based
11437 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11438 respectively). @xref{Hardware Considerations}, for more info on
11439 supported hardware.
11441 @item @code{host-name}
11444 @item @code{hosts-file}
11446 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11447 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11448 Reference Manual}). The default is a file with entries for
11449 @code{localhost} and @var{host-name}.
11451 @item @code{mapped-devices} (default: @code{'()})
11452 A list of mapped devices. @xref{Mapped Devices}.
11454 @item @code{file-systems}
11455 A list of file systems. @xref{File Systems}.
11457 @item @code{swap-devices} (default: @code{'()})
11458 @cindex swap devices
11459 A list of strings identifying devices or files to be used for ``swap
11460 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11461 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11462 It is possible to specify a swap file in a file system on a mapped
11463 device, provided that the necessary device mapping and file system are
11464 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11466 @item @code{users} (default: @code{%base-user-accounts})
11467 @itemx @code{groups} (default: @code{%base-groups})
11468 List of user accounts and groups. @xref{User Accounts}.
11470 If the @code{users} list lacks a user account with UID@tie{}0, a
11471 ``root'' account with UID@tie{}0 is automatically added.
11473 @item @code{skeletons} (default: @code{(default-skeletons)})
11474 A list target file name/file-like object tuples (@pxref{G-Expressions,
11475 file-like objects}). These are the skeleton files that will be added to
11476 the home directory of newly-created user accounts.
11478 For instance, a valid value may look like this:
11481 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11482 (".guile" ,(plain-file "guile"
11483 "(use-modules (ice-9 readline))
11484 (activate-readline)")))
11487 @item @code{issue} (default: @code{%default-issue})
11488 A string denoting the contents of the @file{/etc/issue} file, which is
11489 displayed when users log in on a text console.
11491 @item @code{packages} (default: @code{%base-packages})
11492 The set of packages installed in the global profile, which is accessible
11493 at @file{/run/current-system/profile}.
11495 The default set includes core utilities and it is good practice to
11496 install non-core utilities in user profiles (@pxref{Invoking guix
11499 @item @code{timezone}
11500 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11502 You can run the @command{tzselect} command to find out which timezone
11503 string corresponds to your region. Choosing an invalid timezone name
11504 causes @command{guix system} to fail.
11506 @item @code{locale} (default: @code{"en_US.utf8"})
11507 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11508 Library Reference Manual}). @xref{Locales}, for more information.
11510 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11511 The list of locale definitions to be compiled and that may be used at
11512 run time. @xref{Locales}.
11514 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11515 The list of GNU@tie{}libc packages whose locale data and tools are used
11516 to build the locale definitions. @xref{Locales}, for compatibility
11517 considerations that justify this option.
11519 @item @code{name-service-switch} (default: @code{%default-nss})
11520 Configuration of the libc name service switch (NSS)---a
11521 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11524 @item @code{services} (default: @code{%base-services})
11525 A list of service objects denoting system services. @xref{Services}.
11527 @cindex essential services
11528 @item @code{essential-services} (default: ...)
11529 The list of ``essential services''---i.e., things like instances of
11530 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11531 Reference}), which are derived from the operating system definition itself.
11532 As a user you should @emph{never} need to touch this field.
11534 @item @code{pam-services} (default: @code{(base-pam-services)})
11536 @cindex pluggable authentication modules
11537 Linux @dfn{pluggable authentication module} (PAM) services.
11538 @c FIXME: Add xref to PAM services section.
11540 @item @code{setuid-programs} (default: @code{%setuid-programs})
11541 List of string-valued G-expressions denoting setuid programs.
11542 @xref{Setuid Programs}.
11544 @item @code{sudoers-file} (default: @code{%sudoers-specification})
11545 @cindex sudoers file
11546 The contents of the @file{/etc/sudoers} file as a file-like object
11547 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11549 This file specifies which users can use the @command{sudo} command, what
11550 they are allowed to do, and what privileges they may gain. The default
11551 is that only @code{root} and members of the @code{wheel} group may use
11556 @deffn {Scheme Syntax} this-operating-system
11557 When used in the @emph{lexical scope} of an operating system field definition,
11558 this identifier resolves to the operating system being defined.
11560 The example below shows how to refer to the operating system being defined in
11561 the definition of the @code{label} field:
11564 (use-modules (gnu) (guix))
11568 (label (package-full-name
11569 (operating-system-kernel this-operating-system))))
11572 It is an error to refer to @code{this-operating-system} outside an operating
11579 @section File Systems
11581 The list of file systems to be mounted is specified in the
11582 @code{file-systems} field of the operating system declaration
11583 (@pxref{Using the Configuration System}). Each file system is declared
11584 using the @code{file-system} form, like this:
11588 (mount-point "/home")
11589 (device "/dev/sda3")
11593 As usual, some of the fields are mandatory---those shown in the example
11594 above---while others can be omitted. These are described below.
11596 @deftp {Data Type} file-system
11597 Objects of this type represent file systems to be mounted. They
11598 contain the following members:
11602 This is a string specifying the type of the file system---e.g.,
11605 @item @code{mount-point}
11606 This designates the place where the file system is to be mounted.
11608 @item @code{device}
11609 This names the ``source'' of the file system. It can be one of three
11610 things: a file system label, a file system UUID, or the name of a
11611 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11612 systems without having to hard-code their actual device
11613 name@footnote{Note that, while it is tempting to use
11614 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11615 result, this is not recommended: These special device nodes are created
11616 by the udev daemon and may be unavailable at the time the device is
11619 @findex file-system-label
11620 File system labels are created using the @code{file-system-label}
11621 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11622 plain strings. Here's an example of a file system referred to by its
11623 label, as shown by the @command{e2label} command:
11627 (mount-point "/home")
11629 (device (file-system-label "my-home")))
11633 UUIDs are converted from their string representation (as shown by the
11634 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11635 @code{uuid} form expects 16-byte UUIDs as defined in
11636 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11637 form of UUID used by the ext2 family of file systems and others, but it
11638 is different from ``UUIDs'' found in FAT file systems, for instance.},
11643 (mount-point "/home")
11645 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11648 When the source of a file system is a mapped device (@pxref{Mapped
11649 Devices}), its @code{device} field @emph{must} refer to the mapped
11650 device name---e.g., @file{"/dev/mapper/root-partition"}.
11651 This is required so that
11652 the system knows that mounting the file system depends on having the
11653 corresponding device mapping established.
11655 @item @code{flags} (default: @code{'()})
11656 This is a list of symbols denoting mount flags. Recognized flags
11657 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11658 access to special files), @code{no-suid} (ignore setuid and setgid
11659 bits), @code{no-atime} (do not update file access times),
11660 @code{strict-atime} (update file access time), @code{lazy-time} (only
11661 update time on the in-memory version of the file inode), and
11662 @code{no-exec} (disallow program execution).
11663 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
11664 Manual}, for more information on these flags.
11666 @item @code{options} (default: @code{#f})
11667 This is either @code{#f}, or a string denoting mount options passed to the
11668 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11669 Reference Manual}, for details and run @command{man 8 mount} for options for
11670 various file systems.
11672 @item @code{mount?} (default: @code{#t})
11673 This value indicates whether to automatically mount the file system when
11674 the system is brought up. When set to @code{#f}, the file system gets
11675 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11676 is not automatically mounted.
11678 @item @code{needed-for-boot?} (default: @code{#f})
11679 This Boolean value indicates whether the file system is needed when
11680 booting. If that is true, then the file system is mounted when the
11681 initial RAM disk (initrd) is loaded. This is always the case, for
11682 instance, for the root file system.
11684 @item @code{check?} (default: @code{#t})
11685 This Boolean indicates whether the file system needs to be checked for
11686 errors before being mounted.
11688 @item @code{create-mount-point?} (default: @code{#f})
11689 When true, the mount point is created if it does not exist yet.
11691 @item @code{dependencies} (default: @code{'()})
11692 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11693 representing file systems that must be mounted or mapped devices that
11694 must be opened before (and unmounted or closed after) this one.
11696 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11697 a dependency of @file{/sys/fs/cgroup/cpu} and
11698 @file{/sys/fs/cgroup/memory}.
11700 Another example is a file system that depends on a mapped device, for
11701 example for an encrypted partition (@pxref{Mapped Devices}).
11705 The @code{(gnu system file-systems)} exports the following useful
11708 @defvr {Scheme Variable} %base-file-systems
11709 These are essential file systems that are required on normal systems,
11710 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
11711 below.) Operating system declarations should always contain at least
11715 @defvr {Scheme Variable} %pseudo-terminal-file-system
11716 This is the file system to be mounted as @file{/dev/pts}. It supports
11717 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11718 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11719 Manual}). Pseudo-terminals are used by terminal emulators such as
11723 @defvr {Scheme Variable} %shared-memory-file-system
11724 This file system is mounted as @file{/dev/shm} and is used to support
11725 memory sharing across processes (@pxref{Memory-mapped I/O,
11726 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11729 @defvr {Scheme Variable} %immutable-store
11730 This file system performs a read-only ``bind mount'' of
11731 @file{/gnu/store}, making it read-only for all the users including
11732 @code{root}. This prevents against accidental modification by software
11733 running as @code{root} or by system administrators.
11735 The daemon itself is still able to write to the store: it remounts it
11736 read-write in its own ``name space.''
11739 @defvr {Scheme Variable} %binary-format-file-system
11740 The @code{binfmt_misc} file system, which allows handling of arbitrary
11741 executable file types to be delegated to user space. This requires the
11742 @code{binfmt.ko} kernel module to be loaded.
11745 @defvr {Scheme Variable} %fuse-control-file-system
11746 The @code{fusectl} file system, which allows unprivileged users to mount
11747 and unmount user-space FUSE file systems. This requires the
11748 @code{fuse.ko} kernel module to be loaded.
11751 @node Mapped Devices
11752 @section Mapped Devices
11754 @cindex device mapping
11755 @cindex mapped devices
11756 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11757 such as a hard disk partition, can be @dfn{mapped} into another device,
11758 usually in @code{/dev/mapper/},
11759 with additional processing over the data that flows through
11760 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11761 concept of a ``mapped device'' and that of a file system: both boil down
11762 to @emph{translating} input/output operations made on a file to
11763 operations on its backing store. Thus, the Hurd implements mapped
11764 devices, like file systems, using the generic @dfn{translator} mechanism
11765 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11766 typical example is encryption device mapping: all writes to the mapped
11767 device are encrypted, and all reads are deciphered, transparently.
11768 Guix extends this notion by considering any device or set of devices that
11769 are @dfn{transformed} in some way to create a new device; for instance,
11770 RAID devices are obtained by @dfn{assembling} several other devices, such
11771 as hard disks or partitions, into a new one that behaves as one partition.
11772 Other examples, not yet implemented, are LVM logical volumes.
11774 Mapped devices are declared using the @code{mapped-device} form,
11775 defined as follows; for examples, see below.
11777 @deftp {Data Type} mapped-device
11778 Objects of this type represent device mappings that will be made when
11779 the system boots up.
11783 This is either a string specifying the name of the block device to be mapped,
11784 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11785 need to be assembled for creating a new one.
11788 This string specifies the name of the resulting mapped device. For
11789 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11790 specifying @code{"my-partition"} leads to the creation of
11791 the @code{"/dev/mapper/my-partition"} device.
11792 For RAID devices of type @code{raid-device-mapping}, the full device name
11793 such as @code{"/dev/md0"} needs to be given.
11796 This must be a @code{mapped-device-kind} object, which specifies how
11797 @var{source} is mapped to @var{target}.
11801 @defvr {Scheme Variable} luks-device-mapping
11802 This defines LUKS block device encryption using the @command{cryptsetup}
11803 command from the package with the same name. It relies on the
11804 @code{dm-crypt} Linux kernel module.
11807 @defvr {Scheme Variable} raid-device-mapping
11808 This defines a RAID device, which is assembled using the @code{mdadm}
11809 command from the package with the same name. It requires a Linux kernel
11810 module for the appropriate RAID level to be loaded, such as @code{raid456}
11811 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11814 @cindex disk encryption
11816 The following example specifies a mapping from @file{/dev/sda3} to
11817 @file{/dev/mapper/home} using LUKS---the
11818 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11819 standard mechanism for disk encryption.
11820 The @file{/dev/mapper/home}
11821 device can then be used as the @code{device} of a @code{file-system}
11822 declaration (@pxref{File Systems}).
11826 (source "/dev/sda3")
11828 (type luks-device-mapping))
11831 Alternatively, to become independent of device numbering, one may obtain
11832 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11836 cryptsetup luksUUID /dev/sda3
11839 and use it as follows:
11843 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11845 (type luks-device-mapping))
11848 @cindex swap encryption
11849 It is also desirable to encrypt swap space, since swap space may contain
11850 sensitive data. One way to accomplish that is to use a swap file in a
11851 file system on a device mapped via LUKS encryption. In this way, the
11852 swap file is encrypted because the entire device is encrypted.
11853 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11855 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11856 may be declared as follows:
11860 (source (list "/dev/sda1" "/dev/sdb1"))
11861 (target "/dev/md0")
11862 (type raid-device-mapping))
11865 The @file{/dev/md0} device can then be used as the @code{device} of a
11866 @code{file-system} declaration (@pxref{File Systems}).
11867 Note that the RAID level need not be given; it is chosen during the
11868 initial creation and formatting of the RAID device and is determined
11869 automatically later.
11872 @node User Accounts
11873 @section User Accounts
11877 @cindex user accounts
11878 User accounts and groups are entirely managed through the
11879 @code{operating-system} declaration. They are specified with the
11880 @code{user-account} and @code{user-group} forms:
11886 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11887 "audio" ;sound card
11888 "video" ;video devices such as webcams
11889 "cdrom")) ;the good ol' CD-ROM
11890 (comment "Bob's sister")
11891 (home-directory "/home/alice"))
11894 When booting or upon completion of @command{guix system reconfigure},
11895 the system ensures that only the user accounts and groups specified in
11896 the @code{operating-system} declaration exist, and with the specified
11897 properties. Thus, account or group creations or modifications made by
11898 directly invoking commands such as @command{useradd} are lost upon
11899 reconfiguration or reboot. This ensures that the system remains exactly
11902 @deftp {Data Type} user-account
11903 Objects of this type represent user accounts. The following members may
11908 The name of the user account.
11912 This is the name (a string) or identifier (a number) of the user group
11913 this account belongs to.
11915 @item @code{supplementary-groups} (default: @code{'()})
11916 Optionally, this can be defined as a list of group names that this
11917 account belongs to.
11919 @item @code{uid} (default: @code{#f})
11920 This is the user ID for this account (a number), or @code{#f}. In the
11921 latter case, a number is automatically chosen by the system when the
11922 account is created.
11924 @item @code{comment} (default: @code{""})
11925 A comment about the account, such as the account owner's full name.
11927 @item @code{home-directory}
11928 This is the name of the home directory for the account.
11930 @item @code{create-home-directory?} (default: @code{#t})
11931 Indicates whether the home directory of this account should be created
11932 if it does not exist yet.
11934 @item @code{shell} (default: Bash)
11935 This is a G-expression denoting the file name of a program to be used as
11936 the shell (@pxref{G-Expressions}).
11938 @item @code{system?} (default: @code{#f})
11939 This Boolean value indicates whether the account is a ``system''
11940 account. System accounts are sometimes treated specially; for instance,
11941 graphical login managers do not list them.
11943 @anchor{user-account-password}
11944 @cindex password, for user accounts
11945 @item @code{password} (default: @code{#f})
11946 You would normally leave this field to @code{#f}, initialize user
11947 passwords as @code{root} with the @command{passwd} command, and then let
11948 users change it with @command{passwd}. Passwords set with
11949 @command{passwd} are of course preserved across reboot and
11952 If you @emph{do} want to set an initial password for an account, then
11953 this field must contain the encrypted password, as a string. You can use the
11954 @code{crypt} procedure for this purpose:
11961 ;; Specify a SHA-512-hashed initial password.
11962 (password (crypt "InitialPassword!" "$6$abc")))
11966 The hash of this initial password will be available in a file in
11967 @file{/gnu/store}, readable by all the users, so this method must be used with
11971 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11972 more information on password encryption, and @ref{Encryption,,, guile, GNU
11973 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11979 User group declarations are even simpler:
11982 (user-group (name "students"))
11985 @deftp {Data Type} user-group
11986 This type is for, well, user groups. There are just a few fields:
11990 The name of the group.
11992 @item @code{id} (default: @code{#f})
11993 The group identifier (a number). If @code{#f}, a new number is
11994 automatically allocated when the group is created.
11996 @item @code{system?} (default: @code{#f})
11997 This Boolean value indicates whether the group is a ``system'' group.
11998 System groups have low numerical IDs.
12000 @item @code{password} (default: @code{#f})
12001 What, user groups can have a password? Well, apparently yes. Unless
12002 @code{#f}, this field specifies the password of the group.
12007 For convenience, a variable lists all the basic user groups one may
12010 @defvr {Scheme Variable} %base-groups
12011 This is the list of basic user groups that users and/or packages expect
12012 to be present on the system. This includes groups such as ``root'',
12013 ``wheel'', and ``users'', as well as groups used to control access to
12014 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12017 @defvr {Scheme Variable} %base-user-accounts
12018 This is the list of basic system accounts that programs may expect to
12019 find on a GNU/Linux system, such as the ``nobody'' account.
12021 Note that the ``root'' account is not included here. It is a
12022 special-case and is automatically added whether or not it is specified.
12025 @node Keyboard Layout
12026 @section Keyboard Layout
12028 @cindex keyboard layout
12030 To specify what each key of your keyboard does, you need to tell the operating
12031 system what @dfn{keyboard layout} you want to use. The default, when nothing
12032 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12033 However, German speakers will usually prefer the German QWERTZ layout, French
12034 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12035 or bépo, and they might even want to further customize the effect of some of
12036 the keys. This section explains how to get that done.
12038 @cindex keyboard layout, definition
12039 There are three components that will want to know about your keyboard layout:
12043 The @emph{bootloader} may want to know what keyboard layout you want to use
12044 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12045 you want, for instance, to make sure that you can type the passphrase of your
12046 encrypted root partition using the right layout.
12049 The @emph{operating system kernel}, Linux, will need that so that the console
12050 is properly configured (@pxref{operating-system Reference,
12051 @code{keyboard-layout}}).
12054 The @emph{graphical display server}, usually Xorg, also has its own idea of
12055 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12058 Guix allows you to configure all three separately but, fortunately, it allows
12059 you to share the same keyboard layout for all three components.
12061 @cindex XKB, keyboard layouts
12062 Keyboard layouts are represented by records created by the
12063 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12064 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12065 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12066 optional variant name, an optional keyboard model name, and a possibly empty
12067 list of additional options. In most cases the layout name is all you care
12068 about. Here are a few example:
12071 ;; The German QWERTZ layout. Here we assume a standard
12072 ;; "pc105" keyboard model.
12073 (keyboard-layout "de")
12075 ;; The bépo variant of the French layout.
12076 (keyboard-layout "fr" "bepo")
12078 ;; The Catalan layout.
12079 (keyboard-layout "es" "cat")
12081 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12082 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12084 ;; The Latin American Spanish layout. In addition, the
12085 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12086 ;; and the "Menu" key is used as a "Compose" key to enter
12087 ;; accented letters.
12088 (keyboard-layout "latam"
12089 #:options '("ctrl:nocaps" "compose:menu"))
12091 ;; The Russian layout for a ThinkPad keyboard.
12092 (keyboard-layout "ru" #:model "thinkpad")
12094 ;; The "US international" layout, which is the US layout plus
12095 ;; dead keys to enter accented characters. This is for an
12096 ;; Apple MacBook keyboard.
12097 (keyboard-layout "us" "intl" #:model "macbook78")
12100 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12101 for a complete list of supported layouts, variants, and models.
12103 @cindex keyboard layout, configuration
12104 Let's say you want your system to use the Turkish keyboard layout throughout
12105 your system---bootloader, console, and Xorg. Here's what your system
12106 configuration would look like:
12108 @findex set-xorg-configuration
12110 ;; Using the Turkish layout for the bootloader, the console,
12115 (keyboard-layout (keyboard-layout "tr")) ;for the console
12116 (bootloader (bootloader-configuration
12117 (bootloader grub-efi-bootloader)
12118 (target "/boot/efi")
12119 (keyboard-layout keyboard-layout))) ;for GRUB
12120 (services (cons (set-xorg-configuration
12121 (xorg-configuration ;for Xorg
12122 (keyboard-layout keyboard-layout)))
12123 %desktop-services)))
12126 In the example above, for GRUB and for Xorg, we just refer to the
12127 @code{keyboard-layout} field defined above, but we could just as well refer to
12128 a different layout. The @code{set-xorg-configuration} procedure communicates
12129 the desired Xorg configuration to the graphical log-in manager, by default
12132 We've discussed how to specify the @emph{default} keyboard layout of your
12133 system when it starts, but you can also adjust it at run time:
12137 If you're using GNOME, its settings panel has a ``Region & Language'' entry
12138 where you can select one or more keyboard layouts.
12141 Under Xorg, the @command{setxkbmap} command (from the same-named package)
12142 allows you to change the current layout. For example, this is how you would
12143 change the layout to US Dvorak:
12146 setxkbmap us dvorak
12150 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
12151 console. However, note that @code{loadkeys} does @emph{not} use the XKB
12152 keyboard layout categorization described above. The command below loads the
12153 French bépo layout:
12164 A @dfn{locale} defines cultural conventions for a particular language
12165 and region of the world (@pxref{Locales,,, libc, The GNU C Library
12166 Reference Manual}). Each locale has a name that typically has the form
12167 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
12168 @code{fr_LU.utf8} designates the locale for the French language, with
12169 cultural conventions from Luxembourg, and using the UTF-8 encoding.
12171 @cindex locale definition
12172 Usually, you will want to specify the default locale for the machine
12173 using the @code{locale} field of the @code{operating-system} declaration
12174 (@pxref{operating-system Reference, @code{locale}}).
12176 The selected locale is automatically added to the @dfn{locale
12177 definitions} known to the system if needed, with its codeset inferred
12178 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
12179 @code{UTF-8} codeset. Additional locale definitions can be specified in
12180 the @code{locale-definitions} slot of @code{operating-system}---this is
12181 useful, for instance, if the codeset could not be inferred from the
12182 locale name. The default set of locale definitions includes some widely
12183 used locales, but not all the available locales, in order to save space.
12185 For instance, to add the North Frisian locale for Germany, the value of
12189 (cons (locale-definition
12190 (name "fy_DE.utf8") (source "fy_DE"))
12191 %default-locale-definitions)
12194 Likewise, to save space, one might want @code{locale-definitions} to
12195 list only the locales that are actually used, as in:
12198 (list (locale-definition
12199 (name "ja_JP.eucjp") (source "ja_JP")
12200 (charset "EUC-JP")))
12204 The compiled locale definitions are available at
12205 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
12206 version, which is the default location where the GNU@tie{}libc provided
12207 by Guix looks for locale data. This can be overridden using the
12208 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
12209 @env{LOCPATH} and locale packages}).
12211 The @code{locale-definition} form is provided by the @code{(gnu system
12212 locale)} module. Details are given below.
12214 @deftp {Data Type} locale-definition
12215 This is the data type of a locale definition.
12220 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
12221 Reference Manual}, for more information on locale names.
12223 @item @code{source}
12224 The name of the source for that locale. This is typically the
12225 @code{@var{language}_@var{territory}} part of the locale name.
12227 @item @code{charset} (default: @code{"UTF-8"})
12228 The ``character set'' or ``code set'' for that locale,
12229 @uref{https://www.iana.org/assignments/character-sets, as defined by
12235 @defvr {Scheme Variable} %default-locale-definitions
12236 A list of commonly used UTF-8 locales, used as the default
12237 value of the @code{locale-definitions} field of @code{operating-system}
12240 @cindex locale name
12241 @cindex normalized codeset in locale names
12242 These locale definitions use the @dfn{normalized codeset} for the part
12243 that follows the dot in the name (@pxref{Using gettextized software,
12244 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
12245 instance it has @code{uk_UA.utf8} but @emph{not}, say,
12246 @code{uk_UA.UTF-8}.
12249 @subsection Locale Data Compatibility Considerations
12251 @cindex incompatibility, of locale data
12252 @code{operating-system} declarations provide a @code{locale-libcs} field
12253 to specify the GNU@tie{}libc packages that are used to compile locale
12254 declarations (@pxref{operating-system Reference}). ``Why would I
12255 care?'', you may ask. Well, it turns out that the binary format of
12256 locale data is occasionally incompatible from one libc version to
12259 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
12260 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
12261 For instance, a program linked against libc version 2.21 is unable to
12262 read locale data produced with libc 2.22; worse, that program
12263 @emph{aborts} instead of simply ignoring the incompatible locale
12264 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
12265 the incompatible locale data, which is already an improvement.}.
12266 Similarly, a program linked against libc 2.22 can read most, but not
12267 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
12268 data is incompatible); thus calls to @code{setlocale} may fail, but
12269 programs will not abort.
12271 The ``problem'' with Guix is that users have a lot of freedom: They can
12272 choose whether and when to upgrade software in their profiles, and might
12273 be using a libc version different from the one the system administrator
12274 used to build the system-wide locale data.
12276 Fortunately, unprivileged users can also install their own locale data
12277 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
12278 @env{GUIX_LOCPATH} and locale packages}).
12280 Still, it is best if the system-wide locale data at
12281 @file{/run/current-system/locale} is built for all the libc versions
12282 actually in use on the system, so that all the programs can access
12283 it---this is especially crucial on a multi-user system. To do that, the
12284 administrator can specify several libc packages in the
12285 @code{locale-libcs} field of @code{operating-system}:
12288 (use-package-modules base)
12292 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
12295 This example would lead to a system containing locale definitions for
12296 both libc 2.21 and the current version of libc in
12297 @file{/run/current-system/locale}.
12303 @cindex system services
12304 An important part of preparing an @code{operating-system} declaration is
12305 listing @dfn{system services} and their configuration (@pxref{Using the
12306 Configuration System}). System services are typically daemons launched
12307 when the system boots, or other actions needed at that time---e.g.,
12308 configuring network access.
12310 Guix has a broad definition of ``service'' (@pxref{Service
12311 Composition}), but many services are managed by the GNU@tie{}Shepherd
12312 (@pxref{Shepherd Services}). On a running system, the @command{herd}
12313 command allows you to list the available services, show their status,
12314 start and stop them, or do other specific operations (@pxref{Jump
12315 Start,,, shepherd, The GNU Shepherd Manual}). For example:
12321 The above command, run as @code{root}, lists the currently defined
12322 services. The @command{herd doc} command shows a synopsis of the given
12323 service and its associated actions:
12327 Run libc's name service cache daemon (nscd).
12329 # herd doc nscd action invalidate
12330 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12333 The @command{start}, @command{stop}, and @command{restart} sub-commands
12334 have the effect you would expect. For instance, the commands below stop
12335 the nscd service and restart the Xorg display server:
12339 Service nscd has been stopped.
12340 # herd restart xorg-server
12341 Service xorg-server has been stopped.
12342 Service xorg-server has been started.
12345 The following sections document the available services, starting with
12346 the core services, that may be used in an @code{operating-system}
12350 * Base Services:: Essential system services.
12351 * Scheduled Job Execution:: The mcron service.
12352 * Log Rotation:: The rottlog service.
12353 * Networking Services:: Network setup, SSH daemon, etc.
12354 * X Window:: Graphical display.
12355 * Printing Services:: Local and remote printer support.
12356 * Desktop Services:: D-Bus and desktop services.
12357 * Sound Services:: ALSA and Pulseaudio services.
12358 * Database Services:: SQL databases, key-value stores, etc.
12359 * Mail Services:: IMAP, POP3, SMTP, and all that.
12360 * Messaging Services:: Messaging services.
12361 * Telephony Services:: Telephony services.
12362 * Monitoring Services:: Monitoring services.
12363 * Kerberos Services:: Kerberos services.
12364 * LDAP Services:: LDAP services.
12365 * Web Services:: Web servers.
12366 * Certificate Services:: TLS certificates via Let's Encrypt.
12367 * DNS Services:: DNS daemons.
12368 * VPN Services:: VPN daemons.
12369 * Network File System:: NFS related services.
12370 * Continuous Integration:: The Cuirass service.
12371 * Power Management Services:: Extending battery life.
12372 * Audio Services:: The MPD.
12373 * Virtualization Services:: Virtualization services.
12374 * Version Control Services:: Providing remote access to Git repositories.
12375 * Game Services:: Game servers.
12376 * PAM Mount Service:: Service to mount volumes when logging in.
12377 * Guix Services:: Services relating specifically to Guix.
12378 * Linux Services:: Services tied to the Linux kernel.
12379 * Miscellaneous Services:: Other services.
12382 @node Base Services
12383 @subsection Base Services
12385 The @code{(gnu services base)} module provides definitions for the basic
12386 services that one expects from the system. The services exported by
12387 this module are listed below.
12389 @defvr {Scheme Variable} %base-services
12390 This variable contains a list of basic services (@pxref{Service Types
12391 and Services}, for more information on service objects) one would
12392 expect from the system: a login service (mingetty) on each tty, syslogd,
12393 the libc name service cache daemon (nscd), the udev device manager, and
12396 This is the default value of the @code{services} field of
12397 @code{operating-system} declarations. Usually, when customizing a
12398 system, you will want to append services to @code{%base-services}, like
12402 (append (list (service avahi-service-type)
12403 (service openssh-service-type))
12408 @defvr {Scheme Variable} special-files-service-type
12409 This is the service that sets up ``special files'' such as
12410 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12412 The value associated with @code{special-files-service-type} services
12413 must be a list of tuples where the first element is the ``special file''
12414 and the second element is its target. By default it is:
12416 @cindex @file{/bin/sh}
12417 @cindex @file{sh}, in @file{/bin}
12419 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12422 @cindex @file{/usr/bin/env}
12423 @cindex @file{env}, in @file{/usr/bin}
12424 If you want to add, say, @code{/usr/bin/env} to your system, you can
12428 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12429 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12432 Since this is part of @code{%base-services}, you can use
12433 @code{modify-services} to customize the set of special files
12434 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12435 to add a special file is @i{via} the @code{extra-special-file} procedure
12439 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12440 Use @var{target} as the ``special file'' @var{file}.
12442 For example, adding the following lines to the @code{services} field of
12443 your operating system declaration leads to a @file{/usr/bin/env}
12447 (extra-special-file "/usr/bin/env"
12448 (file-append coreutils "/bin/env"))
12452 @deffn {Scheme Procedure} host-name-service @var{name}
12453 Return a service that sets the host name to @var{name}.
12456 @defvr {Scheme Variable} console-font-service-type
12457 Install the given fonts on the specified ttys (fonts are per
12458 virtual console on the kernel Linux). The value of this service is a list of
12459 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
12460 package or any valid argument to @command{setfont}, as in this example:
12463 `(("tty1" . "LatGrkCyr-8x16")
12464 ("tty2" . ,(file-append
12466 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
12467 ("tty3" . ,(file-append
12469 "/share/consolefonts/ter-132n"))) ; for HDPI
12473 @deffn {Scheme Procedure} login-service @var{config}
12474 Return a service to run login according to @var{config}, a
12475 @code{<login-configuration>} object, which specifies the message of the day,
12476 among other things.
12479 @deftp {Data Type} login-configuration
12480 This is the data type representing the configuration of login.
12485 @cindex message of the day
12486 A file-like object containing the ``message of the day''.
12488 @item @code{allow-empty-passwords?} (default: @code{#t})
12489 Allow empty passwords by default so that first-time users can log in when
12490 the 'root' account has just been created.
12495 @deffn {Scheme Procedure} mingetty-service @var{config}
12496 Return a service to run mingetty according to @var{config}, a
12497 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12501 @deftp {Data Type} mingetty-configuration
12502 This is the data type representing the configuration of Mingetty, which
12503 provides the default implementation of virtual console log-in.
12508 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12510 @item @code{auto-login} (default: @code{#f})
12511 When true, this field must be a string denoting the user name under
12512 which the system automatically logs in. When it is @code{#f}, a
12513 user name and password must be entered to log in.
12515 @item @code{login-program} (default: @code{#f})
12516 This must be either @code{#f}, in which case the default log-in program
12517 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12518 the name of the log-in program.
12520 @item @code{login-pause?} (default: @code{#f})
12521 When set to @code{#t} in conjunction with @var{auto-login}, the user
12522 will have to press a key before the log-in shell is launched.
12524 @item @code{mingetty} (default: @var{mingetty})
12525 The Mingetty package to use.
12530 @deffn {Scheme Procedure} agetty-service @var{config}
12531 Return a service to run agetty according to @var{config}, an
12532 @code{<agetty-configuration>} object, which specifies the tty to run,
12533 among other things.
12536 @deftp {Data Type} agetty-configuration
12537 This is the data type representing the configuration of agetty, which
12538 implements virtual and serial console log-in. See the @code{agetty(8)}
12539 man page for more information.
12544 The name of the console this agetty runs on, as a string---e.g.,
12545 @code{"ttyS0"}. This argument is optional, it will default to
12546 a reasonable default serial port used by the kernel Linux.
12548 For this, if there is a value for an option @code{agetty.tty} in the kernel
12549 command line, agetty will extract the device name of the serial port
12550 from it and use that.
12552 If not and if there is a value for an option @code{console} with a tty in
12553 the Linux command line, agetty will extract the device name of the
12554 serial port from it and use that.
12556 In both cases, agetty will leave the other serial device settings
12557 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12560 @item @code{baud-rate} (default: @code{#f})
12561 A string containing a comma-separated list of one or more baud rates, in
12564 @item @code{term} (default: @code{#f})
12565 A string containing the value used for the @env{TERM} environment
12568 @item @code{eight-bits?} (default: @code{#f})
12569 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12572 @item @code{auto-login} (default: @code{#f})
12573 When passed a login name, as a string, the specified user will be logged
12574 in automatically without prompting for their login name or password.
12576 @item @code{no-reset?} (default: @code{#f})
12577 When @code{#t}, don't reset terminal cflags (control modes).
12579 @item @code{host} (default: @code{#f})
12580 This accepts a string containing the ``login_host'', which will be written
12581 into the @file{/var/run/utmpx} file.
12583 @item @code{remote?} (default: @code{#f})
12584 When set to @code{#t} in conjunction with @var{host}, this will add an
12585 @code{-r} fakehost option to the command line of the login program
12586 specified in @var{login-program}.
12588 @item @code{flow-control?} (default: @code{#f})
12589 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12591 @item @code{no-issue?} (default: @code{#f})
12592 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12593 not be displayed before presenting the login prompt.
12595 @item @code{init-string} (default: @code{#f})
12596 This accepts a string that will be sent to the tty or modem before
12597 sending anything else. It can be used to initialize a modem.
12599 @item @code{no-clear?} (default: @code{#f})
12600 When set to @code{#t}, agetty will not clear the screen before showing
12603 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12604 This must be either a gexp denoting the name of a log-in program, or
12605 unset, in which case the default value is the @command{login} from the
12608 @item @code{local-line} (default: @code{#f})
12609 Control the CLOCAL line flag. This accepts one of three symbols as
12610 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12611 the default value chosen by agetty is @code{'auto}.
12613 @item @code{extract-baud?} (default: @code{#f})
12614 When set to @code{#t}, instruct agetty to try to extract the baud rate
12615 from the status messages produced by certain types of modems.
12617 @item @code{skip-login?} (default: @code{#f})
12618 When set to @code{#t}, do not prompt the user for a login name. This
12619 can be used with @var{login-program} field to use non-standard login
12622 @item @code{no-newline?} (default: @code{#f})
12623 When set to @code{#t}, do not print a newline before printing the
12624 @file{/etc/issue} file.
12626 @c Is this dangerous only when used with login-program, or always?
12627 @item @code{login-options} (default: @code{#f})
12628 This option accepts a string containing options that are passed to the
12629 login program. When used with the @var{login-program}, be aware that a
12630 malicious user could try to enter a login name containing embedded
12631 options that could be parsed by the login program.
12633 @item @code{login-pause} (default: @code{#f})
12634 When set to @code{#t}, wait for any key before showing the login prompt.
12635 This can be used in conjunction with @var{auto-login} to save memory by
12636 lazily spawning shells.
12638 @item @code{chroot} (default: @code{#f})
12639 Change root to the specified directory. This option accepts a directory
12642 @item @code{hangup?} (default: @code{#f})
12643 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12644 specified terminal.
12646 @item @code{keep-baud?} (default: @code{#f})
12647 When set to @code{#t}, try to keep the existing baud rate. The baud
12648 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12651 @item @code{timeout} (default: @code{#f})
12652 When set to an integer value, terminate if no user name could be read
12653 within @var{timeout} seconds.
12655 @item @code{detect-case?} (default: @code{#f})
12656 When set to @code{#t}, turn on support for detecting an uppercase-only
12657 terminal. This setting will detect a login name containing only
12658 uppercase letters as indicating an uppercase-only terminal and turn on
12659 some upper-to-lower case conversions. Note that this will not support
12660 Unicode characters.
12662 @item @code{wait-cr?} (default: @code{#f})
12663 When set to @code{#t}, wait for the user or modem to send a
12664 carriage-return or linefeed character before displaying
12665 @file{/etc/issue} or login prompt. This is typically used with the
12666 @var{init-string} option.
12668 @item @code{no-hints?} (default: @code{#f})
12669 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12672 @item @code{no-hostname?} (default: @code{#f})
12673 By default, the hostname is printed. When this option is set to
12674 @code{#t}, no hostname will be shown at all.
12676 @item @code{long-hostname?} (default: @code{#f})
12677 By default, the hostname is only printed until the first dot. When this
12678 option is set to @code{#t}, the fully qualified hostname by
12679 @code{gethostname} or @code{getaddrinfo} is shown.
12681 @item @code{erase-characters} (default: @code{#f})
12682 This option accepts a string of additional characters that should be
12683 interpreted as backspace when the user types their login name.
12685 @item @code{kill-characters} (default: @code{#f})
12686 This option accepts a string that should be interpreted to mean ``ignore
12687 all previous characters'' (also called a ``kill'' character) when the user
12688 types their login name.
12690 @item @code{chdir} (default: @code{#f})
12691 This option accepts, as a string, a directory path that will be changed
12694 @item @code{delay} (default: @code{#f})
12695 This options accepts, as an integer, the number of seconds to sleep
12696 before opening the tty and displaying the login prompt.
12698 @item @code{nice} (default: @code{#f})
12699 This option accepts, as an integer, the nice value with which to run the
12700 @command{login} program.
12702 @item @code{extra-options} (default: @code{'()})
12703 This option provides an ``escape hatch'' for the user to provide arbitrary
12704 command-line arguments to @command{agetty} as a list of strings.
12709 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12710 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12711 according to @var{config}, a @code{<kmscon-configuration>} object, which
12712 specifies the tty to run, among other things.
12715 @deftp {Data Type} kmscon-configuration
12716 This is the data type representing the configuration of Kmscon, which
12717 implements virtual console log-in.
12721 @item @code{virtual-terminal}
12722 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12724 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12725 A gexp denoting the name of the log-in program. The default log-in program is
12726 @command{login} from the Shadow tool suite.
12728 @item @code{login-arguments} (default: @code{'("-p")})
12729 A list of arguments to pass to @command{login}.
12731 @item @code{auto-login} (default: @code{#f})
12732 When passed a login name, as a string, the specified user will be logged
12733 in automatically without prompting for their login name or password.
12735 @item @code{hardware-acceleration?} (default: #f)
12736 Whether to use hardware acceleration.
12738 @item @code{kmscon} (default: @var{kmscon})
12739 The Kmscon package to use.
12744 @cindex name service cache daemon
12746 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12747 [#:name-services '()]
12748 Return a service that runs the libc name service cache daemon (nscd) with the
12749 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12750 Service Switch}, for an example.
12752 For convenience, the Shepherd service for nscd provides the following actions:
12756 @cindex cache invalidation, nscd
12757 @cindex nscd, cache invalidation
12758 This invalidate the given cache. For instance, running:
12761 herd invalidate nscd hosts
12765 invalidates the host name lookup cache of nscd.
12768 Running @command{herd statistics nscd} displays information about nscd usage
12774 @defvr {Scheme Variable} %nscd-default-configuration
12775 This is the default @code{<nscd-configuration>} value (see below) used
12776 by @code{nscd-service}. It uses the caches defined by
12777 @code{%nscd-default-caches}; see below.
12780 @deftp {Data Type} nscd-configuration
12781 This is the data type representing the name service cache daemon (nscd)
12786 @item @code{name-services} (default: @code{'()})
12787 List of packages denoting @dfn{name services} that must be visible to
12788 the nscd---e.g., @code{(list @var{nss-mdns})}.
12790 @item @code{glibc} (default: @var{glibc})
12791 Package object denoting the GNU C Library providing the @command{nscd}
12794 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12795 Name of the nscd log file. This is where debugging output goes when
12796 @code{debug-level} is strictly positive.
12798 @item @code{debug-level} (default: @code{0})
12799 Integer denoting the debugging levels. Higher numbers mean that more
12800 debugging output is logged.
12802 @item @code{caches} (default: @code{%nscd-default-caches})
12803 List of @code{<nscd-cache>} objects denoting things to be cached; see
12809 @deftp {Data Type} nscd-cache
12810 Data type representing a cache database of nscd and its parameters.
12814 @item @code{database}
12815 This is a symbol representing the name of the database to be cached.
12816 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12817 @code{services}, which designate the corresponding NSS database
12818 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12820 @item @code{positive-time-to-live}
12821 @itemx @code{negative-time-to-live} (default: @code{20})
12822 A number representing the number of seconds during which a positive or
12823 negative lookup result remains in cache.
12825 @item @code{check-files?} (default: @code{#t})
12826 Whether to check for updates of the files corresponding to
12829 For instance, when @var{database} is @code{hosts}, setting this flag
12830 instructs nscd to check for updates in @file{/etc/hosts} and to take
12833 @item @code{persistent?} (default: @code{#t})
12834 Whether the cache should be stored persistently on disk.
12836 @item @code{shared?} (default: @code{#t})
12837 Whether the cache should be shared among users.
12839 @item @code{max-database-size} (default: 32@tie{}MiB)
12840 Maximum size in bytes of the database cache.
12842 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12843 @c settings, so leave them out.
12848 @defvr {Scheme Variable} %nscd-default-caches
12849 List of @code{<nscd-cache>} objects used by default by
12850 @code{nscd-configuration} (see above).
12852 It enables persistent and aggressive caching of service and host name
12853 lookups. The latter provides better host name lookup performance,
12854 resilience in the face of unreliable name servers, and also better
12855 privacy---often the result of host name lookups is in local cache, so
12856 external name servers do not even need to be queried.
12859 @anchor{syslog-configuration-type}
12862 @deftp {Data Type} syslog-configuration
12863 This data type represents the configuration of the syslog daemon.
12866 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12867 The syslog daemon to use.
12869 @item @code{config-file} (default: @code{%default-syslog.conf})
12870 The syslog configuration file to use.
12875 @anchor{syslog-service}
12877 @deffn {Scheme Procedure} syslog-service @var{config}
12878 Return a service that runs a syslog daemon according to @var{config}.
12880 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12881 information on the configuration file syntax.
12884 @defvr {Scheme Variable} guix-service-type
12885 This is the type of the service that runs the build daemon,
12886 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12887 @code{guix-configuration} record as described below.
12890 @anchor{guix-configuration-type}
12891 @deftp {Data Type} guix-configuration
12892 This data type represents the configuration of the Guix build daemon.
12893 @xref{Invoking guix-daemon}, for more information.
12896 @item @code{guix} (default: @var{guix})
12897 The Guix package to use.
12899 @item @code{build-group} (default: @code{"guixbuild"})
12900 Name of the group for build user accounts.
12902 @item @code{build-accounts} (default: @code{10})
12903 Number of build user accounts to create.
12905 @item @code{authorize-key?} (default: @code{#t})
12906 @cindex substitutes, authorization thereof
12907 Whether to authorize the substitute keys listed in
12908 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12909 (@pxref{Substitutes}).
12911 @vindex %default-authorized-guix-keys
12912 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12913 The list of authorized key files for archive imports, as a list of
12914 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12915 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12917 @item @code{use-substitutes?} (default: @code{#t})
12918 Whether to use substitutes.
12920 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12921 The list of URLs where to look for substitutes by default.
12923 @item @code{max-silent-time} (default: @code{0})
12924 @itemx @code{timeout} (default: @code{0})
12925 The number of seconds of silence and the number of seconds of activity,
12926 respectively, after which a build process times out. A value of zero
12927 disables the timeout.
12929 @item @code{log-compression} (default: @code{'bzip2})
12930 The type of compression used for build logs---one of @code{gzip},
12931 @code{bzip2}, or @code{none}.
12933 @item @code{extra-options} (default: @code{'()})
12934 List of extra command-line options for @command{guix-daemon}.
12936 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12937 File where @command{guix-daemon}'s standard output and standard error
12940 @cindex HTTP proxy, for @code{guix-daemon}
12941 @cindex proxy, for @code{guix-daemon} HTTP access
12942 @item @code{http-proxy} (default: @code{#f})
12943 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
12944 derivations and substitutes.
12946 It is also possible to change the daemon's proxy at run time through the
12947 @code{set-http-proxy} action, which restarts it:
12950 herd set-http-proxy guix-daemon http://localhost:8118
12953 To clear the proxy settings, run:
12956 herd set-http-proxy guix-daemon
12959 @item @code{tmpdir} (default: @code{#f})
12960 A directory path where the @command{guix-daemon} will perform builds.
12965 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12966 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12967 udev rules can be provided as a list of files through the @var{rules}
12968 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
12969 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
12970 creation of such rule files.
12972 The @command{herd rules udev} command, as root, returns the name of the
12973 directory containing all the active udev rules.
12976 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12977 Return a udev-rule file named @var{file-name} containing the rules
12978 defined by the @var{contents} literal.
12980 In the following example, a rule for a USB device is defined to be
12981 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12982 upon detecting a USB device with a given product identifier.
12985 (define %example-udev-rule
12987 "90-usb-thing.rules"
12988 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12989 "ATTR@{product@}==\"Example\", "
12990 "RUN+=\"/path/to/script\"")))
12994 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
12995 [#:groups @var{groups}]
12996 Return a service that extends @code{udev-service-type } with @var{rules}
12997 and @code{account-service-type} with @var{groups} as system groups.
12998 This works by creating a singleton service type
12999 @code{@var{name}-udev-rules}, of which the returned service is an
13002 Here we show how it can be used to extend @code{udev-service-type} with the
13003 previously defined rule @code{%example-udev-rule}.
13009 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13010 %desktop-services)))
13014 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13015 Return a udev file named @var{file-name} containing the rules defined
13016 within @var{file}, a file-like object.
13018 The following example showcases how we can use an existing rule file.
13021 (use-modules (guix download) ;for url-fetch
13022 (guix packages) ;for origin
13025 (define %android-udev-rules
13027 "51-android-udev.rules"
13028 (let ((version "20170910"))
13031 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13032 "android-udev-rules/" version "/51-android.rules"))
13034 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13038 Additionally, Guix package definitions can be included in @var{rules} in
13039 order to extend the udev rules with the definitions found under their
13040 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13041 @var{file->udev-rule} example, we could have used the
13042 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13043 packages android)} module.
13045 The following example shows how to use the @var{android-udev-rules}
13046 package so that the Android tool @command{adb} can detect devices
13047 without root privileges. It also details how to create the
13048 @code{adbusers} group, which is required for the proper functioning of
13049 the rules defined within the @code{android-udev-rules} package. To
13050 create such a group, we must define it both as part of the
13051 @code{supplementary-groups} of our @code{user-account} declaration, as
13052 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13055 (use-modules (gnu packages android) ;for android-udev-rules
13056 (gnu system shadow) ;for user-group
13061 (users (cons (user-account
13063 (supplementary-groups
13064 '("adbusers" ;for adb
13065 "wheel" "netdev" "audio" "video")))))
13068 (cons (udev-rules-service 'android android-udev-rules
13069 #:groups '("adbusers"))
13070 %desktop-services)))
13073 @defvr {Scheme Variable} urandom-seed-service-type
13074 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13075 when rebooting. It also tries to seed @file{/dev/urandom} from
13076 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13080 @defvr {Scheme Variable} %random-seed-file
13081 This is the name of the file where some random bytes are saved by
13082 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13083 It defaults to @file{/var/lib/random-seed}.
13088 @defvr {Scheme Variable} gpm-service-type
13089 This is the type of the service that runs GPM, the @dfn{general-purpose
13090 mouse daemon}, which provides mouse support to the Linux console. GPM
13091 allows users to use the mouse in the console, notably to select, copy,
13094 The value for services of this type must be a @code{gpm-configuration}
13095 (see below). This service is not part of @code{%base-services}.
13098 @deftp {Data Type} gpm-configuration
13099 Data type representing the configuration of GPM.
13102 @item @code{options} (default: @code{%default-gpm-options})
13103 Command-line options passed to @command{gpm}. The default set of
13104 options instruct @command{gpm} to listen to mouse events on
13105 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13108 @item @code{gpm} (default: @code{gpm})
13109 The GPM package to use.
13114 @anchor{guix-publish-service-type}
13115 @deffn {Scheme Variable} guix-publish-service-type
13116 This is the service type for @command{guix publish} (@pxref{Invoking
13117 guix publish}). Its value must be a @code{guix-publish-configuration}
13118 object, as described below.
13120 This assumes that @file{/etc/guix} already contains a signing key pair as
13121 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13122 archive}). If that is not the case, the service will fail to start.
13125 @deftp {Data Type} guix-publish-configuration
13126 Data type representing the configuration of the @code{guix publish}
13130 @item @code{guix} (default: @code{guix})
13131 The Guix package to use.
13133 @item @code{port} (default: @code{80})
13134 The TCP port to listen for connections.
13136 @item @code{host} (default: @code{"localhost"})
13137 The host (and thus, network interface) to listen to. Use
13138 @code{"0.0.0.0"} to listen on all the network interfaces.
13140 @item @code{compression} (default: @code{'(("gzip" 3))})
13141 This is a list of compression method/level tuple used when compressing
13142 substitutes. For example, to compress all substitutes with @emph{both} lzip
13143 at level 7 and gzip at level 9, write:
13146 '(("lzip" 7) ("gzip" 9))
13149 Level 9 achieves the best compression ratio at the expense of increased CPU
13150 usage, whereas level 1 achieves fast compression.
13152 An empty list disables compression altogether.
13154 @item @code{nar-path} (default: @code{"nar"})
13155 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
13156 publish, @option{--nar-path}}, for details.
13158 @item @code{cache} (default: @code{#f})
13159 When it is @code{#f}, disable caching and instead generate archives on
13160 demand. Otherwise, this should be the name of a directory---e.g.,
13161 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
13162 archives and meta-data ready to be sent. @xref{Invoking guix publish,
13163 @option{--cache}}, for more information on the tradeoffs involved.
13165 @item @code{workers} (default: @code{#f})
13166 When it is an integer, this is the number of worker threads used for
13167 caching; when @code{#f}, the number of processors is used.
13168 @xref{Invoking guix publish, @option{--workers}}, for more information.
13170 @item @code{ttl} (default: @code{#f})
13171 When it is an integer, this denotes the @dfn{time-to-live} in seconds
13172 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
13173 for more information.
13177 @anchor{rngd-service}
13178 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
13179 [#:device "/dev/hwrng"]
13180 Return a service that runs the @command{rngd} program from @var{rng-tools}
13181 to add @var{device} to the kernel's entropy pool. The service will fail if
13182 @var{device} does not exist.
13185 @anchor{pam-limits-service}
13186 @cindex session limits
13191 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
13193 Return a service that installs a configuration file for the
13194 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
13195 @code{pam_limits} module}. The procedure optionally takes a list of
13196 @code{pam-limits-entry} values, which can be used to specify
13197 @code{ulimit} limits and nice priority limits to user sessions.
13199 The following limits definition sets two hard and soft limits for all
13200 login sessions of users in the @code{realtime} group:
13203 (pam-limits-service
13205 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
13206 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
13209 The first entry increases the maximum realtime priority for
13210 non-privileged processes; the second entry lifts any restriction of the
13211 maximum address space that can be locked in memory. These settings are
13212 commonly used for real-time audio systems.
13215 @node Scheduled Job Execution
13216 @subsection Scheduled Job Execution
13220 @cindex scheduling jobs
13221 The @code{(gnu services mcron)} module provides an interface to
13222 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
13223 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
13224 Unix @command{cron} daemon; the main difference is that it is
13225 implemented in Guile Scheme, which provides a lot of flexibility when
13226 specifying the scheduling of jobs and their actions.
13228 The example below defines an operating system that runs the
13229 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
13230 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
13231 well as the @command{mkid} command on behalf of an unprivileged user
13232 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
13233 gexps to introduce job definitions that are passed to mcron
13234 (@pxref{G-Expressions}).
13237 (use-modules (guix) (gnu) (gnu services mcron))
13238 (use-package-modules base idutils)
13240 (define updatedb-job
13241 ;; Run 'updatedb' at 3AM every day. Here we write the
13242 ;; job's action as a Scheme procedure.
13243 #~(job '(next-hour '(3))
13245 (execl (string-append #$findutils "/bin/updatedb")
13247 "--prunepaths=/tmp /var/tmp /gnu/store"))))
13249 (define garbage-collector-job
13250 ;; Collect garbage 5 minutes after midnight every day.
13251 ;; The job's action is a shell command.
13252 #~(job "5 0 * * *" ;Vixie cron syntax
13255 (define idutils-job
13256 ;; Update the index database as user "charlie" at 12:15PM
13257 ;; and 19:15PM. This runs from the user's home directory.
13258 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
13259 (string-append #$idutils "/bin/mkid src")
13264 (services (cons (service mcron-service-type
13265 (mcron-configuration
13266 (jobs (list garbage-collector-job
13272 For more complex jobs defined in Scheme where you need control over the top
13273 level, for instance to introduce a @code{use-modules} form, you can move your
13274 code to a separate program using the @code{program-file} procedure of the
13275 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
13279 (define %battery-alert-job
13280 ;; Beep when the battery percentage falls below %MIN-LEVEL.
13282 '(next-minute (range 0 60 1))
13284 "battery-alert.scm"
13285 (with-imported-modules (source-module-closure
13286 '((guix build utils)))
13288 (define %min-level 20)
13289 (use-modules (guix build utils)
13292 (ice-9 textual-ports)
13294 (setenv "LC_ALL" "C") ;ensure English output
13295 (and-let* ((input-pipe (open-pipe*
13297 #$(file-append acpi "/bin/acpi")))
13298 (output (get-string-all input-pipe))
13299 (m (string-match "Discharging, ([0-9]+)%" output))
13300 (level (string->number (match:substring m 1)))
13301 ((< level %min-level)))
13302 (format #t "warning: Battery level is low (~a%)~%" level)
13303 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
13306 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
13307 for more information on mcron job specifications. Below is the
13308 reference of the mcron service.
13310 On a running system, you can use the @code{schedule} action of the service to
13311 visualize the mcron jobs that will be executed next:
13314 # herd schedule mcron
13318 The example above lists the next five tasks that will be executed, but you can
13319 also specify the number of tasks to display:
13322 # herd schedule mcron 10
13325 @defvr {Scheme Variable} mcron-service-type
13326 This is the type of the @code{mcron} service, whose value is an
13327 @code{mcron-configuration} object.
13329 This service type can be the target of a service extension that provides
13330 it additional job specifications (@pxref{Service Composition}). In
13331 other words, it is possible to define services that provide additional
13335 @deftp {Data Type} mcron-configuration
13336 Data type representing the configuration of mcron.
13339 @item @code{mcron} (default: @var{mcron})
13340 The mcron package to use.
13343 This is a list of gexps (@pxref{G-Expressions}), where each gexp
13344 corresponds to an mcron job specification (@pxref{Syntax, mcron job
13345 specifications,, mcron, GNU@tie{}mcron}).
13351 @subsection Log Rotation
13354 @cindex log rotation
13356 Log files such as those found in @file{/var/log} tend to grow endlessly,
13357 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13358 their contents in separate files, possibly compressed. The @code{(gnu
13359 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13360 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13362 This service is part of @code{%base-services}, and thus enabled by
13363 default, with the default settings, for commonly encountered log files.
13364 The example below shows how to extend it with an additional
13365 @dfn{rotation}, should you need to do that (usually, services that
13366 produce log files already take care of that):
13369 (use-modules (guix) (gnu))
13370 (use-service-modules admin)
13372 (define my-log-files
13373 ;; Log files that I want to rotate.
13374 '("/var/log/something.log" "/var/log/another.log"))
13378 (services (cons (simple-service 'rotate-my-stuff
13379 rottlog-service-type
13380 (list (log-rotation
13382 (files my-log-files))))
13386 @defvr {Scheme Variable} rottlog-service-type
13387 This is the type of the Rottlog service, whose value is a
13388 @code{rottlog-configuration} object.
13390 Other services can extend this one with new @code{log-rotation} objects
13391 (see below), thereby augmenting the set of files to be rotated.
13393 This service type can define mcron jobs (@pxref{Scheduled Job
13394 Execution}) to run the rottlog service.
13397 @deftp {Data Type} rottlog-configuration
13398 Data type representing the configuration of rottlog.
13401 @item @code{rottlog} (default: @code{rottlog})
13402 The Rottlog package to use.
13404 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13405 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13406 rottlog, GNU Rot[t]log Manual}).
13408 @item @code{rotations} (default: @code{%default-rotations})
13409 A list of @code{log-rotation} objects as defined below.
13412 This is a list of gexps where each gexp corresponds to an mcron job
13413 specification (@pxref{Scheduled Job Execution}).
13417 @deftp {Data Type} log-rotation
13418 Data type representing the rotation of a group of log files.
13420 Taking an example from the Rottlog manual (@pxref{Period Related File
13421 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13427 (files '("/var/log/apache/*"))
13428 (options '("storedir apache-archives"
13434 The list of fields is as follows:
13437 @item @code{frequency} (default: @code{'weekly})
13438 The log rotation frequency, a symbol.
13441 The list of files or file glob patterns to rotate.
13443 @item @code{options} (default: @code{'()})
13444 The list of rottlog options for this rotation (@pxref{Configuration
13445 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13447 @item @code{post-rotate} (default: @code{#f})
13448 Either @code{#f} or a gexp to execute once the rotation has completed.
13452 @defvr {Scheme Variable} %default-rotations
13453 Specifies weekly rotation of @code{%rotated-files} and of
13454 @file{/var/log/guix-daemon.log}.
13457 @defvr {Scheme Variable} %rotated-files
13458 The list of syslog-controlled files to be rotated. By default it is:
13459 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13460 "/var/log/maillog")}.
13463 @node Networking Services
13464 @subsection Networking Services
13466 The @code{(gnu services networking)} module provides services to configure
13467 the network interface.
13469 @cindex DHCP, networking service
13470 @defvr {Scheme Variable} dhcp-client-service-type
13471 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13472 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13473 is the DHCP client package to use, @code{isc-dhcp} by default.
13476 @deffn {Scheme Procedure} dhcpd-service-type
13477 This type defines a service that runs a DHCP daemon. To create a
13478 service of this type, you must supply a @code{<dhcpd-configuration>}.
13482 (service dhcpd-service-type
13483 (dhcpd-configuration
13484 (config-file (local-file "my-dhcpd.conf"))
13485 (interfaces '("enp0s25"))))
13489 @deftp {Data Type} dhcpd-configuration
13491 @item @code{package} (default: @code{isc-dhcp})
13492 The package that provides the DHCP daemon. This package is expected to
13493 provide the daemon at @file{sbin/dhcpd} relative to its output
13494 directory. The default package is the
13495 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13496 @item @code{config-file} (default: @code{#f})
13497 The configuration file to use. This is required. It will be passed to
13498 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13499 object (@pxref{G-Expressions, file-like objects}). See @code{man
13500 dhcpd.conf} for details on the configuration file syntax.
13501 @item @code{version} (default: @code{"4"})
13502 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13503 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13504 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13506 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13507 The run directory to use. At service activation time, this directory
13508 will be created if it does not exist.
13509 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13510 The PID file to use. This corresponds to the @code{-pf} option of
13511 @code{dhcpd}. See @code{man dhcpd} for details.
13512 @item @code{interfaces} (default: @code{'()})
13513 The names of the network interfaces on which dhcpd should listen for
13514 broadcasts. If this list is not empty, then its elements (which must be
13515 strings) will be appended to the @code{dhcpd} invocation when starting
13516 the daemon. It may not be necessary to explicitly specify any
13517 interfaces here; see @code{man dhcpd} for details.
13521 @defvr {Scheme Variable} static-networking-service-type
13522 This is the type for statically-configured network interfaces.
13523 @c TODO Document <static-networking> data structures.
13526 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13527 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13528 [#:requirement @code{'(udev)}]
13529 Return a service that starts @var{interface} with address @var{ip}. If
13530 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13531 it must be a string specifying the default network gateway. @var{requirement}
13532 can be used to declare a dependency on another service before configuring the
13535 This procedure can be called several times, one for each network
13536 interface of interest. Behind the scenes what it does is extend
13537 @code{static-networking-service-type} with additional network interfaces
13543 (static-networking-service "eno1" "192.168.1.82"
13544 #:gateway "192.168.1.2"
13545 #:name-servers '("192.168.1.2"))
13552 @cindex network management
13553 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13554 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13555 management daemon that aims to simplify wired and wireless networking.
13557 This service adds the @var{wicd} package to the global profile, providing
13558 several commands to interact with the daemon and configure networking:
13559 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13560 and @command{wicd-curses} user interfaces.
13563 @cindex ModemManager
13565 @defvr {Scheme Variable} modem-manager-service-type
13566 This is the service type for the
13567 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13568 service. The value for this service type is a
13569 @code{modem-manager-configuration} record.
13571 This service is part of @code{%desktop-services} (@pxref{Desktop
13575 @deftp {Data Type} modem-manager-configuration
13576 Data type representing the configuration of ModemManager.
13579 @item @code{modem-manager} (default: @code{modem-manager})
13580 The ModemManager package to use.
13585 @cindex USB_ModeSwitch
13586 @cindex Modeswitching
13588 @defvr {Scheme Variable} usb-modeswitch-service-type
13589 This is the service type for the
13590 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13591 value for this service type is a @code{usb-modeswitch-configuration} record.
13593 When plugged in, some USB modems (and other USB devices) initially present
13594 themselves as a read-only storage medium and not as a modem. They need to be
13595 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13596 installs udev rules to automatically modeswitch these devices when they are
13599 This service is part of @code{%desktop-services} (@pxref{Desktop
13603 @deftp {Data Type} usb-modeswitch-configuration
13604 Data type representing the configuration of USB_ModeSwitch.
13607 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13608 The USB_ModeSwitch package providing the binaries for modeswitching.
13610 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13611 The package providing the device data and udev rules file used by
13614 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13615 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13616 config file shipped with USB_ModeSwitch is used which disables logging to
13617 @file{/var/log} among other default settings. If set to @code{#f}, no config
13623 @cindex NetworkManager
13625 @defvr {Scheme Variable} network-manager-service-type
13626 This is the service type for the
13627 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13628 service. The value for this service type is a
13629 @code{network-manager-configuration} record.
13631 This service is part of @code{%desktop-services} (@pxref{Desktop
13635 @deftp {Data Type} network-manager-configuration
13636 Data type representing the configuration of NetworkManager.
13639 @item @code{network-manager} (default: @code{network-manager})
13640 The NetworkManager package to use.
13642 @item @code{dns} (default: @code{"default"})
13643 Processing mode for DNS, which affects how NetworkManager uses the
13644 @code{resolv.conf} configuration file.
13648 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13649 provided by currently active connections.
13652 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13653 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13654 then update @code{resolv.conf} to point to the local nameserver.
13656 With this setting, you can share your network connection. For example when
13657 you want to share your network connection to another laptop @i{via} an
13658 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13659 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13660 and reestablish the connection (or reboot).
13662 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13663 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13664 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13665 browser on your host system, or connect to the VM @i{via} SSH
13666 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13667 host-to-guest connection, run this command once:
13670 nmcli connection add type tun \
13671 connection.interface-name tap0 \
13672 tun.mode tap tun.owner $(id -u) \
13673 ipv4.method shared \
13674 ipv4.addresses 172.28.112.1/24
13677 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13678 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13679 @command{qemu-system-...}.
13682 NetworkManager will not modify @code{resolv.conf}.
13685 @item @code{vpn-plugins} (default: @code{'()})
13686 This is the list of available plugins for virtual private networks
13687 (VPNs). An example of this is the @code{network-manager-openvpn}
13688 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13694 @deffn {Scheme Variable} connman-service-type
13695 This is the service type to run @url{https://01.org/connman,Connman},
13696 a network connection manager.
13698 Its value must be an
13699 @code{connman-configuration} record as in this example:
13702 (service connman-service-type
13703 (connman-configuration
13704 (disable-vpn? #t)))
13707 See below for details about @code{connman-configuration}.
13710 @deftp {Data Type} connman-configuration
13711 Data Type representing the configuration of connman.
13714 @item @code{connman} (default: @var{connman})
13715 The connman package to use.
13717 @item @code{disable-vpn?} (default: @code{#f})
13718 When true, disable connman's vpn plugin.
13722 @cindex WPA Supplicant
13723 @defvr {Scheme Variable} wpa-supplicant-service-type
13724 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13725 supplicant}, an authentication daemon required to authenticate against
13726 encrypted WiFi or ethernet networks.
13729 @deftp {Data Type} wpa-supplicant-configuration
13730 Data type representing the configuration of WPA Supplicant.
13732 It takes the following parameters:
13735 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13736 The WPA Supplicant package to use.
13738 @item @code{dbus?} (default: @code{#t})
13739 Whether to listen for requests on D-Bus.
13741 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13742 Where to store the PID file.
13744 @item @code{interface} (default: @code{#f})
13745 If this is set, it must specify the name of a network interface that
13746 WPA supplicant will control.
13748 @item @code{config-file} (default: @code{#f})
13749 Optional configuration file to use.
13751 @item @code{extra-options} (default: @code{'()})
13752 List of additional command-line arguments to pass to the daemon.
13756 @cindex hostapd service, for Wi-Fi access points
13757 @cindex Wi-Fi access points, hostapd service
13758 @defvr {Scheme Variable} hostapd-service-type
13759 This is the service type to run the @uref{https://w1.fi/hostapd/,
13760 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
13761 authentication servers. Its associated value must be a
13762 @code{hostapd-configuration} as shown below:
13765 ;; Use wlan1 to run the access point for "My Network".
13766 (service hostapd-service-type
13767 (hostapd-configuration
13768 (interface "wlan1")
13769 (ssid "My Network")
13774 @deftp {Data Type} hostapd-configuration
13775 This data type represents the configuration of the hostapd service, with
13776 the following fields:
13779 @item @code{package} (default: @code{hostapd})
13780 The hostapd package to use.
13782 @item @code{interface} (default: @code{"wlan0"})
13783 The network interface to run the WiFi access point.
13786 The SSID (@dfn{service set identifier}), a string that identifies this
13789 @item @code{broadcast-ssid?} (default: @code{#t})
13790 Whether to broadcast this SSID.
13792 @item @code{channel} (default: @code{1})
13793 The WiFi channel to use.
13795 @item @code{driver} (default: @code{"nl80211"})
13796 The driver interface type. @code{"nl80211"} is used with all Linux
13797 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
13798 RADIUS server that does # not control any wireless/wired driver.
13800 @item @code{extra-settings} (default: @code{""})
13801 Extra settings to append as-is to the hostapd configuration file. See
13802 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
13803 configuration file reference.
13807 @defvr {Scheme Variable} simulated-wifi-service-type
13808 This is the type of a service to simulate WiFi networking, which can be
13809 useful in virtual machines for testing purposes. The service loads the
13811 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
13812 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
13813 network that can be seen on @code{wlan0}, by default.
13815 The service's value is a @code{hostapd-configuration} record.
13819 @defvr {Scheme Variable} iptables-service-type
13820 This is the service type to set up an iptables configuration. iptables is a
13821 packet filtering framework supported by the Linux kernel. This service
13822 supports configuring iptables for both IPv4 and IPv6. A simple example
13823 configuration rejecting all incoming connections except those to the ssh port
13827 (service iptables-service-type
13828 (iptables-configuration
13829 (ipv4-rules (plain-file "iptables.rules" "*filter
13833 -A INPUT -p tcp --dport 22 -j ACCEPT
13834 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13837 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13841 -A INPUT -p tcp --dport 22 -j ACCEPT
13842 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13848 @deftp {Data Type} iptables-configuration
13849 The data type representing the configuration of iptables.
13852 @item @code{iptables} (default: @code{iptables})
13853 The iptables package that provides @code{iptables-restore} and
13854 @code{ip6tables-restore}.
13855 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13856 The iptables rules to use. It will be passed to @code{iptables-restore}.
13857 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13859 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13860 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13861 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13867 @defvr {Scheme Variable} nftables-service-type
13868 This is the service type to set up a nftables configuration. nftables is a
13869 netfilter project that aims to replace the existing iptables, ip6tables,
13870 arptables and ebtables framework. It provides a new packet filtering
13871 framework, a new user-space utility @command{nft}, and a compatibility layer
13872 for iptables. This service comes with a default ruleset
13873 @code{%default-nftables-ruleset} that rejecting all incomming connections
13874 except those to the ssh port 22. To use it, simply write:
13877 (service nftables-service-type)
13881 @deftp {Data Type} nftables-configuration
13882 The data type representing the configuration of nftables.
13885 @item @code{package} (default: @code{nftables})
13886 The nftables package that provides @command{nft}.
13887 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13888 The nftables ruleset to use. This may be any ``file-like'' object
13889 (@pxref{G-Expressions, file-like objects}).
13893 @cindex NTP (Network Time Protocol), service
13894 @cindex ntpd, service for the Network Time Protocol daemon
13895 @cindex real time clock
13896 @defvr {Scheme Variable} ntp-service-type
13897 This is the type of the service running the @uref{https://www.ntp.org,
13898 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13899 system clock synchronized with that of the specified NTP servers.
13901 The value of this service is an @code{ntpd-configuration} object, as described
13905 @deftp {Data Type} ntp-configuration
13906 This is the data type for the NTP service configuration.
13909 @item @code{servers} (default: @code{%ntp-servers})
13910 This is the list of servers (@code{<ntp-server>} records) with which
13911 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13914 @item @code{allow-large-adjustment?} (default: @code{#t})
13915 This determines whether @command{ntpd} is allowed to make an initial
13916 adjustment of more than 1,000 seconds.
13918 @item @code{ntp} (default: @code{ntp})
13919 The NTP package to use.
13923 @defvr {Scheme Variable} %ntp-servers
13924 List of host names used as the default NTP servers. These are servers of the
13925 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13928 @deftp {Data Type} ntp-server
13929 The data type representing the configuration of a NTP server.
13932 @item @code{type} (default: @code{'server})
13933 The type of the NTP server, given as a symbol. One of @code{'pool},
13934 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13936 @item @code{address}
13937 The address of the server, as a string.
13939 @item @code{options}
13940 NTPD options to use with that specific server, given as a list of option names
13941 and/or of option names and values tuples. The following example define a server
13942 to use with the options @option{iburst} and @option{prefer}, as well as
13943 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13948 (address "some.ntp.server.org")
13949 (options `(iburst (version 3) (maxpoll 16) prefer))))
13955 @deffn {Scheme Procedure} openntpd-service-type
13956 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13957 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13958 clock synchronized with that of the given servers.
13962 openntpd-service-type
13963 (openntpd-configuration
13964 (listen-on '("127.0.0.1" "::1"))
13965 (sensor '("udcf0 correction 70000"))
13966 (constraint-from '("www.gnu.org"))
13967 (constraints-from '("https://www.google.com/"))
13968 (allow-large-adjustment? #t)))
13973 @defvr {Scheme Variable} %openntpd-servers
13974 This variable is a list of the server addresses defined in
13975 @code{%ntp-servers}.
13978 @deftp {Data Type} openntpd-configuration
13980 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13981 The openntpd executable to use.
13982 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13983 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13984 @item @code{query-from} (default: @code{'()})
13985 A list of local IP address the ntpd daemon should use for outgoing queries.
13986 @item @code{sensor} (default: @code{'()})
13987 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13988 will listen to each sensor that actually exists and ignore non-existent ones.
13989 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13991 @item @code{server} (default: @code{'()})
13992 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13993 @item @code{servers} (default: @code{%openntp-servers})
13994 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13995 @item @code{constraint-from} (default: @code{'()})
13996 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13997 This time information is not used for precision but acts as an authenticated
13998 constraint, thereby reducing the impact of unauthenticated NTP
13999 man-in-the-middle attacks.
14000 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14002 @item @code{constraints-from} (default: @code{'()})
14003 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14004 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14005 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14006 @item @code{allow-large-adjustment?} (default: @code{#f})
14007 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14013 @deffn {Scheme variable} inetd-service-type
14014 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14015 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14016 connections on internet sockets, and lazily starts the specified server
14017 program when a connection is made on one of these sockets.
14019 The value of this service is an @code{inetd-configuration} object. The
14020 following example configures the @command{inetd} daemon to provide the
14021 built-in @command{echo} service, as well as an smtp service which
14022 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14023 gateway @code{hostname}:
14028 (inetd-configuration
14032 (socket-type 'stream)
14039 (socket-type 'stream)
14043 (program (file-append openssh "/bin/ssh"))
14045 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14046 "-W" "smtp-server:25" "user@@hostname")))))))
14049 See below for more details about @code{inetd-configuration}.
14052 @deftp {Data Type} inetd-configuration
14053 Data type representing the configuration of @command{inetd}.
14056 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14057 The @command{inetd} executable to use.
14059 @item @code{entries} (default: @code{'()})
14060 A list of @command{inetd} service entries. Each entry should be created
14061 by the @code{inetd-entry} constructor.
14065 @deftp {Data Type} inetd-entry
14066 Data type representing an entry in the @command{inetd} configuration.
14067 Each entry corresponds to a socket where @command{inetd} will listen for
14071 @item @code{node} (default: @code{#f})
14072 Optional string, a comma-separated list of local addresses
14073 @command{inetd} should use when listening for this service.
14074 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14075 description of all options.
14077 A string, the name must correspond to an entry in @code{/etc/services}.
14078 @item @code{socket-type}
14079 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14081 @item @code{protocol}
14082 A string, must correspond to an entry in @code{/etc/protocols}.
14083 @item @code{wait?} (default: @code{#t})
14084 Whether @command{inetd} should wait for the server to exit before
14085 listening to new service requests.
14087 A string containing the user (and, optionally, group) name of the user
14088 as whom the server should run. The group name can be specified in a
14089 suffix, separated by a colon or period, i.e.@: @code{"user"},
14090 @code{"user:group"} or @code{"user.group"}.
14091 @item @code{program} (default: @code{"internal"})
14092 The server program which will serve the requests, or @code{"internal"}
14093 if @command{inetd} should use a built-in service.
14094 @item @code{arguments} (default: @code{'()})
14095 A list strings or file-like objects, which are the server program's
14096 arguments, starting with the zeroth argument, i.e.@: the name of the
14097 program itself. For @command{inetd}'s internal services, this entry
14098 must be @code{'()} or @code{'("internal")}.
14101 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14102 detailed discussion of each configuration field.
14106 @defvr {Scheme Variable} tor-service-type
14107 This is the type for a service that runs the @uref{https://torproject.org,
14108 Tor} anonymous networking daemon. The service is configured using a
14109 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14110 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14114 @deftp {Data Type} tor-configuration
14116 @item @code{tor} (default: @code{tor})
14117 The package that provides the Tor daemon. This package is expected to provide
14118 the daemon at @file{bin/tor} relative to its output directory. The default
14119 package is the @uref{https://www.torproject.org, Tor Project's}
14122 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14123 The configuration file to use. It will be appended to a default configuration
14124 file, and the final configuration file will be passed to @code{tor} via its
14125 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14126 file-like objects}). See @code{man tor} for details on the configuration file
14129 @item @code{hidden-services} (default: @code{'()})
14130 The list of @code{<hidden-service>} records to use. For any hidden service
14131 you include in this list, appropriate configuration to enable the hidden
14132 service will be automatically added to the default configuration file. You
14133 may conveniently create @code{<hidden-service>} records using the
14134 @code{tor-hidden-service} procedure described below.
14136 @item @code{socks-socket-type} (default: @code{'tcp})
14137 The default socket type that Tor should use for its SOCKS socket. This must
14138 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
14139 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
14140 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
14141 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
14144 If you want to customize the SOCKS socket in more detail, leave
14145 @code{socks-socket-type} at its default value of @code{'tcp} and use
14146 @code{config-file} to override the default by providing your own
14147 @code{SocksPort} option.
14151 @cindex hidden service
14152 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
14153 Define a new Tor @dfn{hidden service} called @var{name} and implementing
14154 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
14157 '((22 "127.0.0.1:22")
14158 (80 "127.0.0.1:8080"))
14161 In this example, port 22 of the hidden service is mapped to local port 22, and
14162 port 80 is mapped to local port 8080.
14164 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
14165 the @file{hostname} file contains the @code{.onion} host name for the hidden
14168 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
14169 project's documentation} for more information.
14172 The @code{(gnu services rsync)} module provides the following services:
14174 You might want an rsync daemon if you have files that you want available
14175 so anyone (or just yourself) can download existing files or upload new
14178 @deffn {Scheme Variable} rsync-service-type
14179 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
14180 The value for this service type is a
14181 @command{rsync-configuration} record as in this example:
14184 (service rsync-service-type)
14187 See below for details about @code{rsync-configuration}.
14190 @deftp {Data Type} rsync-configuration
14191 Data type representing the configuration for @code{rsync-service}.
14194 @item @code{package} (default: @var{rsync})
14195 @code{rsync} package to use.
14197 @item @code{port-number} (default: @code{873})
14198 TCP port on which @command{rsync} listens for incoming connections. If port
14199 is less than @code{1024} @command{rsync} needs to be started as the
14200 @code{root} user and group.
14202 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
14203 Name of the file where @command{rsync} writes its PID.
14205 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
14206 Name of the file where @command{rsync} writes its lock file.
14208 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
14209 Name of the file where @command{rsync} writes its log file.
14211 @item @code{use-chroot?} (default: @var{#t})
14212 Whether to use chroot for @command{rsync} shared directory.
14214 @item @code{share-path} (default: @file{/srv/rsync})
14215 Location of the @command{rsync} shared directory.
14217 @item @code{share-comment} (default: @code{"Rsync share"})
14218 Comment of the @command{rsync} shared directory.
14220 @item @code{read-only?} (default: @var{#f})
14221 Read-write permissions to shared directory.
14223 @item @code{timeout} (default: @code{300})
14224 I/O timeout in seconds.
14226 @item @code{user} (default: @var{"root"})
14227 Owner of the @code{rsync} process.
14229 @item @code{group} (default: @var{"root"})
14230 Group of the @code{rsync} process.
14232 @item @code{uid} (default: @var{"rsyncd"})
14233 User name or user ID that file transfers to and from that module should take
14234 place as when the daemon was run as @code{root}.
14236 @item @code{gid} (default: @var{"rsyncd"})
14237 Group name or group ID that will be used when accessing the module.
14242 Furthermore, @code{(gnu services ssh)} provides the following services.
14246 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
14247 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
14248 [#:allow-empty-passwords? #f] [#:root-login? #f] @
14249 [#:syslog-output? #t] [#:x11-forwarding? #t] @
14250 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
14251 [#:public-key-authentication? #t] [#:initialize? #t]
14252 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
14253 @var{host-key} must designate a file containing the host key, and readable
14256 When @var{daemonic?} is true, @command{lshd} will detach from the
14257 controlling terminal and log its output to syslogd, unless one sets
14258 @var{syslog-output?} to false. Obviously, it also makes lsh-service
14259 depend on existence of syslogd service. When @var{pid-file?} is true,
14260 @command{lshd} writes its PID to the file called @var{pid-file}.
14262 When @var{initialize?} is true, automatically create the seed and host key
14263 upon service activation if they do not exist yet. This may take long and
14264 require interaction.
14266 When @var{initialize?} is false, it is up to the user to initialize the
14267 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
14268 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
14269 basics,,, lsh, LSH Manual}).
14271 When @var{interfaces} is empty, lshd listens for connections on all the
14272 network interfaces; otherwise, @var{interfaces} must be a list of host names
14275 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
14276 passwords, and @var{root-login?} specifies whether to accept log-ins as
14279 The other options should be self-descriptive.
14284 @deffn {Scheme Variable} openssh-service-type
14285 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
14286 shell daemon, @command{sshd}. Its value must be an
14287 @code{openssh-configuration} record as in this example:
14290 (service openssh-service-type
14291 (openssh-configuration
14292 (x11-forwarding? #t)
14293 (permit-root-login 'without-password)
14295 `(("alice" ,(local-file "alice.pub"))
14296 ("bob" ,(local-file "bob.pub"))))))
14299 See below for details about @code{openssh-configuration}.
14301 This service can be extended with extra authorized keys, as in this
14305 (service-extension openssh-service-type
14306 (const `(("charlie"
14307 ,(local-file "charlie.pub")))))
14311 @deftp {Data Type} openssh-configuration
14312 This is the configuration record for OpenSSH's @command{sshd}.
14315 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
14316 Name of the file where @command{sshd} writes its PID.
14318 @item @code{port-number} (default: @code{22})
14319 TCP port on which @command{sshd} listens for incoming connections.
14321 @item @code{permit-root-login} (default: @code{#f})
14322 This field determines whether and when to allow logins as root. If
14323 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
14324 If it's the symbol @code{'without-password}, then root logins are
14325 permitted but not with password-based authentication.
14327 @item @code{allow-empty-passwords?} (default: @code{#f})
14328 When true, users with empty passwords may log in. When false, they may
14331 @item @code{password-authentication?} (default: @code{#t})
14332 When true, users may log in with their password. When false, they have
14333 other authentication methods.
14335 @item @code{public-key-authentication?} (default: @code{#t})
14336 When true, users may log in using public key authentication. When
14337 false, users have to use other authentication method.
14339 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
14340 This is used only by protocol version 2.
14342 @item @code{x11-forwarding?} (default: @code{#f})
14343 When true, forwarding of X11 graphical client connections is
14344 enabled---in other words, @command{ssh} options @option{-X} and
14345 @option{-Y} will work.
14347 @item @code{allow-agent-forwarding?} (default: @code{#t})
14348 Whether to allow agent forwarding.
14350 @item @code{allow-tcp-forwarding?} (default: @code{#t})
14351 Whether to allow TCP forwarding.
14353 @item @code{gateway-ports?} (default: @code{#f})
14354 Whether to allow gateway ports.
14356 @item @code{challenge-response-authentication?} (default: @code{#f})
14357 Specifies whether challenge response authentication is allowed (e.g.@: via
14360 @item @code{use-pam?} (default: @code{#t})
14361 Enables the Pluggable Authentication Module interface. If set to
14362 @code{#t}, this will enable PAM authentication using
14363 @code{challenge-response-authentication?} and
14364 @code{password-authentication?}, in addition to PAM account and session
14365 module processing for all authentication types.
14367 Because PAM challenge response authentication usually serves an
14368 equivalent role to password authentication, you should disable either
14369 @code{challenge-response-authentication?} or
14370 @code{password-authentication?}.
14372 @item @code{print-last-log?} (default: @code{#t})
14373 Specifies whether @command{sshd} should print the date and time of the
14374 last user login when a user logs in interactively.
14376 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
14377 Configures external subsystems (e.g.@: file transfer daemon).
14379 This is a list of two-element lists, each of which containing the
14380 subsystem name and a command (with optional arguments) to execute upon
14383 The command @command{internal-sftp} implements an in-process SFTP
14384 server. Alternately, one can specify the @command{sftp-server} command:
14386 (service openssh-service-type
14387 (openssh-configuration
14389 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
14392 @item @code{accepted-environment} (default: @code{'()})
14393 List of strings describing which environment variables may be exported.
14395 Each string gets on its own line. See the @code{AcceptEnv} option in
14396 @code{man sshd_config}.
14398 This example allows ssh-clients to export the @env{COLORTERM} variable.
14399 It is set by terminal emulators, which support colors. You can use it in
14400 your shell's resource file to enable colors for the prompt and commands
14401 if this variable is set.
14404 (service openssh-service-type
14405 (openssh-configuration
14406 (accepted-environment '("COLORTERM"))))
14409 @item @code{authorized-keys} (default: @code{'()})
14410 @cindex authorized keys, SSH
14411 @cindex SSH authorized keys
14412 This is the list of authorized keys. Each element of the list is a user
14413 name followed by one or more file-like objects that represent SSH public
14417 (openssh-configuration
14419 `(("rekado" ,(local-file "rekado.pub"))
14420 ("chris" ,(local-file "chris.pub"))
14421 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
14425 registers the specified public keys for user accounts @code{rekado},
14426 @code{chris}, and @code{root}.
14428 Additional authorized keys can be specified @i{via}
14429 @code{service-extension}.
14431 Note that this does @emph{not} interfere with the use of
14432 @file{~/.ssh/authorized_keys}.
14434 @item @code{log-level} (default: @code{'info})
14435 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
14436 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
14437 page for @file{sshd_config} for the full list of level names.
14439 @item @code{extra-content} (default: @code{""})
14440 This field can be used to append arbitrary text to the configuration file. It
14441 is especially useful for elaborate configurations that cannot be expressed
14442 otherwise. This configuration, for example, would generally disable root
14443 logins, but permit them from one specific IP address:
14446 (openssh-configuration
14448 Match Address 192.168.0.1
14449 PermitRootLogin yes"))
14455 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14456 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14457 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14460 For example, to specify a Dropbear service listening on port 1234, add
14461 this call to the operating system's @code{services} field:
14464 (dropbear-service (dropbear-configuration
14465 (port-number 1234)))
14469 @deftp {Data Type} dropbear-configuration
14470 This data type represents the configuration of a Dropbear SSH daemon.
14473 @item @code{dropbear} (default: @var{dropbear})
14474 The Dropbear package to use.
14476 @item @code{port-number} (default: 22)
14477 The TCP port where the daemon waits for incoming connections.
14479 @item @code{syslog-output?} (default: @code{#t})
14480 Whether to enable syslog output.
14482 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
14483 File name of the daemon's PID file.
14485 @item @code{root-login?} (default: @code{#f})
14486 Whether to allow @code{root} logins.
14488 @item @code{allow-empty-passwords?} (default: @code{#f})
14489 Whether to allow empty passwords.
14491 @item @code{password-authentication?} (default: @code{#t})
14492 Whether to enable password-based authentication.
14497 @deffn {Scheme Variable} autossh-service-type
14498 This is the type for the @uref{https://www.harding.motd.ca/autossh,
14499 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
14500 restarting it as necessary should it die or stop passing traffic.
14501 AutoSSH can be run manually from the command-line by passing arguments
14502 to the binary @command{autossh} from the package @code{autossh}, but it
14503 can also be run as a Guix service. This latter use case is documented
14506 AutoSSH can be used to forward local traffic to a remote machine using
14507 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
14510 For example, to specify a service running autossh as the user
14511 @code{pino} and forwarding all local connections to port @code{8081} to
14512 @code{remote:8081} using an SSH tunnel, add this call to the operating
14513 system's @code{services} field:
14516 (service autossh-service-type
14517 (autossh-configuration
14519 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
14523 @deftp {Data Type} autossh-configuration
14524 This data type represents the configuration of an AutoSSH service.
14528 @item @code{user} (default @code{"autossh"})
14529 The user as which the AutoSSH service is to be run.
14530 This assumes that the specified user exists.
14532 @item @code{poll} (default @code{600})
14533 Specifies the connection poll time in seconds.
14535 @item @code{first-poll} (default @code{#f})
14536 Specifies how many seconds AutoSSH waits before the first connection
14537 test. After this first test, polling is resumed at the pace defined in
14538 @code{poll}. When set to @code{#f}, the first poll is not treated
14539 specially and will also use the connection poll specified in
14542 @item @code{gate-time} (default @code{30})
14543 Specifies how many seconds an SSH connection must be active before it is
14544 considered successful.
14546 @item @code{log-level} (default @code{1})
14547 The log level, corresponding to the levels used by syslog---so @code{0}
14548 is the most silent while @code{7} is the chattiest.
14550 @item @code{max-start} (default @code{#f})
14551 The maximum number of times SSH may be (re)started before AutoSSH exits.
14552 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
14554 @item @code{message} (default @code{""})
14555 The message to append to the echo message sent when testing connections.
14557 @item @code{port} (default @code{"0"})
14558 The ports used for monitoring the connection. When set to @code{"0"},
14559 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
14560 a positive integer, ports @var{n} and @var{n}+1 are used for
14561 monitoring the connection, such that port @var{n} is the base
14562 monitoring port and @code{n+1} is the echo port. When set to
14563 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
14564 integers, the ports @var{n} and @var{n}+1 are used for monitoring the
14565 connection, such that port @var{n} is the base monitoring port and
14566 @var{m} is the echo port.
14568 @item @code{ssh-options} (default @code{'()})
14569 The list of command-line arguments to pass to @command{ssh} when it is
14570 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
14571 may cause undefined behaviour.
14576 @defvr {Scheme Variable} %facebook-host-aliases
14577 This variable contains a string for use in @file{/etc/hosts}
14578 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
14579 line contains a entry that maps a known server name of the Facebook
14580 on-line service---e.g., @code{www.facebook.com}---to the local
14581 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
14583 This variable is typically used in the @code{hosts-file} field of an
14584 @code{operating-system} declaration (@pxref{operating-system Reference,
14585 @file{/etc/hosts}}):
14588 (use-modules (gnu) (guix))
14591 (host-name "mymachine")
14594 ;; Create a /etc/hosts file with aliases for "localhost"
14595 ;; and "mymachine", as well as for Facebook servers.
14596 (plain-file "hosts"
14597 (string-append (local-host-aliases host-name)
14598 %facebook-host-aliases))))
14601 This mechanism can prevent programs running locally, such as Web
14602 browsers, from accessing Facebook.
14605 The @code{(gnu services avahi)} provides the following definition.
14607 @defvr {Scheme Variable} avahi-service-type
14608 This is the service that runs @command{avahi-daemon}, a system-wide
14609 mDNS/DNS-SD responder that allows for service discovery and
14610 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14611 Its value must be a @code{zero-configuration} record---see below.
14613 This service extends the name service cache daemon (nscd) so that it can
14614 resolve @code{.local} host names using
14615 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14616 Service Switch}, for information on host name resolution.
14618 Additionally, add the @var{avahi} package to the system profile so that
14619 commands such as @command{avahi-browse} are directly usable.
14622 @deftp {Data Type} avahi-configuration
14623 Data type representation the configuration for Avahi.
14627 @item @code{host-name} (default: @code{#f})
14628 If different from @code{#f}, use that as the host name to
14629 publish for this machine; otherwise, use the machine's actual host name.
14631 @item @code{publish?} (default: @code{#t})
14632 When true, allow host names and services to be published (broadcast) over the
14635 @item @code{publish-workstation?} (default: @code{#t})
14636 When true, @command{avahi-daemon} publishes the machine's host name and IP
14637 address via mDNS on the local network. To view the host names published on
14638 your local network, you can run:
14641 avahi-browse _workstation._tcp
14644 @item @code{wide-area?} (default: @code{#f})
14645 When true, DNS-SD over unicast DNS is enabled.
14647 @item @code{ipv4?} (default: @code{#t})
14648 @itemx @code{ipv6?} (default: @code{#t})
14649 These fields determine whether to use IPv4/IPv6 sockets.
14651 @item @code{domains-to-browse} (default: @code{'()})
14652 This is a list of domains to browse.
14656 @deffn {Scheme Variable} openvswitch-service-type
14657 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14658 service, whose value should be an @code{openvswitch-configuration}
14662 @deftp {Data Type} openvswitch-configuration
14663 Data type representing the configuration of Open vSwitch, a multilayer
14664 virtual switch which is designed to enable massive network automation
14665 through programmatic extension.
14668 @item @code{package} (default: @var{openvswitch})
14669 Package object of the Open vSwitch.
14674 @defvr {Scheme Variable} pagekite-service-type
14675 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14676 a tunneling solution for making localhost servers publicly visible, even from
14677 behind restrictive firewalls or NAT without forwarded ports. The value for
14678 this service type is a @code{pagekite-configuration} record.
14680 Here's an example exposing the local HTTP and SSH daemons:
14683 (service pagekite-service-type
14684 (pagekite-configuration
14685 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14686 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14687 (extra-file "/etc/pagekite.rc")))
14691 @deftp {Data Type} pagekite-configuration
14692 Data type representing the configuration of PageKite.
14695 @item @code{package} (default: @var{pagekite})
14696 Package object of PageKite.
14698 @item @code{kitename} (default: @code{#f})
14699 PageKite name for authenticating to the frontend server.
14701 @item @code{kitesecret} (default: @code{#f})
14702 Shared secret for authenticating to the frontend server. You should probably
14703 put this inside @code{extra-file} instead.
14705 @item @code{frontend} (default: @code{#f})
14706 Connect to the named PageKite frontend server instead of the
14707 @uref{https://pagekite.net,,pagekite.net} service.
14709 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14710 List of service kites to use. Exposes HTTP on port 80 by default. The format
14711 is @code{proto:kitename:host:port:secret}.
14713 @item @code{extra-file} (default: @code{#f})
14714 Extra configuration file to read, which you are expected to create manually.
14715 Use this to add additional options and manage shared secrets out-of-band.
14721 @subsection X Window
14724 @cindex X Window System
14725 @cindex login manager
14726 Support for the X Window graphical display system---specifically
14727 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14728 there is no @code{xorg-service} procedure. Instead, the X server is
14729 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14732 @cindex GNOME, login manager
14733 GDM of course allows users to log in into window managers and desktop
14734 environments other than GNOME; for those using GNOME, GDM is required for
14735 features such as automatic screen locking.
14737 @cindex window manager
14738 To use X11, you must install at least one @dfn{window manager}---for
14739 example the @code{windowmaker} or @code{openbox} packages---preferably
14740 by adding it to the @code{packages} field of your operating system
14741 definition (@pxref{operating-system Reference, system-wide packages}).
14743 @defvr {Scheme Variable} gdm-service-type
14744 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14745 Desktop Manager} (GDM), a program that manages graphical display servers and
14746 handles graphical user logins. Its value must be a @code{gdm-configuration}
14749 @cindex session types (X11)
14750 @cindex X11 session types
14751 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14752 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14753 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14754 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14755 set of packages automatically makes them available at the log-in screen.
14757 In addition, @file{~/.xsession} files are honored. When available,
14758 @file{~/.xsession} must be an executable that starts a window manager
14759 and/or other X clients.
14762 @deftp {Data Type} gdm-configuration
14764 @item @code{auto-login?} (default: @code{#f})
14765 @itemx @code{default-user} (default: @code{#f})
14766 When @code{auto-login?} is false, GDM presents a log-in screen.
14768 When @code{auto-login?} is true, GDM logs in directly as
14769 @code{default-user}.
14771 @item @code{debug?} (default: @code{#f})
14772 When true, GDM writes debug messages to its log.
14774 @item @code{gnome-shell-assets} (default: ...)
14775 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14777 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14778 Configuration of the Xorg graphical server.
14780 @item @code{xsession} (default: @code{(xinitrc)})
14781 Script to run before starting a X session.
14783 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14784 File name of the @code{dbus-daemon} executable.
14786 @item @code{gdm} (default: @code{gdm})
14787 The GDM package to use.
14791 @defvr {Scheme Variable} slim-service-type
14792 This is the type for the SLiM graphical login manager for X11.
14794 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14795 allows users to choose a session from the log-in screen using @kbd{F1}. It
14796 also honors @file{~/.xsession} files.
14798 Unlike GDM, SLiM does not spawn the user session on a different VT after
14799 logging in, which means that you can only start one graphical session. If you
14800 want to be able to run multiple graphical sessions at the same time you have
14801 to add multiple SLiM services to your system services. The following example
14802 shows how to replace the default GDM service with two SLiM services on tty7
14806 (use-modules (gnu services)
14807 (gnu services desktop)
14808 (gnu services xorg)
14809 (srfi srfi-1)) ;for 'remove'
14813 (services (cons* (service slim-service-type (slim-configuration
14816 (service slim-service-type (slim-configuration
14819 (remove (lambda (service)
14820 (eq? (service-kind service) gdm-service-type))
14821 %desktop-services))))
14826 @deftp {Data Type} slim-configuration
14827 Data type representing the configuration of @code{slim-service-type}.
14830 @item @code{allow-empty-passwords?} (default: @code{#t})
14831 Whether to allow logins with empty passwords.
14833 @item @code{auto-login?} (default: @code{#f})
14834 @itemx @code{default-user} (default: @code{""})
14835 When @code{auto-login?} is false, SLiM presents a log-in screen.
14837 When @code{auto-login?} is true, SLiM logs in directly as
14838 @code{default-user}.
14840 @item @code{theme} (default: @code{%default-slim-theme})
14841 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14842 The graphical theme to use and its name.
14844 @item @code{auto-login-session} (default: @code{#f})
14845 If true, this must be the name of the executable to start as the default
14846 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14848 If false, a session described by one of the available @file{.desktop}
14849 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14853 You must install at least one window manager in the system profile or in
14854 your user profile. Failing to do that, if @code{auto-login-session} is
14855 false, you will be unable to log in.
14858 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14859 Configuration of the Xorg graphical server.
14861 @item @code{display} (default @code{":0"})
14862 The display on which to start the Xorg graphical server.
14864 @item @code{vt} (default @code{"vt7"})
14865 The VT on which to start the Xorg graphical server.
14867 @item @code{xauth} (default: @code{xauth})
14868 The XAuth package to use.
14870 @item @code{shepherd} (default: @code{shepherd})
14871 The Shepherd package used when invoking @command{halt} and
14874 @item @code{sessreg} (default: @code{sessreg})
14875 The sessreg package used in order to register the session.
14877 @item @code{slim} (default: @code{slim})
14878 The SLiM package to use.
14882 @defvr {Scheme Variable} %default-theme
14883 @defvrx {Scheme Variable} %default-theme-name
14884 The default SLiM theme and its name.
14888 @deftp {Data Type} sddm-configuration
14889 This is the data type representing the SDDM service configuration.
14892 @item @code{display-server} (default: "x11")
14893 Select display server to use for the greeter. Valid values are
14894 @samp{"x11"} or @samp{"wayland"}.
14896 @item @code{numlock} (default: "on")
14897 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
14899 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14900 Command to run when halting.
14902 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14903 Command to run when rebooting.
14905 @item @code{theme} (default "maldives")
14906 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
14907 @samp{"maldives"} or @samp{"maya"}.
14909 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14910 Directory to look for themes.
14912 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14913 Directory to look for faces.
14915 @item @code{default-path} (default "/run/current-system/profile/bin")
14916 Default PATH to use.
14918 @item @code{minimum-uid} (default: 1000)
14919 Minimum UID displayed in SDDM and allowed for log-in.
14921 @item @code{maximum-uid} (default: 2000)
14922 Maximum UID to display in SDDM.
14924 @item @code{remember-last-user?} (default #t)
14925 Remember last user.
14927 @item @code{remember-last-session?} (default #t)
14928 Remember last session.
14930 @item @code{hide-users} (default "")
14931 Usernames to hide from SDDM greeter.
14933 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14934 Users with shells listed will be hidden from the SDDM greeter.
14936 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14937 Script to run before starting a wayland session.
14939 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14940 Directory to look for desktop files starting wayland sessions.
14942 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14943 Configuration of the Xorg graphical server.
14945 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14948 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14951 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14952 Script to run after starting xorg-server.
14954 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14955 Script to run before stopping xorg-server.
14957 @item @code{xsession-command} (default: @code{xinitrc})
14958 Script to run before starting a X session.
14960 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14961 Directory to look for desktop files starting X sessions.
14963 @item @code{minimum-vt} (default: 7)
14966 @item @code{auto-login-user} (default "")
14967 User to use for auto-login.
14969 @item @code{auto-login-session} (default "")
14970 Desktop file to use for auto-login.
14972 @item @code{relogin?} (default #f)
14973 Relogin after logout.
14978 @cindex login manager
14980 @defvr {Scheme Variable} sddm-service-type
14981 This is the type of the service to run the
14982 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
14983 must be a @code{sddm-configuration} record (see below).
14985 Here's an example use:
14988 (service sddm-service-type
14989 (sddm-configuration
14990 (auto-login-user "alice")
14991 (auto-login-session "xfce.desktop")))
14995 @deftp {Data Type} sddm-configuration
14996 This data type represents the configuration of the SDDM login manager.
14997 The available fields are:
15000 @item @code{sddm} (default: @code{sddm})
15001 The SDDM package to use.
15003 @item @code{display-server} (default: @code{"x11"})
15004 This must be either @code{"x11"} or @code{"wayland"}.
15006 @c FIXME: Add more fields.
15008 @item @code{auto-login-user} (default: @code{""})
15009 If non-empty, this is the user account under which to log in
15012 @item @code{auto-login-session} (default: @code{""})
15013 If non-empty, this is the @file{.desktop} file name to use as the
15014 auto-login session.
15018 @cindex Xorg, configuration
15019 @deftp {Data Type} xorg-configuration
15020 This data type represents the configuration of the Xorg graphical display
15021 server. Note that there is not Xorg service; instead, the X server is started
15022 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
15023 of these display managers aggregates an @code{xorg-configuration} record.
15026 @item @code{modules} (default: @code{%default-xorg-modules})
15027 This is a list of @dfn{module packages} loaded by the Xorg
15028 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
15030 @item @code{fonts} (default: @code{%default-xorg-fonts})
15031 This is a list of font directories to add to the server's @dfn{font path}.
15033 @item @code{drivers} (default: @code{'()})
15034 This must be either the empty list, in which case Xorg chooses a graphics
15035 driver automatically, or a list of driver names that will be tried in this
15036 order---e.g., @code{("modesetting" "vesa")}.
15038 @item @code{resolutions} (default: @code{'()})
15039 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
15040 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
15043 @cindex keyboard layout, for Xorg
15044 @cindex keymap, for Xorg
15045 @item @code{keyboard-layout} (default: @code{#f})
15046 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
15047 English (``qwerty'') for a 105-key PC keyboard.
15049 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
15050 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
15051 information on how to specify the keyboard layout.
15053 @item @code{extra-config} (default: @code{'()})
15054 This is a list of strings or objects appended to the configuration file. It
15055 is used to pass extra text to be added verbatim to the configuration file.
15057 @item @code{server} (default: @code{xorg-server})
15058 This is the package providing the Xorg server.
15060 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
15061 This is the list of command-line arguments to pass to the X server. The
15062 default is @code{-nolisten tcp}.
15066 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
15067 [@var{login-manager-service-type}]
15068 Tell the log-in manager (of type @var{login-manager-service-type}) to use
15069 @var{config}, an @code{<xorg-configuration>} record.
15071 Since the Xorg configuration is embedded in the log-in manager's
15072 configuration---e.g., @code{gdm-configuration}---this procedure provides a
15073 shorthand to set the Xorg configuration.
15076 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
15077 Return a @code{startx} script in which the modules, fonts, etc. specified
15078 in @var{config}, are available. The result should be used in place of
15081 Usually the X server is started by a login manager.
15085 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
15086 Add @var{package}, a package for a screen locker or screen saver whose
15087 command is @var{program}, to the set of setuid programs and add a PAM entry
15088 for it. For example:
15091 (screen-locker-service xlockmore "xlock")
15094 makes the good ol' XlockMore usable.
15098 @node Printing Services
15099 @subsection Printing Services
15101 @cindex printer support with CUPS
15102 The @code{(gnu services cups)} module provides a Guix service definition
15103 for the CUPS printing service. To add printer support to a Guix
15104 system, add a @code{cups-service} to the operating system definition:
15106 @deffn {Scheme Variable} cups-service-type
15107 The service type for the CUPS print server. Its value should be a valid
15108 CUPS configuration (see below). To use the default settings, simply
15111 (service cups-service-type)
15115 The CUPS configuration controls the basic things about your CUPS
15116 installation: what interfaces it listens on, what to do if a print job
15117 fails, how much logging to do, and so on. To actually add a printer,
15118 you have to visit the @url{http://localhost:631} URL, or use a tool such
15119 as GNOME's printer configuration services. By default, configuring a
15120 CUPS service will generate a self-signed certificate if needed, for
15121 secure connections to the print server.
15123 Suppose you want to enable the Web interface of CUPS and also add
15124 support for Epson printers @i{via} the @code{escpr} package and for HP
15125 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
15126 like this (you need to use the @code{(gnu packages cups)} module):
15129 (service cups-service-type
15130 (cups-configuration
15131 (web-interface? #t)
15133 (list cups-filters escpr hplip-minimal))))
15136 Note: If you wish to use the Qt5 based GUI which comes with the hplip
15137 package then it is suggested that you install the @code{hplip} package,
15138 either in your OS configuration file or as your user.
15140 The available configuration parameters follow. Each parameter
15141 definition is preceded by its type; for example, @samp{string-list foo}
15142 indicates that the @code{foo} parameter should be specified as a list of
15143 strings. There is also a way to specify the configuration as a string,
15144 if you have an old @code{cupsd.conf} file that you want to port over
15145 from some other system; see the end for more details.
15147 @c The following documentation was initially generated by
15148 @c (generate-documentation) in (gnu services cups). Manually maintained
15149 @c documentation is better, so we shouldn't hesitate to edit below as
15150 @c needed. However if the change you want to make to this documentation
15151 @c can be done in an automated way, it's probably easier to change
15152 @c (generate-documentation) than to make it below and have to deal with
15153 @c the churn as CUPS updates.
15156 Available @code{cups-configuration} fields are:
15158 @deftypevr {@code{cups-configuration} parameter} package cups
15162 @deftypevr {@code{cups-configuration} parameter} package-list extensions
15163 Drivers and other extensions to the CUPS package.
15166 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
15167 Configuration of where to write logs, what directories to use for print
15168 spools, and related privileged configuration parameters.
15170 Available @code{files-configuration} fields are:
15172 @deftypevr {@code{files-configuration} parameter} log-location access-log
15173 Defines the access log filename. Specifying a blank filename disables
15174 access log generation. The value @code{stderr} causes log entries to be
15175 sent to the standard error file when the scheduler is running in the
15176 foreground, or to the system log daemon when run in the background. The
15177 value @code{syslog} causes log entries to be sent to the system log
15178 daemon. The server name may be included in filenames using the string
15179 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
15181 Defaults to @samp{"/var/log/cups/access_log"}.
15184 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
15185 Where CUPS should cache data.
15187 Defaults to @samp{"/var/cache/cups"}.
15190 @deftypevr {@code{files-configuration} parameter} string config-file-perm
15191 Specifies the permissions for all configuration files that the scheduler
15194 Note that the permissions for the printers.conf file are currently
15195 masked to only allow access from the scheduler user (typically root).
15196 This is done because printer device URIs sometimes contain sensitive
15197 authentication information that should not be generally known on the
15198 system. There is no way to disable this security feature.
15200 Defaults to @samp{"0640"}.
15203 @deftypevr {@code{files-configuration} parameter} log-location error-log
15204 Defines the error log filename. Specifying a blank filename disables
15205 error log generation. The value @code{stderr} causes log entries to be
15206 sent to the standard error file when the scheduler is running in the
15207 foreground, or to the system log daemon when run in the background. The
15208 value @code{syslog} causes log entries to be sent to the system log
15209 daemon. The server name may be included in filenames using the string
15210 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
15212 Defaults to @samp{"/var/log/cups/error_log"}.
15215 @deftypevr {@code{files-configuration} parameter} string fatal-errors
15216 Specifies which errors are fatal, causing the scheduler to exit. The
15221 No errors are fatal.
15224 All of the errors below are fatal.
15227 Browsing initialization errors are fatal, for example failed connections
15228 to the DNS-SD daemon.
15231 Configuration file syntax errors are fatal.
15234 Listen or Port errors are fatal, except for IPv6 failures on the
15235 loopback or @code{any} addresses.
15238 Log file creation or write errors are fatal.
15241 Bad startup file permissions are fatal, for example shared TLS
15242 certificate and key files with world-read permissions.
15245 Defaults to @samp{"all -browse"}.
15248 @deftypevr {@code{files-configuration} parameter} boolean file-device?
15249 Specifies whether the file pseudo-device can be used for new printer
15250 queues. The URI @uref{file:///dev/null} is always allowed.
15252 Defaults to @samp{#f}.
15255 @deftypevr {@code{files-configuration} parameter} string group
15256 Specifies the group name or ID that will be used when executing external
15259 Defaults to @samp{"lp"}.
15262 @deftypevr {@code{files-configuration} parameter} string log-file-perm
15263 Specifies the permissions for all log files that the scheduler writes.
15265 Defaults to @samp{"0644"}.
15268 @deftypevr {@code{files-configuration} parameter} log-location page-log
15269 Defines the page log filename. Specifying a blank filename disables
15270 page log generation. The value @code{stderr} causes log entries to be
15271 sent to the standard error file when the scheduler is running in the
15272 foreground, or to the system log daemon when run in the background. The
15273 value @code{syslog} causes log entries to be sent to the system log
15274 daemon. The server name may be included in filenames using the string
15275 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
15277 Defaults to @samp{"/var/log/cups/page_log"}.
15280 @deftypevr {@code{files-configuration} parameter} string remote-root
15281 Specifies the username that is associated with unauthenticated accesses
15282 by clients claiming to be the root user. The default is @code{remroot}.
15284 Defaults to @samp{"remroot"}.
15287 @deftypevr {@code{files-configuration} parameter} file-name request-root
15288 Specifies the directory that contains print jobs and other HTTP request
15291 Defaults to @samp{"/var/spool/cups"}.
15294 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
15295 Specifies the level of security sandboxing that is applied to print
15296 filters, backends, and other child processes of the scheduler; either
15297 @code{relaxed} or @code{strict}. This directive is currently only
15298 used/supported on macOS.
15300 Defaults to @samp{strict}.
15303 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
15304 Specifies the location of TLS certificates and private keys. CUPS will
15305 look for public and private keys in this directory: @file{.crt} files
15306 for PEM-encoded certificates and corresponding @file{.key} files for
15307 PEM-encoded private keys.
15309 Defaults to @samp{"/etc/cups/ssl"}.
15312 @deftypevr {@code{files-configuration} parameter} file-name server-root
15313 Specifies the directory containing the server configuration files.
15315 Defaults to @samp{"/etc/cups"}.
15318 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
15319 Specifies whether the scheduler calls fsync(2) after writing
15320 configuration or state files.
15322 Defaults to @samp{#f}.
15325 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
15326 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
15329 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
15330 Specifies the directory where temporary files are stored.
15332 Defaults to @samp{"/var/spool/cups/tmp"}.
15335 @deftypevr {@code{files-configuration} parameter} string user
15336 Specifies the user name or ID that is used when running external
15339 Defaults to @samp{"lp"}.
15342 @deftypevr {@code{files-configuration} parameter} string set-env
15343 Set the specified environment variable to be passed to child processes.
15345 Defaults to @samp{"variable value"}.
15349 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
15350 Specifies the logging level for the AccessLog file. The @code{config}
15351 level logs when printers and classes are added, deleted, or modified and
15352 when configuration files are accessed or updated. The @code{actions}
15353 level logs when print jobs are submitted, held, released, modified, or
15354 canceled, and any of the conditions for @code{config}. The @code{all}
15355 level logs all requests.
15357 Defaults to @samp{actions}.
15360 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
15361 Specifies whether to purge job history data automatically when it is no
15362 longer required for quotas.
15364 Defaults to @samp{#f}.
15367 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
15368 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
15369 For example, @samp{"_cups" "_print"} will tell network clients that both
15370 CUPS sharing and IPP Everywhere are supported.
15372 Defaults to @samp{"_cups"}.
15375 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
15376 Specifies which protocols to use for local printer sharing.
15378 Defaults to @samp{dnssd}.
15381 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
15382 Specifies whether the CUPS web interface is advertised.
15384 Defaults to @samp{#f}.
15387 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
15388 Specifies whether shared printers are advertised.
15390 Defaults to @samp{#f}.
15393 @deftypevr {@code{cups-configuration} parameter} string classification
15394 Specifies the security classification of the server. Any valid banner
15395 name can be used, including @samp{"classified"}, @samp{"confidential"},
15396 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
15397 banner can be omitted to disable secure printing functions.
15399 Defaults to @samp{""}.
15402 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
15403 Specifies whether users may override the classification (cover page) of
15404 individual print jobs using the @code{job-sheets} option.
15406 Defaults to @samp{#f}.
15409 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
15410 Specifies the default type of authentication to use.
15412 Defaults to @samp{Basic}.
15415 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
15416 Specifies whether encryption will be used for authenticated requests.
15418 Defaults to @samp{Required}.
15421 @deftypevr {@code{cups-configuration} parameter} string default-language
15422 Specifies the default language to use for text and web content.
15424 Defaults to @samp{"en"}.
15427 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
15428 Specifies the default paper size for new print queues. @samp{"Auto"}
15429 uses a locale-specific default, while @samp{"None"} specifies there is
15430 no default paper size. Specific size names are typically
15431 @samp{"Letter"} or @samp{"A4"}.
15433 Defaults to @samp{"Auto"}.
15436 @deftypevr {@code{cups-configuration} parameter} string default-policy
15437 Specifies the default access policy to use.
15439 Defaults to @samp{"default"}.
15442 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
15443 Specifies whether local printers are shared by default.
15445 Defaults to @samp{#t}.
15448 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
15449 Specifies the delay for updating of configuration and state files, in
15450 seconds. A value of 0 causes the update to happen as soon as possible,
15451 typically within a few milliseconds.
15453 Defaults to @samp{30}.
15456 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
15457 Specifies what to do when an error occurs. Possible values are
15458 @code{abort-job}, which will discard the failed print job;
15459 @code{retry-job}, which will retry the job at a later time;
15460 @code{retry-current-job}, which retries the failed job immediately; and
15461 @code{stop-printer}, which stops the printer.
15463 Defaults to @samp{stop-printer}.
15466 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
15467 Specifies the maximum cost of filters that are run concurrently, which
15468 can be used to minimize disk, memory, and CPU resource problems. A
15469 limit of 0 disables filter limiting. An average print to a
15470 non-PostScript printer needs a filter limit of about 200. A PostScript
15471 printer needs about half that (100). Setting the limit below these
15472 thresholds will effectively limit the scheduler to printing a single job
15475 Defaults to @samp{0}.
15478 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
15479 Specifies the scheduling priority of filters that are run to print a
15480 job. The nice value ranges from 0, the highest priority, to 19, the
15483 Defaults to @samp{0}.
15486 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
15487 Specifies whether to do reverse lookups on connecting clients. The
15488 @code{double} setting causes @code{cupsd} to verify that the hostname
15489 resolved from the address matches one of the addresses returned for that
15490 hostname. Double lookups also prevent clients with unregistered
15491 addresses from connecting to your server. Only set this option to
15492 @code{#t} or @code{double} if absolutely required.
15494 Defaults to @samp{#f}.
15497 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
15498 Specifies the number of seconds to wait before killing the filters and
15499 backend associated with a canceled or held job.
15501 Defaults to @samp{30}.
15504 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
15505 Specifies the interval between retries of jobs in seconds. This is
15506 typically used for fax queues but can also be used with normal print
15507 queues whose error policy is @code{retry-job} or
15508 @code{retry-current-job}.
15510 Defaults to @samp{30}.
15513 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
15514 Specifies the number of retries that are done for jobs. This is
15515 typically used for fax queues but can also be used with normal print
15516 queues whose error policy is @code{retry-job} or
15517 @code{retry-current-job}.
15519 Defaults to @samp{5}.
15522 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
15523 Specifies whether to support HTTP keep-alive connections.
15525 Defaults to @samp{#t}.
15528 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
15529 Specifies how long an idle client connection remains open, in seconds.
15531 Defaults to @samp{30}.
15534 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
15535 Specifies the maximum size of print files, IPP requests, and HTML form
15536 data. A limit of 0 disables the limit check.
15538 Defaults to @samp{0}.
15541 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
15542 Listens on the specified interfaces for connections. Valid values are
15543 of the form @var{address}:@var{port}, where @var{address} is either an
15544 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
15545 indicate all addresses. Values can also be file names of local UNIX
15546 domain sockets. The Listen directive is similar to the Port directive
15547 but allows you to restrict access to specific interfaces or networks.
15550 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
15551 Specifies the number of pending connections that will be allowed. This
15552 normally only affects very busy servers that have reached the MaxClients
15553 limit, but can also be triggered by large numbers of simultaneous
15554 connections. When the limit is reached, the operating system will
15555 refuse additional connections until the scheduler can accept the pending
15558 Defaults to @samp{128}.
15561 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
15562 Specifies a set of additional access controls.
15564 Available @code{location-access-controls} fields are:
15566 @deftypevr {@code{location-access-controls} parameter} file-name path
15567 Specifies the URI path to which the access control applies.
15570 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
15571 Access controls for all access to this path, in the same format as the
15572 @code{access-controls} of @code{operation-access-control}.
15574 Defaults to @samp{()}.
15577 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
15578 Access controls for method-specific access to this path.
15580 Defaults to @samp{()}.
15582 Available @code{method-access-controls} fields are:
15584 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
15585 If @code{#t}, apply access controls to all methods except the listed
15586 methods. Otherwise apply to only the listed methods.
15588 Defaults to @samp{#f}.
15591 @deftypevr {@code{method-access-controls} parameter} method-list methods
15592 Methods to which this access control applies.
15594 Defaults to @samp{()}.
15597 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
15598 Access control directives, as a list of strings. Each string should be
15599 one directive, such as @samp{"Order allow,deny"}.
15601 Defaults to @samp{()}.
15606 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15607 Specifies the number of debugging messages that are retained for logging
15608 if an error occurs in a print job. Debug messages are logged regardless
15609 of the LogLevel setting.
15611 Defaults to @samp{100}.
15614 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15615 Specifies the level of logging for the ErrorLog file. The value
15616 @code{none} stops all logging while @code{debug2} logs everything.
15618 Defaults to @samp{info}.
15621 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15622 Specifies the format of the date and time in the log files. The value
15623 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15625 Defaults to @samp{standard}.
15628 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15629 Specifies the maximum number of simultaneous clients that are allowed by
15632 Defaults to @samp{100}.
15635 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15636 Specifies the maximum number of simultaneous clients that are allowed
15637 from a single address.
15639 Defaults to @samp{100}.
15642 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15643 Specifies the maximum number of copies that a user can print of each
15646 Defaults to @samp{9999}.
15649 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15650 Specifies the maximum time a job may remain in the @code{indefinite}
15651 hold state before it is canceled. A value of 0 disables cancellation of
15654 Defaults to @samp{0}.
15657 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15658 Specifies the maximum number of simultaneous jobs that are allowed. Set
15659 to 0 to allow an unlimited number of jobs.
15661 Defaults to @samp{500}.
15664 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15665 Specifies the maximum number of simultaneous jobs that are allowed per
15666 printer. A value of 0 allows up to MaxJobs jobs per printer.
15668 Defaults to @samp{0}.
15671 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15672 Specifies the maximum number of simultaneous jobs that are allowed per
15673 user. A value of 0 allows up to MaxJobs jobs per user.
15675 Defaults to @samp{0}.
15678 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15679 Specifies the maximum time a job may take to print before it is
15680 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
15682 Defaults to @samp{10800}.
15685 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15686 Specifies the maximum size of the log files before they are rotated, in
15687 bytes. The value 0 disables log rotation.
15689 Defaults to @samp{1048576}.
15692 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15693 Specifies the maximum amount of time to allow between files in a
15694 multiple file print job, in seconds.
15696 Defaults to @samp{300}.
15699 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15700 Specifies the format of PageLog lines. Sequences beginning with percent
15701 (@samp{%}) characters are replaced with the corresponding information,
15702 while all other characters are copied literally. The following percent
15703 sequences are recognized:
15707 insert a single percent character
15710 insert the value of the specified IPP attribute
15713 insert the number of copies for the current page
15716 insert the current page number
15719 insert the current date and time in common log format
15725 insert the printer name
15728 insert the username
15731 A value of the empty string disables page logging. The string @code{%p
15732 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15733 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15736 Defaults to @samp{""}.
15739 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15740 Passes the specified environment variable(s) to child processes; a list
15743 Defaults to @samp{()}.
15746 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15747 Specifies named access control policies.
15749 Available @code{policy-configuration} fields are:
15751 @deftypevr {@code{policy-configuration} parameter} string name
15752 Name of the policy.
15755 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15756 Specifies an access list for a job's private values. @code{@@ACL} maps
15757 to the printer's requesting-user-name-allowed or
15758 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15759 owner. @code{@@SYSTEM} maps to the groups listed for the
15760 @code{system-group} field of the @code{files-config} configuration,
15761 which is reified into the @code{cups-files.conf(5)} file. Other
15762 possible elements of the access list include specific user names, and
15763 @code{@@@var{group}} to indicate members of a specific group. The
15764 access list may also be simply @code{all} or @code{default}.
15766 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15769 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15770 Specifies the list of job values to make private, or @code{all},
15771 @code{default}, or @code{none}.
15773 Defaults to @samp{"job-name job-originating-host-name
15774 job-originating-user-name phone"}.
15777 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15778 Specifies an access list for a subscription's private values.
15779 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15780 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15781 owner. @code{@@SYSTEM} maps to the groups listed for the
15782 @code{system-group} field of the @code{files-config} configuration,
15783 which is reified into the @code{cups-files.conf(5)} file. Other
15784 possible elements of the access list include specific user names, and
15785 @code{@@@var{group}} to indicate members of a specific group. The
15786 access list may also be simply @code{all} or @code{default}.
15788 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15791 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15792 Specifies the list of job values to make private, or @code{all},
15793 @code{default}, or @code{none}.
15795 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15796 notify-subscriber-user-name notify-user-data"}.
15799 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15800 Access control by IPP operation.
15802 Defaults to @samp{()}.
15806 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15807 Specifies whether job files (documents) are preserved after a job is
15808 printed. If a numeric value is specified, job files are preserved for
15809 the indicated number of seconds after printing. Otherwise a boolean
15810 value applies indefinitely.
15812 Defaults to @samp{86400}.
15815 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15816 Specifies whether the job history is preserved after a job is printed.
15817 If a numeric value is specified, the job history is preserved for the
15818 indicated number of seconds after printing. If @code{#t}, the job
15819 history is preserved until the MaxJobs limit is reached.
15821 Defaults to @samp{#t}.
15824 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15825 Specifies the amount of time to wait for job completion before
15826 restarting the scheduler.
15828 Defaults to @samp{30}.
15831 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15832 Specifies the maximum amount of memory to use when converting documents
15833 into bitmaps for a printer.
15835 Defaults to @samp{"128m"}.
15838 @deftypevr {@code{cups-configuration} parameter} string server-admin
15839 Specifies the email address of the server administrator.
15841 Defaults to @samp{"root@@localhost.localdomain"}.
15844 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15845 The ServerAlias directive is used for HTTP Host header validation when
15846 clients connect to the scheduler from external interfaces. Using the
15847 special name @code{*} can expose your system to known browser-based DNS
15848 rebinding attacks, even when accessing sites through a firewall. If the
15849 auto-discovery of alternate names does not work, we recommend listing
15850 each alternate name with a ServerAlias directive instead of using
15853 Defaults to @samp{*}.
15856 @deftypevr {@code{cups-configuration} parameter} string server-name
15857 Specifies the fully-qualified host name of the server.
15859 Defaults to @samp{"localhost"}.
15862 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15863 Specifies what information is included in the Server header of HTTP
15864 responses. @code{None} disables the Server header. @code{ProductOnly}
15865 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15866 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15867 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15868 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15869 2.0.0 (@var{uname}) IPP/2.0}.
15871 Defaults to @samp{Minimal}.
15874 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15875 Listens on the specified interfaces for encrypted connections. Valid
15876 values are of the form @var{address}:@var{port}, where @var{address} is
15877 either an IPv6 address enclosed in brackets, an IPv4 address, or
15878 @code{*} to indicate all addresses.
15880 Defaults to @samp{()}.
15883 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15884 Sets encryption options. By default, CUPS only supports encryption
15885 using TLS v1.0 or higher using known secure cipher suites. Security is
15886 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15887 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15888 suites, which are required for some older clients. The @code{AllowSSL3} option
15889 enables SSL v3.0, which is required for some older clients that do not support
15890 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15891 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15892 protocol version to TLS v1.1.
15894 Defaults to @samp{()}.
15897 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15898 Specifies whether the scheduler requires clients to strictly adhere to
15899 the IPP specifications.
15901 Defaults to @samp{#f}.
15904 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15905 Specifies the HTTP request timeout, in seconds.
15907 Defaults to @samp{300}.
15911 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15912 Specifies whether the web interface is enabled.
15914 Defaults to @samp{#f}.
15917 At this point you're probably thinking ``oh dear, Guix manual, I like
15918 you but you can stop already with the configuration options''. Indeed.
15919 However, one more point: it could be that you have an existing
15920 @code{cupsd.conf} that you want to use. In that case, you can pass an
15921 @code{opaque-cups-configuration} as the configuration of a
15922 @code{cups-service-type}.
15924 Available @code{opaque-cups-configuration} fields are:
15926 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15930 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15931 The contents of the @code{cupsd.conf}, as a string.
15934 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15935 The contents of the @code{cups-files.conf} file, as a string.
15938 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15939 strings of the same name, you could instantiate a CUPS service like
15943 (service cups-service-type
15944 (opaque-cups-configuration
15945 (cupsd.conf cupsd.conf)
15946 (cups-files.conf cups-files.conf)))
15950 @node Desktop Services
15951 @subsection Desktop Services
15953 The @code{(gnu services desktop)} module provides services that are
15954 usually useful in the context of a ``desktop'' setup---that is, on a
15955 machine running a graphical display server, possibly with graphical user
15956 interfaces, etc. It also defines services that provide specific desktop
15957 environments like GNOME, Xfce or MATE.
15959 To simplify things, the module defines a variable containing the set of
15960 services that users typically expect on a machine with a graphical
15961 environment and networking:
15963 @defvr {Scheme Variable} %desktop-services
15964 This is a list of services that builds upon @code{%base-services} and
15965 adds or adjusts services for a typical ``desktop'' setup.
15967 In particular, it adds a graphical login manager (@pxref{X Window,
15968 @code{gdm-service-type}}), screen lockers, a network management tool
15969 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15970 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15971 energy and color management services, the @code{elogind} login and seat
15972 manager, the Polkit privilege service, the GeoClue location service, the
15973 AccountsService daemon that allows authorized users change system passwords,
15974 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15975 name service switch service configured to be able to use @code{nss-mdns}
15976 (@pxref{Name Service Switch, mDNS}).
15979 The @code{%desktop-services} variable can be used as the @code{services}
15980 field of an @code{operating-system} declaration (@pxref{operating-system
15981 Reference, @code{services}}).
15983 Additionally, the @code{gnome-desktop-service-type},
15984 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15985 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15986 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15987 services like the backlight adjustment helpers and the power management
15988 utilities are added to the system, extending @code{polkit} and @code{dbus}
15989 appropriately, allowing GNOME to operate with elevated privileges on a
15990 limited number of special-purpose system interfaces. Additionally,
15991 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15992 metapackage to the system profile. Likewise, adding the Xfce service
15993 not only adds the @code{xfce} metapackage to the system profile, but it
15994 also gives the Thunar file manager the ability to open a ``root-mode''
15995 file management window, if the user authenticates using the
15996 administrator's password via the standard polkit graphical interface.
15997 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15998 appropriately, allowing MATE to operate with elevated privileges on a
15999 limited number of special-purpose system interfaces. Additionally,
16000 adding a service of type @code{mate-desktop-service-type} adds the MATE
16001 metapackage to the system profile. ``Adding Enlightenment'' means that
16002 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
16003 are set as setuid, allowing Enlightenment's screen locker and other
16004 functionality to work as expected.
16006 The desktop environments in Guix use the Xorg display server by
16007 default. If you'd like to use the newer display server protocol
16008 called Wayland, you need to use the @code{sddm-service} instead of
16009 GDM as the graphical login manager. You should then
16010 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
16011 also try starting GNOME on Wayland manually from a TTY with the
16012 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
16013 gnome-session``. Currently only GNOME has support for Wayland.
16015 @defvr {Scheme Variable} gnome-desktop-service-type
16016 This is the type of the service that adds the @uref{https://www.gnome.org,
16017 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
16018 object (see below.)
16020 This service adds the @code{gnome} package to the system profile, and extends
16021 polkit with the actions from @code{gnome-settings-daemon}.
16024 @deftp {Data Type} gnome-desktop-configuration
16025 Configuration record for the GNOME desktop environment.
16028 @item @code{gnome} (default: @code{gnome})
16029 The GNOME package to use.
16033 @defvr {Scheme Variable} xfce-desktop-service-type
16034 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
16035 desktop environment. Its value is an @code{xfce-desktop-configuration} object
16038 This service adds the @code{xfce} package to the system profile, and
16039 extends polkit with the ability for @code{thunar} to manipulate the file
16040 system as root from within a user session, after the user has authenticated
16041 with the administrator's password.
16044 @deftp {Data Type} xfce-desktop-configuration
16045 Configuration record for the Xfce desktop environment.
16048 @item @code{xfce} (default: @code{xfce})
16049 The Xfce package to use.
16053 @deffn {Scheme Variable} mate-desktop-service-type
16054 This is the type of the service that runs the @uref{https://mate-desktop.org/,
16055 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
16056 object (see below.)
16058 This service adds the @code{mate} package to the system
16059 profile, and extends polkit with the actions from
16060 @code{mate-settings-daemon}.
16063 @deftp {Data Type} mate-desktop-configuration
16064 Configuration record for the MATE desktop environment.
16067 @item @code{mate} (default: @code{mate})
16068 The MATE package to use.
16072 @deffn {Scheme Variable} enlightenment-desktop-service-type
16073 Return a service that adds the @code{enlightenment} package to the system
16074 profile, and extends dbus with actions from @code{efl}.
16077 @deftp {Data Type} enlightenment-desktop-service-configuration
16079 @item @code{enlightenment} (default: @code{enlightenment})
16080 The enlightenment package to use.
16084 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
16085 the default @code{%desktop-services} variable doesn't include any of
16086 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
16087 @code{%desktop-services} in the @code{services} field of your
16088 @code{operating-system}:
16091 (use-modules (gnu))
16092 (use-service-modules desktop)
16095 ;; cons* adds items to the list given as its last argument.
16096 (services (cons* (service gnome-desktop-service-type)
16097 (service xfce-desktop-service)
16098 %desktop-services))
16102 These desktop environments will then be available as options in the
16103 graphical login window.
16105 The actual service definitions included in @code{%desktop-services} and
16106 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
16107 are described below.
16109 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
16110 Return a service that runs the ``system bus'', using @var{dbus}, with
16111 support for @var{services}.
16113 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
16114 facility. Its system bus is used to allow system services to communicate
16115 and to be notified of system-wide events.
16117 @var{services} must be a list of packages that provide an
16118 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
16119 and policy files. For example, to allow avahi-daemon to use the system bus,
16120 @var{services} must be equal to @code{(list avahi)}.
16123 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
16124 Return a service that runs the @code{elogind} login and
16125 seat management daemon. @uref{https://github.com/elogind/elogind,
16126 Elogind} exposes a D-Bus interface that can be used to know which users
16127 are logged in, know what kind of sessions they have open, suspend the
16128 system, inhibit system suspend, reboot the system, and other tasks.
16130 Elogind handles most system-level power events for a computer, for
16131 example suspending the system when a lid is closed, or shutting it down
16132 when the power button is pressed.
16134 The @var{config} keyword argument specifies the configuration for
16135 elogind, and should be the result of an @code{(elogind-configuration
16136 (@var{parameter} @var{value})...)} invocation. Available parameters and
16137 their default values are:
16140 @item kill-user-processes?
16142 @item kill-only-users
16144 @item kill-exclude-users
16146 @item inhibit-delay-max-seconds
16148 @item handle-power-key
16150 @item handle-suspend-key
16152 @item handle-hibernate-key
16154 @item handle-lid-switch
16156 @item handle-lid-switch-docked
16158 @item power-key-ignore-inhibited?
16160 @item suspend-key-ignore-inhibited?
16162 @item hibernate-key-ignore-inhibited?
16164 @item lid-switch-ignore-inhibited?
16166 @item holdoff-timeout-seconds
16170 @item idle-action-seconds
16172 @item runtime-directory-size-percent
16174 @item runtime-directory-size
16178 @item suspend-state
16179 @code{("mem" "standby" "freeze")}
16182 @item hibernate-state
16184 @item hibernate-mode
16185 @code{("platform" "shutdown")}
16186 @item hybrid-sleep-state
16188 @item hybrid-sleep-mode
16189 @code{("suspend" "platform" "shutdown")}
16193 @deffn {Scheme Procedure} accountsservice-service @
16194 [#:accountsservice @var{accountsservice}]
16195 Return a service that runs AccountsService, a system service that can
16196 list available accounts, change their passwords, and so on.
16197 AccountsService integrates with PolicyKit to enable unprivileged users
16198 to acquire the capability to modify their system configuration.
16199 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
16200 accountsservice web site} for more information.
16202 The @var{accountsservice} keyword argument is the @code{accountsservice}
16203 package to expose as a service.
16206 @deffn {Scheme Procedure} polkit-service @
16207 [#:polkit @var{polkit}]
16208 Return a service that runs the
16209 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
16210 management service}, which allows system administrators to grant access to
16211 privileged operations in a structured way. By querying the Polkit service, a
16212 privileged system component can know when it should grant additional
16213 capabilities to ordinary users. For example, an ordinary user can be granted
16214 the capability to suspend the system if the user is logged in locally.
16217 @defvr {Scheme Variable} polkit-wheel-service
16218 Service that adds the @code{wheel} group as admins to the Polkit
16219 service. This makes it so that users in the @code{wheel} group are queried
16220 for their own passwords when performing administrative actions instead of
16221 @code{root}'s, similar to the behaviour used by @code{sudo}.
16224 @defvr {Scheme Variable} upower-service-type
16225 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
16226 system-wide monitor for power consumption and battery levels, with the given
16227 configuration settings.
16229 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
16230 notably used by GNOME.
16233 @deftp {Data Type} upower-configuration
16234 Data type representation the configuration for UPower.
16238 @item @code{upower} (default: @var{upower})
16239 Package to use for @code{upower}.
16241 @item @code{watts-up-pro?} (default: @code{#f})
16242 Enable the Watts Up Pro device.
16244 @item @code{poll-batteries?} (default: @code{#t})
16245 Enable polling the kernel for battery level changes.
16247 @item @code{ignore-lid?} (default: @code{#f})
16248 Ignore the lid state, this can be useful if it's incorrect on a device.
16250 @item @code{use-percentage-for-policy?} (default: @code{#f})
16251 Whether battery percentage based policy should be used. The default is to use
16252 the time left, change to @code{#t} to use the percentage.
16254 @item @code{percentage-low} (default: @code{10})
16255 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16256 at which the battery is considered low.
16258 @item @code{percentage-critical} (default: @code{3})
16259 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16260 at which the battery is considered critical.
16262 @item @code{percentage-action} (default: @code{2})
16263 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16264 at which action will be taken.
16266 @item @code{time-low} (default: @code{1200})
16267 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16268 seconds at which the battery is considered low.
16270 @item @code{time-critical} (default: @code{300})
16271 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16272 seconds at which the battery is considered critical.
16274 @item @code{time-action} (default: @code{120})
16275 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16276 seconds at which action will be taken.
16278 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
16279 The action taken when @code{percentage-action} or @code{time-action} is
16280 reached (depending on the configuration of @code{use-percentage-for-policy?}).
16282 Possible values are:
16292 @code{'hybrid-sleep}.
16298 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
16299 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
16300 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
16301 notifications and ways to mount/unmount disks. Programs that talk to UDisks
16302 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
16305 @deffn {Scheme Variable} colord-service-type
16306 This is the type of the service that runs @command{colord}, a system
16307 service with a D-Bus
16308 interface to manage the color profiles of input and output devices such as
16309 screens and scanners. It is notably used by the GNOME Color Manager graphical
16310 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
16311 site} for more information.
16314 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
16315 Return a configuration allowing an application to access GeoClue
16316 location data. @var{name} is the Desktop ID of the application, without
16317 the @code{.desktop} part. If @var{allowed?} is true, the application
16318 will have access to location information by default. The boolean
16319 @var{system?} value indicates whether an application is a system component
16320 or not. Finally @var{users} is a list of UIDs of all users for which
16321 this application is allowed location info access. An empty users list
16322 means that all users are allowed.
16325 @cindex scanner access
16326 @deffn {Scheme Procedure} sane-service-type
16327 This service provides access to scanners @i{via}
16328 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
16332 @defvr {Scheme Variable} %standard-geoclue-applications
16333 The standard list of well-known GeoClue application configurations,
16334 granting authority to the GNOME date-and-time utility to ask for the
16335 current location in order to set the time zone, and allowing the
16336 IceCat and Epiphany web browsers to request location information.
16337 IceCat and Epiphany both query the user before allowing a web page to
16338 know the user's location.
16341 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
16342 [#:whitelist '()] @
16343 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
16344 [#:submit-data? #f]
16345 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
16346 [#:submission-nick "geoclue"] @
16347 [#:applications %standard-geoclue-applications]
16348 Return a service that runs the GeoClue location service. This service
16349 provides a D-Bus interface to allow applications to request access to a
16350 user's physical location, and optionally to add information to online
16351 location databases. See
16352 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
16353 web site} for more information.
16356 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
16357 [@w{#:auto-enable? #f}]
16358 Return a service that runs the @command{bluetoothd} daemon, which
16359 manages all the Bluetooth devices and provides a number of D-Bus
16360 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
16361 powered automatically at boot, which can be useful when using a
16362 bluetooth keyboard or mouse.
16364 Users need to be in the @code{lp} group to access the D-Bus service.
16367 @defvr {Scheme Variable} gnome-keyring-service-type
16368 This is the type of the service that adds the
16369 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
16370 value is a @code{gnome-keyring-configuration} object (see below.)
16372 This service adds the @code{gnome-keyring} package to the system profile
16373 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
16374 a user's login keyring when they log in or setting its password with passwd.
16377 @deftp {Data Type} gnome-keyring-configuration
16378 Configuration record for the GNOME Keyring service.
16381 @item @code{keyring} (default: @code{gnome-keyring})
16382 The GNOME keyring package to use.
16384 @item @code{pam-services}
16385 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
16386 services to extend, where @var{service} is the name of an existing
16387 service to extend and @var{kind} is one of @code{login} or
16390 If @code{login} is given, it adds an optional
16391 @code{pam_gnome_keyring.so} to the auth block without arguments and to
16392 the session block with @code{auto_start}. If @code{passwd} is given, it
16393 adds an optional @code{pam_gnome_keyring.so} to the password block
16396 By default, this field contains ``gdm-password'' with the value @code{login}
16397 and ``passwd'' is with the value @code{passwd}.
16402 @node Sound Services
16403 @subsection Sound Services
16405 @cindex sound support
16407 @cindex PulseAudio, sound support
16409 The @code{(gnu services sound)} module provides a service to configure the
16410 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
16411 preferred ALSA output driver.
16413 @deffn {Scheme Variable} alsa-service-type
16414 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
16415 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
16416 configuration file. The value for this type is a @command{alsa-configuration}
16417 record as in this example:
16420 (service alsa-service-type)
16423 See below for details about @code{alsa-configuration}.
16426 @deftp {Data Type} alsa-configuration
16427 Data type representing the configuration for @code{alsa-service}.
16430 @item @code{alsa-plugins} (default: @var{alsa-plugins})
16431 @code{alsa-plugins} package to use.
16433 @item @code{pulseaudio?} (default: @var{#t})
16434 Whether ALSA applications should transparently be made to use the
16435 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
16437 Using PulseAudio allows you to run several sound-producing applications
16438 at the same time and to individual control them @i{via}
16439 @command{pavucontrol}, among other things.
16441 @item @code{extra-options} (default: @var{""})
16442 String to append to the @file{/etc/asound.conf} file.
16447 Individual users who want to override the system configuration of ALSA can do
16448 it with the @file{~/.asoundrc} file:
16451 # In guix, we have to specify the absolute path for plugins.
16453 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
16456 # Routing ALSA to jack:
16457 # <http://jackaudio.org/faq/routing_alsa.html>.
16461 0 system:playback_1
16462 1 system:playback_2
16479 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
16482 @deffn {Scheme Variable} pulseaudio-service-type
16483 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
16484 sound server. It exists to allow system overrides of the default settings
16485 via @code{pulseaudio-configuration}, see below.
16488 This service overrides per-user configuration files. If you want
16489 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
16490 have to unset the environment variables @env{PULSE_CONFIG} and
16491 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
16495 This service on its own does not ensure, that the @code{pulseaudio} package
16496 exists on your machine. It merely adds configuration files for it, as
16497 detailed below. In the (admittedly unlikely) case, that you find yourself
16498 without a @code{pulseaudio} package, consider enabling it through the
16499 @code{alsa-service-type} above.
16503 @deftp {Data Type} pulseaudio-configuration
16504 Data type representing the configuration for @code{pulseaudio-service}.
16507 @item @var{client-conf} (default: @code{'()})
16508 List of settings to set in @file{client.conf}.
16509 Accepts a list of strings or a symbol-value pairs. A string will be
16510 inserted as-is with a newline added. A pair will be formatted as
16511 ``key = value'', again with a newline added.
16513 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
16514 List of settings to set in @file{daemon.conf}, formatted just like
16517 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
16518 Script file to use as as @file{default.pa}.
16520 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
16521 Script file to use as as @file{system.pa}.
16525 @deffn {Scheme Variable} ladspa-service-type
16526 This service sets the @var{LADSPA_PATH} variable, so that programs, which
16527 respect it, e.g. PulseAudio, can load LADSPA plugins.
16529 The following example will setup the service to enable modules from the
16530 @code{swh-plugins} package:
16533 (service ladspa-service-type
16534 (ladspa-configuration (plugins (list swh-plugins))))
16537 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
16542 @node Database Services
16543 @subsection Database Services
16547 The @code{(gnu services databases)} module provides the following services.
16549 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
16550 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
16551 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
16552 Return a service that runs @var{postgresql}, the PostgreSQL database
16555 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
16556 creates a database cluster with @var{locale} as the default
16557 locale, stored in @var{data-directory}. It then listens on @var{port}.
16559 @cindex postgresql extension-packages
16560 Additional extensions are loaded from packages listed in
16561 @var{extension-packages}. Extensions are available at runtime. For instance,
16562 to create a geographic database using the @code{postgis} extension, a user can
16563 configure the postgresql-service as in this example:
16567 (use-package-modules databases geo)
16571 ;; postgresql is required to run `psql' but postgis is not required for
16572 ;; proper operation.
16573 (packages (cons* postgresql %base-packages))
16576 (postgresql-service #:extension-packages (list postgis))
16580 Then the extension becomes visible and you can initialise an empty geographic
16581 database in this way:
16585 > create database postgistest;
16586 > \connect postgistest;
16587 > create extension postgis;
16588 > create extension postgis_topology;
16591 There is no need to add this field for contrib extensions such as hstore or
16592 dblink as they are already loadable by postgresql. This field is only
16593 required to add extensions provided by other packages.
16596 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
16597 Return a service that runs @command{mysqld}, the MySQL or MariaDB
16600 The optional @var{config} argument specifies the configuration for
16601 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
16604 @deftp {Data Type} mysql-configuration
16605 Data type representing the configuration of @var{mysql-service}.
16608 @item @code{mysql} (default: @var{mariadb})
16609 Package object of the MySQL database server, can be either @var{mariadb}
16612 For MySQL, a temporary root password will be displayed at activation time.
16613 For MariaDB, the root password is empty.
16615 @item @code{port} (default: @code{3306})
16616 TCP port on which the database server listens for incoming connections.
16620 @defvr {Scheme Variable} memcached-service-type
16621 This is the service type for the @uref{https://memcached.org/,
16622 Memcached} service, which provides a distributed in memory cache. The
16623 value for the service type is a @code{memcached-configuration} object.
16627 (service memcached-service-type)
16630 @deftp {Data Type} memcached-configuration
16631 Data type representing the configuration of memcached.
16634 @item @code{memcached} (default: @code{memcached})
16635 The Memcached package to use.
16637 @item @code{interfaces} (default: @code{'("0.0.0.0")})
16638 Network interfaces on which to listen.
16640 @item @code{tcp-port} (default: @code{11211})
16641 Port on which to accept connections on,
16643 @item @code{udp-port} (default: @code{11211})
16644 Port on which to accept UDP connections on, a value of 0 will disable
16645 listening on a UDP socket.
16647 @item @code{additional-options} (default: @code{'()})
16648 Additional command line options to pass to @code{memcached}.
16652 @defvr {Scheme Variable} mongodb-service-type
16653 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
16654 The value for the service type is a @code{mongodb-configuration} object.
16658 (service mongodb-service-type)
16661 @deftp {Data Type} mongodb-configuration
16662 Data type representing the configuration of mongodb.
16665 @item @code{mongodb} (default: @code{mongodb})
16666 The MongoDB package to use.
16668 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
16669 The configuration file for MongoDB.
16671 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16672 This value is used to create the directory, so that it exists and is
16673 owned by the mongodb user. It should match the data-directory which
16674 MongoDB is configured to use through the configuration file.
16678 @defvr {Scheme Variable} redis-service-type
16679 This is the service type for the @uref{https://redis.io/, Redis}
16680 key/value store, whose value is a @code{redis-configuration} object.
16683 @deftp {Data Type} redis-configuration
16684 Data type representing the configuration of redis.
16687 @item @code{redis} (default: @code{redis})
16688 The Redis package to use.
16690 @item @code{bind} (default: @code{"127.0.0.1"})
16691 Network interface on which to listen.
16693 @item @code{port} (default: @code{6379})
16694 Port on which to accept connections on, a value of 0 will disable
16695 listening on a TCP socket.
16697 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16698 Directory in which to store the database and related files.
16702 @node Mail Services
16703 @subsection Mail Services
16707 The @code{(gnu services mail)} module provides Guix service definitions
16708 for email services: IMAP, POP3, and LMTP servers, as well as mail
16709 transport agents (MTAs). Lots of acronyms! These services are detailed
16710 in the subsections below.
16712 @subsubheading Dovecot Service
16714 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16715 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16718 By default, Dovecot does not need much configuration; the default
16719 configuration object created by @code{(dovecot-configuration)} will
16720 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16721 certificate will be generated for TLS-protected connections, though
16722 Dovecot will also listen on cleartext ports by default. There are a
16723 number of options, though, which mail administrators might need to change,
16724 and as is the case with other services, Guix allows the system
16725 administrator to specify these parameters via a uniform Scheme interface.
16727 For example, to specify that mail is located at @code{maildir~/.mail},
16728 one would instantiate the Dovecot service like this:
16731 (dovecot-service #:config
16732 (dovecot-configuration
16733 (mail-location "maildir:~/.mail")))
16736 The available configuration parameters follow. Each parameter
16737 definition is preceded by its type; for example, @samp{string-list foo}
16738 indicates that the @code{foo} parameter should be specified as a list of
16739 strings. There is also a way to specify the configuration as a string,
16740 if you have an old @code{dovecot.conf} file that you want to port over
16741 from some other system; see the end for more details.
16743 @c The following documentation was initially generated by
16744 @c (generate-documentation) in (gnu services mail). Manually maintained
16745 @c documentation is better, so we shouldn't hesitate to edit below as
16746 @c needed. However if the change you want to make to this documentation
16747 @c can be done in an automated way, it's probably easier to change
16748 @c (generate-documentation) than to make it below and have to deal with
16749 @c the churn as dovecot updates.
16751 Available @code{dovecot-configuration} fields are:
16753 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16754 The dovecot package.
16757 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16758 A list of IPs or hosts where to listen for connections. @samp{*}
16759 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16760 interfaces. If you want to specify non-default ports or anything more
16761 complex, customize the address and port fields of the
16762 @samp{inet-listener} of the specific services you are interested in.
16765 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16766 List of protocols we want to serve. Available protocols include
16767 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16769 Available @code{protocol-configuration} fields are:
16771 @deftypevr {@code{protocol-configuration} parameter} string name
16772 The name of the protocol.
16775 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16776 UNIX socket path to the master authentication server to find users.
16777 This is used by imap (for shared users) and lda.
16778 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16781 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16782 Space separated list of plugins to load.
16785 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16786 Maximum number of IMAP connections allowed for a user from each IP
16787 address. NOTE: The username is compared case-sensitively.
16788 Defaults to @samp{10}.
16793 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16794 List of services to enable. Available services include @samp{imap},
16795 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16798 Available @code{service-configuration} fields are:
16800 @deftypevr {@code{service-configuration} parameter} string kind
16801 The service kind. Valid values include @code{director},
16802 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16803 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16804 @code{tcpwrap}, @code{quota-warning}, or anything else.
16807 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16808 Listeners for the service. A listener is either a
16809 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16810 an @code{inet-listener-configuration}.
16811 Defaults to @samp{()}.
16813 Available @code{unix-listener-configuration} fields are:
16815 @deftypevr {@code{unix-listener-configuration} parameter} string path
16816 Path to the file, relative to @code{base-dir} field. This is also used as
16820 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16821 The access mode for the socket.
16822 Defaults to @samp{"0600"}.
16825 @deftypevr {@code{unix-listener-configuration} parameter} string user
16826 The user to own the socket.
16827 Defaults to @samp{""}.
16830 @deftypevr {@code{unix-listener-configuration} parameter} string group
16831 The group to own the socket.
16832 Defaults to @samp{""}.
16836 Available @code{fifo-listener-configuration} fields are:
16838 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16839 Path to the file, relative to @code{base-dir} field. This is also used as
16843 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16844 The access mode for the socket.
16845 Defaults to @samp{"0600"}.
16848 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16849 The user to own the socket.
16850 Defaults to @samp{""}.
16853 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16854 The group to own the socket.
16855 Defaults to @samp{""}.
16859 Available @code{inet-listener-configuration} fields are:
16861 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16862 The protocol to listen for.
16865 @deftypevr {@code{inet-listener-configuration} parameter} string address
16866 The address on which to listen, or empty for all addresses.
16867 Defaults to @samp{""}.
16870 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16871 The port on which to listen.
16874 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16875 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16877 Defaults to @samp{#t}.
16882 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16883 Maximum number of simultaneous client connections per process. Once
16884 this number of connections is received, the next incoming connection
16885 will prompt Dovecot to spawn another process. If set to 0,
16886 @code{default-client-limit} is used instead.
16888 Defaults to @samp{0}.
16892 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16893 Number of connections to handle before starting a new process.
16894 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16895 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16896 Defaults to @samp{1}.
16900 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16901 Maximum number of processes that can exist for this service. If set to
16902 0, @code{default-process-limit} is used instead.
16904 Defaults to @samp{0}.
16908 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16909 Number of processes to always keep waiting for more connections.
16910 Defaults to @samp{0}.
16913 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16914 If you set @samp{service-count 0}, you probably need to grow
16916 Defaults to @samp{256000000}.
16921 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16922 Dict configuration, as created by the @code{dict-configuration}
16925 Available @code{dict-configuration} fields are:
16927 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16928 A list of key-value pairs that this dict should hold.
16929 Defaults to @samp{()}.
16934 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16935 A list of passdb configurations, each one created by the
16936 @code{passdb-configuration} constructor.
16938 Available @code{passdb-configuration} fields are:
16940 @deftypevr {@code{passdb-configuration} parameter} string driver
16941 The driver that the passdb should use. Valid values include
16942 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16944 Defaults to @samp{"pam"}.
16947 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16948 Space separated list of arguments to the passdb driver.
16949 Defaults to @samp{""}.
16954 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16955 List of userdb configurations, each one created by the
16956 @code{userdb-configuration} constructor.
16958 Available @code{userdb-configuration} fields are:
16960 @deftypevr {@code{userdb-configuration} parameter} string driver
16961 The driver that the userdb should use. Valid values include
16962 @samp{passwd} and @samp{static}.
16963 Defaults to @samp{"passwd"}.
16966 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16967 Space separated list of arguments to the userdb driver.
16968 Defaults to @samp{""}.
16971 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16972 Override fields from passwd.
16973 Defaults to @samp{()}.
16978 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16979 Plug-in configuration, created by the @code{plugin-configuration}
16983 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16984 List of namespaces. Each item in the list is created by the
16985 @code{namespace-configuration} constructor.
16987 Available @code{namespace-configuration} fields are:
16989 @deftypevr {@code{namespace-configuration} parameter} string name
16990 Name for this namespace.
16993 @deftypevr {@code{namespace-configuration} parameter} string type
16994 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16995 Defaults to @samp{"private"}.
16998 @deftypevr {@code{namespace-configuration} parameter} string separator
16999 Hierarchy separator to use. You should use the same separator for
17000 all namespaces or some clients get confused. @samp{/} is usually a good
17001 one. The default however depends on the underlying mail storage
17003 Defaults to @samp{""}.
17006 @deftypevr {@code{namespace-configuration} parameter} string prefix
17007 Prefix required to access this namespace. This needs to be
17008 different for all namespaces. For example @samp{Public/}.
17009 Defaults to @samp{""}.
17012 @deftypevr {@code{namespace-configuration} parameter} string location
17013 Physical location of the mailbox. This is in the same format as
17014 mail_location, which is also the default for it.
17015 Defaults to @samp{""}.
17018 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
17019 There can be only one INBOX, and this setting defines which
17021 Defaults to @samp{#f}.
17024 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
17025 If namespace is hidden, it's not advertised to clients via NAMESPACE
17026 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
17027 useful when converting from another server with different namespaces
17028 which you want to deprecate but still keep working. For example you can
17029 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
17031 Defaults to @samp{#f}.
17034 @deftypevr {@code{namespace-configuration} parameter} boolean list?
17035 Show the mailboxes under this namespace with the LIST command. This
17036 makes the namespace visible for clients that do not support the NAMESPACE
17037 extension. The special @code{children} value lists child mailboxes, but
17038 hides the namespace prefix.
17039 Defaults to @samp{#t}.
17042 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
17043 Namespace handles its own subscriptions. If set to @code{#f}, the
17044 parent namespace handles them. The empty prefix should always have this
17046 Defaults to @samp{#t}.
17049 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
17050 List of predefined mailboxes in this namespace.
17051 Defaults to @samp{()}.
17053 Available @code{mailbox-configuration} fields are:
17055 @deftypevr {@code{mailbox-configuration} parameter} string name
17056 Name for this mailbox.
17059 @deftypevr {@code{mailbox-configuration} parameter} string auto
17060 @samp{create} will automatically create this mailbox.
17061 @samp{subscribe} will both create and subscribe to the mailbox.
17062 Defaults to @samp{"no"}.
17065 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
17066 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
17067 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
17068 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
17069 Defaults to @samp{()}.
17076 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
17077 Base directory where to store runtime data.
17078 Defaults to @samp{"/var/run/dovecot/"}.
17081 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
17082 Greeting message for clients.
17083 Defaults to @samp{"Dovecot ready."}.
17086 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
17087 List of trusted network ranges. Connections from these IPs are
17088 allowed to override their IP addresses and ports (for logging and for
17089 authentication checks). @samp{disable-plaintext-auth} is also ignored
17090 for these networks. Typically you would specify your IMAP proxy servers
17092 Defaults to @samp{()}.
17095 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
17096 List of login access check sockets (e.g.@: tcpwrap).
17097 Defaults to @samp{()}.
17100 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
17101 Show more verbose process titles (in ps). Currently shows user name
17102 and IP address. Useful for seeing who is actually using the IMAP
17103 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
17105 Defaults to @samp{#f}.
17108 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
17109 Should all processes be killed when Dovecot master process shuts down.
17110 Setting this to @code{#f} means that Dovecot can be upgraded without
17111 forcing existing client connections to close (although that could also
17112 be a problem if the upgrade is e.g.@: due to a security fix).
17113 Defaults to @samp{#t}.
17116 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
17117 If non-zero, run mail commands via this many connections to doveadm
17118 server, instead of running them directly in the same process.
17119 Defaults to @samp{0}.
17122 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
17123 UNIX socket or host:port used for connecting to doveadm server.
17124 Defaults to @samp{"doveadm-server"}.
17127 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
17128 List of environment variables that are preserved on Dovecot startup
17129 and passed down to all of its child processes. You can also give
17130 key=value pairs to always set specific settings.
17133 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
17134 Disable LOGIN command and all other plaintext authentications unless
17135 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
17136 matches the local IP (i.e.@: you're connecting from the same computer),
17137 the connection is considered secure and plaintext authentication is
17138 allowed. See also ssl=required setting.
17139 Defaults to @samp{#t}.
17142 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
17143 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
17144 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
17145 for caching to be used.
17146 Defaults to @samp{0}.
17149 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
17150 Time to live for cached data. After TTL expires the cached record
17151 is no longer used, *except* if the main database lookup returns internal
17152 failure. We also try to handle password changes automatically: If
17153 user's previous authentication was successful, but this one wasn't, the
17154 cache isn't used. For now this works only with plaintext
17156 Defaults to @samp{"1 hour"}.
17159 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
17160 TTL for negative hits (user not found, password mismatch).
17161 0 disables caching them completely.
17162 Defaults to @samp{"1 hour"}.
17165 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
17166 List of realms for SASL authentication mechanisms that need them.
17167 You can leave it empty if you don't want to support multiple realms.
17168 Many clients simply use the first one listed here, so keep the default
17170 Defaults to @samp{()}.
17173 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
17174 Default realm/domain to use if none was specified. This is used for
17175 both SASL realms and appending @@domain to username in plaintext
17177 Defaults to @samp{""}.
17180 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
17181 List of allowed characters in username. If the user-given username
17182 contains a character not listed in here, the login automatically fails.
17183 This is just an extra check to make sure user can't exploit any
17184 potential quote escaping vulnerabilities with SQL/LDAP databases. If
17185 you want to allow all characters, set this value to empty.
17186 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
17189 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
17190 Username character translations before it's looked up from
17191 databases. The value contains series of from -> to characters. For
17192 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
17193 translated to @samp{@@}.
17194 Defaults to @samp{""}.
17197 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
17198 Username formatting before it's looked up from databases. You can
17199 use the standard variables here, e.g.@: %Lu would lowercase the username,
17200 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
17201 change the @samp{@@} into @samp{-AT-}. This translation is done after
17202 @samp{auth-username-translation} changes.
17203 Defaults to @samp{"%Lu"}.
17206 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
17207 If you want to allow master users to log in by specifying the master
17208 username within the normal username string (i.e.@: not using SASL
17209 mechanism's support for it), you can specify the separator character
17210 here. The format is then <username><separator><master username>.
17211 UW-IMAP uses @samp{*} as the separator, so that could be a good
17213 Defaults to @samp{""}.
17216 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
17217 Username to use for users logging in with ANONYMOUS SASL
17219 Defaults to @samp{"anonymous"}.
17222 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
17223 Maximum number of dovecot-auth worker processes. They're used to
17224 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
17225 They're automatically created and destroyed as needed.
17226 Defaults to @samp{30}.
17229 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
17230 Host name to use in GSSAPI principal names. The default is to use
17231 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
17232 allow all keytab entries.
17233 Defaults to @samp{""}.
17236 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
17237 Kerberos keytab to use for the GSSAPI mechanism. Will use the
17238 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
17239 need to change the auth service to run as root to be able to read this
17241 Defaults to @samp{""}.
17244 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
17245 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
17246 and @samp{ntlm-auth} helper.
17247 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
17248 Defaults to @samp{#f}.
17251 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
17252 Path for Samba's @samp{ntlm-auth} helper binary.
17253 Defaults to @samp{"/usr/bin/ntlm_auth"}.
17256 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
17257 Time to delay before replying to failed authentications.
17258 Defaults to @samp{"2 secs"}.
17261 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
17262 Require a valid SSL client certificate or the authentication
17264 Defaults to @samp{#f}.
17267 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
17268 Take the username from client's SSL certificate, using
17269 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
17271 Defaults to @samp{#f}.
17274 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
17275 List of wanted authentication mechanisms. Supported mechanisms are:
17276 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
17277 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
17278 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
17279 @samp{disable-plaintext-auth} setting.
17282 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
17283 List of IPs or hostnames to all director servers, including ourself.
17284 Ports can be specified as ip:port. The default port is the same as what
17285 director service's @samp{inet-listener} is using.
17286 Defaults to @samp{()}.
17289 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
17290 List of IPs or hostnames to all backend mail servers. Ranges are
17291 allowed too, like 10.0.0.10-10.0.0.30.
17292 Defaults to @samp{()}.
17295 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
17296 How long to redirect users to a specific server after it no longer
17297 has any connections.
17298 Defaults to @samp{"15 min"}.
17301 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
17302 How the username is translated before being hashed. Useful values
17303 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
17304 are shared within domain.
17305 Defaults to @samp{"%Lu"}.
17308 @deftypevr {@code{dovecot-configuration} parameter} string log-path
17309 Log file to use for error messages. @samp{syslog} logs to syslog,
17310 @samp{/dev/stderr} logs to stderr.
17311 Defaults to @samp{"syslog"}.
17314 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
17315 Log file to use for informational messages. Defaults to
17317 Defaults to @samp{""}.
17320 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
17321 Log file to use for debug messages. Defaults to
17322 @samp{info-log-path}.
17323 Defaults to @samp{""}.
17326 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
17327 Syslog facility to use if you're logging to syslog. Usually if you
17328 don't want to use @samp{mail}, you'll use local0..local7. Also other
17329 standard facilities are supported.
17330 Defaults to @samp{"mail"}.
17333 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
17334 Log unsuccessful authentication attempts and the reasons why they
17336 Defaults to @samp{#f}.
17339 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
17340 In case of password mismatches, log the attempted password. Valid
17341 values are no, plain and sha1. sha1 can be useful for detecting brute
17342 force password attempts vs. user simply trying the same password over
17343 and over again. You can also truncate the value to n chars by appending
17344 ":n" (e.g.@: sha1:6).
17345 Defaults to @samp{"no"}.
17348 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
17349 Even more verbose logging for debugging purposes. Shows for example
17351 Defaults to @samp{#f}.
17354 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
17355 In case of password mismatches, log the passwords and used scheme so
17356 the problem can be debugged. Enabling this also enables
17358 Defaults to @samp{#f}.
17361 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
17362 Enable mail process debugging. This can help you figure out why
17363 Dovecot isn't finding your mails.
17364 Defaults to @samp{#f}.
17367 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
17368 Show protocol level SSL errors.
17369 Defaults to @samp{#f}.
17372 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
17373 Prefix for each line written to log file. % codes are in
17374 strftime(3) format.
17375 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
17378 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
17379 List of elements we want to log. The elements which have a
17380 non-empty variable value are joined together to form a comma-separated
17384 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
17385 Login log format. %s contains @samp{login-log-format-elements}
17386 string, %$ contains the data we want to log.
17387 Defaults to @samp{"%$: %s"}.
17390 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
17391 Log prefix for mail processes. See doc/wiki/Variables.txt for list
17392 of possible variables you can use.
17393 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
17396 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
17397 Format to use for logging mail deliveries. You can use variables:
17400 Delivery status message (e.g.@: @samp{saved to INBOX})
17412 Defaults to @samp{"msgid=%m: %$"}.
17415 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
17416 Location for users' mailboxes. The default is empty, which means
17417 that Dovecot tries to find the mailboxes automatically. This won't work
17418 if the user doesn't yet have any mail, so you should explicitly tell
17419 Dovecot the full location.
17421 If you're using mbox, giving a path to the INBOX
17422 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
17423 where the other mailboxes are kept. This is called the @emph{root mail
17424 directory}, and it must be the first path given in the
17425 @samp{mail-location} setting.
17427 There are a few special variables you can use, e.g.:
17433 user part in user@@domain, same as %u if there's no domain
17435 domain part in user@@domain, empty if there's no domain
17440 See doc/wiki/Variables.txt for full list. Some examples:
17442 @item maildir:~/Maildir
17443 @item mbox:~/mail:INBOX=/var/mail/%u
17444 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
17446 Defaults to @samp{""}.
17449 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
17450 System user and group used to access mails. If you use multiple,
17451 userdb can override these by returning uid or gid fields. You can use
17452 either numbers or names. <doc/wiki/UserIds.txt>.
17453 Defaults to @samp{""}.
17456 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
17458 Defaults to @samp{""}.
17461 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
17462 Group to enable temporarily for privileged operations. Currently
17463 this is used only with INBOX when either its initial creation or
17464 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
17466 Defaults to @samp{""}.
17469 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
17470 Grant access to these supplementary groups for mail processes.
17471 Typically these are used to set up access to shared mailboxes. Note
17472 that it may be dangerous to set these if users can create symlinks
17473 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
17474 could allow a user to delete others' mailboxes, or @code{ln -s
17475 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
17479 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
17480 Allow full file system access to clients. There's no access checks
17481 other than what the operating system does for the active UID/GID. It
17482 works with both maildir and mboxes, allowing you to prefix mailboxes
17483 names with e.g.@: @file{/path/} or @file{~user/}.
17484 Defaults to @samp{#f}.
17487 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
17488 Don't use @code{mmap()} at all. This is required if you store indexes to
17489 shared file systems (NFS or clustered file system).
17490 Defaults to @samp{#f}.
17493 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
17494 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
17495 supports @samp{O_EXCL} since version 3, so this should be safe to use
17496 nowadays by default.
17497 Defaults to @samp{#t}.
17500 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
17501 When to use fsync() or fdatasync() calls:
17504 Whenever necessary to avoid losing important data
17506 Useful with e.g.@: NFS when @code{write()}s are delayed
17508 Never use it (best performance, but crashes can lose data).
17510 Defaults to @samp{"optimized"}.
17513 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
17514 Mail storage exists in NFS. Set this to yes to make Dovecot flush
17515 NFS caches whenever needed. If you're using only a single mail server
17517 Defaults to @samp{#f}.
17520 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
17521 Mail index files also exist in NFS. Setting this to yes requires
17522 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
17523 Defaults to @samp{#f}.
17526 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
17527 Locking method for index files. Alternatives are fcntl, flock and
17528 dotlock. Dotlocking uses some tricks which may create more disk I/O
17529 than other locking methods. NFS users: flock doesn't work, remember to
17530 change @samp{mmap-disable}.
17531 Defaults to @samp{"fcntl"}.
17534 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
17535 Directory in which LDA/LMTP temporarily stores incoming mails >128
17537 Defaults to @samp{"/tmp"}.
17540 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
17541 Valid UID range for users. This is mostly to make sure that users can't
17542 log in as daemons or other system users. Note that denying root logins is
17543 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
17545 Defaults to @samp{500}.
17548 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
17550 Defaults to @samp{0}.
17553 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
17554 Valid GID range for users. Users having non-valid GID as primary group ID
17555 aren't allowed to log in. If user belongs to supplementary groups with
17556 non-valid GIDs, those groups are not set.
17557 Defaults to @samp{1}.
17560 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
17562 Defaults to @samp{0}.
17565 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
17566 Maximum allowed length for mail keyword name. It's only forced when
17567 trying to create new keywords.
17568 Defaults to @samp{50}.
17571 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
17572 List of directories under which chrooting is allowed for mail
17573 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
17574 too). This setting doesn't affect @samp{login-chroot}
17575 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
17576 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
17577 which local users can modify, that may lead to root exploit. Usually
17578 this should be done only if you don't allow shell access for users.
17579 <doc/wiki/Chrooting.txt>.
17580 Defaults to @samp{()}.
17583 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
17584 Default chroot directory for mail processes. This can be overridden
17585 for specific users in user database by giving @samp{/./} in user's home
17586 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
17587 there is no real need to do chrooting, Dovecot doesn't allow users to
17588 access files outside their mail directory anyway. If your home
17589 directories are prefixed with the chroot directory, append @samp{/.} to
17590 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
17591 Defaults to @samp{""}.
17594 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
17595 UNIX socket path to master authentication server to find users.
17596 This is used by imap (for shared users) and lda.
17597 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17600 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
17601 Directory where to look up mail plugins.
17602 Defaults to @samp{"/usr/lib/dovecot"}.
17605 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
17606 List of plugins to load for all services. Plugins specific to IMAP,
17607 LDA, etc.@: are added to this list in their own .conf files.
17608 Defaults to @samp{()}.
17611 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
17612 The minimum number of mails in a mailbox before updates are done to
17613 cache file. This allows optimizing Dovecot's behavior to do less disk
17614 writes at the cost of more disk reads.
17615 Defaults to @samp{0}.
17618 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
17619 When IDLE command is running, mailbox is checked once in a while to
17620 see if there are any new mails or other changes. This setting defines
17621 the minimum time to wait between those checks. Dovecot can also use
17622 dnotify, inotify and kqueue to find out immediately when changes
17624 Defaults to @samp{"30 secs"}.
17627 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
17628 Save mails with CR+LF instead of plain LF. This makes sending those
17629 mails take less CPU, especially with sendfile() syscall with Linux and
17630 FreeBSD. But it also creates a bit more disk I/O which may just make it
17631 slower. Also note that if other software reads the mboxes/maildirs,
17632 they may handle the extra CRs wrong and cause problems.
17633 Defaults to @samp{#f}.
17636 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
17637 By default LIST command returns all entries in maildir beginning
17638 with a dot. Enabling this option makes Dovecot return only entries
17639 which are directories. This is done by stat()ing each entry, so it
17640 causes more disk I/O.
17641 (For systems setting struct @samp{dirent->d_type} this check is free
17642 and it's done always regardless of this setting).
17643 Defaults to @samp{#f}.
17646 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
17647 When copying a message, do it with hard links whenever possible.
17648 This makes the performance much better, and it's unlikely to have any
17650 Defaults to @samp{#t}.
17653 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
17654 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
17655 directory only when its mtime changes unexpectedly or when we can't find
17656 the mail otherwise.
17657 Defaults to @samp{#f}.
17660 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
17661 Which locking methods to use for locking mbox. There are four
17666 Create <mailbox>.lock file. This is the oldest and most NFS-safe
17667 solution. If you want to use /var/mail/ like directory, the users will
17668 need write access to that directory.
17670 Same as dotlock, but if it fails because of permissions or because there
17671 isn't enough disk space, just skip it.
17673 Use this if possible. Works with NFS too if lockd is used.
17675 May not exist in all systems. Doesn't work with NFS.
17677 May not exist in all systems. Doesn't work with NFS.
17680 You can use multiple locking methods; if you do the order they're declared
17681 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17682 locking methods as well. Some operating systems don't allow using some of
17683 them simultaneously.
17686 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17690 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17691 Maximum time to wait for lock (all of them) before aborting.
17692 Defaults to @samp{"5 mins"}.
17695 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17696 If dotlock exists but the mailbox isn't modified in any way,
17697 override the lock file after this much time.
17698 Defaults to @samp{"2 mins"}.
17701 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17702 When mbox changes unexpectedly we have to fully read it to find out
17703 what changed. If the mbox is large this can take a long time. Since
17704 the change is usually just a newly appended mail, it'd be faster to
17705 simply read the new mails. If this setting is enabled, Dovecot does
17706 this but still safely fallbacks to re-reading the whole mbox file
17707 whenever something in mbox isn't how it's expected to be. The only real
17708 downside to this setting is that if some other MUA changes message
17709 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17710 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17711 Defaults to @samp{#t}.
17714 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17715 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17716 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17717 @samp{mbox-dirty-syncs} is ignored.
17718 Defaults to @samp{#f}.
17721 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17722 Delay writing mbox headers until doing a full write sync (EXPUNGE
17723 and CHECK commands and when closing the mailbox). This is especially
17724 useful for POP3 where clients often delete all mails. The downside is
17725 that our changes aren't immediately visible to other MUAs.
17726 Defaults to @samp{#t}.
17729 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17730 If mbox size is smaller than this (e.g.@: 100k), don't write index
17731 files. If an index file already exists it's still read, just not
17733 Defaults to @samp{0}.
17736 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17737 Maximum dbox file size until it's rotated.
17738 Defaults to @samp{10000000}.
17741 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17742 Maximum dbox file age until it's rotated. Typically in days. Day
17743 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17745 Defaults to @samp{"1d"}.
17748 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17749 When creating new mdbox files, immediately preallocate their size to
17750 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17751 with some file systems (ext4, xfs).
17752 Defaults to @samp{#f}.
17755 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17756 sdbox and mdbox support saving mail attachments to external files,
17757 which also allows single instance storage for them. Other backends
17758 don't support this for now.
17760 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17762 Directory root where to store mail attachments. Disabled, if empty.
17763 Defaults to @samp{""}.
17766 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17767 Attachments smaller than this aren't saved externally. It's also
17768 possible to write a plugin to disable saving specific attachments
17770 Defaults to @samp{128000}.
17773 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17774 File system backend to use for saving attachments:
17777 No SiS done by Dovecot (but this might help FS's own deduplication)
17779 SiS with immediate byte-by-byte comparison during saving
17780 @item sis-queue posix
17781 SiS with delayed comparison and deduplication.
17783 Defaults to @samp{"sis posix"}.
17786 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17787 Hash format to use in attachment filenames. You can add any text and
17788 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17789 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17790 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17791 Defaults to @samp{"%@{sha1@}"}.
17794 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17796 Defaults to @samp{100}.
17799 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17801 Defaults to @samp{1000}.
17804 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17805 Default VSZ (virtual memory size) limit for service processes.
17806 This is mainly intended to catch and kill processes that leak memory
17807 before they eat up everything.
17808 Defaults to @samp{256000000}.
17811 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17812 Login user is internally used by login processes. This is the most
17813 untrusted user in Dovecot system. It shouldn't have access to anything
17815 Defaults to @samp{"dovenull"}.
17818 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17819 Internal user is used by unprivileged processes. It should be
17820 separate from login user, so that login processes can't disturb other
17822 Defaults to @samp{"dovecot"}.
17825 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17826 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17827 Defaults to @samp{"required"}.
17830 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17831 PEM encoded X.509 SSL/TLS certificate (public key).
17832 Defaults to @samp{"</etc/dovecot/default.pem"}.
17835 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17836 PEM encoded SSL/TLS private key. The key is opened before
17837 dropping root privileges, so keep the key file unreadable by anyone but
17839 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17842 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17843 If key file is password protected, give the password here.
17844 Alternatively give it when starting dovecot with -p parameter. Since
17845 this file is often world-readable, you may want to place this setting
17846 instead to a different.
17847 Defaults to @samp{""}.
17850 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17851 PEM encoded trusted certificate authority. Set this only if you
17852 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17853 contain the CA certificate(s) followed by the matching
17854 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17855 Defaults to @samp{""}.
17858 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17859 Require that CRL check succeeds for client certificates.
17860 Defaults to @samp{#t}.
17863 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17864 Request client to send a certificate. If you also want to require
17865 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17866 Defaults to @samp{#f}.
17869 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17870 Which field from certificate to use for username. commonName and
17871 x500UniqueIdentifier are the usual choices. You'll also need to set
17872 @samp{auth-ssl-username-from-cert? #t}.
17873 Defaults to @samp{"commonName"}.
17876 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17877 Minimum SSL protocol version to accept.
17878 Defaults to @samp{"TLSv1"}.
17881 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17882 SSL ciphers to use.
17883 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17886 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17887 SSL crypto device to use, for valid values run "openssl engine".
17888 Defaults to @samp{""}.
17891 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17892 Address to use when sending rejection mails.
17893 %d expands to recipient domain.
17894 Defaults to @samp{"postmaster@@%d"}.
17897 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17898 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17899 and in LMTP replies. Default is the system's real hostname@@domain.
17900 Defaults to @samp{""}.
17903 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17904 If user is over quota, return with temporary failure instead of
17906 Defaults to @samp{#f}.
17909 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17910 Binary to use for sending mails.
17911 Defaults to @samp{"/usr/sbin/sendmail"}.
17914 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17915 If non-empty, send mails via this SMTP host[:port] instead of
17917 Defaults to @samp{""}.
17920 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17921 Subject: header to use for rejection mails. You can use the same
17922 variables as for @samp{rejection-reason} below.
17923 Defaults to @samp{"Rejected: %s"}.
17926 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17927 Human readable error message for rejection mails. You can use
17940 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17943 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17944 Delimiter character between local-part and detail in email
17946 Defaults to @samp{"+"}.
17949 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17950 Header where the original recipient address (SMTP's RCPT TO:
17951 address) is taken from if not available elsewhere. With dovecot-lda -a
17952 parameter overrides this. A commonly used header for this is
17954 Defaults to @samp{""}.
17957 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17958 Should saving a mail to a nonexistent mailbox automatically create
17960 Defaults to @samp{#f}.
17963 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17964 Should automatically created mailboxes be also automatically
17966 Defaults to @samp{#f}.
17969 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17970 Maximum IMAP command line length. Some clients generate very long
17971 command lines with huge mailboxes, so you may need to raise this if you
17972 get "Too long argument" or "IMAP command line too large" errors
17974 Defaults to @samp{64000}.
17977 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17978 IMAP logout format string:
17981 total number of bytes read from client
17983 total number of bytes sent to client.
17985 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17986 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@}"}.
17989 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17990 Override the IMAP CAPABILITY response. If the value begins with '+',
17991 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17992 Defaults to @samp{""}.
17995 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17996 How long to wait between "OK Still here" notifications when client
17998 Defaults to @samp{"2 mins"}.
18001 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
18002 ID field names and values to send to clients. Using * as the value
18003 makes Dovecot use the default value. The following fields have default
18004 values currently: name, version, os, os-version, support-url,
18006 Defaults to @samp{""}.
18009 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
18010 ID fields sent by client to log. * means everything.
18011 Defaults to @samp{""}.
18014 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
18015 Workarounds for various client bugs:
18018 @item delay-newmail
18019 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
18020 CHECK commands. Some clients ignore them otherwise, for example OSX
18021 Mail (<v2.1). Outlook Express breaks more badly though, without this it
18022 may show user "Message no longer in server" errors. Note that OE6
18023 still breaks even with this workaround if synchronization is set to
18026 @item tb-extra-mailbox-sep
18027 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
18028 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
18029 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
18031 @item tb-lsub-flags
18032 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
18033 This makes Thunderbird realize they aren't selectable and show them
18034 greyed out, instead of only later giving "not selectable" popup error.
18036 Defaults to @samp{()}.
18039 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
18040 Host allowed in URLAUTH URLs sent by client. "*" allows all.
18041 Defaults to @samp{""}.
18045 Whew! Lots of configuration options. The nice thing about it though is
18046 that Guix has a complete interface to Dovecot's configuration
18047 language. This allows not only a nice way to declare configurations,
18048 but also offers reflective capabilities as well: users can write code to
18049 inspect and transform configurations from within Scheme.
18051 However, it could be that you just want to get a @code{dovecot.conf} up
18052 and running. In that case, you can pass an
18053 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
18054 @code{dovecot-service}. As its name indicates, an opaque configuration
18055 does not have easy reflective capabilities.
18057 Available @code{opaque-dovecot-configuration} fields are:
18059 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
18060 The dovecot package.
18063 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
18064 The contents of the @code{dovecot.conf}, as a string.
18067 For example, if your @code{dovecot.conf} is just the empty string, you
18068 could instantiate a dovecot service like this:
18071 (dovecot-service #:config
18072 (opaque-dovecot-configuration
18076 @subsubheading OpenSMTPD Service
18078 @deffn {Scheme Variable} opensmtpd-service-type
18079 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
18080 service, whose value should be an @code{opensmtpd-configuration} object
18081 as in this example:
18084 (service opensmtpd-service-type
18085 (opensmtpd-configuration
18086 (config-file (local-file "./my-smtpd.conf"))))
18090 @deftp {Data Type} opensmtpd-configuration
18091 Data type representing the configuration of opensmtpd.
18094 @item @code{package} (default: @var{opensmtpd})
18095 Package object of the OpenSMTPD SMTP server.
18097 @item @code{config-file} (default: @code{%default-opensmtpd-file})
18098 File-like object of the OpenSMTPD configuration file to use. By default
18099 it listens on the loopback network interface, and allows for mail from
18100 users and daemons on the local machine, as well as permitting email to
18101 remote servers. Run @command{man smtpd.conf} for more information.
18106 @subsubheading Exim Service
18108 @cindex mail transfer agent (MTA)
18109 @cindex MTA (mail transfer agent)
18112 @deffn {Scheme Variable} exim-service-type
18113 This is the type of the @uref{https://exim.org, Exim} mail transfer
18114 agent (MTA), whose value should be an @code{exim-configuration} object
18115 as in this example:
18118 (service exim-service-type
18119 (exim-configuration
18120 (config-file (local-file "./my-exim.conf"))))
18124 In order to use an @code{exim-service-type} service you must also have a
18125 @code{mail-aliases-service-type} service present in your
18126 @code{operating-system} (even if it has no aliases).
18128 @deftp {Data Type} exim-configuration
18129 Data type representing the configuration of exim.
18132 @item @code{package} (default: @var{exim})
18133 Package object of the Exim server.
18135 @item @code{config-file} (default: @code{#f})
18136 File-like object of the Exim configuration file to use. If its value is
18137 @code{#f} then use the default configuration file from the package
18138 provided in @code{package}. The resulting configuration file is loaded
18139 after setting the @code{exim_user} and @code{exim_group} configuration
18145 @subsubheading Getmail service
18150 @deffn {Scheme Variable} getmail-service-type
18151 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
18152 mail retriever, whose value should be an @code{getmail-configuration}.
18155 Available @code{getmail-configuration} fields are:
18157 @deftypevr {@code{getmail-configuration} parameter} symbol name
18158 A symbol to identify the getmail service.
18160 Defaults to @samp{"unset"}.
18164 @deftypevr {@code{getmail-configuration} parameter} package package
18165 The getmail package to use.
18169 @deftypevr {@code{getmail-configuration} parameter} string user
18170 The user to run getmail as.
18172 Defaults to @samp{"getmail"}.
18176 @deftypevr {@code{getmail-configuration} parameter} string group
18177 The group to run getmail as.
18179 Defaults to @samp{"getmail"}.
18183 @deftypevr {@code{getmail-configuration} parameter} string directory
18184 The getmail directory to use.
18186 Defaults to @samp{"/var/lib/getmail/default"}.
18190 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
18191 The getmail configuration file to use.
18193 Available @code{getmail-configuration-file} fields are:
18195 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
18196 What mail account to retrieve mail from, and how to access that account.
18198 Available @code{getmail-retriever-configuration} fields are:
18200 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
18201 The type of mail retriever to use. Valid values include @samp{passwd}
18204 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
18208 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
18209 Username to login to the mail server with.
18211 Defaults to @samp{unset}.
18215 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
18216 Username to login to the mail server with.
18218 Defaults to @samp{unset}.
18222 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
18223 Port number to connect to.
18225 Defaults to @samp{#f}.
18229 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
18230 Override fields from passwd.
18232 Defaults to @samp{""}.
18236 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
18237 Override fields from passwd.
18239 Defaults to @samp{()}.
18243 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
18244 PEM-formatted key file to use for the TLS negotiation.
18246 Defaults to @samp{""}.
18250 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
18251 PEM-formatted certificate file to use for the TLS negotiation.
18253 Defaults to @samp{""}.
18257 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
18258 CA certificates to use.
18260 Defaults to @samp{""}.
18264 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
18265 Extra retriever parameters.
18267 Defaults to @samp{()}.
18273 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
18274 What to do with retrieved messages.
18276 Available @code{getmail-destination-configuration} fields are:
18278 @deftypevr {@code{getmail-destination-configuration} parameter} string type
18279 The type of mail destination. Valid values include @samp{Maildir},
18280 @samp{Mboxrd} and @samp{MDA_external}.
18282 Defaults to @samp{unset}.
18286 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
18287 The path option for the mail destination. The behaviour depends on the
18290 Defaults to @samp{""}.
18294 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
18295 Extra destination parameters
18297 Defaults to @samp{()}.
18303 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
18306 Available @code{getmail-options-configuration} fields are:
18308 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
18309 If set to @samp{0}, getmail will only print warnings and errors. A
18310 value of @samp{1} means that messages will be printed about retrieving
18311 and deleting messages. If set to @samp{2}, getmail will print messages
18312 about each of it's actions.
18314 Defaults to @samp{1}.
18318 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
18319 If true, getmail will retrieve all available messages. Otherwise it
18320 will only retrieve messages it hasn't seen previously.
18322 Defaults to @samp{#t}.
18326 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
18327 If set to true, messages will be deleted from the server after
18328 retrieving and successfully delivering them. Otherwise, messages will
18329 be left on the server.
18331 Defaults to @samp{#f}.
18335 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
18336 Getmail will delete messages this number of days after seeing them, if
18337 they have been delivered. This means messages will be left on the
18338 server this number of days after delivering them. A value of @samp{0}
18339 disabled this feature.
18341 Defaults to @samp{0}.
18345 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
18346 Delete messages larger than this of bytes after retrieving them, even if
18347 the delete and delete-after options are disabled. A value of @samp{0}
18348 disables this feature.
18350 Defaults to @samp{0}.
18354 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
18355 Retrieve messages totalling up to this number of bytes before closing
18356 the session with the server. A value of @samp{0} disables this feature.
18358 Defaults to @samp{0}.
18362 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
18363 Don't retrieve messages larger than this number of bytes. A value of
18364 @samp{0} disables this feature.
18366 Defaults to @samp{0}.
18370 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
18371 If true, getmail will add a Delivered-To header to messages.
18373 Defaults to @samp{#t}.
18377 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
18378 If set, getmail adds a Received header to the messages.
18380 Defaults to @samp{#t}.
18384 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
18385 Getmail will record a log of its actions to the named file. A value of
18386 @samp{""} disables this feature.
18388 Defaults to @samp{""}.
18392 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
18393 If true, getmail will record a log of its actions using the system
18396 Defaults to @samp{#f}.
18400 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
18401 If true, getmail will log information about messages not retrieved and
18402 the reason for not retrieving them, as well as starting and ending
18405 Defaults to @samp{#f}.
18409 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
18410 Extra options to include.
18412 Defaults to @samp{()}.
18420 @deftypevr {@code{getmail-configuration} parameter} list idle
18421 A list of mailboxes that getmail should wait on the server for new mail
18422 notifications. This depends on the server supporting the IDLE
18425 Defaults to @samp{()}.
18429 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
18430 Environment variables to set for getmail.
18432 Defaults to @samp{()}.
18436 @subsubheading Mail Aliases Service
18438 @cindex email aliases
18439 @cindex aliases, for email addresses
18441 @deffn {Scheme Variable} mail-aliases-service-type
18442 This is the type of the service which provides @code{/etc/aliases},
18443 specifying how to deliver mail to users on this system.
18446 (service mail-aliases-service-type
18447 '(("postmaster" "bob")
18448 ("bob" "bob@@example.com" "bob@@example2.com")))
18452 The configuration for a @code{mail-aliases-service-type} service is an
18453 association list denoting how to deliver mail that comes to this
18454 system. Each entry is of the form @code{(alias addresses ...)}, with
18455 @code{alias} specifying the local alias and @code{addresses} specifying
18456 where to deliver this user's mail.
18458 The aliases aren't required to exist as users on the local system. In
18459 the above example, there doesn't need to be a @code{postmaster} entry in
18460 the @code{operating-system}'s @code{user-accounts} in order to deliver
18461 the @code{postmaster} mail to @code{bob} (which subsequently would
18462 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
18464 @subsubheading GNU Mailutils IMAP4 Daemon
18465 @cindex GNU Mailutils IMAP4 Daemon
18467 @deffn {Scheme Variable} imap4d-service-type
18468 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
18469 mailutils, GNU Mailutils Manual}), whose value should be an
18470 @code{imap4d-configuration} object as in this example:
18473 (service imap4d-service-type
18474 (imap4d-configuration
18475 (config-file (local-file "imap4d.conf"))))
18479 @deftp {Data Type} imap4d-configuration
18480 Data type representing the configuration of @command{imap4d}.
18483 @item @code{package} (default: @code{mailutils})
18484 The package that provides @command{imap4d}.
18486 @item @code{config-file} (default: @code{%default-imap4d-config-file})
18487 File-like object of the configuration file to use, by default it will listen
18488 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
18489 Mailutils Manual}, for details.
18494 @node Messaging Services
18495 @subsection Messaging Services
18500 The @code{(gnu services messaging)} module provides Guix service
18501 definitions for messaging services: currently only Prosody is supported.
18503 @subsubheading Prosody Service
18505 @deffn {Scheme Variable} prosody-service-type
18506 This is the type for the @uref{https://prosody.im, Prosody XMPP
18507 communication server}. Its value must be a @code{prosody-configuration}
18508 record as in this example:
18511 (service prosody-service-type
18512 (prosody-configuration
18513 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
18516 (int-component-configuration
18517 (hostname "conference.example.net")
18519 (mod-muc (mod-muc-configuration)))))
18522 (virtualhost-configuration
18523 (domain "example.net"))))))
18526 See below for details about @code{prosody-configuration}.
18530 By default, Prosody does not need much configuration. Only one
18531 @code{virtualhosts} field is needed: it specifies the domain you wish
18534 You can perform various sanity checks on the generated configuration
18535 with the @code{prosodyctl check} command.
18537 Prosodyctl will also help you to import certificates from the
18538 @code{letsencrypt} directory so that the @code{prosody} user can access
18539 them. See @url{https://prosody.im/doc/letsencrypt}.
18542 prosodyctl --root cert import /etc/letsencrypt/live
18545 The available configuration parameters follow. Each parameter
18546 definition is preceded by its type; for example, @samp{string-list foo}
18547 indicates that the @code{foo} parameter should be specified as a list of
18548 strings. Types starting with @code{maybe-} denote parameters that won't
18549 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
18551 There is also a way to specify the configuration as a string, if you
18552 have an old @code{prosody.cfg.lua} file that you want to port over from
18553 some other system; see the end for more details.
18555 The @code{file-object} type designates either a file-like object
18556 (@pxref{G-Expressions, file-like objects}) or a file name.
18558 @c The following documentation was initially generated by
18559 @c (generate-documentation) in (gnu services messaging). Manually maintained
18560 @c documentation is better, so we shouldn't hesitate to edit below as
18561 @c needed. However if the change you want to make to this documentation
18562 @c can be done in an automated way, it's probably easier to change
18563 @c (generate-documentation) than to make it below and have to deal with
18564 @c the churn as Prosody updates.
18566 Available @code{prosody-configuration} fields are:
18568 @deftypevr {@code{prosody-configuration} parameter} package prosody
18569 The Prosody package.
18572 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
18573 Location of the Prosody data storage directory. See
18574 @url{https://prosody.im/doc/configure}.
18575 Defaults to @samp{"/var/lib/prosody"}.
18578 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
18579 Additional plugin directories. They are searched in all the specified
18580 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
18581 Defaults to @samp{()}.
18584 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
18585 Every virtual host and component needs a certificate so that clients and
18586 servers can securely verify its identity. Prosody will automatically load
18587 certificates/keys from the directory specified here.
18588 Defaults to @samp{"/etc/prosody/certs"}.
18591 @deftypevr {@code{prosody-configuration} parameter} string-list admins
18592 This is a list of accounts that are admins for the server. Note that you
18593 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
18594 @url{https://prosody.im/doc/creating_accounts}.
18595 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
18596 Defaults to @samp{()}.
18599 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
18600 Enable use of libevent for better performance under high load. See
18601 @url{https://prosody.im/doc/libevent}.
18602 Defaults to @samp{#f}.
18605 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
18606 This is the list of modules Prosody will load on startup. It looks for
18607 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
18608 Documentation on modules can be found at:
18609 @url{https://prosody.im/doc/modules}.
18610 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
18613 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
18614 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
18615 should you want to disable them then add them to this list.
18616 Defaults to @samp{()}.
18619 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
18620 Path to a text file where the shared groups are defined. If this path is
18621 empty then @samp{mod_groups} does nothing. See
18622 @url{https://prosody.im/doc/modules/mod_groups}.
18623 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
18626 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
18627 Disable account creation by default, for security. See
18628 @url{https://prosody.im/doc/creating_accounts}.
18629 Defaults to @samp{#f}.
18632 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
18633 These are the SSL/TLS-related settings. Most of them are disabled so to
18634 use Prosody's defaults. If you do not completely understand these options, do
18635 not add them to your config, it is easy to lower the security of your server
18636 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
18638 Available @code{ssl-configuration} fields are:
18640 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
18641 This determines what handshake to use.
18644 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
18645 Path to your private key file.
18648 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
18649 Path to your certificate file.
18652 @deftypevr {@code{ssl-configuration} parameter} file-object capath
18653 Path to directory containing root certificates that you wish Prosody to
18654 trust when verifying the certificates of remote servers.
18655 Defaults to @samp{"/etc/ssl/certs"}.
18658 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
18659 Path to a file containing root certificates that you wish Prosody to trust.
18660 Similar to @code{capath} but with all certificates concatenated together.
18663 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
18664 A list of verification options (these mostly map to OpenSSL's
18665 @code{set_verify()} flags).
18668 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
18669 A list of general options relating to SSL/TLS. These map to OpenSSL's
18670 @code{set_options()}. For a full list of options available in LuaSec, see the
18674 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18675 How long a chain of certificate authorities to check when looking for a
18676 trusted root certificate.
18679 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18680 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18681 clients, and in what order.
18684 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18685 A path to a file containing parameters for Diffie-Hellman key exchange. You
18686 can create such a file with:
18687 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18690 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18691 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18692 @samp{"secp384r1"}.
18695 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18696 A list of ``extra'' verification options.
18699 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18700 Password for encrypted private keys.
18705 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18706 Whether to force all client-to-server connections to be encrypted or not.
18707 See @url{https://prosody.im/doc/modules/mod_tls}.
18708 Defaults to @samp{#f}.
18711 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18712 Set of mechanisms that will never be offered. See
18713 @url{https://prosody.im/doc/modules/mod_saslauth}.
18714 Defaults to @samp{("DIGEST-MD5")}.
18717 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18718 Whether to force all server-to-server connections to be encrypted or not.
18719 See @url{https://prosody.im/doc/modules/mod_tls}.
18720 Defaults to @samp{#f}.
18723 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18724 Whether to require encryption and certificate authentication. This
18725 provides ideal security, but requires servers you communicate with to support
18726 encryption AND present valid, trusted certificates. See
18727 @url{https://prosody.im/doc/s2s#security}.
18728 Defaults to @samp{#f}.
18731 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18732 Many servers don't support encryption or have invalid or self-signed
18733 certificates. You can list domains here that will not be required to
18734 authenticate using certificates. They will be authenticated using DNS. See
18735 @url{https://prosody.im/doc/s2s#security}.
18736 Defaults to @samp{()}.
18739 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18740 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18741 valid certificates for some domains by specifying a list here. See
18742 @url{https://prosody.im/doc/s2s#security}.
18743 Defaults to @samp{()}.
18746 @deftypevr {@code{prosody-configuration} parameter} string authentication
18747 Select the authentication backend to use. The default provider stores
18748 passwords in plaintext and uses Prosody's configured data storage to store the
18749 authentication data. If you do not trust your server please see
18750 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18751 about using the hashed backend. See also
18752 @url{https://prosody.im/doc/authentication}
18753 Defaults to @samp{"internal_plain"}.
18756 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18757 Set logging options. Advanced logging configuration is not yet supported
18758 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18759 Defaults to @samp{"*syslog"}.
18762 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18763 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18764 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18767 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18768 Maximum allowed size of the HTTP body (in bytes).
18771 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18772 Some modules expose their own URL in various ways. This URL is built
18773 from the protocol, host and port used. If Prosody sits behind a proxy, the
18774 public URL will be @code{http-external-url} instead. See
18775 @url{https://prosody.im/doc/http#external_url}.
18778 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18779 A host in Prosody is a domain on which user accounts can be created. For
18780 example if you want your users to have addresses like
18781 @samp{"john.smith@@example.com"} then you need to add a host
18782 @samp{"example.com"}. All options in this list will apply only to this host.
18784 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
18785 the actual physical host that Prosody is installed on. A single Prosody
18786 instance can serve many domains, each one defined as a VirtualHost entry in
18787 Prosody's configuration. Conversely a server that hosts a single domain would
18788 have just one VirtualHost entry.
18790 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18792 Available @code{virtualhost-configuration} fields are:
18794 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:
18795 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18796 Domain you wish Prosody to serve.
18801 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18802 Components are extra services on a server which are available to clients,
18803 usually on a subdomain of the main server (such as
18804 @samp{"mycomponent.example.com"}). Example components might be chatroom
18805 servers, user directories, or gateways to other protocols.
18807 Internal components are implemented with Prosody-specific plugins. To add an
18808 internal component, you simply fill the hostname field, and the plugin you wish
18809 to use for the component.
18811 See @url{https://prosody.im/doc/components}.
18812 Defaults to @samp{()}.
18814 Available @code{int-component-configuration} fields are:
18816 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:
18817 @deftypevr {@code{int-component-configuration} parameter} string hostname
18818 Hostname of the component.
18821 @deftypevr {@code{int-component-configuration} parameter} string plugin
18822 Plugin you wish to use for the component.
18825 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18826 Multi-user chat (MUC) is Prosody's module for allowing you to create
18827 hosted chatrooms/conferences for XMPP users.
18829 General information on setting up and using multi-user chatrooms can be found
18830 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
18831 which you should read if you are new to XMPP chatrooms.
18833 See also @url{https://prosody.im/doc/modules/mod_muc}.
18835 Available @code{mod-muc-configuration} fields are:
18837 @deftypevr {@code{mod-muc-configuration} parameter} string name
18838 The name to return in service discovery responses.
18839 Defaults to @samp{"Prosody Chatrooms"}.
18842 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18843 If @samp{#t}, this will only allow admins to create new chatrooms.
18844 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18845 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18846 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18847 restricts to service administrators only.
18848 Defaults to @samp{#f}.
18851 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18852 Maximum number of history messages that will be sent to the member that has
18853 just joined the room.
18854 Defaults to @samp{20}.
18861 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18862 External components use XEP-0114, which most standalone components
18863 support. To add an external component, you simply fill the hostname field. See
18864 @url{https://prosody.im/doc/components}.
18865 Defaults to @samp{()}.
18867 Available @code{ext-component-configuration} fields are:
18869 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:
18870 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18871 Password which the component will use to log in.
18874 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18875 Hostname of the component.
18880 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18881 Port(s) Prosody listens on for component connections.
18882 Defaults to @samp{(5347)}.
18885 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18886 Interface Prosody listens on for component connections.
18887 Defaults to @samp{"127.0.0.1"}.
18890 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18891 Raw content that will be added to the configuration file.
18894 It could be that you just want to get a @code{prosody.cfg.lua}
18895 up and running. In that case, you can pass an
18896 @code{opaque-prosody-configuration} record as the value of
18897 @code{prosody-service-type}. As its name indicates, an opaque configuration
18898 does not have easy reflective capabilities.
18899 Available @code{opaque-prosody-configuration} fields are:
18901 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18902 The prosody package.
18905 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18906 The contents of the @code{prosody.cfg.lua} to use.
18909 For example, if your @code{prosody.cfg.lua} is just the empty
18910 string, you could instantiate a prosody service like this:
18913 (service prosody-service-type
18914 (opaque-prosody-configuration
18915 (prosody.cfg.lua "")))
18918 @c end of Prosody auto-generated documentation
18920 @subsubheading BitlBee Service
18922 @cindex IRC (Internet Relay Chat)
18923 @cindex IRC gateway
18924 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18925 interface to a variety of messaging protocols such as XMPP.
18927 @defvr {Scheme Variable} bitlbee-service-type
18928 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18929 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18932 To have BitlBee listen on port 6667 on localhost, add this line to your
18936 (service bitlbee-service-type)
18940 @deftp {Data Type} bitlbee-configuration
18941 This is the configuration for BitlBee, with the following fields:
18944 @item @code{interface} (default: @code{"127.0.0.1"})
18945 @itemx @code{port} (default: @code{6667})
18946 Listen on the network interface corresponding to the IP address
18947 specified in @var{interface}, on @var{port}.
18949 When @var{interface} is @code{127.0.0.1}, only local clients can
18950 connect; when it is @code{0.0.0.0}, connections can come from any
18951 networking interface.
18953 @item @code{bitlbee} (default: @code{bitlbee})
18954 The BitlBee package to use.
18956 @item @code{plugins} (default: @code{'()})
18957 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18959 @item @code{extra-settings} (default: @code{""})
18960 Configuration snippet added as-is to the BitlBee configuration file.
18964 @subsubheading Quassel Service
18966 @cindex IRC (Internet Relay Chat)
18967 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18968 meaning that one or more clients can attach to and detach from the
18971 @defvr {Scheme Variable} quassel-service-type
18972 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18973 IRC backend daemon. Its value is a @code{quassel-configuration}
18977 @deftp {Data Type} quassel-configuration
18978 This is the configuration for Quassel, with the following fields:
18981 @item @code{quassel} (default: @code{quassel})
18982 The Quassel package to use.
18984 @item @code{interface} (default: @code{"::,0.0.0.0"})
18985 @item @code{port} (default: @code{4242})
18986 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18987 interfaces specified in the comma delimited @var{interface}, on
18990 @item @code{loglevel} (default: @code{"Info"})
18991 The level of logging desired. Accepted values are Debug, Info, Warning
18996 @node Telephony Services
18997 @subsection Telephony Services
18999 @cindex Murmur (VoIP server)
19000 @cindex VoIP server
19001 This section describes how to set up and run a Murmur server. Murmur is
19002 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
19005 @deftp {Data Type} murmur-configuration
19006 The service type for the Murmur server. An example configuration can
19010 (service murmur-service-type
19011 (murmur-configuration
19013 "Welcome to this Mumble server running on Guix!")
19014 (cert-required? #t) ;disallow text password logins
19015 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
19016 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
19019 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
19020 password with the command that is printed during the activation phase.
19022 It is recommended to register a normal Mumble user account
19023 and grant it admin or moderator rights.
19024 You can use the @code{mumble} client to
19025 login as new normal user, register yourself, and log out.
19026 For the next step login with the name @code{SuperUser} use
19027 the @code{SuperUser} password that you set previously,
19028 and grant your newly registered mumble user administrator or moderator
19029 rights and create some channels.
19031 Available @code{murmur-configuration} fields are:
19034 @item @code{package} (default: @code{mumble})
19035 Package that contains @code{bin/murmurd}.
19037 @item @code{user} (default: @code{"murmur"})
19038 User who will run the Murmur server.
19040 @item @code{group} (default: @code{"murmur"})
19041 Group of the user who will run the murmur server.
19043 @item @code{port} (default: @code{64738})
19044 Port on which the server will listen.
19046 @item @code{welcome-text} (default: @code{""})
19047 Welcome text sent to clients when they connect.
19049 @item @code{server-password} (default: @code{""})
19050 Password the clients have to enter in order to connect.
19052 @item @code{max-users} (default: @code{100})
19053 Maximum of users that can be connected to the server at once.
19055 @item @code{max-user-bandwidth} (default: @code{#f})
19056 Maximum voice traffic a user can send per second.
19058 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
19059 File name of the sqlite database.
19060 The service's user will become the owner of the directory.
19062 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
19063 File name of the log file.
19064 The service's user will become the owner of the directory.
19066 @item @code{autoban-attempts} (default: @code{10})
19067 Maximum number of logins a user can make in @code{autoban-timeframe}
19068 without getting auto banned for @code{autoban-time}.
19070 @item @code{autoban-timeframe} (default: @code{120})
19071 Timeframe for autoban in seconds.
19073 @item @code{autoban-time} (default: @code{300})
19074 Amount of time in seconds for which a client gets banned
19075 when violating the autoban limits.
19077 @item @code{opus-threshold} (default: @code{100})
19078 Percentage of clients that need to support opus
19079 before switching over to opus audio codec.
19081 @item @code{channel-nesting-limit} (default: @code{10})
19082 How deep channels can be nested at maximum.
19084 @item @code{channelname-regex} (default: @code{#f})
19085 A string in form of a Qt regular expression that channel names must conform to.
19087 @item @code{username-regex} (default: @code{#f})
19088 A string in form of a Qt regular expression that user names must conform to.
19090 @item @code{text-message-length} (default: @code{5000})
19091 Maximum size in bytes that a user can send in one text chat message.
19093 @item @code{image-message-length} (default: @code{(* 128 1024)})
19094 Maximum size in bytes that a user can send in one image message.
19096 @item @code{cert-required?} (default: @code{#f})
19097 If it is set to @code{#t} clients that use weak password authentication
19098 will not be accepted. Users must have completed the certificate wizard to join.
19100 @item @code{remember-channel?} (default: @code{#f})
19101 Should murmur remember the last channel each user was in when they disconnected
19102 and put them into the remembered channel when they rejoin.
19104 @item @code{allow-html?} (default: @code{#f})
19105 Should html be allowed in text messages, user comments, and channel descriptions.
19107 @item @code{allow-ping?} (default: @code{#f})
19108 Setting to true exposes the current user count, the maximum user count, and
19109 the server's maximum bandwidth per client to unauthenticated users. In the
19110 Mumble client, this information is shown in the Connect dialog.
19112 Disabling this setting will prevent public listing of the server.
19114 @item @code{bonjour?} (default: @code{#f})
19115 Should the server advertise itself in the local network through the bonjour protocol.
19117 @item @code{send-version?} (default: @code{#f})
19118 Should the murmur server version be exposed in ping requests.
19120 @item @code{log-days} (default: @code{31})
19121 Murmur also stores logs in the database, which are accessible via RPC.
19122 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
19123 or -1 to disable logging to the database.
19125 @item @code{obfuscate-ips?} (default: @code{#t})
19126 Should logged ips be obfuscated to protect the privacy of users.
19128 @item @code{ssl-cert} (default: @code{#f})
19129 File name of the SSL/TLS certificate used for encrypted connections.
19132 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
19134 @item @code{ssl-key} (default: @code{#f})
19135 Filepath to the ssl private key used for encrypted connections.
19137 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
19140 @item @code{ssl-dh-params} (default: @code{#f})
19141 File name of a PEM-encoded file with Diffie-Hellman parameters
19142 for the SSL/TLS encryption. Alternatively you set it to
19143 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
19144 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
19146 @item @code{ssl-ciphers} (default: @code{#f})
19147 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
19150 This option is specified using
19151 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
19152 OpenSSL cipher list notation}.
19154 It is recommended that you try your cipher string using 'openssl ciphers <string>'
19155 before setting it here, to get a feel for which cipher suites you will get.
19156 After setting this option, it is recommend that you inspect your Murmur log
19157 to ensure that Murmur is using the cipher suites that you expected it to.
19159 Note: Changing this option may impact the backwards compatibility of your
19160 Murmur server, and can remove the ability for older Mumble clients to be able
19163 @item @code{public-registration} (default: @code{#f})
19164 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
19166 You can optionally register your server in the public server list that the
19167 @code{mumble} client shows on startup.
19168 You cannot register your server if you have set a @code{server-password},
19169 or set @code{allow-ping} to @code{#f}.
19171 It might take a few hours until it shows up in the public list.
19173 @item @code{file} (default: @code{#f})
19174 Optional alternative override for this configuration.
19178 @deftp {Data Type} murmur-public-registration-configuration
19179 Configuration for public registration of a murmur service.
19183 This is a display name for your server. Not to be confused with the hostname.
19185 @item @code{password}
19186 A password to identify your registration.
19187 Subsequent updates will need the same password. Don't lose your password.
19190 This should be a @code{http://} or @code{https://} link to your web
19193 @item @code{hostname} (default: @code{#f})
19194 By default your server will be listed by its IP address.
19195 If it is set your server will be linked by this host name instead.
19201 @node Monitoring Services
19202 @subsection Monitoring Services
19204 @subsubheading Tailon Service
19206 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
19207 viewing and searching log files.
19209 The following example will configure the service with default values.
19210 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
19213 (service tailon-service-type)
19216 The following example customises more of the Tailon configuration,
19217 adding @command{sed} to the list of allowed commands.
19220 (service tailon-service-type
19221 (tailon-configuration
19223 (tailon-configuration-file
19224 (allowed-commands '("tail" "grep" "awk" "sed"))))))
19228 @deftp {Data Type} tailon-configuration
19229 Data type representing the configuration of Tailon.
19230 This type has the following parameters:
19233 @item @code{config-file} (default: @code{(tailon-configuration-file)})
19234 The configuration file to use for Tailon. This can be set to a
19235 @dfn{tailon-configuration-file} record value, or any gexp
19236 (@pxref{G-Expressions}).
19238 For example, to instead use a local file, the @code{local-file} function
19242 (service tailon-service-type
19243 (tailon-configuration
19244 (config-file (local-file "./my-tailon.conf"))))
19247 @item @code{package} (default: @code{tailon})
19248 The tailon package to use.
19253 @deftp {Data Type} tailon-configuration-file
19254 Data type representing the configuration options for Tailon.
19255 This type has the following parameters:
19258 @item @code{files} (default: @code{(list "/var/log")})
19259 List of files to display. The list can include strings for a single file
19260 or directory, or a list, where the first item is the name of a
19261 subsection, and the remaining items are the files or directories in that
19264 @item @code{bind} (default: @code{"localhost:8080"})
19265 Address and port to which Tailon should bind on.
19267 @item @code{relative-root} (default: @code{#f})
19268 URL path to use for Tailon, set to @code{#f} to not use a path.
19270 @item @code{allow-transfers?} (default: @code{#t})
19271 Allow downloading the log files in the web interface.
19273 @item @code{follow-names?} (default: @code{#t})
19274 Allow tailing of not-yet existent files.
19276 @item @code{tail-lines} (default: @code{200})
19277 Number of lines to read initially from each file.
19279 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
19280 Commands to allow running. By default, @code{sed} is disabled.
19282 @item @code{debug?} (default: @code{#f})
19283 Set @code{debug?} to @code{#t} to show debug messages.
19285 @item @code{wrap-lines} (default: @code{#t})
19286 Initial line wrapping state in the web interface. Set to @code{#t} to
19287 initially wrap lines (the default), or to @code{#f} to initially not
19290 @item @code{http-auth} (default: @code{#f})
19291 HTTP authentication type to use. Set to @code{#f} to disable
19292 authentication (the default). Supported values are @code{"digest"} or
19295 @item @code{users} (default: @code{#f})
19296 If HTTP authentication is enabled (see @code{http-auth}), access will be
19297 restricted to the credentials provided here. To configure users, use a
19298 list of pairs, where the first element of the pair is the username, and
19299 the 2nd element of the pair is the password.
19302 (tailon-configuration-file
19303 (http-auth "basic")
19304 (users '(("user1" . "password1")
19305 ("user2" . "password2"))))
19312 @subsubheading Darkstat Service
19314 Darkstat is a packet sniffer that captures network traffic, calculates
19315 statistics about usage, and serves reports over HTTP.
19317 @defvar {Scheme Variable} darkstat-service-type
19318 This is the service type for the
19319 @uref{https://unix4lyfe.org/darkstat/, darkstat}
19320 service, its value must be a @code{darkstat-configuration} record as in
19324 (service darkstat-service-type
19325 (darkstat-configuration
19326 (interface "eno1")))
19330 @deftp {Data Type} darkstat-configuration
19331 Data type representing the configuration of @command{darkstat}.
19334 @item @code{package} (default: @code{darkstat})
19335 The darkstat package to use.
19337 @item @code{interface}
19338 Capture traffic on the specified network interface.
19340 @item @code{port} (default: @code{"667"})
19341 Bind the web interface to the specified port.
19343 @item @code{bind-address} (default: @code{"127.0.0.1"})
19344 Bind the web interface to the specified address.
19346 @item @code{base} (default: @code{"/"})
19347 Specify the path of the base URL. This can be useful if
19348 @command{darkstat} is accessed via a reverse proxy.
19353 @subsubheading Prometheus Node Exporter Service
19355 @cindex prometheus-node-exporter
19356 The Prometheus ``node exporter'' makes hardware and operating system statistics
19357 provided by the Linux kernel available for the Prometheus monitoring system.
19358 This service should be deployed on all physical nodes and virtual machines,
19359 where monitoring these statistics is desirable.
19361 @defvar {Scheme variable} prometheus-node-exporter-service-type
19362 This is the service type for the
19363 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
19364 service, its value must be a @code{prometheus-node-exporter-configuration}
19365 record as in this example:
19368 (service prometheus-node-exporter-service-type
19369 (prometheus-node-exporter-configuration
19370 (web-listen-address ":9100")))
19374 @deftp {Data Type} prometheus-node-exporter-configuration
19375 Data type representing the configuration of @command{node_exporter}.
19378 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
19379 The prometheus-node-exporter package to use.
19381 @item @code{web-listen-address} (default: @code{":9100"})
19382 Bind the web interface to the specified address.
19387 @subsubheading Zabbix server
19388 @cindex zabbix zabbix-server
19389 Zabbix provides monitoring metrics, among others network utilization, CPU load
19390 and disk space consumption:
19393 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
19394 @item Auto-discovery of servers and network devices and interfaces.
19395 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
19396 @item Distributed monitoring with centralized web administration.
19397 @item Native high performance agents.
19398 @item SLA, and ITIL KPI metrics on reporting.
19399 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
19400 @item Remote command execution through Zabbix proxies.
19403 @c %start of fragment
19405 Available @code{zabbix-server-configuration} fields are:
19407 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
19408 The zabbix-server package.
19412 @deftypevr {@code{zabbix-server-configuration} parameter} string user
19413 User who will run the Zabbix server.
19415 Defaults to @samp{"zabbix"}.
19419 @deftypevr {@code{zabbix-server-configuration} parameter} group group
19420 Group who will run the Zabbix server.
19422 Defaults to @samp{"zabbix"}.
19426 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
19427 Database host name.
19429 Defaults to @samp{"127.0.0.1"}.
19433 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
19436 Defaults to @samp{"zabbix"}.
19440 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
19443 Defaults to @samp{"zabbix"}.
19447 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
19448 Database password. Please, use @code{include-files} with
19449 @code{DBPassword=SECRET} inside a specified file instead.
19451 Defaults to @samp{""}.
19455 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
19458 Defaults to @samp{5432}.
19462 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
19463 Specifies where log messages are written to:
19467 @code{system} - syslog.
19470 @code{file} - file specified with @code{log-file} parameter.
19473 @code{console} - standard output.
19477 Defaults to @samp{""}.
19481 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
19482 Log file name for @code{log-type} @code{file} parameter.
19484 Defaults to @samp{"/var/log/zabbix/server.log"}.
19488 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
19491 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
19495 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
19496 The location of certificate authority (CA) files for SSL server
19497 certificate verification.
19499 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
19503 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
19504 Location of SSL client certificates.
19506 Defaults to @samp{"/etc/ssl/certs"}.
19510 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
19511 Extra options will be appended to Zabbix server configuration file.
19513 Defaults to @samp{""}.
19517 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
19518 You may include individual files or all files in a directory in the
19519 configuration file.
19521 Defaults to @samp{()}.
19525 @c %end of fragment
19527 @subsubheading Zabbix agent
19528 @cindex zabbix zabbix-agent
19530 Zabbix agent gathers information for Zabbix server.
19532 @c %start of fragment
19534 Available @code{zabbix-agent-configuration} fields are:
19536 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
19537 The zabbix-agent package.
19541 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
19542 User who will run the Zabbix agent.
19544 Defaults to @samp{"zabbix"}.
19548 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
19549 Group who will run the Zabbix agent.
19551 Defaults to @samp{"zabbix"}.
19555 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
19556 Unique, case sensitive hostname which is required for active checks and
19557 must match hostname as configured on the server.
19559 Defaults to @samp{"Zabbix server"}.
19563 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
19564 Specifies where log messages are written to:
19568 @code{system} - syslog.
19571 @code{file} - file specified with @code{log-file} parameter.
19574 @code{console} - standard output.
19578 Defaults to @samp{""}.
19582 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
19583 Log file name for @code{log-type} @code{file} parameter.
19585 Defaults to @samp{"/var/log/zabbix/agent.log"}.
19589 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
19592 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
19596 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
19597 List of IP addresses, optionally in CIDR notation, or hostnames of
19598 Zabbix servers and Zabbix proxies. Incoming connections will be
19599 accepted only from the hosts listed here.
19601 Defaults to @samp{("127.0.0.1")}.
19605 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
19606 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
19607 proxies for active checks. If port is not specified, default port is
19608 used. If this parameter is not specified, active checks are disabled.
19610 Defaults to @samp{("127.0.0.1")}.
19614 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
19615 Extra options will be appended to Zabbix server configuration file.
19617 Defaults to @samp{""}.
19621 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
19622 You may include individual files or all files in a directory in the
19623 configuration file.
19625 Defaults to @samp{()}.
19629 @c %end of fragment
19631 @subsubheading Zabbix front-end
19632 @cindex zabbix zabbix-front-end
19634 This service provides a WEB interface to Zabbix server.
19636 @c %start of fragment
19638 Available @code{zabbix-front-end-configuration} fields are:
19640 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
19641 NGINX configuration.
19645 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
19646 Database host name.
19648 Defaults to @samp{"localhost"}.
19652 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
19655 Defaults to @samp{5432}.
19659 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
19662 Defaults to @samp{"zabbix"}.
19666 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
19669 Defaults to @samp{"zabbix"}.
19673 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19674 Database password. Please, use @code{db-secret-file} instead.
19676 Defaults to @samp{""}.
19680 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19681 Secret file which will be appended to @file{zabbix.conf.php} file. This
19682 file contains credentials for use by Zabbix front-end. You are expected
19683 to create it manually.
19685 Defaults to @samp{""}.
19689 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19690 Zabbix server hostname.
19692 Defaults to @samp{"localhost"}.
19696 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19697 Zabbix server port.
19699 Defaults to @samp{10051}.
19704 @c %end of fragment
19706 @node Kerberos Services
19707 @subsection Kerberos Services
19710 The @code{(gnu services kerberos)} module provides services relating to
19711 the authentication protocol @dfn{Kerberos}.
19713 @subsubheading Krb5 Service
19715 Programs using a Kerberos client library normally
19716 expect a configuration file in @file{/etc/krb5.conf}.
19717 This service generates such a file from a definition provided in the
19718 operating system declaration.
19719 It does not cause any daemon to be started.
19721 No ``keytab'' files are provided by this service---you must explicitly create them.
19722 This service is known to work with the MIT client library, @code{mit-krb5}.
19723 Other implementations have not been tested.
19725 @defvr {Scheme Variable} krb5-service-type
19726 A service type for Kerberos 5 clients.
19730 Here is an example of its use:
19732 (service krb5-service-type
19733 (krb5-configuration
19734 (default-realm "EXAMPLE.COM")
19735 (allow-weak-crypto? #t)
19738 (name "EXAMPLE.COM")
19739 (admin-server "groucho.example.com")
19740 (kdc "karl.example.com"))
19743 (admin-server "kerb-admin.argrx.edu")
19744 (kdc "keys.argrx.edu"))))))
19748 This example provides a Kerberos@tie{}5 client configuration which:
19750 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19751 of which have distinct administration servers and key distribution centers;
19752 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19753 specified by clients;
19754 @item Accepts services which only support encryption types known to be weak.
19757 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19758 Only the most commonly used ones are described here.
19759 For a full list, and more detailed explanation of each, see the MIT
19760 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19764 @deftp {Data Type} krb5-realm
19765 @cindex realm, kerberos
19768 This field is a string identifying the name of the realm.
19769 A common convention is to use the fully qualified DNS name of your organization,
19770 converted to upper case.
19772 @item @code{admin-server}
19773 This field is a string identifying the host where the administration server is
19777 This field is a string identifying the key distribution center
19782 @deftp {Data Type} krb5-configuration
19785 @item @code{allow-weak-crypto?} (default: @code{#f})
19786 If this flag is @code{#t} then services which only offer encryption algorithms
19787 known to be weak will be accepted.
19789 @item @code{default-realm} (default: @code{#f})
19790 This field should be a string identifying the default Kerberos
19791 realm for the client.
19792 You should set this field to the name of your Kerberos realm.
19793 If this value is @code{#f}
19794 then a realm must be specified with every Kerberos principal when invoking programs
19795 such as @command{kinit}.
19797 @item @code{realms}
19798 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19800 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19806 @subsubheading PAM krb5 Service
19809 The @code{pam-krb5} service allows for login authentication and password
19810 management via Kerberos.
19811 You will need this service if you want PAM enabled applications to authenticate
19812 users using Kerberos.
19814 @defvr {Scheme Variable} pam-krb5-service-type
19815 A service type for the Kerberos 5 PAM module.
19818 @deftp {Data Type} pam-krb5-configuration
19819 Data type representing the configuration of the Kerberos 5 PAM module.
19820 This type has the following parameters:
19822 @item @code{pam-krb5} (default: @code{pam-krb5})
19823 The pam-krb5 package to use.
19825 @item @code{minimum-uid} (default: @code{1000})
19826 The smallest user ID for which Kerberos authentications should be attempted.
19827 Local accounts with lower values will silently fail to authenticate.
19832 @node LDAP Services
19833 @subsection LDAP Services
19835 @cindex nslcd, LDAP service
19837 The @code{(gnu services authentication)} module provides the
19838 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19839 server. In addition to configuring the service itself, you may want to add
19840 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19841 Switch} for detailed information.
19843 Here is a simple operating system declaration with a default configuration of
19844 the @code{nslcd-service-type} and a Name Service Switch configuration that
19845 consults the @code{ldap} name service last:
19848 (use-service-modules authentication)
19849 (use-modules (gnu system nss))
19855 (service nslcd-service-type)
19856 (service dhcp-client-service-type)
19858 (name-service-switch
19859 (let ((services (list (name-service (name "db"))
19860 (name-service (name "files"))
19861 (name-service (name "ldap")))))
19862 (name-service-switch
19863 (inherit %mdns-host-lookup-nss)
19864 (password services)
19867 (netgroup services)
19868 (gshadow services)))))
19871 @c %start of generated documentation for nslcd-configuration
19873 Available @code{nslcd-configuration} fields are:
19875 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19876 The @code{nss-pam-ldapd} package to use.
19880 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19881 The number of threads to start that can handle requests and perform LDAP
19882 queries. Each thread opens a separate connection to the LDAP server.
19883 The default is to start 5 threads.
19885 Defaults to @samp{disabled}.
19889 @deftypevr {@code{nslcd-configuration} parameter} string uid
19890 This specifies the user id with which the daemon should be run.
19892 Defaults to @samp{"nslcd"}.
19896 @deftypevr {@code{nslcd-configuration} parameter} string gid
19897 This specifies the group id with which the daemon should be run.
19899 Defaults to @samp{"nslcd"}.
19903 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19904 This option controls the way logging is done via a list containing
19905 SCHEME and LEVEL. The SCHEME argument may either be the symbols
19906 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
19907 argument is optional and specifies the log level. The log level may be
19908 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
19909 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
19910 specified log level or higher are logged.
19912 Defaults to @samp{("/var/log/nslcd" info)}.
19916 @deftypevr {@code{nslcd-configuration} parameter} list uri
19917 The list of LDAP server URIs. Normally, only the first server will be
19918 used with the following servers as fall-back.
19920 Defaults to @samp{("ldap://localhost:389/")}.
19924 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19925 The version of the LDAP protocol to use. The default is to use the
19926 maximum version supported by the LDAP library.
19928 Defaults to @samp{disabled}.
19932 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19933 Specifies the distinguished name with which to bind to the directory
19934 server for lookups. The default is to bind anonymously.
19936 Defaults to @samp{disabled}.
19940 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19941 Specifies the credentials with which to bind. This option is only
19942 applicable when used with binddn.
19944 Defaults to @samp{disabled}.
19948 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19949 Specifies the distinguished name to use when the root user tries to
19950 modify a user's password using the PAM module.
19952 Defaults to @samp{disabled}.
19956 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19957 Specifies the credentials with which to bind if the root user tries to
19958 change a user's password. This option is only applicable when used with
19961 Defaults to @samp{disabled}.
19965 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19966 Specifies the SASL mechanism to be used when performing SASL
19969 Defaults to @samp{disabled}.
19973 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19974 Specifies the SASL realm to be used when performing SASL authentication.
19976 Defaults to @samp{disabled}.
19980 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19981 Specifies the authentication identity to be used when performing SASL
19984 Defaults to @samp{disabled}.
19988 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19989 Specifies the authorization identity to be used when performing SASL
19992 Defaults to @samp{disabled}.
19996 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19997 Determines whether the LDAP server host name should be canonicalised. If
19998 this is enabled the LDAP library will do a reverse host name lookup. By
19999 default, it is left up to the LDAP library whether this check is
20002 Defaults to @samp{disabled}.
20006 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
20007 Set the name for the GSS-API Kerberos credentials cache.
20009 Defaults to @samp{disabled}.
20013 @deftypevr {@code{nslcd-configuration} parameter} string base
20014 The directory search base.
20016 Defaults to @samp{"dc=example,dc=com"}.
20020 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
20021 Specifies the search scope (subtree, onelevel, base or children). The
20022 default scope is subtree; base scope is almost never useful for name
20023 service lookups; children scope is not supported on all servers.
20025 Defaults to @samp{(subtree)}.
20029 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
20030 Specifies the policy for dereferencing aliases. The default policy is
20031 to never dereference aliases.
20033 Defaults to @samp{disabled}.
20037 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
20038 Specifies whether automatic referral chasing should be enabled. The
20039 default behaviour is to chase referrals.
20041 Defaults to @samp{disabled}.
20045 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
20046 This option allows for custom attributes to be looked up instead of the
20047 default RFC 2307 attributes. It is a list of maps, each consisting of
20048 the name of a map, the RFC 2307 attribute to match and the query
20049 expression for the attribute as it is available in the directory.
20051 Defaults to @samp{()}.
20055 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
20056 A list of filters consisting of the name of a map to which the filter
20057 applies and an LDAP search filter expression.
20059 Defaults to @samp{()}.
20063 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
20064 Specifies the time limit in seconds to use when connecting to the
20065 directory server. The default value is 10 seconds.
20067 Defaults to @samp{disabled}.
20071 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
20072 Specifies the time limit (in seconds) to wait for a response from the
20073 LDAP server. A value of zero, which is the default, is to wait
20074 indefinitely for searches to be completed.
20076 Defaults to @samp{disabled}.
20080 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
20081 Specifies the period if inactivity (in seconds) after which the con‐
20082 nection to the LDAP server will be closed. The default is not to time
20085 Defaults to @samp{disabled}.
20089 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
20090 Specifies the number of seconds to sleep when connecting to all LDAP
20091 servers fails. By default one second is waited between the first
20092 failure and the first retry.
20094 Defaults to @samp{disabled}.
20098 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
20099 Specifies the time after which the LDAP server is considered to be
20100 permanently unavailable. Once this time is reached retries will be done
20101 only once per this time period. The default value is 10 seconds.
20103 Defaults to @samp{disabled}.
20107 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
20108 Specifies whether to use SSL/TLS or not (the default is not to). If
20109 'start-tls is specified then StartTLS is used rather than raw LDAP over
20112 Defaults to @samp{disabled}.
20116 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
20117 Specifies what checks to perform on a server-supplied certificate. The
20118 meaning of the values is described in the ldap.conf(5) manual page.
20120 Defaults to @samp{disabled}.
20124 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
20125 Specifies the directory containing X.509 certificates for peer authen‐
20126 tication. This parameter is ignored when using GnuTLS.
20128 Defaults to @samp{disabled}.
20132 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
20133 Specifies the path to the X.509 certificate for peer authentication.
20135 Defaults to @samp{disabled}.
20139 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
20140 Specifies the path to an entropy source. This parameter is ignored when
20143 Defaults to @samp{disabled}.
20147 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
20148 Specifies the ciphers to use for TLS as a string.
20150 Defaults to @samp{disabled}.
20154 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
20155 Specifies the path to the file containing the local certificate for
20156 client TLS authentication.
20158 Defaults to @samp{disabled}.
20162 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
20163 Specifies the path to the file containing the private key for client TLS
20166 Defaults to @samp{disabled}.
20170 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
20171 Set this to a number greater than 0 to request paged results from the
20172 LDAP server in accordance with RFC2696. The default (0) is to not
20173 request paged results.
20175 Defaults to @samp{disabled}.
20179 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
20180 This option prevents group membership lookups through LDAP for the
20181 specified users. Alternatively, the value 'all-local may be used. With
20182 that value nslcd builds a full list of non-LDAP users on startup.
20184 Defaults to @samp{disabled}.
20188 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
20189 This option ensures that LDAP users with a numeric user id lower than
20190 the specified value are ignored.
20192 Defaults to @samp{disabled}.
20196 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
20197 This option specifies an offset that is added to all LDAP numeric user
20198 ids. This can be used to avoid user id collisions with local users.
20200 Defaults to @samp{disabled}.
20204 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
20205 This option specifies an offset that is added to all LDAP numeric group
20206 ids. This can be used to avoid user id collisions with local groups.
20208 Defaults to @samp{disabled}.
20212 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
20213 If this option is set, the member attribute of a group may point to
20214 another group. Members of nested groups are also returned in the higher
20215 level group and parent groups are returned when finding groups for a
20216 specific user. The default is not to perform extra searches for nested
20219 Defaults to @samp{disabled}.
20223 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
20224 If this option is set, the group member list is not retrieved when
20225 looking up groups. Lookups for finding which groups a user belongs to
20226 will remain functional so the user will likely still get the correct
20227 groups assigned on login.
20229 Defaults to @samp{disabled}.
20233 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
20234 If this option is set, functions which cause all user/group entries to
20235 be loaded from the directory will not succeed in doing so. This can
20236 dramatically reduce LDAP server load in situations where there are a
20237 great number of users and/or groups. This option is not recommended for
20238 most configurations.
20240 Defaults to @samp{disabled}.
20244 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
20245 This option can be used to specify how user and group names are verified
20246 within the system. This pattern is used to check all user and group
20247 names that are requested and returned from LDAP.
20249 Defaults to @samp{disabled}.
20253 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
20254 This specifies whether or not to perform searches using case-insensitive
20255 matching. Enabling this could open up the system to authorization
20256 bypass vulnerabilities and introduce nscd cache poisoning
20257 vulnerabilities which allow denial of service.
20259 Defaults to @samp{disabled}.
20263 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
20264 This option specifies whether password policy controls are requested and
20265 handled from the LDAP server when performing user authentication.
20267 Defaults to @samp{disabled}.
20271 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
20272 By default nslcd performs an LDAP search with the user's credentials
20273 after BIND (authentication) to ensure that the BIND operation was
20274 successful. The default search is a simple check to see if the user's
20275 DN exists. A search filter can be specified that will be used instead.
20276 It should return at least one entry.
20278 Defaults to @samp{disabled}.
20282 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
20283 This option allows flexible fine tuning of the authorisation check that
20284 should be performed. The search filter specified is executed and if any
20285 entries match, access is granted, otherwise access is denied.
20287 Defaults to @samp{disabled}.
20291 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
20292 If this option is set password modification using pam_ldap will be
20293 denied and the specified message will be presented to the user instead.
20294 The message can be used to direct the user to an alternative means of
20295 changing their password.
20297 Defaults to @samp{disabled}.
20301 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
20302 List of pam service names for which LDAP authentication should suffice.
20304 Defaults to @samp{()}.
20308 @c %end of generated documentation for nslcd-configuration
20312 @subsection Web Services
20317 The @code{(gnu services web)} module provides the Apache HTTP Server,
20318 the nginx web server, and also a fastcgi wrapper daemon.
20320 @subsubheading Apache HTTP Server
20322 @deffn {Scheme Variable} httpd-service-type
20323 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
20324 (@dfn{httpd}). The value for this service type is a
20325 @code{httpd-configuration} record.
20327 A simple example configuration is given below.
20330 (service httpd-service-type
20331 (httpd-configuration
20334 (server-name "www.example.com")
20335 (document-root "/srv/http/www.example.com")))))
20338 Other services can also extend the @code{httpd-service-type} to add to
20342 (simple-service 'www.example.com-server httpd-service-type
20346 (list (string-join '("ServerName www.example.com"
20347 "DocumentRoot /srv/http/www.example.com")
20352 The details for the @code{httpd-configuration}, @code{httpd-module},
20353 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
20356 @deffn {Data Type} httpd-configuration
20357 This data type represents the configuration for the httpd service.
20360 @item @code{package} (default: @code{httpd})
20361 The httpd package to use.
20363 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20364 The pid file used by the shepherd-service.
20366 @item @code{config} (default: @code{(httpd-config-file)})
20367 The configuration file to use with the httpd service. The default value
20368 is a @code{httpd-config-file} record, but this can also be a different
20369 G-expression that generates a file, for example a @code{plain-file}. A
20370 file outside of the store can also be specified through a string.
20375 @deffn {Data Type} httpd-module
20376 This data type represents a module for the httpd service.
20380 The name of the module.
20383 The file for the module. This can be relative to the httpd package being
20384 used, the absolute location of a file, or a G-expression for a file
20385 within the store, for example @code{(file-append mod-wsgi
20386 "/modules/mod_wsgi.so")}.
20391 @defvr {Scheme Variable} %default-httpd-modules
20392 A default list of @code{httpd-module} objects.
20395 @deffn {Data Type} httpd-config-file
20396 This data type represents a configuration file for the httpd service.
20399 @item @code{modules} (default: @code{%default-httpd-modules})
20400 The modules to load. Additional modules can be added here, or loaded by
20401 additional configuration.
20403 For example, in order to handle requests for PHP files, you can use Apache’s
20404 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
20407 (service httpd-service-type
20408 (httpd-configuration
20413 (name "proxy_module")
20414 (file "modules/mod_proxy.so"))
20416 (name "proxy_fcgi_module")
20417 (file "modules/mod_proxy_fcgi.so"))
20418 %default-httpd-modules))
20419 (extra-config (list "\
20420 <FilesMatch \\.php$>
20421 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
20422 </FilesMatch>"))))))
20423 (service php-fpm-service-type
20424 (php-fpm-configuration
20425 (socket "/var/run/php-fpm.sock")
20426 (socket-group "httpd")))
20429 @item @code{server-root} (default: @code{httpd})
20430 The @code{ServerRoot} in the configuration file, defaults to the httpd
20431 package. Directives including @code{Include} and @code{LoadModule} are
20432 taken as relative to the server root.
20434 @item @code{server-name} (default: @code{#f})
20435 The @code{ServerName} in the configuration file, used to specify the
20436 request scheme, hostname and port that the server uses to identify
20439 This doesn't need to be set in the server config, and can be specified
20440 in virtual hosts. The default is @code{#f} to not specify a
20443 @item @code{document-root} (default: @code{"/srv/http"})
20444 The @code{DocumentRoot} from which files will be served.
20446 @item @code{listen} (default: @code{'("80")})
20447 The list of values for the @code{Listen} directives in the config
20448 file. The value should be a list of strings, when each string can
20449 specify the port number to listen on, and optionally the IP address and
20452 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20453 The @code{PidFile} to use. This should match the @code{pid-file} set in
20454 the @code{httpd-configuration} so that the Shepherd service is
20455 configured correctly.
20457 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
20458 The @code{ErrorLog} to which the server will log errors.
20460 @item @code{user} (default: @code{"httpd"})
20461 The @code{User} which the server will answer requests as.
20463 @item @code{group} (default: @code{"httpd"})
20464 The @code{Group} which the server will answer requests as.
20466 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
20467 A flat list of strings and G-expressions which will be added to the end
20468 of the configuration file.
20470 Any values which the service is extended with will be appended to this
20476 @deffn {Data Type} httpd-virtualhost
20477 This data type represents a virtualhost configuration block for the httpd service.
20479 These should be added to the extra-config for the httpd-service.
20482 (simple-service 'www.example.com-server httpd-service-type
20486 (list (string-join '("ServerName www.example.com"
20487 "DocumentRoot /srv/http/www.example.com")
20492 @item @code{addresses-and-ports}
20493 The addresses and ports for the @code{VirtualHost} directive.
20495 @item @code{contents}
20496 The contents of the @code{VirtualHost} directive, this should be a list
20497 of strings and G-expressions.
20502 @subsubheading NGINX
20504 @deffn {Scheme Variable} nginx-service-type
20505 Service type for the @uref{https://nginx.org/,NGinx} web server. The
20506 value for this service type is a @code{<nginx-configuration>} record.
20508 A simple example configuration is given below.
20511 (service nginx-service-type
20512 (nginx-configuration
20514 (list (nginx-server-configuration
20515 (server-name '("www.example.com"))
20516 (root "/srv/http/www.example.com"))))))
20519 In addition to adding server blocks to the service configuration
20520 directly, this service can be extended by other services to add server
20521 blocks, as in this example:
20524 (simple-service 'my-extra-server nginx-service-type
20525 (list (nginx-server-configuration
20526 (root "/srv/http/extra-website")
20527 (try-files (list "$uri" "$uri/index.html")))))
20531 At startup, @command{nginx} has not yet read its configuration file, so
20532 it uses a default file to log error messages. If it fails to load its
20533 configuration file, that is where error messages are logged. After the
20534 configuration file is loaded, the default error log file changes as per
20535 configuration. In our case, startup error messages can be found in
20536 @file{/var/run/nginx/logs/error.log}, and after configuration in
20537 @file{/var/log/nginx/error.log}. The second location can be changed
20538 with the @var{log-directory} configuration option.
20540 @deffn {Data Type} nginx-configuration
20541 This data type represents the configuration for NGinx. Some
20542 configuration can be done through this and the other provided record
20543 types, or alternatively, a config file can be provided.
20546 @item @code{nginx} (default: @code{nginx})
20547 The nginx package to use.
20549 @item @code{log-directory} (default: @code{"/var/log/nginx"})
20550 The directory to which NGinx will write log files.
20552 @item @code{run-directory} (default: @code{"/var/run/nginx"})
20553 The directory in which NGinx will create a pid file, and write temporary
20556 @item @code{server-blocks} (default: @code{'()})
20557 A list of @dfn{server blocks} to create in the generated configuration
20558 file, the elements should be of type
20559 @code{<nginx-server-configuration>}.
20561 The following example would setup NGinx to serve @code{www.example.com}
20562 from the @code{/srv/http/www.example.com} directory, without using
20565 (service nginx-service-type
20566 (nginx-configuration
20568 (list (nginx-server-configuration
20569 (server-name '("www.example.com"))
20570 (root "/srv/http/www.example.com"))))))
20573 @item @code{upstream-blocks} (default: @code{'()})
20574 A list of @dfn{upstream blocks} to create in the generated configuration
20575 file, the elements should be of type
20576 @code{<nginx-upstream-configuration>}.
20578 Configuring upstreams through the @code{upstream-blocks} can be useful
20579 when combined with @code{locations} in the
20580 @code{<nginx-server-configuration>} records. The following example
20581 creates a server configuration with one location configuration, that
20582 will proxy requests to a upstream configuration, which will handle
20583 requests with two servers.
20588 (nginx-configuration
20590 (list (nginx-server-configuration
20591 (server-name '("www.example.com"))
20592 (root "/srv/http/www.example.com")
20595 (nginx-location-configuration
20597 (body '("proxy_pass http://server-proxy;"))))))))
20599 (list (nginx-upstream-configuration
20600 (name "server-proxy")
20601 (servers (list "server1.example.com"
20602 "server2.example.com")))))))
20605 @item @code{file} (default: @code{#f})
20606 If a configuration @var{file} is provided, this will be used, rather than
20607 generating a configuration file from the provided @code{log-directory},
20608 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
20609 proper operation, these arguments should match what is in @var{file} to ensure
20610 that the directories are created when the service is activated.
20612 This can be useful if you have an existing configuration file, or it's
20613 not possible to do what is required through the other parts of the
20614 nginx-configuration record.
20616 @item @code{server-names-hash-bucket-size} (default: @code{#f})
20617 Bucket size for the server names hash tables, defaults to @code{#f} to
20618 use the size of the processors cache line.
20620 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
20621 Maximum bucket size for the server names hash tables.
20623 @item @code{modules} (default: @code{'()})
20624 List of nginx dynamic modules to load. This should be a list of file
20625 names of loadable modules, as in this example:
20630 (file-append nginx-accept-language-module "\
20631 /etc/nginx/modules/ngx_http_accept_language_module.so")))
20634 @item @code{global-directives} (default: @code{'((events . ()))})
20635 Association list of global directives for the top level of the nginx
20636 configuration. Values may themselves be association lists.
20640 `((worker_processes . 16)
20642 (events . ((worker_connections . 1024)))))
20645 @item @code{extra-content} (default: @code{""})
20646 Extra content for the @code{http} block. Should be string or a string
20647 valued G-expression.
20652 @deftp {Data Type} nginx-server-configuration
20653 Data type representing the configuration of an nginx server block.
20654 This type has the following parameters:
20657 @item @code{listen} (default: @code{'("80" "443 ssl")})
20658 Each @code{listen} directive sets the address and port for IP, or the
20659 path for a UNIX-domain socket on which the server will accept requests.
20660 Both address and port, or only address or only port can be specified.
20661 An address may also be a hostname, for example:
20664 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
20667 @item @code{server-name} (default: @code{(list 'default)})
20668 A list of server names this server represents. @code{'default} represents the
20669 default server for connections matching no other server.
20671 @item @code{root} (default: @code{"/srv/http"})
20672 Root of the website nginx will serve.
20674 @item @code{locations} (default: @code{'()})
20675 A list of @dfn{nginx-location-configuration} or
20676 @dfn{nginx-named-location-configuration} records to use within this
20679 @item @code{index} (default: @code{(list "index.html")})
20680 Index files to look for when clients ask for a directory. If it cannot be found,
20681 Nginx will send the list of files in the directory.
20683 @item @code{try-files} (default: @code{'()})
20684 A list of files whose existence is checked in the specified order.
20685 @code{nginx} will use the first file it finds to process the request.
20687 @item @code{ssl-certificate} (default: @code{#f})
20688 Where to find the certificate for secure connections. Set it to @code{#f} if
20689 you don't have a certificate or you don't want to use HTTPS.
20691 @item @code{ssl-certificate-key} (default: @code{#f})
20692 Where to find the private key for secure connections. Set it to @code{#f} if
20693 you don't have a key or you don't want to use HTTPS.
20695 @item @code{server-tokens?} (default: @code{#f})
20696 Whether the server should add its configuration to response.
20698 @item @code{raw-content} (default: @code{'()})
20699 A list of raw lines added to the server block.
20704 @deftp {Data Type} nginx-upstream-configuration
20705 Data type representing the configuration of an nginx @code{upstream}
20706 block. This type has the following parameters:
20710 Name for this group of servers.
20712 @item @code{servers}
20713 Specify the addresses of the servers in the group. The address can be
20714 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20715 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20716 prefix @samp{unix:}. For addresses using an IP address or domain name,
20717 the default port is 80, and a different port can be specified
20723 @deftp {Data Type} nginx-location-configuration
20724 Data type representing the configuration of an nginx @code{location}
20725 block. This type has the following parameters:
20729 URI which this location block matches.
20731 @anchor{nginx-location-configuration body}
20733 Body of the location block, specified as a list of strings. This can contain
20735 configuration directives. For example, to pass requests to a upstream
20736 server group defined using an @code{nginx-upstream-configuration} block,
20737 the following directive would be specified in the body @samp{(list "proxy_pass
20738 http://upstream-name;")}.
20743 @deftp {Data Type} nginx-named-location-configuration
20744 Data type representing the configuration of an nginx named location
20745 block. Named location blocks are used for request redirection, and not
20746 used for regular request processing. This type has the following
20751 Name to identify this location block.
20754 @xref{nginx-location-configuration body}, as the body for named location
20755 blocks can be used in a similar way to the
20756 @code{nginx-location-configuration body}. One restriction is that the
20757 body of a named location block cannot contain location blocks.
20762 @subsubheading Varnish Cache
20764 Varnish is a fast cache server that sits in between web applications
20765 and end users. It proxies requests from clients and caches the
20766 accessed URLs such that multiple requests for the same resource only
20767 creates one request to the back-end.
20769 @defvr {Scheme Variable} varnish-service-type
20770 Service type for the Varnish daemon.
20773 @deftp {Data Type} varnish-configuration
20774 Data type representing the @code{varnish} service configuration.
20775 This type has the following parameters:
20778 @item @code{package} (default: @code{varnish})
20779 The Varnish package to use.
20781 @item @code{name} (default: @code{"default"})
20782 A name for this Varnish instance. Varnish will create a directory in
20783 @file{/var/varnish/} with this name and keep temporary files there. If
20784 the name starts with a forward slash, it is interpreted as an absolute
20787 Pass the @code{-n} argument to other Varnish programs to connect to the
20788 named instance, e.g.@: @command{varnishncsa -n default}.
20790 @item @code{backend} (default: @code{"localhost:8080"})
20791 The backend to use. This option has no effect if @code{vcl} is set.
20793 @item @code{vcl} (default: #f)
20794 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20795 is @code{#f}, Varnish will proxy @code{backend} using the default
20796 configuration. Otherwise this must be a file-like object with valid
20799 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20800 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
20801 can do something along these lines:
20804 (define %gnu-mirror
20805 (plain-file "gnu.vcl"
20807 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20811 (services (cons (service varnish-service-type
20812 (varnish-configuration
20814 (vcl %gnu-mirror)))
20818 The configuration of an already running Varnish instance can be inspected
20819 and changed using the @command{varnishadm} program.
20821 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20822 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20823 comprehensive documentation on Varnish and its configuration language.
20825 @item @code{listen} (default: @code{'("localhost:80")})
20826 List of addresses Varnish will listen on.
20828 @item @code{storage} (default: @code{'("malloc,128m")})
20829 List of storage backends that will be available in VCL.
20831 @item @code{parameters} (default: @code{'()})
20832 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20834 @item @code{extra-options} (default: @code{'()})
20835 Additional arguments to pass to the @command{varnishd} process.
20840 @subsubheading Patchwork
20842 Patchwork is a patch tracking system. It can collect patches sent to a
20843 mailing list, and display them in a web interface.
20845 @defvr {Scheme Variable} patchwork-service-type
20846 Service type for Patchwork.
20849 The following example is an example of a minimal service for Patchwork, for
20850 the @code{patchwork.example.com} domain.
20853 (service patchwork-service-type
20854 (patchwork-configuration
20855 (domain "patchwork.example.com")
20857 (patchwork-settings-module
20858 (allowed-hosts (list domain))
20859 (default-from-email "patchwork@@patchwork.example.com")))
20860 (getmail-retriever-config
20861 (getmail-retriever-configuration
20862 (type "SimpleIMAPSSLRetriever")
20863 (server "imap.example.com")
20865 (username "patchwork")
20867 (list (file-append coreutils "/bin/cat")
20868 "/etc/getmail-patchwork-imap-password"))
20870 '((mailboxes . ("Patches"))))))))
20874 There are three records for configuring the Patchwork service. The
20875 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20876 within the HTTPD service.
20878 The @code{settings-module} field within the @code{<patchwork-configuration>}
20879 record can be populated with the @code{<patchwork-settings-module>} record,
20880 which describes a settings module that is generated within the Guix store.
20882 For the @code{database-configuration} field within the
20883 @code{<patchwork-settings-module>}, the
20884 @code{<patchwork-database-configuration>} must be used.
20886 @deftp {Data Type} patchwork-configuration
20887 Data type representing the Patchwork service configuration. This type has the
20888 following parameters:
20891 @item @code{patchwork} (default: @code{patchwork})
20892 The Patchwork package to use.
20894 @item @code{domain}
20895 The domain to use for Patchwork, this is used in the HTTPD service virtual
20898 @item @code{settings-module}
20899 The settings module to use for Patchwork. As a Django application, Patchwork
20900 is configured with a Python module containing the settings. This can either be
20901 an instance of the @code{<patchwork-settings-module>} record, any other record
20902 that represents the settings in the store, or a directory outside of the
20905 @item @code{static-path} (default: @code{"/static/"})
20906 The path under which the HTTPD service should serve the static files.
20908 @item @code{getmail-retriever-config}
20909 The getmail-retriever-configuration record value to use with
20910 Patchwork. Getmail will be configured with this value, the messages will be
20911 delivered to Patchwork.
20916 @deftp {Data Type} patchwork-settings-module
20917 Data type representing a settings module for Patchwork. Some of these
20918 settings relate directly to Patchwork, but others relate to Django, the web
20919 framework used by Patchwork, or the Django Rest Framework library. This type
20920 has the following parameters:
20923 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20924 The database connection settings used for Patchwork. See the
20925 @code{<patchwork-database-configuration>} record type for more information.
20927 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20928 Patchwork, as a Django web application uses a secret key for cryptographically
20929 signing values. This file should contain a unique unpredictable value.
20931 If this file does not exist, it will be created and populated with a random
20932 value by the patchwork-setup shepherd service.
20934 This setting relates to Django.
20936 @item @code{allowed-hosts}
20937 A list of valid hosts for this Patchwork service. This should at least include
20938 the domain specified in the @code{<patchwork-configuration>} record.
20940 This is a Django setting.
20942 @item @code{default-from-email}
20943 The email address from which Patchwork should send email by default.
20945 This is a Patchwork setting.
20947 @item @code{static-url} (default: @code{#f})
20948 The URL to use when serving static assets. It can be part of a URL, or a full
20949 URL, but must end in a @code{/}.
20951 If the default value is used, the @code{static-path} value from the
20952 @code{<patchwork-configuration>} record will be used.
20954 This is a Django setting.
20956 @item @code{admins} (default: @code{'()})
20957 Email addresses to send the details of errors that occur. Each value should
20958 be a list containing two elements, the name and then the email address.
20960 This is a Django setting.
20962 @item @code{debug?} (default: @code{#f})
20963 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20964 messages will be shown.
20966 This is a Django setting.
20968 @item @code{enable-rest-api?} (default: @code{#t})
20969 Whether to enable the Patchwork REST API.
20971 This is a Patchwork setting.
20973 @item @code{enable-xmlrpc?} (default: @code{#t})
20974 Whether to enable the XML RPC API.
20976 This is a Patchwork setting.
20978 @item @code{force-https-links?} (default: @code{#t})
20979 Whether to use HTTPS links on Patchwork pages.
20981 This is a Patchwork setting.
20983 @item @code{extra-settings} (default: @code{""})
20984 Extra code to place at the end of the Patchwork settings module.
20989 @deftp {Data Type} patchwork-database-configuration
20990 Data type representing the database configuration for Patchwork.
20993 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20994 The database engine to use.
20996 @item @code{name} (default: @code{"patchwork"})
20997 The name of the database to use.
20999 @item @code{user} (default: @code{"httpd"})
21000 The user to connect to the database as.
21002 @item @code{password} (default: @code{""})
21003 The password to use when connecting to the database.
21005 @item @code{host} (default: @code{""})
21006 The host to make the database connection to.
21008 @item @code{port} (default: @code{""})
21009 The port on which to connect to the database.
21014 @subsubheading Mumi
21016 @cindex Mumi, Debbugs Web interface
21017 @cindex Debbugs, Mumi Web interface
21018 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
21019 Web interface to the Debbugs bug tracker, by default for
21020 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
21021 but it also fetches and indexes mail retrieved from Debbugs.
21023 @defvr {Scheme Variable} mumi-service-type
21024 This is the service type for Mumi.
21027 @deftp {Data Type} mumi-configuration
21028 Data type representing the Mumi service configuration. This type has the
21032 @item @code{mumi} (default: @code{mumi})
21033 The Mumi package to use.
21035 @item @code{mailer?} (default: @code{#true})
21036 Whether to enable or disable the mailer component.
21038 @item @code{mumi-configuration-sender}
21039 The email address used as the sender for comments.
21041 @item @code{mumi-configuration-smtp}
21042 A URI to configure the SMTP settings for Mailutils. This could be
21043 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
21044 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
21045 mailutils, GNU@tie{}Mailutils}.
21051 @subsubheading FastCGI
21054 FastCGI is an interface between the front-end and the back-end of a web
21055 service. It is a somewhat legacy facility; new web services should
21056 generally just talk HTTP between the front-end and the back-end.
21057 However there are a number of back-end services such as PHP or the
21058 optimized HTTP Git repository access that use FastCGI, so we have
21059 support for it in Guix.
21061 To use FastCGI, you configure the front-end web server (e.g., nginx) to
21062 dispatch some subset of its requests to the fastcgi backend, which
21063 listens on a local TCP or UNIX socket. There is an intermediary
21064 @code{fcgiwrap} program that sits between the actual backend process and
21065 the web server. The front-end indicates which backend program to run,
21066 passing that information to the @code{fcgiwrap} process.
21068 @defvr {Scheme Variable} fcgiwrap-service-type
21069 A service type for the @code{fcgiwrap} FastCGI proxy.
21072 @deftp {Data Type} fcgiwrap-configuration
21073 Data type representing the configuration of the @code{fcgiwrap} service.
21074 This type has the following parameters:
21076 @item @code{package} (default: @code{fcgiwrap})
21077 The fcgiwrap package to use.
21079 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
21080 The socket on which the @code{fcgiwrap} process should listen, as a
21081 string. Valid @var{socket} values include
21082 @code{unix:@var{/path/to/unix/socket}},
21083 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
21084 @code{tcp6:[@var{ipv6_addr}]:port}.
21086 @item @code{user} (default: @code{fcgiwrap})
21087 @itemx @code{group} (default: @code{fcgiwrap})
21088 The user and group names, as strings, under which to run the
21089 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
21090 the user asks for the specific user or group names @code{fcgiwrap} that
21091 the corresponding user and/or group is present on the system.
21093 It is possible to configure a FastCGI-backed web service to pass HTTP
21094 authentication information from the front-end to the back-end, and to
21095 allow @code{fcgiwrap} to run the back-end process as a corresponding
21096 local user. To enable this capability on the back-end, run
21097 @code{fcgiwrap} as the @code{root} user and group. Note that this
21098 capability also has to be configured on the front-end as well.
21103 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
21104 with some additional features useful for sites of any size.
21106 These features include:
21108 @item Adaptive process spawning
21109 @item Basic statistics (similar to Apache's mod_status)
21110 @item Advanced process management with graceful stop/start
21111 @item Ability to start workers with different uid/gid/chroot/environment
21112 and different php.ini (replaces safe_mode)
21113 @item Stdout & stderr logging
21114 @item Emergency restart in case of accidental opcode cache destruction
21115 @item Accelerated upload support
21116 @item Support for a "slowlog"
21117 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
21118 a special function to finish request & flush all data while continuing to do
21119 something time-consuming (video converting, stats processing, etc.)
21121 ...@: and much more.
21123 @defvr {Scheme Variable} php-fpm-service-type
21124 A Service type for @code{php-fpm}.
21127 @deftp {Data Type} php-fpm-configuration
21128 Data Type for php-fpm service configuration.
21130 @item @code{php} (default: @code{php})
21131 The php package to use.
21132 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
21133 The address on which to accept FastCGI requests. Valid syntaxes are:
21135 @item @code{"ip.add.re.ss:port"}
21136 Listen on a TCP socket to a specific address on a specific port.
21137 @item @code{"port"}
21138 Listen on a TCP socket to all addresses on a specific port.
21139 @item @code{"/path/to/unix/socket"}
21140 Listen on a unix socket.
21143 @item @code{user} (default: @code{php-fpm})
21144 User who will own the php worker processes.
21145 @item @code{group} (default: @code{php-fpm})
21146 Group of the worker processes.
21147 @item @code{socket-user} (default: @code{php-fpm})
21148 User who can speak to the php-fpm socket.
21149 @item @code{socket-group} (default: @code{nginx})
21150 Group that can speak to the php-fpm socket.
21151 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
21152 The process id of the php-fpm process is written to this file
21153 once the service has started.
21154 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
21155 Log for the php-fpm master process.
21156 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
21157 Detailed settings for the php-fpm process manager.
21160 @item @code{<php-fpm-dynamic-process-manager-configuration>}
21161 @item @code{<php-fpm-static-process-manager-configuration>}
21162 @item @code{<php-fpm-on-demand-process-manager-configuration>}
21164 @item @code{display-errors} (default @code{#f})
21165 Determines whether php errors and warning should be sent to clients
21166 and displayed in their browsers.
21167 This is useful for local php development, but a security risk for public sites,
21168 as error messages can reveal passwords and personal data.
21169 @item @code{timezone} (default @code{#f})
21170 Specifies @code{php_admin_value[date.timezone]} parameter.
21171 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
21172 This file will log the @code{stderr} outputs of php worker processes.
21173 Can be set to @code{#f} to disable logging.
21174 @item @code{file} (default @code{#f})
21175 An optional override of the whole configuration.
21176 You can use the @code{mixed-text-file} function or an absolute filepath for it.
21180 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
21181 Data Type for the @code{dynamic} php-fpm process manager. With the
21182 @code{dynamic} process manager, spare worker processes are kept around
21183 based on it's configured limits.
21185 @item @code{max-children} (default: @code{5})
21186 Maximum of worker processes.
21187 @item @code{start-servers} (default: @code{2})
21188 How many worker processes should be started on start-up.
21189 @item @code{min-spare-servers} (default: @code{1})
21190 How many spare worker processes should be kept around at minimum.
21191 @item @code{max-spare-servers} (default: @code{3})
21192 How many spare worker processes should be kept around at maximum.
21196 @deftp {Data type} php-fpm-static-process-manager-configuration
21197 Data Type for the @code{static} php-fpm process manager. With the
21198 @code{static} process manager, an unchanging number of worker processes
21201 @item @code{max-children} (default: @code{5})
21202 Maximum of worker processes.
21206 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
21207 Data Type for the @code{on-demand} php-fpm process manager. With the
21208 @code{on-demand} process manager, worker processes are only created as
21211 @item @code{max-children} (default: @code{5})
21212 Maximum of worker processes.
21213 @item @code{process-idle-timeout} (default: @code{10})
21214 The time in seconds after which a process with no requests is killed.
21219 @deffn {Scheme Procedure} nginx-php-location @
21220 [#:nginx-package nginx] @
21221 [socket (string-append "/var/run/php" @
21222 (version-major (package-version php)) @
21224 A helper function to quickly add php to an @code{nginx-server-configuration}.
21227 A simple services setup for nginx with php can look like this:
21229 (services (cons* (service dhcp-client-service-type)
21230 (service php-fpm-service-type)
21231 (service nginx-service-type
21232 (nginx-server-configuration
21233 (server-name '("example.com"))
21234 (root "/srv/http/")
21236 (list (nginx-php-location)))
21238 (ssl-certificate #f)
21239 (ssl-certificate-key #f)))
21243 @cindex cat-avatar-generator
21244 The cat avatar generator is a simple service to demonstrate the use of php-fpm
21245 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
21246 the hash of a user's email address.
21248 @deffn {Scheme Procedure} cat-avatar-generator-service @
21249 [#:cache-dir "/var/cache/cat-avatar-generator"] @
21250 [#:package cat-avatar-generator] @
21251 [#:configuration (nginx-server-configuration)]
21252 Returns an nginx-server-configuration that inherits @code{configuration}. It
21253 extends the nginx configuration to add a server block that serves @code{package},
21254 a version of cat-avatar-generator. During execution, cat-avatar-generator will
21255 be able to use @code{cache-dir} as its cache directory.
21258 A simple setup for cat-avatar-generator can look like this:
21260 (services (cons* (cat-avatar-generator-service
21262 (nginx-server-configuration
21263 (server-name '("example.com"))))
21268 @subsubheading Hpcguix-web
21270 @cindex hpcguix-web
21271 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
21272 program is a customizable web interface to browse Guix packages,
21273 initially designed for users of high-performance computing (HPC)
21276 @defvr {Scheme Variable} hpcguix-web-service-type
21277 The service type for @code{hpcguix-web}.
21280 @deftp {Data Type} hpcguix-web-configuration
21281 Data type for the hpcguix-web service configuration.
21285 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
21286 configuration. The main items available in this spec are:
21289 @item @code{title-prefix} (default: @code{"hpcguix | "})
21290 The page title prefix.
21292 @item @code{guix-command} (default: @code{"guix"})
21293 The @command{guix} command.
21295 @item @code{package-filter-proc} (default: @code{(const #t)})
21296 A procedure specifying how to filter packages that are displayed.
21298 @item @code{package-page-extension-proc} (default: @code{(const '())})
21299 Extension package for @code{hpcguix-web}.
21301 @item @code{menu} (default: @code{'()})
21302 Additional entry in page @code{menu}.
21304 @item @code{channels} (default: @code{%default-channels})
21305 List of channels from which the package list is built (@pxref{Channels}).
21307 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
21308 The expiration time, in seconds, after which the package list is rebuilt from
21309 the latest instances of the given channels.
21312 See the hpcguix-web repository for a
21313 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
21316 @item @code{package} (default: @code{hpcguix-web})
21317 The hpcguix-web package to use.
21321 A typical hpcguix-web service declaration looks like this:
21324 (service hpcguix-web-service-type
21325 (hpcguix-web-configuration
21327 #~(define site-config
21328 (hpcweb-configuration
21329 (title-prefix "Guix-HPC - ")
21330 (menu '(("/about" "ABOUT"))))))))
21334 The hpcguix-web service periodically updates the package list it publishes by
21335 pulling channels from Git. To that end, it needs to access X.509 certificates
21336 so that it can authenticate Git servers when communicating over HTTPS, and it
21337 assumes that @file{/etc/ssl/certs} contains those certificates.
21339 Thus, make sure to add @code{nss-certs} or another certificate package to the
21340 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
21341 more information on X.509 certificates.
21344 @node Certificate Services
21345 @subsection Certificate Services
21348 @cindex HTTP, HTTPS
21349 @cindex Let's Encrypt
21350 @cindex TLS certificates
21351 The @code{(gnu services certbot)} module provides a service to
21352 automatically obtain a valid TLS certificate from the Let's Encrypt
21353 certificate authority. These certificates can then be used to serve
21354 content securely over HTTPS or other TLS-based protocols, with the
21355 knowledge that the client will be able to verify the server's
21358 @url{https://letsencrypt.org/, Let's Encrypt} provides the
21359 @code{certbot} tool to automate the certification process. This tool
21360 first securely generates a key on the server. It then makes a request
21361 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
21362 checks that the request originates from the host in question by using a
21363 challenge-response protocol, requiring the server to provide its
21364 response over HTTP. If that protocol completes successfully, the CA
21365 signs the key, resulting in a certificate. That certificate is valid
21366 for a limited period of time, and therefore to continue to provide TLS
21367 services, the server needs to periodically ask the CA to renew its
21370 The certbot service automates this process: the initial key
21371 generation, the initial certification request to the Let's Encrypt
21372 service, the web server challenge/response integration, writing the
21373 certificate to disk, the automated periodic renewals, and the deployment
21374 tasks associated with the renewal (e.g.@: reloading services, copying keys
21375 with different permissions).
21377 Certbot is run twice a day, at a random minute within the hour. It
21378 won't do anything until your certificates are due for renewal or
21379 revoked, but running it regularly would give your service a chance of
21380 staying online in case a Let's Encrypt-initiated revocation happened for
21383 By using this service, you agree to the ACME Subscriber Agreement, which
21384 can be found there:
21385 @url{https://acme-v01.api.letsencrypt.org/directory}.
21387 @defvr {Scheme Variable} certbot-service-type
21388 A service type for the @code{certbot} Let's Encrypt client. Its value
21389 must be a @code{certbot-configuration} record as in this example:
21392 (define %nginx-deploy-hook
21394 "nginx-deploy-hook"
21395 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
21396 (kill pid SIGHUP))))
21398 (service certbot-service-type
21399 (certbot-configuration
21400 (email "foo@@example.net")
21403 (certificate-configuration
21404 (domains '("example.net" "www.example.net"))
21405 (deploy-hook %nginx-deploy-hook))
21406 (certificate-configuration
21407 (domains '("bar.example.net")))))))
21410 See below for details about @code{certbot-configuration}.
21413 @deftp {Data Type} certbot-configuration
21414 Data type representing the configuration of the @code{certbot} service.
21415 This type has the following parameters:
21418 @item @code{package} (default: @code{certbot})
21419 The certbot package to use.
21421 @item @code{webroot} (default: @code{/var/www})
21422 The directory from which to serve the Let's Encrypt challenge/response
21425 @item @code{certificates} (default: @code{()})
21426 A list of @code{certificates-configuration}s for which to generate
21427 certificates and request signatures. Each certificate has a @code{name}
21428 and several @code{domains}.
21431 Mandatory email used for registration, recovery contact, and important
21432 account notifications.
21434 @item @code{server} (default: @code{#f})
21435 Optional URL of ACME server. Setting this overrides certbot's default,
21436 which is the Let's Encrypt server.
21438 @item @code{rsa-key-size} (default: @code{2048})
21439 Size of the RSA key.
21441 @item @code{default-location} (default: @i{see below})
21442 The default @code{nginx-location-configuration}. Because @code{certbot}
21443 needs to be able to serve challenges and responses, it needs to be able
21444 to run a web server. It does so by extending the @code{nginx} web
21445 service with an @code{nginx-server-configuration} listening on the
21446 @var{domains} on port 80, and which has a
21447 @code{nginx-location-configuration} for the @code{/.well-known/} URI
21448 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
21449 these nginx configuration data types.
21451 Requests to other URL paths will be matched by the
21452 @code{default-location}, which if present is added to all
21453 @code{nginx-server-configuration}s.
21455 By default, the @code{default-location} will issue a redirect from
21456 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
21457 you to define what to serve on your site via @code{https}.
21459 Pass @code{#f} to not issue a default location.
21463 @deftp {Data Type} certificate-configuration
21464 Data type representing the configuration of a certificate.
21465 This type has the following parameters:
21468 @item @code{name} (default: @i{see below})
21469 This name is used by Certbot for housekeeping and in file paths; it
21470 doesn't affect the content of the certificate itself. To see
21471 certificate names, run @code{certbot certificates}.
21473 Its default is the first provided domain.
21475 @item @code{domains} (default: @code{()})
21476 The first domain provided will be the subject CN of the certificate, and
21477 all domains will be Subject Alternative Names on the certificate.
21479 @item @code{challenge} (default: @code{#f})
21480 The challenge type that has to be run by certbot. If @code{#f} is specified,
21481 default to the HTTP challenge. If a value is specified, defaults to the
21482 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
21483 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
21484 and gives Let's Encrypt permission to log the public IP address of the
21485 requesting machine.
21487 @item @code{authentication-hook} (default: @code{#f})
21488 Command to be run in a shell once for each certificate challenge to be
21489 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
21490 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
21491 contains the validation string and @code{$CERTBOT_TOKEN} contains the
21492 file name of the resource requested when performing an HTTP-01 challenge.
21494 @item @code{cleanup-hook} (default: @code{#f})
21495 Command to be run in a shell once for each certificate challenge that
21496 have been answered by the @code{auth-hook}. For this command, the shell
21497 variables available in the @code{auth-hook} script are still available, and
21498 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
21499 of the @code{auth-hook} script.
21501 @item @code{deploy-hook} (default: @code{#f})
21502 Command to be run in a shell once for each successfully issued
21503 certificate. For this command, the shell variable
21504 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
21505 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
21506 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
21507 contain a space-delimited list of renewed certificate domains (for
21508 example, @samp{"example.com www.example.com"}.
21513 For each @code{certificate-configuration}, the certificate is saved to
21514 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
21515 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
21517 @subsection DNS Services
21518 @cindex DNS (domain name system)
21519 @cindex domain name system (DNS)
21521 The @code{(gnu services dns)} module provides services related to the
21522 @dfn{domain name system} (DNS). It provides a server service for hosting
21523 an @emph{authoritative} DNS server for multiple zones, slave or master.
21524 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
21525 caching and forwarding DNS server for the LAN, which uses
21526 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
21528 @subsubheading Knot Service
21530 An example configuration of an authoritative server for two zones, one master
21534 (define-zone-entries example.org.zone
21535 ;; Name TTL Class Type Data
21536 ("@@" "" "IN" "A" "127.0.0.1")
21537 ("@@" "" "IN" "NS" "ns")
21538 ("ns" "" "IN" "A" "127.0.0.1"))
21540 (define master-zone
21541 (knot-zone-configuration
21542 (domain "example.org")
21544 (origin "example.org")
21545 (entries example.org.zone)))))
21548 (knot-zone-configuration
21549 (domain "plop.org")
21550 (dnssec-policy "default")
21551 (master (list "plop-master"))))
21553 (define plop-master
21554 (knot-remote-configuration
21556 (address (list "208.76.58.171"))))
21560 (services (cons* (service knot-service-type
21561 (knot-configuration
21562 (remotes (list plop-master))
21563 (zones (list master-zone slave-zone))))
21568 @deffn {Scheme Variable} knot-service-type
21569 This is the type for the Knot DNS server.
21571 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
21572 zones, that is to say domain names you would buy from a registrar. This server
21573 is not a resolver, meaning that it can only resolve names for which it is
21574 authoritative. This server can be configured to serve zones as a master server
21575 or a slave server as a per-zone basis. Slave zones will get their data from
21576 masters, and will serve it as an authoritative server. From the point of view
21577 of a resolver, there is no difference between master and slave.
21579 The following data types are used to configure the Knot DNS server:
21582 @deftp {Data Type} knot-key-configuration
21583 Data type representing a key.
21584 This type has the following parameters:
21587 @item @code{id} (default: @code{""})
21588 An identifier for other configuration fields to refer to this key. IDs must
21589 be unique and must not be empty.
21591 @item @code{algorithm} (default: @code{#f})
21592 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
21593 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
21594 and @code{'hmac-sha512}.
21596 @item @code{secret} (default: @code{""})
21597 The secret key itself.
21602 @deftp {Data Type} knot-acl-configuration
21603 Data type representing an Access Control List (ACL) configuration.
21604 This type has the following parameters:
21607 @item @code{id} (default: @code{""})
21608 An identifier for ether configuration fields to refer to this key. IDs must be
21609 unique and must not be empty.
21611 @item @code{address} (default: @code{'()})
21612 An ordered list of IP addresses, network subnets, or network ranges represented
21613 with strings. The query must match one of them. Empty value means that
21614 address match is not required.
21616 @item @code{key} (default: @code{'()})
21617 An ordered list of references to keys represented with strings. The string
21618 must match a key ID defined in a @code{knot-key-configuration}. No key means
21619 that a key is not require to match that ACL.
21621 @item @code{action} (default: @code{'()})
21622 An ordered list of actions that are permitted or forbidden by this ACL. Possible
21623 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
21624 and @code{'update}.
21626 @item @code{deny?} (default: @code{#f})
21627 When true, the ACL defines restrictions. Listed actions are forbidden. When
21628 false, listed actions are allowed.
21633 @deftp {Data Type} zone-entry
21634 Data type representing a record entry in a zone file.
21635 This type has the following parameters:
21638 @item @code{name} (default: @code{"@@"})
21639 The name of the record. @code{"@@"} refers to the origin of the zone. Names
21640 are relative to the origin of the zone. For example, in the @code{example.org}
21641 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
21642 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
21643 refers to @code{ns.example.org}.
21645 @item @code{ttl} (default: @code{""})
21646 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
21648 @item @code{class} (default: @code{"IN"})
21649 The class of the record. Knot currently supports only @code{"IN"} and
21650 partially @code{"CH"}.
21652 @item @code{type} (default: @code{"A"})
21653 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
21654 address), NS (Name Server) and MX (Mail eXchange). Many other types are
21657 @item @code{data} (default: @code{""})
21658 The data contained in the record. For instance an IP address associated with
21659 an A record, or a domain name associated with an NS record. Remember that
21660 domain names are relative to the origin unless they end with a dot.
21665 @deftp {Data Type} zone-file
21666 Data type representing the content of a zone file.
21667 This type has the following parameters:
21670 @item @code{entries} (default: @code{'()})
21671 The list of entries. The SOA record is taken care of, so you don't need to
21672 put it in the list of entries. This list should probably contain an entry
21673 for your primary authoritative DNS server. Other than using a list of entries
21674 directly, you can use @code{define-zone-entries} to define a object containing
21675 the list of entries more easily, that you can later pass to the @code{entries}
21676 field of the @code{zone-file}.
21678 @item @code{origin} (default: @code{""})
21679 The name of your zone. This parameter cannot be empty.
21681 @item @code{ns} (default: @code{"ns"})
21682 The domain of your primary authoritative DNS server. The name is relative to
21683 the origin, unless it ends with a dot. It is mandatory that this primary
21684 DNS server corresponds to an NS record in the zone and that it is associated
21685 to an IP address in the list of entries.
21687 @item @code{mail} (default: @code{"hostmaster"})
21688 An email address people can contact you at, as the owner of the zone. This
21689 is translated as @code{<mail>@@<origin>}.
21691 @item @code{serial} (default: @code{1})
21692 The serial number of the zone. As this is used to keep track of changes by
21693 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
21694 Always increment it when you make a change in your zone.
21696 @item @code{refresh} (default: @code{(* 2 24 3600)})
21697 The frequency at which slaves will do a zone transfer. This value is a number
21698 of seconds. It can be computed by multiplications or with
21699 @code{(string->duration)}.
21701 @item @code{retry} (default: @code{(* 15 60)})
21702 The period after which a slave will retry to contact its master when it fails
21703 to do so a first time.
21705 @item @code{expiry} (default: @code{(* 14 24 3600)})
21706 Default TTL of records. Existing records are considered correct for at most
21707 this amount of time. After this period, resolvers will invalidate their cache
21708 and check again that it still exists.
21710 @item @code{nx} (default: @code{3600})
21711 Default TTL of inexistant records. This delay is usually short because you want
21712 your new domains to reach everyone quickly.
21717 @deftp {Data Type} knot-remote-configuration
21718 Data type representing a remote configuration.
21719 This type has the following parameters:
21722 @item @code{id} (default: @code{""})
21723 An identifier for other configuration fields to refer to this remote. IDs must
21724 be unique and must not be empty.
21726 @item @code{address} (default: @code{'()})
21727 An ordered list of destination IP addresses. Addresses are tried in sequence.
21728 An optional port can be given with the @@ separator. For instance:
21729 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21731 @item @code{via} (default: @code{'()})
21732 An ordered list of source IP addresses. An empty list will have Knot choose
21733 an appropriate source IP. An optional port can be given with the @@ separator.
21734 The default is to choose at random.
21736 @item @code{key} (default: @code{#f})
21737 A reference to a key, that is a string containing the identifier of a key
21738 defined in a @code{knot-key-configuration} field.
21743 @deftp {Data Type} knot-keystore-configuration
21744 Data type representing a keystore to hold dnssec keys.
21745 This type has the following parameters:
21748 @item @code{id} (default: @code{""})
21749 The id of the keystore. It must not be empty.
21751 @item @code{backend} (default: @code{'pem})
21752 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21754 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21755 The configuration string of the backend. An example for the PKCS#11 is:
21756 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21757 For the pem backend, the string represents a path in the file system.
21762 @deftp {Data Type} knot-policy-configuration
21763 Data type representing a dnssec policy. Knot DNS is able to automatically
21764 sign your zones. It can either generate and manage your keys automatically or
21765 use keys that you generate.
21767 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21768 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21769 zone. In order to be trusted, the KSK needs to be present in the parent zone
21770 (usually a top-level domain). If your registrar supports dnssec, you will
21771 have to send them your KSK's hash so they can add a DS record in their zone.
21772 This is not automated and need to be done each time you change your KSK.
21774 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21775 easily and use weaker cryptographic functions (they use lower parameters) in
21776 order to sign records quickly, so they are changed often. The KSK however
21777 requires manual interaction with the registrar, so they are changed less often
21778 and use stronger parameters because they sign only one record.
21780 This type has the following parameters:
21783 @item @code{id} (default: @code{""})
21784 The id of the policy. It must not be empty.
21786 @item @code{keystore} (default: @code{"default"})
21787 A reference to a keystore, that is a string containing the identifier of a
21788 keystore defined in a @code{knot-keystore-configuration} field. The
21789 @code{"default"} identifier means the default keystore (a kasp database that
21790 was setup by this service).
21792 @item @code{manual?} (default: @code{#f})
21793 Whether the key management is manual or automatic.
21795 @item @code{single-type-signing?} (default: @code{#f})
21796 When @code{#t}, use the Single-Type Signing Scheme.
21798 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21799 An algorithm of signing keys and issued signatures.
21801 @item @code{ksk-size} (default: @code{256})
21802 The length of the KSK. Note that this value is correct for the default
21803 algorithm, but would be unsecure for other algorithms.
21805 @item @code{zsk-size} (default: @code{256})
21806 The length of the ZSK. Note that this value is correct for the default
21807 algorithm, but would be unsecure for other algorithms.
21809 @item @code{dnskey-ttl} (default: @code{'default})
21810 The TTL value for DNSKEY records added into zone apex. The special
21811 @code{'default} value means same as the zone SOA TTL.
21813 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21814 The period between ZSK publication and the next rollover initiation.
21816 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21817 An extra delay added for each key rollover step. This value should be high
21818 enough to cover propagation of data from the master server to all slaves.
21820 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21821 A validity period of newly issued signatures.
21823 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21824 A period how long before a signature expiration the signature will be refreshed.
21826 @item @code{nsec3?} (default: @code{#f})
21827 When @code{#t}, NSEC3 will be used instead of NSEC.
21829 @item @code{nsec3-iterations} (default: @code{5})
21830 The number of additional times the hashing is performed.
21832 @item @code{nsec3-salt-length} (default: @code{8})
21833 The length of a salt field in octets, which is appended to the original owner
21834 name before hashing.
21836 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21837 The validity period of newly issued salt field.
21842 @deftp {Data Type} knot-zone-configuration
21843 Data type representing a zone served by Knot.
21844 This type has the following parameters:
21847 @item @code{domain} (default: @code{""})
21848 The domain served by this configuration. It must not be empty.
21850 @item @code{file} (default: @code{""})
21851 The file where this zone is saved. This parameter is ignored by master zones.
21852 Empty means default location that depends on the domain name.
21854 @item @code{zone} (default: @code{(zone-file)})
21855 The content of the zone file. This parameter is ignored by slave zones. It
21856 must contain a zone-file record.
21858 @item @code{master} (default: @code{'()})
21859 A list of master remotes. When empty, this zone is a master. When set, this
21860 zone is a slave. This is a list of remotes identifiers.
21862 @item @code{ddns-master} (default: @code{#f})
21863 The main master. When empty, it defaults to the first master in the list of
21866 @item @code{notify} (default: @code{'()})
21867 A list of slave remote identifiers.
21869 @item @code{acl} (default: @code{'()})
21870 A list of acl identifiers.
21872 @item @code{semantic-checks?} (default: @code{#f})
21873 When set, this adds more semantic checks to the zone.
21875 @item @code{disable-any?} (default: @code{#f})
21876 When set, this forbids queries of the ANY type.
21878 @item @code{zonefile-sync} (default: @code{0})
21879 The delay between a modification in memory and on disk. 0 means immediate
21882 @item @code{zonefile-load} (default: @code{#f})
21883 The way the zone file contents are applied during zone load. Possible values
21887 @item @code{#f} for using the default value from Knot,
21888 @item @code{'none} for not using the zone file at all,
21889 @item @code{'difference} for computing the difference between already available
21890 contents and zone contents and applying it to the current zone contents,
21891 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21892 ignoring the SOA serial in the zone file, while the server takes care of it
21894 @item @code{'whole} for loading zone contents from the zone file.
21897 @item @code{journal-content} (default: @code{#f})
21898 The way the journal is used to store zone and its changes. Possible values
21899 are @code{'none} to not use it at all, @code{'changes} to store changes and
21900 @code{'all} to store contents. @code{#f} does not set this option, so the
21901 default value from Knot is used.
21903 @item @code{max-journal-usage} (default: @code{#f})
21904 The maximum size for the journal on disk. @code{#f} does not set this option,
21905 so the default value from Knot is used.
21907 @item @code{max-journal-depth} (default: @code{#f})
21908 The maximum size of the history. @code{#f} does not set this option, so the
21909 default value from Knot is used.
21911 @item @code{max-zone-size} (default: @code{#f})
21912 The maximum size of the zone file. This limit is enforced for incoming
21913 transfer and updates. @code{#f} does not set this option, so the default
21914 value from Knot is used.
21916 @item @code{dnssec-policy} (default: @code{#f})
21917 A reference to a @code{knot-policy-configuration} record, or the special
21918 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21921 @item @code{serial-policy} (default: @code{'increment})
21922 A policy between @code{'increment} and @code{'unixtime}.
21927 @deftp {Data Type} knot-configuration
21928 Data type representing the Knot configuration.
21929 This type has the following parameters:
21932 @item @code{knot} (default: @code{knot})
21935 @item @code{run-directory} (default: @code{"/var/run/knot"})
21936 The run directory. This directory will be used for pid file and sockets.
21938 @item @code{includes} (default: @code{'()})
21939 A list of strings or file-like objects denoting other files that must be
21940 included at the top of the configuration file.
21942 @cindex secrets, Knot service
21943 This can be used to manage secrets out-of-band. For example, secret
21944 keys may be stored in an out-of-band file not managed by Guix, and
21945 thus not visible in @file{/gnu/store}---e.g., you could store secret
21946 key configuration in @file{/etc/knot/secrets.conf} and add this file
21947 to the @code{includes} list.
21949 One can generate a secret tsig key (for nsupdate and zone transfers with the
21950 keymgr command from the knot package. Note that the package is not automatically
21951 installed by the service. The following example shows how to generate a new
21955 keymgr -t mysecret > /etc/knot/secrets.conf
21956 chmod 600 /etc/knot/secrets.conf
21959 Also note that the generated key will be named @var{mysecret}, so it is the
21960 name that needs to be used in the @var{key} field of the
21961 @code{knot-acl-configuration} record and in other places that need to refer
21964 It can also be used to add configuration not supported by this interface.
21966 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21967 An ip address on which to listen.
21969 @item @code{listen-v6} (default: @code{"::"})
21970 An ip address on which to listen.
21972 @item @code{listen-port} (default: @code{53})
21973 A port on which to listen.
21975 @item @code{keys} (default: @code{'()})
21976 The list of knot-key-configuration used by this configuration.
21978 @item @code{acls} (default: @code{'()})
21979 The list of knot-acl-configuration used by this configuration.
21981 @item @code{remotes} (default: @code{'()})
21982 The list of knot-remote-configuration used by this configuration.
21984 @item @code{zones} (default: @code{'()})
21985 The list of knot-zone-configuration used by this configuration.
21990 @subsubheading Knot Resolver Service
21992 @deffn {Scheme Variable} knot-resolver-service-type
21993 This this the type of the knot resolver service, whose value should be
21994 an @code{knot-resolver-configuration} object as in this example:
21997 (service knot-resolver-service-type
21998 (knot-resolver-configuration
21999 (kresd-config-file (plain-file "kresd.conf" "
22000 net.listen('192.168.0.1', 5353)
22001 user('knot-resolver', 'knot-resolver')
22002 modules = @{ 'hints > iterate', 'stats', 'predict' @}
22003 cache.size = 100 * MB
22007 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
22010 @deftp {Data Type} knot-resolver-configuration
22011 Data type representing the configuration of knot-resolver.
22014 @item @code{package} (default: @var{knot-resolver})
22015 Package object of the knot DNS resolver.
22017 @item @code{kresd-config-file} (default: %kresd.conf)
22018 File-like object of the kresd configuration file to use, by default it
22019 will listen on @code{127.0.0.1} and @code{::1}.
22021 @item @code{garbage-collection-interval} (default: 1000)
22022 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
22028 @subsubheading Dnsmasq Service
22030 @deffn {Scheme Variable} dnsmasq-service-type
22031 This is the type of the dnsmasq service, whose value should be an
22032 @code{dnsmasq-configuration} object as in this example:
22035 (service dnsmasq-service-type
22036 (dnsmasq-configuration
22038 (servers '("192.168.1.1"))))
22042 @deftp {Data Type} dnsmasq-configuration
22043 Data type representing the configuration of dnsmasq.
22046 @item @code{package} (default: @var{dnsmasq})
22047 Package object of the dnsmasq server.
22049 @item @code{no-hosts?} (default: @code{#f})
22050 When true, don't read the hostnames in /etc/hosts.
22052 @item @code{port} (default: @code{53})
22053 The port to listen on. Setting this to zero completely disables DNS
22054 responses, leaving only DHCP and/or TFTP functions.
22056 @item @code{local-service?} (default: @code{#t})
22057 Accept DNS queries only from hosts whose address is on a local subnet,
22058 ie a subnet for which an interface exists on the server.
22060 @item @code{listen-addresses} (default: @code{'()})
22061 Listen on the given IP addresses.
22063 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
22064 The file to read the IP address of the upstream nameservers from.
22066 @item @code{no-resolv?} (default: @code{#f})
22067 When true, don't read @var{resolv-file}.
22069 @item @code{servers} (default: @code{'()})
22070 Specify IP address of upstream servers directly.
22072 @item @code{addresses} (default: @code{'()})
22073 For each entry, specify an IP address to return for any host in the
22074 given domains. Queries in the domains are never forwarded and always
22075 replied to with the specified IP address.
22077 This is useful for redirecting hosts locally, for example:
22080 (service dnsmasq-service-type
22081 (dnsmasq-configuration
22083 '(; Redirect to a local web-server.
22084 "/example.org/127.0.0.1"
22085 ; Redirect subdomain to a specific IP.
22086 "/subdomain.example.org/192.168.1.42"))))
22089 Note that rules in @file{/etc/hosts} take precedence over this.
22091 @item @code{cache-size} (default: @code{150})
22092 Set the size of dnsmasq's cache. Setting the cache size to zero
22095 @item @code{negative-cache?} (default: @code{#t})
22096 When false, disable negative caching.
22101 @subsubheading ddclient Service
22104 The ddclient service described below runs the ddclient daemon, which takes
22105 care of automatically updating DNS entries for service providers such as
22106 @uref{https://dyn.com/dns/, Dyn}.
22108 The following example show instantiates the service with its default
22112 (service ddclient-service-type)
22115 Note that ddclient needs to access credentials that are stored in a
22116 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
22117 @code{secret-file} below.) You are expected to create this file manually, in
22118 an ``out-of-band'' fashion (you @emph{could} make this file part of the
22119 service configuration, for instance by using @code{plain-file}, but it will be
22120 world-readable @i{via} @file{/gnu/store}.) See the examples in the
22121 @file{share/ddclient} directory of the @code{ddclient} package.
22123 @c %start of fragment
22125 Available @code{ddclient-configuration} fields are:
22127 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
22128 The ddclient package.
22132 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
22133 The period after which ddclient will retry to check IP and domain name.
22135 Defaults to @samp{300}.
22139 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
22140 Use syslog for the output.
22142 Defaults to @samp{#t}.
22146 @deftypevr {@code{ddclient-configuration} parameter} string mail
22149 Defaults to @samp{"root"}.
22153 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
22154 Mail failed update to user.
22156 Defaults to @samp{"root"}.
22160 @deftypevr {@code{ddclient-configuration} parameter} string pid
22161 The ddclient PID file.
22163 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
22167 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
22168 Enable SSL support.
22170 Defaults to @samp{#t}.
22174 @deftypevr {@code{ddclient-configuration} parameter} string user
22175 Specifies the user name or ID that is used when running ddclient
22178 Defaults to @samp{"ddclient"}.
22182 @deftypevr {@code{ddclient-configuration} parameter} string group
22183 Group of the user who will run the ddclient program.
22185 Defaults to @samp{"ddclient"}.
22189 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
22190 Secret file which will be appended to @file{ddclient.conf} file. This
22191 file contains credentials for use by ddclient. You are expected to
22192 create it manually.
22194 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
22198 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
22199 Extra options will be appended to @file{ddclient.conf} file.
22201 Defaults to @samp{()}.
22206 @c %end of fragment
22210 @subsection VPN Services
22211 @cindex VPN (virtual private network)
22212 @cindex virtual private network (VPN)
22214 The @code{(gnu services vpn)} module provides services related to
22215 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
22216 your machine to connect to a VPN, and a @emph{server} service for your machine
22217 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
22219 @deffn {Scheme Procedure} openvpn-client-service @
22220 [#:config (openvpn-client-configuration)]
22222 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
22225 @deffn {Scheme Procedure} openvpn-server-service @
22226 [#:config (openvpn-server-configuration)]
22228 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
22230 Both can be run simultaneously.
22233 @c %automatically generated documentation
22235 Available @code{openvpn-client-configuration} fields are:
22237 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
22238 The OpenVPN package.
22242 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
22243 The OpenVPN pid file.
22245 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22249 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
22250 The protocol (UDP or TCP) used to open a channel between clients and
22253 Defaults to @samp{udp}.
22257 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
22258 The device type used to represent the VPN connection.
22260 Defaults to @samp{tun}.
22264 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
22265 The certificate authority to check connections against.
22267 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22271 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
22272 The certificate of the machine the daemon is running on. It should be
22273 signed by the authority given in @code{ca}.
22275 Defaults to @samp{"/etc/openvpn/client.crt"}.
22279 @deftypevr {@code{openvpn-client-configuration} parameter} string key
22280 The key of the machine the daemon is running on. It must be the key whose
22281 certificate is @code{cert}.
22283 Defaults to @samp{"/etc/openvpn/client.key"}.
22287 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
22288 Whether to use the lzo compression algorithm.
22290 Defaults to @samp{#t}.
22294 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
22295 Don't re-read key files across SIGUSR1 or --ping-restart.
22297 Defaults to @samp{#t}.
22301 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
22302 Don't close and reopen TUN/TAP device or run up/down scripts across
22303 SIGUSR1 or --ping-restart restarts.
22305 Defaults to @samp{#t}.
22309 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
22310 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22311 poll/epoll/select prior to the write operation.
22313 Defaults to @samp{#f}.
22316 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
22319 Defaults to @samp{3}.
22323 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
22324 Add an additional layer of HMAC authentication on top of the TLS control
22325 channel to protect against DoS attacks.
22327 Defaults to @samp{#f}.
22331 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
22332 Authenticate with server using username/password. The option is a file
22333 containing username/password on 2 lines. Do not use a file-like object as it
22334 would be added to the store and readable by any user.
22336 Defaults to @samp{'disabled}.
22339 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
22340 Whether to check the server certificate has server usage extension.
22342 Defaults to @samp{#t}.
22346 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
22347 Bind to a specific local port number.
22349 Defaults to @samp{#f}.
22353 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
22354 Retry resolving server address.
22356 Defaults to @samp{#t}.
22360 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
22361 A list of remote servers to connect to.
22363 Defaults to @samp{()}.
22365 Available @code{openvpn-remote-configuration} fields are:
22367 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
22370 Defaults to @samp{"my-server"}.
22374 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
22375 Port number the server listens to.
22377 Defaults to @samp{1194}.
22382 @c %end of automatic openvpn-client documentation
22384 @c %automatically generated documentation
22386 Available @code{openvpn-server-configuration} fields are:
22388 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
22389 The OpenVPN package.
22393 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
22394 The OpenVPN pid file.
22396 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22400 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
22401 The protocol (UDP or TCP) used to open a channel between clients and
22404 Defaults to @samp{udp}.
22408 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
22409 The device type used to represent the VPN connection.
22411 Defaults to @samp{tun}.
22415 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
22416 The certificate authority to check connections against.
22418 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22422 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
22423 The certificate of the machine the daemon is running on. It should be
22424 signed by the authority given in @code{ca}.
22426 Defaults to @samp{"/etc/openvpn/client.crt"}.
22430 @deftypevr {@code{openvpn-server-configuration} parameter} string key
22431 The key of the machine the daemon is running on. It must be the key whose
22432 certificate is @code{cert}.
22434 Defaults to @samp{"/etc/openvpn/client.key"}.
22438 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
22439 Whether to use the lzo compression algorithm.
22441 Defaults to @samp{#t}.
22445 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
22446 Don't re-read key files across SIGUSR1 or --ping-restart.
22448 Defaults to @samp{#t}.
22452 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
22453 Don't close and reopen TUN/TAP device or run up/down scripts across
22454 SIGUSR1 or --ping-restart restarts.
22456 Defaults to @samp{#t}.
22460 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
22461 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22462 poll/epoll/select prior to the write operation.
22464 Defaults to @samp{#f}.
22467 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
22470 Defaults to @samp{3}.
22474 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
22475 Add an additional layer of HMAC authentication on top of the TLS control
22476 channel to protect against DoS attacks.
22478 Defaults to @samp{#f}.
22482 @deftypevr {@code{openvpn-server-configuration} parameter} number port
22483 Specifies the port number on which the server listens.
22485 Defaults to @samp{1194}.
22489 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
22490 An ip and mask specifying the subnet inside the virtual network.
22492 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
22496 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
22497 A CIDR notation specifying the IPv6 subnet inside the virtual network.
22499 Defaults to @samp{#f}.
22503 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
22504 The Diffie-Hellman parameters file.
22506 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
22510 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
22511 The file that records client IPs.
22513 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
22517 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
22518 When true, the server will act as a gateway for its clients.
22520 Defaults to @samp{#f}.
22524 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
22525 When true, clients are allowed to talk to each other inside the VPN.
22527 Defaults to @samp{#f}.
22531 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
22532 Causes ping-like messages to be sent back and forth over the link so
22533 that each side knows when the other side has gone down. @code{keepalive}
22534 requires a pair. The first element is the period of the ping sending,
22535 and the second element is the timeout before considering the other side
22540 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
22541 The maximum number of clients.
22543 Defaults to @samp{100}.
22547 @deftypevr {@code{openvpn-server-configuration} parameter} string status
22548 The status file. This file shows a small report on current connection.
22549 It is truncated and rewritten every minute.
22551 Defaults to @samp{"/var/run/openvpn/status"}.
22555 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
22556 The list of configuration for some clients.
22558 Defaults to @samp{()}.
22560 Available @code{openvpn-ccd-configuration} fields are:
22562 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
22565 Defaults to @samp{"client"}.
22569 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
22572 Defaults to @samp{#f}.
22576 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
22579 Defaults to @samp{#f}.
22586 @c %end of automatic openvpn-server documentation
22589 @node Network File System
22590 @subsection Network File System
22593 The @code{(gnu services nfs)} module provides the following services,
22594 which are most commonly used in relation to mounting or exporting
22595 directory trees as @dfn{network file systems} (NFS).
22597 While it is possible to use the individual components that together make
22598 up a Network File System service, we recommended to configure an NFS
22599 server with the @code{nfs-service-type}.
22601 @subsubheading NFS Service
22602 @cindex NFS, server
22604 The NFS service takes care of setting up all NFS component services,
22605 kernel configuration file systems, and installs configuration files in
22606 the locations that NFS expects.
22608 @defvr {Scheme Variable} nfs-service-type
22609 A service type for a complete NFS server.
22612 @deftp {Data Type} nfs-configuration
22613 This data type represents the configuration of the NFS service and all
22616 It has the following parameters:
22618 @item @code{nfs-utils} (default: @code{nfs-utils})
22619 The nfs-utils package to use.
22621 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
22622 If a list of string values is provided, the @command{rpc.nfsd} daemon
22623 will be limited to supporting the given versions of the NFS protocol.
22625 @item @code{exports} (default: @code{'()})
22626 This is a list of directories the NFS server should export. Each entry
22627 is a list consisting of two elements: a directory name and a string
22628 containing all options. This is an example in which the directory
22629 @file{/export} is served to all NFS clients as a read-only share:
22635 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
22638 @item @code{rpcmountd-port} (default: @code{#f})
22639 The network port that the @command{rpc.mountd} daemon should use.
22641 @item @code{rpcstatd-port} (default: @code{#f})
22642 The network port that the @command{rpc.statd} daemon should use.
22644 @item @code{rpcbind} (default: @code{rpcbind})
22645 The rpcbind package to use.
22647 @item @code{idmap-domain} (default: @code{"localdomain"})
22648 The local NFSv4 domain name.
22650 @item @code{nfsd-port} (default: @code{2049})
22651 The network port that the @command{nfsd} daemon should use.
22653 @item @code{nfsd-threads} (default: @code{8})
22654 The number of threads used by the @command{nfsd} daemon.
22656 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22657 The directory where the pipefs file system is mounted.
22659 @item @code{debug} (default: @code{'()"})
22660 A list of subsystems for which debugging output should be enabled. This
22661 is a list of symbols. Any of these symbols are valid: @code{nfsd},
22662 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
22666 If you don't need a complete NFS service or prefer to build it yourself
22667 you can use the individual component services that are documented below.
22669 @subsubheading RPC Bind Service
22672 The RPC Bind service provides a facility to map program numbers into
22673 universal addresses.
22674 Many NFS related services use this facility. Hence it is automatically
22675 started when a dependent service starts.
22677 @defvr {Scheme Variable} rpcbind-service-type
22678 A service type for the RPC portmapper daemon.
22682 @deftp {Data Type} rpcbind-configuration
22683 Data type representing the configuration of the RPC Bind Service.
22684 This type has the following parameters:
22686 @item @code{rpcbind} (default: @code{rpcbind})
22687 The rpcbind package to use.
22689 @item @code{warm-start?} (default: @code{#t})
22690 If this parameter is @code{#t}, then the daemon will read a
22691 state file on startup thus reloading state information saved by a previous
22697 @subsubheading Pipefs Pseudo File System
22701 The pipefs file system is used to transfer NFS related data
22702 between the kernel and user space programs.
22704 @defvr {Scheme Variable} pipefs-service-type
22705 A service type for the pipefs pseudo file system.
22708 @deftp {Data Type} pipefs-configuration
22709 Data type representing the configuration of the pipefs pseudo file system service.
22710 This type has the following parameters:
22712 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22713 The directory to which the file system is to be attached.
22718 @subsubheading GSS Daemon Service
22721 @cindex global security system
22723 The @dfn{global security system} (GSS) daemon provides strong security for RPC
22725 Before exchanging RPC requests an RPC client must establish a security
22726 context. Typically this is done using the Kerberos command @command{kinit}
22727 or automatically at login time using PAM services (@pxref{Kerberos Services}).
22729 @defvr {Scheme Variable} gss-service-type
22730 A service type for the Global Security System (GSS) daemon.
22733 @deftp {Data Type} gss-configuration
22734 Data type representing the configuration of the GSS daemon service.
22735 This type has the following parameters:
22737 @item @code{nfs-utils} (default: @code{nfs-utils})
22738 The package in which the @command{rpc.gssd} command is to be found.
22740 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22741 The directory where the pipefs file system is mounted.
22747 @subsubheading IDMAP Daemon Service
22749 @cindex name mapper
22751 The idmap daemon service provides mapping between user IDs and user names.
22752 Typically it is required in order to access file systems mounted via NFSv4.
22754 @defvr {Scheme Variable} idmap-service-type
22755 A service type for the Identity Mapper (IDMAP) daemon.
22758 @deftp {Data Type} idmap-configuration
22759 Data type representing the configuration of the IDMAP daemon service.
22760 This type has the following parameters:
22762 @item @code{nfs-utils} (default: @code{nfs-utils})
22763 The package in which the @command{rpc.idmapd} command is to be found.
22765 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22766 The directory where the pipefs file system is mounted.
22768 @item @code{domain} (default: @code{#f})
22769 The local NFSv4 domain name.
22770 This must be a string or @code{#f}.
22771 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
22773 @item @code{verbosity} (default: @code{0})
22774 The verbosity level of the daemon.
22779 @node Continuous Integration
22780 @subsection Continuous Integration
22782 @cindex continuous integration
22783 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
22784 continuous integration tool for Guix. It can be used both for development and
22785 for providing substitutes to others (@pxref{Substitutes}).
22787 The @code{(gnu services cuirass)} module provides the following service.
22789 @defvr {Scheme Procedure} cuirass-service-type
22790 The type of the Cuirass service. Its value must be a
22791 @code{cuirass-configuration} object, as described below.
22794 To add build jobs, you have to set the @code{specifications} field of the
22795 configuration. Here is an example of a service that polls the Guix repository
22796 and builds the packages from a manifest. Some of the packages are defined in
22797 the @code{"custom-packages"} input, which is the equivalent of
22798 @env{GUIX_PACKAGE_PATH}.
22801 (define %cuirass-specs
22803 '((#:name . "my-manifest")
22804 (#:load-path-inputs . ("guix"))
22805 (#:package-path-inputs . ("custom-packages"))
22806 (#:proc-input . "guix")
22807 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
22808 (#:proc . cuirass-jobs)
22809 (#:proc-args . ((subset . "manifests")
22810 (systems . ("x86_64-linux"))
22811 (manifests . (("config" . "guix/manifest.scm")))))
22812 (#:inputs . (((#:name . "guix")
22813 (#:url . "git://git.savannah.gnu.org/guix.git")
22814 (#:load-path . ".")
22815 (#:branch . "master")
22816 (#:no-compile? . #t))
22817 ((#:name . "config")
22818 (#:url . "https://git.example.org/config.git")
22819 (#:load-path . ".")
22820 (#:branch . "master")
22821 (#:no-compile? . #t))
22822 ((#:name . "custom-packages")
22823 (#:url . "https://git.example.org/custom-packages.git")
22824 (#:load-path . ".")
22825 (#:branch . "master")
22826 (#:no-compile? . #t)))))))
22828 (service cuirass-service-type
22829 (cuirass-configuration
22830 (specifications %cuirass-specs)))
22833 While information related to build jobs is located directly in the
22834 specifications, global settings for the @command{cuirass} process are
22835 accessible in other @code{cuirass-configuration} fields.
22837 @deftp {Data Type} cuirass-configuration
22838 Data type representing the configuration of Cuirass.
22841 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22842 Location of the log file.
22844 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22845 Location of the log file used by the web interface.
22847 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22848 Location of the repository cache.
22850 @item @code{user} (default: @code{"cuirass"})
22851 Owner of the @code{cuirass} process.
22853 @item @code{group} (default: @code{"cuirass"})
22854 Owner's group of the @code{cuirass} process.
22856 @item @code{interval} (default: @code{60})
22857 Number of seconds between the poll of the repositories followed by the
22860 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22861 Location of sqlite database which contains the build results and previously
22862 added specifications.
22864 @item @code{ttl} (default: @code{(* 30 24 3600)})
22865 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22866 are registered for build results. This means that build results are protected
22867 from garbage collection for at least @var{ttl} seconds.
22869 @item @code{port} (default: @code{8081})
22870 Port number used by the HTTP server.
22872 @item @code{host} (default: @code{"localhost"})
22873 Listen on the network interface for @var{host}. The default is to
22874 accept connections from localhost.
22876 @item @code{specifications} (default: @code{#~'()})
22877 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22878 where a specification is an association list
22879 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22880 keys are keywords (@code{#:keyword-example}) as shown in the example
22883 @item @code{use-substitutes?} (default: @code{#f})
22884 This allows using substitutes to avoid building every dependencies of a job
22887 @item @code{one-shot?} (default: @code{#f})
22888 Only evaluate specifications and build derivations once.
22890 @item @code{fallback?} (default: @code{#f})
22891 When substituting a pre-built binary fails, fall back to building
22894 @item @code{extra-options} (default: @code{'()})
22895 Extra options to pass when running the Cuirass processes.
22897 @item @code{cuirass} (default: @code{cuirass})
22898 The Cuirass package to use.
22902 @node Power Management Services
22903 @subsection Power Management Services
22906 @cindex power management with TLP
22907 @subsubheading TLP daemon
22909 The @code{(gnu services pm)} module provides a Guix service definition
22910 for the Linux power management tool TLP.
22912 TLP enables various powersaving modes in userspace and kernel.
22913 Contrary to @code{upower-service}, it is not a passive,
22914 monitoring tool, as it will apply custom settings each time a new power
22915 source is detected. More information can be found at
22916 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22918 @deffn {Scheme Variable} tlp-service-type
22919 The service type for the TLP tool. Its value should be a valid
22920 TLP configuration (see below). To use the default settings, simply
22923 (service tlp-service-type)
22927 By default TLP does not need much configuration but most TLP parameters
22928 can be tweaked using @code{tlp-configuration}.
22930 Each parameter definition is preceded by its type; for example,
22931 @samp{boolean foo} indicates that the @code{foo} parameter
22932 should be specified as a boolean. Types starting with
22933 @code{maybe-} denote parameters that won't show up in TLP config file
22934 when their value is @code{'disabled}.
22936 @c The following documentation was initially generated by
22937 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22938 @c documentation is better, so we shouldn't hesitate to edit below as
22939 @c needed. However if the change you want to make to this documentation
22940 @c can be done in an automated way, it's probably easier to change
22941 @c (generate-documentation) than to make it below and have to deal with
22942 @c the churn as TLP updates.
22944 Available @code{tlp-configuration} fields are:
22946 @deftypevr {@code{tlp-configuration} parameter} package tlp
22951 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22952 Set to true if you wish to enable TLP.
22954 Defaults to @samp{#t}.
22958 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22959 Default mode when no power supply can be detected. Alternatives are AC
22962 Defaults to @samp{"AC"}.
22966 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22967 Number of seconds Linux kernel has to wait after the disk goes idle,
22968 before syncing on AC.
22970 Defaults to @samp{0}.
22974 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22975 Same as @code{disk-idle-ac} but on BAT mode.
22977 Defaults to @samp{2}.
22981 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22982 Dirty pages flushing periodicity, expressed in seconds.
22984 Defaults to @samp{15}.
22988 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22989 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22991 Defaults to @samp{60}.
22995 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22996 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22997 alternatives are powersave and performance. With acpi-cpufreq driver,
22998 alternatives are ondemand, powersave, performance and conservative.
23000 Defaults to @samp{disabled}.
23004 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
23005 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
23007 Defaults to @samp{disabled}.
23011 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
23012 Set the min available frequency for the scaling governor on AC.
23014 Defaults to @samp{disabled}.
23018 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
23019 Set the max available frequency for the scaling governor on AC.
23021 Defaults to @samp{disabled}.
23025 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
23026 Set the min available frequency for the scaling governor on BAT.
23028 Defaults to @samp{disabled}.
23032 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
23033 Set the max available frequency for the scaling governor on BAT.
23035 Defaults to @samp{disabled}.
23039 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
23040 Limit the min P-state to control the power dissipation of the CPU, in AC
23041 mode. Values are stated as a percentage of the available performance.
23043 Defaults to @samp{disabled}.
23047 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
23048 Limit the max P-state to control the power dissipation of the CPU, in AC
23049 mode. Values are stated as a percentage of the available performance.
23051 Defaults to @samp{disabled}.
23055 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
23056 Same as @code{cpu-min-perf-on-ac} on BAT mode.
23058 Defaults to @samp{disabled}.
23062 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
23063 Same as @code{cpu-max-perf-on-ac} on BAT mode.
23065 Defaults to @samp{disabled}.
23069 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
23070 Enable CPU turbo boost feature on AC mode.
23072 Defaults to @samp{disabled}.
23076 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
23077 Same as @code{cpu-boost-on-ac?} on BAT mode.
23079 Defaults to @samp{disabled}.
23083 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
23084 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
23085 used under light load conditions.
23087 Defaults to @samp{#f}.
23091 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
23092 Same as @code{sched-powersave-on-ac?} but on BAT mode.
23094 Defaults to @samp{#t}.
23098 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
23099 Enable Linux kernel NMI watchdog.
23101 Defaults to @samp{#f}.
23105 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
23106 For Linux kernels with PHC patch applied, change CPU voltages. An
23107 example value would be @samp{"F:V F:V F:V F:V"}.
23109 Defaults to @samp{disabled}.
23113 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
23114 Set CPU performance versus energy saving policy on AC. Alternatives are
23115 performance, normal, powersave.
23117 Defaults to @samp{"performance"}.
23121 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
23122 Same as @code{energy-perf-policy-ac} but on BAT mode.
23124 Defaults to @samp{"powersave"}.
23128 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
23133 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
23134 Hard disk advanced power management level.
23138 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
23139 Same as @code{disk-apm-bat} but on BAT mode.
23143 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
23144 Hard disk spin down timeout. One value has to be specified for each
23145 declared hard disk.
23147 Defaults to @samp{disabled}.
23151 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
23152 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
23154 Defaults to @samp{disabled}.
23158 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
23159 Select IO scheduler for disk devices. One value has to be specified for
23160 each declared hard disk. Example alternatives are cfq, deadline and
23163 Defaults to @samp{disabled}.
23167 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
23168 SATA aggressive link power management (ALPM) level. Alternatives are
23169 min_power, medium_power, max_performance.
23171 Defaults to @samp{"max_performance"}.
23175 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
23176 Same as @code{sata-linkpwr-ac} but on BAT mode.
23178 Defaults to @samp{"min_power"}.
23182 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
23183 Exclude specified SATA host devices for link power management.
23185 Defaults to @samp{disabled}.
23189 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
23190 Enable Runtime Power Management for AHCI controller and disks on AC
23193 Defaults to @samp{disabled}.
23197 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
23198 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
23200 Defaults to @samp{disabled}.
23204 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
23205 Seconds of inactivity before disk is suspended.
23207 Defaults to @samp{15}.
23211 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
23212 PCI Express Active State Power Management level. Alternatives are
23213 default, performance, powersave.
23215 Defaults to @samp{"performance"}.
23219 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
23220 Same as @code{pcie-aspm-ac} but on BAT mode.
23222 Defaults to @samp{"powersave"}.
23226 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
23227 Radeon graphics clock speed level. Alternatives are low, mid, high,
23230 Defaults to @samp{"high"}.
23234 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
23235 Same as @code{radeon-power-ac} but on BAT mode.
23237 Defaults to @samp{"low"}.
23241 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
23242 Radeon dynamic power management method (DPM). Alternatives are battery,
23245 Defaults to @samp{"performance"}.
23249 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
23250 Same as @code{radeon-dpm-state-ac} but on BAT mode.
23252 Defaults to @samp{"battery"}.
23256 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
23257 Radeon DPM performance level. Alternatives are auto, low, high.
23259 Defaults to @samp{"auto"}.
23263 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
23264 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
23266 Defaults to @samp{"auto"}.
23270 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
23271 Wifi power saving mode.
23273 Defaults to @samp{#f}.
23277 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
23278 Same as @code{wifi-power-ac?} but on BAT mode.
23280 Defaults to @samp{#t}.
23284 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
23285 Disable wake on LAN.
23287 Defaults to @samp{#t}.
23291 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
23292 Timeout duration in seconds before activating audio power saving on
23293 Intel HDA and AC97 devices. A value of 0 disables power saving.
23295 Defaults to @samp{0}.
23299 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
23300 Same as @code{sound-powersave-ac} but on BAT mode.
23302 Defaults to @samp{1}.
23306 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
23307 Disable controller in powersaving mode on Intel HDA devices.
23309 Defaults to @samp{#t}.
23313 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
23314 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
23315 powered on again by releasing (and reinserting) the eject lever or by
23316 pressing the disc eject button on newer models.
23318 Defaults to @samp{#f}.
23322 @deftypevr {@code{tlp-configuration} parameter} string bay-device
23323 Name of the optical drive device to power off.
23325 Defaults to @samp{"sr0"}.
23329 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
23330 Runtime Power Management for PCI(e) bus devices. Alternatives are on
23333 Defaults to @samp{"on"}.
23337 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
23338 Same as @code{runtime-pm-ac} but on BAT mode.
23340 Defaults to @samp{"auto"}.
23344 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
23345 Runtime Power Management for all PCI(e) bus devices, except blacklisted
23348 Defaults to @samp{#t}.
23352 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
23353 Exclude specified PCI(e) device addresses from Runtime Power Management.
23355 Defaults to @samp{disabled}.
23359 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
23360 Exclude PCI(e) devices assigned to the specified drivers from Runtime
23365 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
23366 Enable USB autosuspend feature.
23368 Defaults to @samp{#t}.
23372 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
23373 Exclude specified devices from USB autosuspend.
23375 Defaults to @samp{disabled}.
23379 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
23380 Exclude WWAN devices from USB autosuspend.
23382 Defaults to @samp{#t}.
23386 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
23387 Include specified devices into USB autosuspend, even if they are already
23388 excluded by the driver or via @code{usb-blacklist-wwan?}.
23390 Defaults to @samp{disabled}.
23394 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
23395 Enable USB autosuspend before shutdown.
23397 Defaults to @samp{disabled}.
23401 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
23402 Restore radio device state (bluetooth, wifi, wwan) from previous
23403 shutdown on system startup.
23405 Defaults to @samp{#f}.
23410 @cindex CPU frequency scaling with thermald
23411 @subsubheading Thermald daemon
23413 The @code{(gnu services pm)} module provides an interface to
23414 thermald, a CPU frequency scaling service which helps prevent overheating.
23416 @defvr {Scheme Variable} thermald-service-type
23417 This is the service type for
23418 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
23419 Thermal Daemon, which is responsible for controlling the thermal state
23420 of processors and preventing overheating.
23423 @deftp {Data Type} thermald-configuration
23424 Data type representing the configuration of @code{thermald-service-type}.
23427 @item @code{ignore-cpuid-check?} (default: @code{#f})
23428 Ignore cpuid check for supported CPU models.
23430 @item @code{thermald} (default: @var{thermald})
23431 Package object of thermald.
23436 @node Audio Services
23437 @subsection Audio Services
23439 The @code{(gnu services audio)} module provides a service to start MPD
23440 (the Music Player Daemon).
23443 @subsubheading Music Player Daemon
23445 The Music Player Daemon (MPD) is a service that can play music while
23446 being controlled from the local machine or over the network by a variety
23449 The following example shows how one might run @code{mpd} as user
23450 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
23453 (service mpd-service-type
23459 @defvr {Scheme Variable} mpd-service-type
23460 The service type for @command{mpd}
23463 @deftp {Data Type} mpd-configuration
23464 Data type representing the configuration of @command{mpd}.
23467 @item @code{user} (default: @code{"mpd"})
23468 The user to run mpd as.
23470 @item @code{music-dir} (default: @code{"~/Music"})
23471 The directory to scan for music files.
23473 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
23474 The directory to store playlists.
23476 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
23477 The location of the music database.
23479 @item @code{state-file} (default: @code{"~/.mpd/state"})
23480 The location of the file that stores current MPD's state.
23482 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
23483 The location of the sticker database.
23485 @item @code{port} (default: @code{"6600"})
23486 The port to run mpd on.
23488 @item @code{address} (default: @code{"any"})
23489 The address that mpd will bind to. To use a Unix domain socket,
23490 an absolute path can be specified here.
23492 @item @code{outputs} (default: @code{"(list (mpd-output))"})
23493 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
23498 @deftp {Data Type} mpd-output
23499 Data type representing an @command{mpd} audio output.
23502 @item @code{name} (default: @code{"MPD"})
23503 The name of the audio output.
23505 @item @code{type} (default: @code{"pulse"})
23506 The type of audio output.
23508 @item @code{enabled?} (default: @code{#t})
23509 Specifies whether this audio output is enabled when MPD is started. By
23510 default, all audio outputs are enabled. This is just the default
23511 setting when there is no state file; with a state file, the previous
23514 @item @code{tags?} (default: @code{#t})
23515 If set to @code{#f}, then MPD will not send tags to this output. This
23516 is only useful for output plugins that can receive tags, for example the
23517 @code{httpd} output plugin.
23519 @item @code{always-on?} (default: @code{#f})
23520 If set to @code{#t}, then MPD attempts to keep this audio output always
23521 open. This may be useful for streaming servers, when you don’t want to
23522 disconnect all listeners even when playback is accidentally stopped.
23524 @item @code{mixer-type}
23525 This field accepts a symbol that specifies which mixer should be used
23526 for this audio output: the @code{hardware} mixer, the @code{software}
23527 mixer, the @code{null} mixer (allows setting the volume, but with no
23528 effect; this can be used as a trick to implement an external mixer
23529 External Mixer) or no mixer (@code{none}).
23531 @item @code{extra-options} (default: @code{'()"})
23532 An association list of option symbols to string values to be appended to
23533 the audio output configuration.
23538 The following example shows a configuration of @code{mpd} that provides
23539 an HTTP audio streaming output.
23542 (service mpd-service-type
23550 `((encoder . "vorbis")
23551 (port . "8080"))))))))
23555 @node Virtualization Services
23556 @subsection Virtualization services
23558 The @code{(gnu services virtualization)} module provides services for
23559 the libvirt and virtlog daemons, as well as other virtualization-related
23562 @subsubheading Libvirt daemon
23563 @code{libvirtd} is the server side daemon component of the libvirt
23564 virtualization management system. This daemon runs on host servers
23565 and performs required management tasks for virtualized guests.
23567 @deffn {Scheme Variable} libvirt-service-type
23568 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
23569 Its value must be a @code{libvirt-configuration}.
23572 (service libvirt-service-type
23573 (libvirt-configuration
23574 (unix-sock-group "libvirt")
23575 (tls-port "16555")))
23579 @c Auto-generated with (generate-libvirt-documentation)
23580 Available @code{libvirt-configuration} fields are:
23582 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
23587 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
23588 Flag listening for secure TLS connections on the public TCP/IP port.
23589 must set @code{listen} for this to have any effect.
23591 It is necessary to setup a CA and issue server certificates before using
23594 Defaults to @samp{#t}.
23598 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
23599 Listen for unencrypted TCP connections on the public TCP/IP port. must
23600 set @code{listen} for this to have any effect.
23602 Using the TCP socket requires SASL authentication by default. Only SASL
23603 mechanisms which support data encryption are allowed. This is
23604 DIGEST_MD5 and GSSAPI (Kerberos5)
23606 Defaults to @samp{#f}.
23610 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
23611 Port for accepting secure TLS connections This can be a port number, or
23614 Defaults to @samp{"16514"}.
23618 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
23619 Port for accepting insecure TCP connections This can be a port number,
23622 Defaults to @samp{"16509"}.
23626 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
23627 IP address or hostname used for client connections.
23629 Defaults to @samp{"0.0.0.0"}.
23633 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
23634 Flag toggling mDNS advertisement of the libvirt service.
23636 Alternatively can disable for all services on a host by stopping the
23639 Defaults to @samp{#f}.
23643 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
23644 Default mDNS advertisement name. This must be unique on the immediate
23647 Defaults to @samp{"Virtualization Host <hostname>"}.
23651 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
23652 UNIX domain socket group ownership. This can be used to allow a
23653 'trusted' set of users access to management capabilities without
23656 Defaults to @samp{"root"}.
23660 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
23661 UNIX socket permissions for the R/O socket. This is used for monitoring
23664 Defaults to @samp{"0777"}.
23668 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
23669 UNIX socket permissions for the R/W socket. Default allows only root.
23670 If PolicyKit is enabled on the socket, the default will change to allow
23671 everyone (eg, 0777)
23673 Defaults to @samp{"0770"}.
23677 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
23678 UNIX socket permissions for the admin socket. Default allows only owner
23679 (root), do not change it unless you are sure to whom you are exposing
23682 Defaults to @samp{"0777"}.
23686 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
23687 The directory in which sockets will be found/created.
23689 Defaults to @samp{"/var/run/libvirt"}.
23693 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
23694 Authentication scheme for UNIX read-only sockets. By default socket
23695 permissions allow anyone to connect
23697 Defaults to @samp{"polkit"}.
23701 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
23702 Authentication scheme for UNIX read-write sockets. By default socket
23703 permissions only allow root. If PolicyKit support was compiled into
23704 libvirt, the default will be to use 'polkit' auth.
23706 Defaults to @samp{"polkit"}.
23710 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
23711 Authentication scheme for TCP sockets. If you don't enable SASL, then
23712 all TCP traffic is cleartext. Don't do this outside of a dev/test
23715 Defaults to @samp{"sasl"}.
23719 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
23720 Authentication scheme for TLS sockets. TLS sockets already have
23721 encryption provided by the TLS layer, and limited authentication is done
23724 It is possible to make use of any SASL authentication mechanism as well,
23725 by using 'sasl' for this option
23727 Defaults to @samp{"none"}.
23731 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
23732 API access control scheme.
23734 By default an authenticated user is allowed access to all APIs. Access
23735 drivers can place restrictions on this.
23737 Defaults to @samp{()}.
23741 @deftypevr {@code{libvirt-configuration} parameter} string key-file
23742 Server key file path. If set to an empty string, then no private key is
23745 Defaults to @samp{""}.
23749 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
23750 Server key file path. If set to an empty string, then no certificate is
23753 Defaults to @samp{""}.
23757 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
23758 Server key file path. If set to an empty string, then no CA certificate
23761 Defaults to @samp{""}.
23765 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
23766 Certificate revocation list path. If set to an empty string, then no
23769 Defaults to @samp{""}.
23773 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
23774 Disable verification of our own server certificates.
23776 When libvirtd starts it performs some sanity checks against its own
23779 Defaults to @samp{#f}.
23783 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
23784 Disable verification of client certificates.
23786 Client certificate verification is the primary authentication mechanism.
23787 Any client which does not present a certificate signed by the CA will be
23790 Defaults to @samp{#f}.
23794 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
23795 Whitelist of allowed x509 Distinguished Name.
23797 Defaults to @samp{()}.
23801 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
23802 Whitelist of allowed SASL usernames. The format for username depends on
23803 the SASL authentication mechanism.
23805 Defaults to @samp{()}.
23809 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
23810 Override the compile time default TLS priority string. The default is
23811 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
23812 is desired for libvirt to deviate from the global default settings.
23814 Defaults to @samp{"NORMAL"}.
23818 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
23819 Maximum number of concurrent client connections to allow over all
23822 Defaults to @samp{5000}.
23826 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
23827 Maximum length of queue of connections waiting to be accepted by the
23828 daemon. Note, that some protocols supporting retransmission may obey
23829 this so that a later reattempt at connection succeeds.
23831 Defaults to @samp{1000}.
23835 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
23836 Maximum length of queue of accepted but not yet authenticated clients.
23837 Set this to zero to turn this feature off
23839 Defaults to @samp{20}.
23843 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23844 Number of workers to start up initially.
23846 Defaults to @samp{5}.
23850 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23851 Maximum number of worker threads.
23853 If the number of active clients exceeds @code{min-workers}, then more
23854 threads are spawned, up to max_workers limit. Typically you'd want
23855 max_workers to equal maximum number of clients allowed.
23857 Defaults to @samp{20}.
23861 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23862 Number of priority workers. If all workers from above pool are stuck,
23863 some calls marked as high priority (notably domainDestroy) can be
23864 executed in this pool.
23866 Defaults to @samp{5}.
23870 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23871 Total global limit on concurrent RPC calls.
23873 Defaults to @samp{20}.
23877 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23878 Limit on concurrent requests from a single client connection. To avoid
23879 one client monopolizing the server this should be a small fraction of
23880 the global max_requests and max_workers parameter.
23882 Defaults to @samp{5}.
23886 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23887 Same as @code{min-workers} but for the admin interface.
23889 Defaults to @samp{1}.
23893 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23894 Same as @code{max-workers} but for the admin interface.
23896 Defaults to @samp{5}.
23900 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23901 Same as @code{max-clients} but for the admin interface.
23903 Defaults to @samp{5}.
23907 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23908 Same as @code{max-queued-clients} but for the admin interface.
23910 Defaults to @samp{5}.
23914 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23915 Same as @code{max-client-requests} but for the admin interface.
23917 Defaults to @samp{5}.
23921 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23922 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23924 Defaults to @samp{3}.
23928 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23931 A filter allows to select a different logging level for a given category
23932 of logs The format for a filter is one of:
23943 where @code{name} is a string which is matched against the category
23944 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23945 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
23946 name in the filter can be a substring of the full category name, in
23947 order to match multiple similar categories), the optional @samp{"+"}
23948 prefix tells libvirt to log stack trace for each message matching name,
23949 and @code{x} is the minimal level where matching messages should be
23967 Multiple filters can be defined in a single filters statement, they just
23968 need to be separated by spaces.
23970 Defaults to @samp{"3:remote 4:event"}.
23974 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23977 An output is one of the places to save logging information. The format
23978 for an output can be:
23982 output goes to stderr
23984 @item x:syslog:name
23985 use syslog for the output and use the given name as the ident
23987 @item x:file:file_path
23988 output to a file, with the given filepath
23991 output to journald logging system
23995 In all case the x prefix is the minimal level, acting as a filter
24012 Multiple outputs can be defined, they just need to be separated by
24015 Defaults to @samp{"3:stderr"}.
24019 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
24020 Allows usage of the auditing subsystem to be altered
24024 0: disable all auditing
24027 1: enable auditing, only if enabled on host
24030 2: enable auditing, and exit if disabled on host.
24034 Defaults to @samp{1}.
24038 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
24039 Send audit messages via libvirt logging infrastructure.
24041 Defaults to @samp{#f}.
24045 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
24046 Host UUID. UUID must not have all digits be the same.
24048 Defaults to @samp{""}.
24052 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
24053 Source to read host UUID.
24057 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
24060 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
24064 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
24067 Defaults to @samp{"smbios"}.
24071 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
24072 A keepalive message is sent to a client after @code{keepalive_interval}
24073 seconds of inactivity to check if the client is still responding. If
24074 set to -1, libvirtd will never send keepalive requests; however clients
24075 can still send them and the daemon will send responses.
24077 Defaults to @samp{5}.
24081 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
24082 Maximum number of keepalive messages that are allowed to be sent to the
24083 client without getting any response before the connection is considered
24086 In other words, the connection is automatically closed approximately
24087 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
24088 the last message received from the client. When @code{keepalive-count}
24089 is set to 0, connections will be automatically closed after
24090 @code{keepalive-interval} seconds of inactivity without sending any
24091 keepalive messages.
24093 Defaults to @samp{5}.
24097 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
24098 Same as above but for admin interface.
24100 Defaults to @samp{5}.
24104 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
24105 Same as above but for admin interface.
24107 Defaults to @samp{5}.
24111 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
24112 Timeout for Open vSwitch calls.
24114 The @code{ovs-vsctl} utility is used for the configuration and its
24115 timeout option is set by default to 5 seconds to avoid potential
24116 infinite waits blocking libvirt.
24118 Defaults to @samp{5}.
24122 @c %end of autogenerated docs
24124 @subsubheading Virtlog daemon
24125 The virtlogd service is a server side daemon component of libvirt that is
24126 used to manage logs from virtual machine consoles.
24128 This daemon is not used directly by libvirt client applications, rather it
24129 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
24130 standalone daemon, the main @code{libvirtd} daemon can be restarted without
24131 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
24132 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
24134 @deffn {Scheme Variable} virtlog-service-type
24135 This is the type of the virtlog daemon.
24136 Its value must be a @code{virtlog-configuration}.
24139 (service virtlog-service-type
24140 (virtlog-configuration
24141 (max-clients 1000)))
24145 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
24146 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24148 Defaults to @samp{3}.
24152 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
24155 A filter allows to select a different logging level for a given category
24156 of logs The format for a filter is one of:
24167 where @code{name} is a string which is matched against the category
24168 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24169 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
24170 be a substring of the full category name, in order to match multiple
24171 similar categories), the optional "+" prefix tells libvirt to log stack
24172 trace for each message matching name, and @code{x} is the minimal level
24173 where matching messages should be logged:
24190 Multiple filters can be defined in a single filters statement, they just
24191 need to be separated by spaces.
24193 Defaults to @samp{"3:remote 4:event"}.
24197 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
24200 An output is one of the places to save logging information The format
24201 for an output can be:
24205 output goes to stderr
24207 @item x:syslog:name
24208 use syslog for the output and use the given name as the ident
24210 @item x:file:file_path
24211 output to a file, with the given filepath
24214 output to journald logging system
24218 In all case the x prefix is the minimal level, acting as a filter
24235 Multiple outputs can be defined, they just need to be separated by
24238 Defaults to @samp{"3:stderr"}.
24242 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
24243 Maximum number of concurrent client connections to allow over all
24246 Defaults to @samp{1024}.
24250 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
24251 Maximum file size before rolling over.
24253 Defaults to @samp{2MB}
24257 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
24258 Maximum number of backup files to keep.
24260 Defaults to @samp{3}
24264 @subsubheading Transparent Emulation with QEMU
24267 @cindex @code{binfmt_misc}
24268 @code{qemu-binfmt-service-type} provides support for transparent
24269 emulation of program binaries built for different architectures---e.g.,
24270 it allows you to transparently execute an ARMv7 program on an x86_64
24271 machine. It achieves this by combining the @uref{https://www.qemu.org,
24272 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
24274 @defvr {Scheme Variable} qemu-binfmt-service-type
24275 This is the type of the QEMU/binfmt service for transparent emulation.
24276 Its value must be a @code{qemu-binfmt-configuration} object, which
24277 specifies the QEMU package to use as well as the architecture we want to
24281 (service qemu-binfmt-service-type
24282 (qemu-binfmt-configuration
24283 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
24286 In this example, we enable transparent emulation for the ARM and aarch64
24287 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
24288 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
24289 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
24292 @deftp {Data Type} qemu-binfmt-configuration
24293 This is the configuration for the @code{qemu-binfmt} service.
24296 @item @code{platforms} (default: @code{'()})
24297 The list of emulated QEMU platforms. Each item must be a @dfn{platform
24298 object} as returned by @code{lookup-qemu-platforms} (see below).
24300 @item @code{guix-support?} (default: @code{#f})
24301 When it is true, QEMU and all its dependencies are added to the build
24302 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
24303 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
24304 handlers to be used within the build environment, which in turn means
24305 that you can transparently build programs for another architecture.
24307 For example, let's suppose you're on an x86_64 machine and you have this
24311 (service qemu-binfmt-service-type
24312 (qemu-binfmt-configuration
24313 (platforms (lookup-qemu-platforms "arm"))
24314 (guix-support? #t)))
24320 guix build -s armhf-linux inkscape
24324 and it will build Inkscape for ARMv7 @emph{as if it were a native
24325 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
24326 if you'd like to test a package build for an architecture you don't have
24329 @item @code{qemu} (default: @code{qemu})
24330 The QEMU package to use.
24334 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
24335 Return the list of QEMU platform objects corresponding to
24336 @var{platforms}@dots{}. @var{platforms} must be a list of strings
24337 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
24338 @code{"mips64el"}, and so on.
24341 @deffn {Scheme Procedure} qemu-platform? @var{obj}
24342 Return true if @var{obj} is a platform object.
24345 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
24346 Return the name of @var{platform}---a string such as @code{"arm"}.
24349 @node Version Control Services
24350 @subsection Version Control Services
24352 The @code{(gnu services version-control)} module provides a service to
24353 allow remote access to local Git repositories. There are three options:
24354 the @code{git-daemon-service}, which provides access to repositories via
24355 the @code{git://} unsecured TCP-based protocol, extending the
24356 @code{nginx} web server to proxy some requests to
24357 @code{git-http-backend}, or providing a web interface with
24358 @code{cgit-service-type}.
24360 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
24362 Return a service that runs @command{git daemon}, a simple TCP server to
24363 expose repositories over the Git protocol for anonymous access.
24365 The optional @var{config} argument should be a
24366 @code{<git-daemon-configuration>} object, by default it allows read-only
24367 access to exported@footnote{By creating the magic file
24368 @file{git-daemon-export-ok} in the repository directory.} repositories under
24373 @deftp {Data Type} git-daemon-configuration
24374 Data type representing the configuration for @code{git-daemon-service}.
24377 @item @code{package} (default: @var{git})
24378 Package object of the Git distributed version control system.
24380 @item @code{export-all?} (default: @var{#f})
24381 Whether to allow access for all Git repositories, even if they do not
24382 have the @file{git-daemon-export-ok} file.
24384 @item @code{base-path} (default: @file{/srv/git})
24385 Whether to remap all the path requests as relative to the given path.
24386 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
24387 then if you later try to pull @code{git://example.com/hello.git}, git
24388 daemon will interpret the path as @code{/srv/git/hello.git}.
24390 @item @code{user-path} (default: @var{#f})
24391 Whether to allow @code{~user} notation to be used in requests. When
24392 specified with empty string, requests to @code{git://host/~alice/foo} is
24393 taken as a request to access @code{foo} repository in the home directory
24394 of user @code{alice}. If @var{(user-path "path")} is specified, the
24395 same request is taken as a request to access @code{path/foo} repository
24396 in the home directory of user @code{alice}.
24398 @item @code{listen} (default: @var{'()})
24399 Whether to listen on specific IP addresses or hostnames, defaults to
24402 @item @code{port} (default: @var{#f})
24403 Whether to listen on an alternative port, which defaults to 9418.
24405 @item @code{whitelist} (default: @var{'()})
24406 If not empty, only allow access to this list of directories.
24408 @item @code{extra-options} (default: @var{'()})
24409 Extra options will be passed to @code{git daemon}, please run
24410 @command{man git-daemon} for more information.
24415 The @code{git://} protocol lacks authentication. When you pull from a
24416 repository fetched via @code{git://}, you don't know whether the data you
24417 receive was modified or is even coming from the specified host, and your
24418 connection is subject to eavesdropping. It's better to use an authenticated
24419 and encrypted transport, such as @code{https}. Although Git allows you
24420 to serve repositories using unsophisticated file-based web servers,
24421 there is a faster protocol implemented by the @code{git-http-backend}
24422 program. This program is the back-end of a proper Git web service. It
24423 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
24424 on running the necessary @code{fcgiwrap} daemon.
24426 Guix has a separate configuration data type for serving Git repositories
24429 @deftp {Data Type} git-http-configuration
24430 Data type representing the configuration for a future
24431 @code{git-http-service-type}; can currently be used to configure Nginx
24432 trough @code{git-http-nginx-location-configuration}.
24435 @item @code{package} (default: @var{git})
24436 Package object of the Git distributed version control system.
24438 @item @code{git-root} (default: @file{/srv/git})
24439 Directory containing the Git repositories to expose to the world.
24441 @item @code{export-all?} (default: @var{#f})
24442 Whether to expose access for all Git repositories in @var{git-root},
24443 even if they do not have the @file{git-daemon-export-ok} file.
24445 @item @code{uri-path} (default: @file{/git/})
24446 Path prefix for Git access. With the default @code{/git/} prefix, this
24447 will map @code{http://@var{server}/git/@var{repo}.git} to
24448 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
24449 with this prefix are not passed on to this Git instance.
24451 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
24452 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
24457 There is no @code{git-http-service-type}, currently; instead you can
24458 create an @code{nginx-location-configuration} from a
24459 @code{git-http-configuration} and then add that location to a web
24462 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
24463 [config=(git-http-configuration)]
24464 Compute an @code{nginx-location-configuration} that corresponds to the
24465 given Git http configuration. An example nginx service definition to
24466 serve the default @file{/srv/git} over HTTPS might be:
24469 (service nginx-service-type
24470 (nginx-configuration
24473 (nginx-server-configuration
24474 (listen '("443 ssl"))
24475 (server-name "git.my-host.org")
24477 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
24478 (ssl-certificate-key
24479 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
24482 (git-http-nginx-location-configuration
24483 (git-http-configuration (uri-path "/"))))))))))
24486 This example assumes that you are using Let's Encrypt to get your TLS
24487 certificate. @xref{Certificate Services}. The default @code{certbot}
24488 service will redirect all HTTP traffic on @code{git.my-host.org} to
24489 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
24490 system services. @xref{Web Services}.
24493 @subsubheading Cgit Service
24495 @cindex Cgit service
24496 @cindex Git, web interface
24497 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
24498 repositories written in C.
24500 The following example will configure the service with default values.
24501 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
24504 (service cgit-service-type)
24507 The @code{file-object} type designates either a file-like object
24508 (@pxref{G-Expressions, file-like objects}) or a string.
24510 @c %start of fragment
24512 Available @code{cgit-configuration} fields are:
24514 @deftypevr {@code{cgit-configuration} parameter} package package
24519 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
24520 NGINX configuration.
24524 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
24525 Specifies a command which will be invoked to format the content of about
24526 pages (both top-level and for each repository).
24528 Defaults to @samp{""}.
24532 @deftypevr {@code{cgit-configuration} parameter} string agefile
24533 Specifies a path, relative to each repository path, which can be used to
24534 specify the date and time of the youngest commit in the repository.
24536 Defaults to @samp{""}.
24540 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
24541 Specifies a command that will be invoked for authenticating repository
24544 Defaults to @samp{""}.
24548 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
24549 Flag which, when set to @samp{age}, enables date ordering in the branch
24550 ref list, and when set @samp{name} enables ordering by branch name.
24552 Defaults to @samp{"name"}.
24556 @deftypevr {@code{cgit-configuration} parameter} string cache-root
24557 Path used to store the cgit cache entries.
24559 Defaults to @samp{"/var/cache/cgit"}.
24563 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
24564 Number which specifies the time-to-live, in minutes, for the cached
24565 version of repository pages accessed with a fixed SHA1.
24567 Defaults to @samp{-1}.
24571 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
24572 Number which specifies the time-to-live, in minutes, for the cached
24573 version of repository pages accessed without a fixed SHA1.
24575 Defaults to @samp{5}.
24579 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
24580 Number which specifies the time-to-live, in minutes, for the cached
24581 version of the repository summary page.
24583 Defaults to @samp{5}.
24587 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
24588 Number which specifies the time-to-live, in minutes, for the cached
24589 version of the repository index page.
24591 Defaults to @samp{5}.
24595 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
24596 Number which specifies the time-to-live, in minutes, for the result of
24597 scanning a path for Git repositories.
24599 Defaults to @samp{15}.
24603 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
24604 Number which specifies the time-to-live, in minutes, for the cached
24605 version of the repository about page.
24607 Defaults to @samp{15}.
24611 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
24612 Number which specifies the time-to-live, in minutes, for the cached
24613 version of snapshots.
24615 Defaults to @samp{5}.
24619 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
24620 The maximum number of entries in the cgit cache. When set to @samp{0},
24621 caching is disabled.
24623 Defaults to @samp{0}.
24627 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
24628 Sort items in the repo list case sensitively.
24630 Defaults to @samp{#t}.
24634 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
24635 List of common prefixes which, when combined with a repository URL,
24636 generates valid clone URLs for the repository.
24638 Defaults to @samp{()}.
24642 @deftypevr {@code{cgit-configuration} parameter} list clone-url
24643 List of @code{clone-url} templates.
24645 Defaults to @samp{()}.
24649 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
24650 Command which will be invoked to format commit messages.
24652 Defaults to @samp{""}.
24656 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
24657 Flag which, when set to @samp{date}, enables strict date ordering in the
24658 commit log, and when set to @samp{topo} enables strict topological
24661 Defaults to @samp{"git log"}.
24665 @deftypevr {@code{cgit-configuration} parameter} file-object css
24666 URL which specifies the css document to include in all cgit pages.
24668 Defaults to @samp{"/share/cgit/cgit.css"}.
24672 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
24673 Specifies a command which will be invoked to format names and email
24674 address of committers, authors, and taggers, as represented in various
24675 places throughout the cgit interface.
24677 Defaults to @samp{""}.
24681 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
24682 Flag which, when set to @samp{#t}, will make cgit generate a HTML
24683 fragment suitable for embedding in other HTML pages.
24685 Defaults to @samp{#f}.
24689 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
24690 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
24691 commit history graph to the left of the commit messages in the
24692 repository log page.
24694 Defaults to @samp{#f}.
24698 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
24699 Flag which, when set to @samp{#t}, allows all filter settings to be
24700 overridden in repository-specific cgitrc files.
24702 Defaults to @samp{#f}.
24706 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
24707 Flag which, when set to @samp{#t}, allows users to follow a file in the
24710 Defaults to @samp{#f}.
24714 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
24715 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
24718 Defaults to @samp{#t}.
24722 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
24723 Flag which, when set to @samp{#t}, will make cgit generate extra links
24724 "summary", "commit", "tree" for each repo in the repository index.
24726 Defaults to @samp{#f}.
24730 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
24731 Flag which, when set to @samp{#t}, will make cgit display the owner of
24732 each repo in the repository index.
24734 Defaults to @samp{#t}.
24738 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
24739 Flag which, when set to @samp{#t}, will make cgit print the number of
24740 modified files for each commit on the repository log page.
24742 Defaults to @samp{#f}.
24746 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
24747 Flag which, when set to @samp{#t}, will make cgit print the number of
24748 added and removed lines for each commit on the repository log page.
24750 Defaults to @samp{#f}.
24754 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
24755 Flag which, when set to @code{#t}, will make cgit display remote
24756 branches in the summary and refs views.
24758 Defaults to @samp{#f}.
24762 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
24763 Flag which, when set to @code{1}, will make cgit use the subject of the
24764 parent commit as link text when generating links to parent commits in
24767 Defaults to @samp{#f}.
24771 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
24772 Flag which, when set to @samp{#t}, will make cgit use the subject of the
24773 parent commit as link text when generating links to parent commits in
24776 Defaults to @samp{#f}.
24780 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
24781 Flag which, when set to @samp{#t}, will make cgit generate linenumber
24782 links for plaintext blobs printed in the tree view.
24784 Defaults to @samp{#t}.
24788 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
24789 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
24790 set any repo specific settings.
24792 Defaults to @samp{#f}.
24796 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
24797 URL used as link to a shortcut icon for cgit.
24799 Defaults to @samp{"/favicon.ico"}.
24803 @deftypevr {@code{cgit-configuration} parameter} string footer
24804 The content of the file specified with this option will be included
24805 verbatim at the bottom of all pages (i.e.@: it replaces the standard
24806 "generated by..."@: message).
24808 Defaults to @samp{""}.
24812 @deftypevr {@code{cgit-configuration} parameter} string head-include
24813 The content of the file specified with this option will be included
24814 verbatim in the HTML HEAD section on all pages.
24816 Defaults to @samp{""}.
24820 @deftypevr {@code{cgit-configuration} parameter} string header
24821 The content of the file specified with this option will be included
24822 verbatim at the top of all pages.
24824 Defaults to @samp{""}.
24828 @deftypevr {@code{cgit-configuration} parameter} file-object include
24829 Name of a configfile to include before the rest of the current config-
24832 Defaults to @samp{""}.
24836 @deftypevr {@code{cgit-configuration} parameter} string index-header
24837 The content of the file specified with this option will be included
24838 verbatim above the repository index.
24840 Defaults to @samp{""}.
24844 @deftypevr {@code{cgit-configuration} parameter} string index-info
24845 The content of the file specified with this option will be included
24846 verbatim below the heading on the repository index page.
24848 Defaults to @samp{""}.
24852 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24853 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24854 in the servers timezone.
24856 Defaults to @samp{#f}.
24860 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24861 URL which specifies the source of an image which will be used as a logo
24864 Defaults to @samp{"/share/cgit/cgit.png"}.
24868 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24869 URL loaded when clicking on the cgit logo image.
24871 Defaults to @samp{""}.
24875 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24876 Command which will be invoked to format the Owner column of the main
24879 Defaults to @samp{""}.
24883 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24884 Number of items to display in atom feeds view.
24886 Defaults to @samp{10}.
24890 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24891 Number of entries to list per page in "log" view.
24893 Defaults to @samp{50}.
24897 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24898 Number of commit message characters to display in "log" view.
24900 Defaults to @samp{80}.
24904 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24905 Specifies the number of entries to list per page on the repository index
24908 Defaults to @samp{50}.
24912 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24913 Specifies the maximum number of repo description characters to display
24914 on the repository index page.
24916 Defaults to @samp{80}.
24920 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24921 Specifies the maximum size of a blob to display HTML for in KBytes.
24923 Defaults to @samp{0}.
24927 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24928 Maximum statistics period. Valid values are @samp{week},@samp{month},
24929 @samp{quarter} and @samp{year}.
24931 Defaults to @samp{""}.
24935 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24936 Mimetype for the specified filename extension.
24938 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24939 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24940 "image/png") (svg "image/svg+xml"))}.
24944 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24945 Specifies the file to use for automatic mimetype lookup.
24947 Defaults to @samp{""}.
24951 @deftypevr {@code{cgit-configuration} parameter} string module-link
24952 Text which will be used as the formatstring for a hyperlink when a
24953 submodule is printed in a directory listing.
24955 Defaults to @samp{""}.
24959 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24960 If set to the value @samp{#t} caching will be disabled.
24962 Defaults to @samp{#f}.
24966 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24967 If set to @samp{#t} showing full author email addresses will be
24970 Defaults to @samp{#f}.
24974 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24975 Flag which, when set to @samp{#t}, will make cgit omit the standard
24976 header on all pages.
24978 Defaults to @samp{#f}.
24982 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24983 A list of subdirectories inside of @code{repository-directory}, relative
24984 to it, that should loaded as Git repositories. An empty list means that
24985 all subdirectories will be loaded.
24987 Defaults to @samp{()}.
24991 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24992 Text which will be used as default value for @code{cgit-repo-readme}.
24994 Defaults to @samp{""}.
24998 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24999 If set to @code{#t} and @code{repository-directory} is enabled, if any
25000 repositories are found with a suffix of @code{.git}, this suffix will be
25001 removed for the URL and name.
25003 Defaults to @samp{#f}.
25007 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
25008 Maximum number of files to consider when detecting renames.
25010 Defaults to @samp{-1}.
25014 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
25015 The way in which repositories in each section are sorted.
25017 Defaults to @samp{""}.
25021 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
25022 Text used as content for the @code{robots} meta-tag.
25024 Defaults to @samp{("noindex" "nofollow")}.
25028 @deftypevr {@code{cgit-configuration} parameter} string root-desc
25029 Text printed below the heading on the repository index page.
25031 Defaults to @samp{"a fast webinterface for the git dscm"}.
25035 @deftypevr {@code{cgit-configuration} parameter} string root-readme
25036 The content of the file specified with this option will be included
25037 verbatim below the ``about'' link on the repository index page.
25039 Defaults to @samp{""}.
25043 @deftypevr {@code{cgit-configuration} parameter} string root-title
25044 Text printed as heading on the repository index page.
25046 Defaults to @samp{""}.
25050 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
25051 If set to @samp{#t} and repository-directory is enabled,
25052 repository-directory will recurse into directories whose name starts
25053 with a period. Otherwise, repository-directory will stay away from such
25054 directories, considered as ``hidden''. Note that this does not apply to
25055 the @file{.git} directory in non-bare repos.
25057 Defaults to @samp{#f}.
25061 @deftypevr {@code{cgit-configuration} parameter} list snapshots
25062 Text which specifies the default set of snapshot formats that cgit
25063 generates links for.
25065 Defaults to @samp{()}.
25069 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
25070 Name of the directory to scan for repositories (represents
25073 Defaults to @samp{"/srv/git"}.
25077 @deftypevr {@code{cgit-configuration} parameter} string section
25078 The name of the current repository section - all repositories defined
25079 after this option will inherit the current section name.
25081 Defaults to @samp{""}.
25085 @deftypevr {@code{cgit-configuration} parameter} string section-sort
25086 Flag which, when set to @samp{1}, will sort the sections on the
25087 repository listing by name.
25089 Defaults to @samp{""}.
25093 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
25094 A number which, if defined prior to repository-directory, specifies how
25095 many path elements from each repo path to use as a default section name.
25097 Defaults to @samp{0}.
25101 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
25102 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
25105 Defaults to @samp{#f}.
25109 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
25110 Specifies a command which will be invoked to format plaintext blobs in
25113 Defaults to @samp{""}.
25117 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
25118 Specifies the number of branches to display in the repository ``summary''
25121 Defaults to @samp{10}.
25125 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
25126 Specifies the number of log entries to display in the repository
25129 Defaults to @samp{10}.
25133 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
25134 Specifies the number of tags to display in the repository ``summary''
25137 Defaults to @samp{10}.
25141 @deftypevr {@code{cgit-configuration} parameter} string strict-export
25142 Filename which, if specified, needs to be present within the repository
25143 for cgit to allow access to that repository.
25145 Defaults to @samp{""}.
25149 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
25150 URL which, if specified, will be used as root for all cgit links.
25152 Defaults to @samp{"/"}.
25156 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
25157 A list of @dfn{cgit-repo} records to use with config.
25159 Defaults to @samp{()}.
25161 Available @code{repository-cgit-configuration} fields are:
25163 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
25164 A mask of snapshot formats for this repo that cgit generates links for,
25165 restricted by the global @code{snapshots} setting.
25167 Defaults to @samp{()}.
25171 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
25172 Override the default @code{source-filter}.
25174 Defaults to @samp{""}.
25178 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
25179 The relative URL used to access the repository.
25181 Defaults to @samp{""}.
25185 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
25186 Override the default @code{about-filter}.
25188 Defaults to @samp{""}.
25192 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
25193 Flag which, when set to @samp{age}, enables date ordering in the branch
25194 ref list, and when set to @samp{name} enables ordering by branch name.
25196 Defaults to @samp{""}.
25200 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
25201 A list of URLs which can be used to clone repo.
25203 Defaults to @samp{()}.
25207 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
25208 Override the default @code{commit-filter}.
25210 Defaults to @samp{""}.
25214 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
25215 Flag which, when set to @samp{date}, enables strict date ordering in the
25216 commit log, and when set to @samp{topo} enables strict topological
25219 Defaults to @samp{""}.
25223 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
25224 The name of the default branch for this repository. If no such branch
25225 exists in the repository, the first branch name (when sorted) is used as
25226 default instead. By default branch pointed to by HEAD, or ``master'' if
25227 there is no suitable HEAD.
25229 Defaults to @samp{""}.
25233 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
25234 The value to show as repository description.
25236 Defaults to @samp{""}.
25240 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
25241 The value to show as repository homepage.
25243 Defaults to @samp{""}.
25247 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
25248 Override the default @code{email-filter}.
25250 Defaults to @samp{""}.
25254 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
25255 A flag which can be used to disable the global setting
25256 @code{enable-commit-graph?}.
25258 Defaults to @samp{disabled}.
25262 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
25263 A flag which can be used to disable the global setting
25264 @code{enable-log-filecount?}.
25266 Defaults to @samp{disabled}.
25270 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
25271 A flag which can be used to disable the global setting
25272 @code{enable-log-linecount?}.
25274 Defaults to @samp{disabled}.
25278 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
25279 Flag which, when set to @code{#t}, will make cgit display remote
25280 branches in the summary and refs views.
25282 Defaults to @samp{disabled}.
25286 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
25287 A flag which can be used to override the global setting
25288 @code{enable-subject-links?}.
25290 Defaults to @samp{disabled}.
25294 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
25295 A flag which can be used to override the global setting
25296 @code{enable-html-serving?}.
25298 Defaults to @samp{disabled}.
25302 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
25303 Flag which, when set to @code{#t}, hides the repository from the
25306 Defaults to @samp{#f}.
25310 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
25311 Flag which, when set to @samp{#t}, ignores the repository.
25313 Defaults to @samp{#f}.
25317 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
25318 URL which specifies the source of an image which will be used as a logo
25319 on this repo’s pages.
25321 Defaults to @samp{""}.
25325 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
25326 URL loaded when clicking on the cgit logo image.
25328 Defaults to @samp{""}.
25332 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
25333 Override the default @code{owner-filter}.
25335 Defaults to @samp{""}.
25339 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
25340 Text which will be used as the formatstring for a hyperlink when a
25341 submodule is printed in a directory listing. The arguments for the
25342 formatstring are the path and SHA1 of the submodule commit.
25344 Defaults to @samp{""}.
25348 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
25349 Text which will be used as the formatstring for a hyperlink when a
25350 submodule with the specified subdirectory path is printed in a directory
25353 Defaults to @samp{()}.
25357 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
25358 Override the default maximum statistics period.
25360 Defaults to @samp{""}.
25364 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
25365 The value to show as repository name.
25367 Defaults to @samp{""}.
25371 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
25372 A value used to identify the owner of the repository.
25374 Defaults to @samp{""}.
25378 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
25379 An absolute path to the repository directory.
25381 Defaults to @samp{""}.
25385 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
25386 A path (relative to repo) which specifies a file to include verbatim as
25387 the ``About'' page for this repo.
25389 Defaults to @samp{""}.
25393 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
25394 The name of the current repository section - all repositories defined
25395 after this option will inherit the current section name.
25397 Defaults to @samp{""}.
25401 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
25402 Extra options will be appended to cgitrc file.
25404 Defaults to @samp{()}.
25410 @deftypevr {@code{cgit-configuration} parameter} list extra-options
25411 Extra options will be appended to cgitrc file.
25413 Defaults to @samp{()}.
25418 @c %end of fragment
25420 However, it could be that you just want to get a @code{cgitrc} up and
25421 running. In that case, you can pass an @code{opaque-cgit-configuration}
25422 as a record to @code{cgit-service-type}. As its name indicates, an
25423 opaque configuration does not have easy reflective capabilities.
25425 Available @code{opaque-cgit-configuration} fields are:
25427 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
25431 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
25432 The contents of the @code{cgitrc}, as a string.
25435 For example, if your @code{cgitrc} is just the empty string, you
25436 could instantiate a cgit service like this:
25439 (service cgit-service-type
25440 (opaque-cgit-configuration
25444 @subsubheading Gitolite Service
25446 @cindex Gitolite service
25447 @cindex Git, hosting
25448 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
25449 repositories on a central server.
25451 Gitolite can handle multiple repositories and users, and supports flexible
25452 configuration of the permissions for the users on the repositories.
25454 The following example will configure Gitolite using the default @code{git}
25455 user, and the provided SSH public key.
25458 (service gitolite-service-type
25459 (gitolite-configuration
25460 (admin-pubkey (plain-file
25462 "ssh-rsa AAAA... guix@@example.com"))))
25465 Gitolite is configured through a special admin repository which you can clone,
25466 for example, if you setup Gitolite on @code{example.com}, you would run the
25467 following command to clone the admin repository.
25470 git clone git@@example.com:gitolite-admin
25473 When the Gitolite service is activated, the provided @code{admin-pubkey} will
25474 be inserted in to the @file{keydir} directory in the gitolite-admin
25475 repository. If this results in a change in the repository, it will be
25476 committed using the message ``gitolite setup by GNU Guix''.
25478 @deftp {Data Type} gitolite-configuration
25479 Data type representing the configuration for @code{gitolite-service-type}.
25482 @item @code{package} (default: @var{gitolite})
25483 Gitolite package to use.
25485 @item @code{user} (default: @var{git})
25486 User to use for Gitolite. This will be user that you use when accessing
25489 @item @code{group} (default: @var{git})
25490 Group to use for Gitolite.
25492 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
25493 Directory in which to store the Gitolite configuration and repositories.
25495 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
25496 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
25497 representing the configuration for Gitolite.
25499 @item @code{admin-pubkey} (default: @var{#f})
25500 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
25501 setup Gitolite. This will be inserted in to the @file{keydir} directory
25502 within the gitolite-admin repository.
25504 To specify the SSH key as a string, use the @code{plain-file} function.
25507 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
25513 @deftp {Data Type} gitolite-rc-file
25514 Data type representing the Gitolite RC file.
25517 @item @code{umask} (default: @code{#o0077})
25518 This controls the permissions Gitolite sets on the repositories and their
25521 A value like @code{#o0027} will give read access to the group used by Gitolite
25522 (by default: @code{git}). This is necessary when using Gitolite with software
25523 like cgit or gitweb.
25525 @item @code{git-config-keys} (default: @code{""})
25526 Gitolite allows you to set git config values using the @samp{config} keyword. This
25527 setting allows control over the config keys to accept.
25529 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
25530 Set the role names allowed to be used by users running the perms command.
25532 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
25533 This setting controls the commands and features to enable within Gitolite.
25539 @node Game Services
25540 @subsection Game Services
25542 @subsubheading The Battle for Wesnoth Service
25544 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
25545 based tactical strategy game, with several single player campaigns, and
25546 multiplayer games (both networked and local).
25548 @defvar {Scheme Variable} wesnothd-service-type
25549 Service type for the wesnothd service. Its value must be a
25550 @code{wesnothd-configuration} object. To run wesnothd in the default
25551 configuration, instantiate it as:
25554 (service wesnothd-service-type)
25558 @deftp {Data Type} wesnothd-configuration
25559 Data type representing the configuration of @command{wesnothd}.
25562 @item @code{package} (default: @code{wesnoth-server})
25563 The wesnoth server package to use.
25565 @item @code{port} (default: @code{15000})
25566 The port to bind the server to.
25571 @node PAM Mount Service
25572 @subsection PAM Mount Service
25575 The @code{(gnu services pam-mount)} module provides a service allowing
25576 users to mount volumes when they log in. It should be able to mount any
25577 volume format supported by the system.
25579 @defvar {Scheme Variable} pam-mount-service-type
25580 Service type for PAM Mount support.
25583 @deftp {Data Type} pam-mount-configuration
25584 Data type representing the configuration of PAM Mount.
25586 It takes the following parameters:
25590 The configuration rules that will be used to generate
25591 @file{/etc/security/pam_mount.conf.xml}.
25593 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
25594 Guile Reference Manual}), and the the default ones don't mount anything
25595 for anyone at login:
25598 `((debug (@@ (enable "0")))
25599 (mntoptions (@@ (allow ,(string-join
25600 '("nosuid" "nodev" "loop"
25601 "encryption" "fsck" "nonempty"
25602 "allow_root" "allow_other")
25604 (mntoptions (@@ (require "nosuid,nodev")))
25605 (logout (@@ (wait "0")
25609 (mkmountpoint (@@ (enable "1")
25613 Some @code{volume} elements must be added to automatically mount volumes
25614 at login. Here's an example allowing the user @code{alice} to mount her
25615 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
25616 the partition where he stores his data:
25619 (define pam-mount-rules
25620 `((debug (@@ (enable "0")))
25621 (volume (@@ (user "alice")
25624 (mountpoint "/home/alice")))
25625 (volume (@@ (user "bob")
25628 (mountpoint "/home/bob/data")
25629 (options "defaults,autodefrag,compress")))
25630 (mntoptions (@@ (allow ,(string-join
25631 '("nosuid" "nodev" "loop"
25632 "encryption" "fsck" "nonempty"
25633 "allow_root" "allow_other")
25635 (mntoptions (@@ (require "nosuid,nodev")))
25636 (logout (@@ (wait "0")
25640 (mkmountpoint (@@ (enable "1")
25641 (remove "true")))))
25643 (service pam-mount-service-type
25644 (pam-mount-configuration
25645 (rules pam-mount-rules)))
25648 The complete list of possible options can be found in the man page for
25649 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
25654 @node Guix Services
25655 @subsection Guix Services
25657 @subsubheading Guix Data Service
25658 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
25659 and provides data about GNU Guix. This includes information about
25660 packages, derivations and lint warnings.
25662 The data is stored in a PostgreSQL database, and available through a web
25665 @defvar {Scheme Variable} guix-data-service-type
25666 Service type for the Guix Data Service. Its value must be a
25667 @code{guix-data-service-configuration} object. The service optionally
25668 extends the getmail service, as the guix-commits mailing list is used to
25669 find out about changes in the Guix git repository.
25672 @deftp {Data Type} guix-data-service-configuration
25673 Data type representing the configuration of the Guix Data Service.
25676 @item @code{package} (default: @code{guix-data-service})
25677 The Guix Data Service package to use.
25679 @item @code{user} (default: @code{"guix-data-service"})
25680 The system user to run the service as.
25682 @item @code{group} (default: @code{"guix-data-service"})
25683 The system group to run the service as.
25685 @item @code{port} (default: @code{8765})
25686 The port to bind the web service to.
25688 @item @code{host} (default: @code{"127.0.0.1"})
25689 The host to bind the web service to.
25691 @item @code{getmail-idle-mailboxes} (default: @code{#f})
25692 If set, this is the list of mailboxes that the getmail service will be
25693 configured to listen to.
25695 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
25696 If set, this is the @code{getmail-retriever-configuration} object with
25697 which to configure getmail to fetch mail from the guix-commits mailing
25700 @item @code{extra-options} (default: @var{'()})
25701 Extra command line options for @code{guix-data-service}.
25703 @item @code{extra-process-jobs-options} (default: @var{'()})
25704 Extra command line options for @code{guix-data-service-process-jobs}.
25709 @node Linux Services
25710 @subsection Linux Services
25713 @cindex out of memory killer
25715 @cindex early out of memory daemon
25716 @subsubheading Early OOM Service
25718 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
25719 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
25720 space and provides a more responsive and configurable alternative to the
25721 in-kernel OOM killer. It is useful to prevent the system from becoming
25722 unresponsive when it runs out of memory.
25724 @deffn {Scheme Variable} earlyoom-service-type
25725 The service type for running @command{earlyoom}, the Early OOM daemon.
25726 Its value must be a @code{earlyoom-configuration} object, described
25727 below. The service can be instantiated in its default configuration
25731 (service earlyoom-service-type)
25735 @deftp {Data Type} earlyoom-configuration
25736 This is the configuration record for the @code{earlyoom-service-type}.
25739 @item @code{earlyoom} (default: @var{earlyoom})
25740 The Earlyoom package to use.
25742 @item @code{minimum-available-memory} (default: @code{10})
25743 The threshold for the minimum @emph{available} memory, in percentages.
25745 @item @code{minimum-free-swap} (default: @code{10})
25746 The threshold for the minimum free swap memory, in percentages.
25748 @item @code{prefer-regexp} (default: @code{#f})
25749 A regular expression (as a string) to match the names of the processes
25750 that should be preferably killed.
25752 @item @code{avoid-regexp} (default: @code{#f})
25753 A regular expression (as a string) to match the names of the processes
25754 that should @emph{not} be killed.
25756 @item @code{memory-report-interval} (default: @code{0})
25757 The interval in seconds at which a memory report is printed. It is
25758 disabled by default.
25760 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
25761 A boolean indicating whether the positive adjustments set in
25762 @file{/proc/*/oom_score_adj}.
25764 @item @code{show-debug-messages?} (default: @code{#f})
25765 A boolean indicating whether debug messages should be printed. The logs
25766 are saved at @file{/var/log/earlyoom.log}.
25768 @item @code{send-notification-command} (default: @code{#f})
25769 This can be used to provide a custom command used for sending
25775 @cindex kernel module loader
25776 @subsubheading Kernel Module Loader Service
25778 The kernel module loader service allows one to load loadable kernel
25779 modules at boot. This is especially useful for modules that don't
25780 autoload and need to be manually loaded, as it's the case with
25783 @deffn {Scheme Variable} kernel-module-loader-service-type
25784 The service type for loading loadable kernel modules at boot with
25785 @command{modprobe}. Its value must be a list of strings representing
25786 module names. For example loading the drivers provided by
25787 @code{ddcci-driver-linux}, in debugging mode by passing some module
25788 parameters, can be done as follow:
25791 (use-modules (gnu) (gnu services))
25792 (use-package-modules linux)
25793 (use-service-modules linux)
25795 (define ddcci-config
25796 (plain-file "ddcci.conf"
25797 "options ddcci dyndbg delay=120"))
25801 (services (cons* (service kernel-module-loader-service-type
25802 '("ddcci" "ddcci_backlight"))
25803 (simple-service 'ddcci-config etc-service-type
25804 (list `("modprobe.d/ddcci.conf"
25807 (kernel-loadable-modules (list ddcci-driver-linux)))
25811 @node Miscellaneous Services
25812 @subsection Miscellaneous Services
25814 @cindex fingerprint
25815 @subsubheading Fingerprint Service
25817 The @code{(gnu services authentication)} module provides a DBus service to
25818 read and identify fingerprints via a fingerprint sensor.
25820 @defvr {Scheme Variable} fprintd-service-type
25821 The service type for @command{fprintd}, which provides the fingerprint
25822 reading capability.
25825 (service fprintd-service-type)
25830 @subsubheading System Control Service
25832 The @code{(gnu services sysctl)} provides a service to configure kernel
25833 parameters at boot.
25835 @defvr {Scheme Variable} sysctl-service-type
25836 The service type for @command{sysctl}, which modifies kernel parameters
25837 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
25841 (service sysctl-service-type
25842 (sysctl-configuration
25843 (settings '(("net.ipv4.ip_forward" . "1")))))
25847 @deftp {Data Type} sysctl-configuration
25848 The data type representing the configuration of @command{sysctl}.
25851 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
25852 The @command{sysctl} executable to use.
25854 @item @code{settings} (default: @code{'()})
25855 An association list specifies kernel parameters and their values.
25860 @subsubheading PC/SC Smart Card Daemon Service
25862 The @code{(gnu services security-token)} module provides the following service
25863 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
25864 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
25865 manager that coordinates communications with smart card readers, smart cards
25866 and cryptographic tokens that are connected to the system.
25868 @defvr {Scheme Variable} pcscd-service-type
25869 Service type for the @command{pcscd} service. Its value must be a
25870 @code{pcscd-configuration} object. To run pcscd in the default
25871 configuration, instantiate it as:
25874 (service pcscd-service-type)
25878 @deftp {Data Type} pcscd-configuration
25879 The data type representing the configuration of @command{pcscd}.
25882 @item @code{pcsc-lite} (default: @code{pcsc-lite})
25883 The pcsc-lite package that provides pcscd.
25884 @item @code{usb-drivers} (default: @code{(list ccid)})
25885 List of packages that provide USB drivers to pcscd. Drivers are expected to be
25886 under @file{pcsc/drivers} in the store directory of the package.
25891 @subsubheading Lirc Service
25893 The @code{(gnu services lirc)} module provides the following service.
25895 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
25896 [#:device #f] [#:driver #f] [#:config-file #f] @
25897 [#:extra-options '()]
25898 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
25899 decodes infrared signals from remote controls.
25901 Optionally, @var{device}, @var{driver} and @var{config-file}
25902 (configuration file name) may be specified. See @command{lircd} manual
25905 Finally, @var{extra-options} is a list of additional command-line options
25906 passed to @command{lircd}.
25910 @subsubheading Spice Service
25912 The @code{(gnu services spice)} module provides the following service.
25914 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
25915 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
25916 that enables sharing the clipboard with a vm and setting the guest display
25917 resolution when the graphical console window resizes.
25920 @cindex inputattach
25921 @subsubheading inputattach Service
25923 @cindex tablet input, for Xorg
25924 @cindex touchscreen input, for Xorg
25925 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
25926 use input devices such as Wacom tablets, touchscreens, or joysticks with the
25927 Xorg display server.
25929 @deffn {Scheme Variable} inputattach-service-type
25930 Type of a service that runs @command{inputattach} on a device and
25931 dispatches events from it.
25934 @deftp {Data Type} inputattach-configuration
25936 @item @code{device-type} (default: @code{"wacom"})
25937 The type of device to connect to. Run @command{inputattach --help}, from the
25938 @code{inputattach} package, to see the list of supported device types.
25940 @item @code{device} (default: @code{"/dev/ttyS0"})
25941 The device file to connect to the device.
25943 @item @code{baud-rate} (default: @code{#f})
25944 Baud rate to use for the serial connection.
25945 Should be a number or @code{#f}.
25947 @item @code{log-file} (default: @code{#f})
25948 If true, this must be the name of a file to log messages to.
25952 @subsubheading Dictionary Service
25954 The @code{(gnu services dict)} module provides the following service:
25956 @defvr {Scheme Variable} dicod-service-type
25957 This is the type of the service that runs the @command{dicod} daemon, an
25958 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25961 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25962 Return a service that runs the @command{dicod} daemon, an implementation
25963 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25965 The optional @var{config} argument specifies the configuration for
25966 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25967 default it serves the GNU Collaborative International Dictionary of English.
25969 You can add @command{open localhost} to your @file{~/.dico} file to make
25970 @code{localhost} the default server for @command{dico} client
25971 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25974 @deftp {Data Type} dicod-configuration
25975 Data type representing the configuration of dicod.
25978 @item @code{dico} (default: @var{dico})
25979 Package object of the GNU Dico dictionary server.
25981 @item @code{interfaces} (default: @var{'("localhost")})
25982 This is the list of IP addresses and ports and possibly socket file
25983 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25984 dico, GNU Dico Manual}).
25986 @item @code{handlers} (default: @var{'()})
25987 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25989 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25990 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25994 @deftp {Data Type} dicod-handler
25995 Data type representing a dictionary handler (module instance).
25999 Name of the handler (module instance).
26001 @item @code{module} (default: @var{#f})
26002 Name of the dicod module of the handler (instance). If it is @code{#f},
26003 the module has the same name as the handler.
26004 (@pxref{Modules,,, dico, GNU Dico Manual}).
26006 @item @code{options}
26007 List of strings or gexps representing the arguments for the module handler
26011 @deftp {Data Type} dicod-database
26012 Data type representing a dictionary database.
26016 Name of the database, will be used in DICT commands.
26018 @item @code{handler}
26019 Name of the dicod handler (module instance) used by this database
26020 (@pxref{Handlers,,, dico, GNU Dico Manual}).
26022 @item @code{complex?} (default: @var{#f})
26023 Whether the database configuration complex. The complex configuration
26024 will need a corresponding @code{<dicod-handler>} object, otherwise not.
26026 @item @code{options}
26027 List of strings or gexps representing the arguments for the database
26028 (@pxref{Databases,,, dico, GNU Dico Manual}).
26032 @defvr {Scheme Variable} %dicod-database:gcide
26033 A @code{<dicod-database>} object serving the GNU Collaborative International
26034 Dictionary of English using the @code{gcide} package.
26037 The following is an example @code{dicod-service} configuration.
26040 (dicod-service #:config
26041 (dicod-configuration
26042 (handlers (list (dicod-handler
26046 (list #~(string-append "dbdir=" #$wordnet))))))
26047 (databases (list (dicod-database
26050 (handler "wordnet")
26051 (options '("database=wn")))
26052 %dicod-database:gcide))))
26056 @subsubheading Docker Service
26058 The @code{(gnu services docker)} module provides the following services.
26060 @defvr {Scheme Variable} docker-service-type
26062 This is the type of the service that runs @url{https://www.docker.com,Docker},
26063 a daemon that can execute application bundles (sometimes referred to as
26064 ``containers'') in isolated environments.
26068 @deftp {Data Type} docker-configuration
26069 This is the data type representing the configuration of Docker and Containerd.
26073 @item @code{package} (default: @code{docker})
26074 The Docker package to use.
26076 @item @code{containerd} (default: @var{containerd})
26077 The Containerd package to use.
26083 @subsubheading Auditd Service
26085 The @code{(gnu services auditd)} module provides the following service.
26087 @defvr {Scheme Variable} auditd-service-type
26089 This is the type of the service that runs
26090 @url{https://people.redhat.com/sgrubb/audit/,auditd},
26091 a daemon that tracks security-relevant information on your system.
26093 Examples of things that can be tracked:
26103 Failed login attempts
26110 @command{auditctl} from the @code{audit} package can be used in order
26111 to add or remove events to be tracked (until the next reboot).
26112 In order to permanently track events, put the command line arguments
26113 of auditctl into @file{/etc/audit/audit.rules}.
26114 @command{aureport} from the @code{audit} package can be used in order
26115 to view a report of all recorded events.
26116 The audit daemon usually logs into the directory @file{/var/log/audit}.
26120 @deftp {Data Type} auditd-configuration
26121 This is the data type representing the configuration of auditd.
26125 @item @code{audit} (default: @code{audit})
26126 The audit package to use.
26131 @defvr {Scheme Variable} singularity-service-type
26132 This is the type of the service that allows you to run
26133 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
26134 create and run application bundles (aka. ``containers''). The value for this
26135 service is the Singularity package to use.
26137 The service does not install a daemon; instead, it installs helper programs as
26138 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
26139 @command{singularity run} and similar commands.
26143 @subsubheading Nix service
26145 The @code{(gnu services nix)} module provides the following service.
26147 @defvr {Scheme Variable} nix-service-type
26149 This is the type of the service that runs build daemon of the
26150 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
26154 (use-modules (gnu))
26155 (use-service-modules nix)
26156 (use-package-modules package-management)
26160 (packages (append (list nix)
26163 (services (append (list (service nix-service-type))
26167 After @command{guix system reconfigure} configure Nix for your user:
26170 @item Add a Nix channel and update it. See
26171 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
26173 @item Create a symlink to your profile and activate Nix profile:
26177 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
26178 $ source /run/current-system/profile/etc/profile.d/nix.sh
26183 @node Setuid Programs
26184 @section Setuid Programs
26186 @cindex setuid programs
26187 Some programs need to run with ``root'' privileges, even when they are
26188 launched by unprivileged users. A notorious example is the
26189 @command{passwd} program, which users can run to change their
26190 password, and which needs to access the @file{/etc/passwd} and
26191 @file{/etc/shadow} files---something normally restricted to root, for
26192 obvious security reasons. To address that, these executables are
26193 @dfn{setuid-root}, meaning that they always run with root privileges
26194 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
26195 for more info about the setuid mechanism.)
26197 The store itself @emph{cannot} contain setuid programs: that would be a
26198 security issue since any user on the system can write derivations that
26199 populate the store (@pxref{The Store}). Thus, a different mechanism is
26200 used: instead of changing the setuid bit directly on files that are in
26201 the store, we let the system administrator @emph{declare} which programs
26202 should be setuid root.
26204 The @code{setuid-programs} field of an @code{operating-system}
26205 declaration contains a list of G-expressions denoting the names of
26206 programs to be setuid-root (@pxref{Using the Configuration System}).
26207 For instance, the @command{passwd} program, which is part of the Shadow
26208 package, can be designated by this G-expression (@pxref{G-Expressions}):
26211 #~(string-append #$shadow "/bin/passwd")
26214 A default set of setuid programs is defined by the
26215 @code{%setuid-programs} variable of the @code{(gnu system)} module.
26217 @defvr {Scheme Variable} %setuid-programs
26218 A list of G-expressions denoting common programs that are setuid-root.
26220 The list includes commands such as @command{passwd}, @command{ping},
26221 @command{su}, and @command{sudo}.
26224 Under the hood, the actual setuid programs are created in the
26225 @file{/run/setuid-programs} directory at system activation time. The
26226 files in this directory refer to the ``real'' binaries, which are in the
26229 @node X.509 Certificates
26230 @section X.509 Certificates
26232 @cindex HTTPS, certificates
26233 @cindex X.509 certificates
26235 Web servers available over HTTPS (that is, HTTP over the transport-layer
26236 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
26237 that the client can then use to @emph{authenticate} the server. To do
26238 that, clients verify that the server's certificate is signed by a
26239 so-called @dfn{certificate authority} (CA). But to verify the CA's
26240 signature, clients must have first acquired the CA's certificate.
26242 Web browsers such as GNU@tie{}IceCat include their own set of CA
26243 certificates, such that they are able to verify CA signatures
26246 However, most other programs that can talk HTTPS---@command{wget},
26247 @command{git}, @command{w3m}, etc.---need to be told where CA
26248 certificates can be found.
26250 @cindex @code{nss-certs}
26251 In Guix, this is done by adding a package that provides certificates
26252 to the @code{packages} field of the @code{operating-system} declaration
26253 (@pxref{operating-system Reference}). Guix includes one such package,
26254 @code{nss-certs}, which is a set of CA certificates provided as part of
26255 Mozilla's Network Security Services.
26257 Note that it is @emph{not} part of @code{%base-packages}, so you need to
26258 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
26259 most applications and libraries look for certificates by default, points
26260 to the certificates installed globally.
26262 Unprivileged users, including users of Guix on a foreign distro,
26263 can also install their own certificate package in
26264 their profile. A number of environment variables need to be defined so
26265 that applications and libraries know where to find them. Namely, the
26266 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
26267 variables. Some applications add their own environment variables; for
26268 instance, the Git version control system honors the certificate bundle
26269 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
26270 would typically run something like:
26273 guix install nss-certs
26274 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
26275 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
26276 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
26279 As another example, R requires the @env{CURL_CA_BUNDLE} environment
26280 variable to point to a certificate bundle, so you would have to run
26281 something like this:
26284 guix install nss-certs
26285 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
26288 For other applications you may want to look up the required environment
26289 variable in the relevant documentation.
26292 @node Name Service Switch
26293 @section Name Service Switch
26295 @cindex name service switch
26297 The @code{(gnu system nss)} module provides bindings to the
26298 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
26299 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
26300 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
26301 extended with new ``name'' lookup methods for system databases, which
26302 includes host names, service names, user accounts, and more (@pxref{Name
26303 Service Switch, System Databases and Name Service Switch,, libc, The GNU
26304 C Library Reference Manual}).
26306 The NSS configuration specifies, for each system database, which lookup
26307 method is to be used, and how the various methods are chained
26308 together---for instance, under which circumstances NSS should try the
26309 next method in the list. The NSS configuration is given in the
26310 @code{name-service-switch} field of @code{operating-system} declarations
26311 (@pxref{operating-system Reference, @code{name-service-switch}}).
26314 @cindex .local, host name lookup
26315 As an example, the declaration below configures the NSS to use the
26316 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
26317 back-end}, which supports host name lookups over multicast DNS (mDNS)
26318 for host names ending in @code{.local}:
26321 (name-service-switch
26322 (hosts (list %files ;first, check /etc/hosts
26324 ;; If the above did not succeed, try
26325 ;; with 'mdns_minimal'.
26327 (name "mdns_minimal")
26329 ;; 'mdns_minimal' is authoritative for
26330 ;; '.local'. When it returns "not found",
26331 ;; no need to try the next methods.
26332 (reaction (lookup-specification
26333 (not-found => return))))
26335 ;; Then fall back to DNS.
26339 ;; Finally, try with the "full" 'mdns'.
26344 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
26345 contains this configuration, so you will not have to type it if all you
26346 want is to have @code{.local} host lookup working.
26348 Note that, in this case, in addition to setting the
26349 @code{name-service-switch} of the @code{operating-system} declaration,
26350 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
26351 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
26352 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
26353 to the name service cache daemon (@pxref{Base Services,
26354 @code{nscd-service}}).
26356 For convenience, the following variables provide typical NSS
26359 @defvr {Scheme Variable} %default-nss
26360 This is the default name service switch configuration, a
26361 @code{name-service-switch} object.
26364 @defvr {Scheme Variable} %mdns-host-lookup-nss
26365 This is the name service switch configuration with support for host name
26366 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
26369 The reference for name service switch configuration is given below. It
26370 is a direct mapping of the configuration file format of the C library , so
26371 please refer to the C library manual for more information (@pxref{NSS
26372 Configuration File,,, libc, The GNU C Library Reference Manual}).
26373 Compared to the configuration file format of libc NSS, it has the advantage
26374 not only of adding this warm parenthetic feel that we like, but also
26375 static checks: you will know about syntax errors and typos as soon as you
26376 run @command{guix system}.
26378 @deftp {Data Type} name-service-switch
26380 This is the data type representation the configuration of libc's name
26381 service switch (NSS). Each field below represents one of the supported
26398 The system databases handled by the NSS. Each of these fields must be a
26399 list of @code{<name-service>} objects (see below).
26403 @deftp {Data Type} name-service
26405 This is the data type representing an actual name service and the
26406 associated lookup action.
26410 A string denoting the name service (@pxref{Services in the NSS
26411 configuration,,, libc, The GNU C Library Reference Manual}).
26413 Note that name services listed here must be visible to nscd. This is
26414 achieved by passing the @code{#:name-services} argument to
26415 @code{nscd-service} the list of packages providing the needed name
26416 services (@pxref{Base Services, @code{nscd-service}}).
26419 An action specified using the @code{lookup-specification} macro
26420 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
26421 Reference Manual}). For example:
26424 (lookup-specification (unavailable => continue)
26425 (success => return))
26430 @node Initial RAM Disk
26431 @section Initial RAM Disk
26434 @cindex initial RAM disk
26435 For bootstrapping purposes, the Linux-Libre kernel is passed an
26436 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
26437 root file system as well as an initialization script. The latter is
26438 responsible for mounting the real root file system, and for loading any
26439 kernel modules that may be needed to achieve that.
26441 The @code{initrd-modules} field of an @code{operating-system}
26442 declaration allows you to specify Linux-libre kernel modules that must
26443 be available in the initrd. In particular, this is where you would list
26444 modules needed to actually drive the hard disk where your root partition
26445 is---although the default value of @code{initrd-modules} should cover
26446 most use cases. For example, assuming you need the @code{megaraid_sas}
26447 module in addition to the default modules to be able to access your root
26448 file system, you would write:
26453 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
26456 @defvr {Scheme Variable} %base-initrd-modules
26457 This is the list of kernel modules included in the initrd by default.
26460 Furthermore, if you need lower-level customization, the @code{initrd}
26461 field of an @code{operating-system} declaration allows
26462 you to specify which initrd you would like to use. The @code{(gnu
26463 system linux-initrd)} module provides three ways to build an initrd: the
26464 high-level @code{base-initrd} procedure and the low-level
26465 @code{raw-initrd} and @code{expression->initrd} procedures.
26467 The @code{base-initrd} procedure is intended to cover most common uses.
26468 For example, if you want to add a bunch of kernel modules to be loaded
26469 at boot time, you can define the @code{initrd} field of the operating
26470 system declaration like this:
26473 (initrd (lambda (file-systems . rest)
26474 ;; Create a standard initrd but set up networking
26475 ;; with the parameters QEMU expects by default.
26476 (apply base-initrd file-systems
26477 #:qemu-networking? #t
26481 The @code{base-initrd} procedure also handles common use cases that
26482 involves using the system as a QEMU guest, or as a ``live'' system with
26483 volatile root file system.
26485 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
26486 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
26487 such as trying to guess which kernel modules and packages should be included
26488 to the initrd. An example use of @code{raw-initrd} is when a user has
26489 a custom Linux kernel configuration and default kernel modules included by
26490 @code{base-initrd} are not available.
26492 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
26493 honors several options passed on the Linux kernel command line
26494 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
26495 @code{-append} option of QEMU), notably:
26498 @item --load=@var{boot}
26499 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
26500 program, once it has mounted the root file system.
26502 Guix uses this option to yield control to a boot program that runs the
26503 service activation programs and then spawns the GNU@tie{}Shepherd, the
26504 initialization system.
26506 @item --root=@var{root}
26507 Mount @var{root} as the root file system. @var{root} can be a
26508 device name like @code{/dev/sda1}, a file system label, or a file system
26511 @item --system=@var{system}
26512 Have @file{/run/booted-system} and @file{/run/current-system} point to
26515 @item modprobe.blacklist=@var{modules}@dots{}
26516 @cindex module, black-listing
26517 @cindex black list, of kernel modules
26518 Instruct the initial RAM disk as well as the @command{modprobe} command
26519 (from the kmod package) to refuse to load @var{modules}. @var{modules}
26520 must be a comma-separated list of module names---e.g.,
26521 @code{usbkbd,9pnet}.
26524 Start a read-eval-print loop (REPL) from the initial RAM disk before it
26525 tries to load kernel modules and to mount the root file system. Our
26526 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
26527 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
26528 Manual}, for more information on Guile's REPL.
26532 Now that you know all the features that initial RAM disks produced by
26533 @code{base-initrd} and @code{raw-initrd} provide,
26534 here is how to use it and customize it further.
26537 @cindex initial RAM disk
26538 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
26539 [#:linux-modules '()] [#:mapped-devices '()] @
26540 [#:keyboard-layout #f] @
26541 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
26542 Return a derivation that builds a raw initrd. @var{file-systems} is
26543 a list of file systems to be mounted by the initrd, possibly in addition to
26544 the root file system specified on the kernel command line via @option{--root}.
26545 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
26546 @var{mapped-devices} is a list of device mappings to realize before
26547 @var{file-systems} are mounted (@pxref{Mapped Devices}).
26548 @var{helper-packages} is a list of packages to be copied in the initrd. It may
26549 include @code{e2fsck/static} or other packages needed by the initrd to check
26550 the root file system.
26552 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26553 the desired console keyboard layout. This is done before @var{mapped-devices}
26554 are set up and before @var{file-systems} are mounted such that, should the
26555 user need to enter a passphrase or use the REPL, this happens using the
26556 intended keyboard layout.
26558 When @var{qemu-networking?} is true, set up networking with the standard QEMU
26559 parameters. When @var{virtio?} is true, load additional modules so that the
26560 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
26562 When @var{volatile-root?} is true, the root file system is writable but any changes
26566 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
26567 [#:mapped-devices '()] [#:keyboard-layout #f] @
26568 [#:qemu-networking? #f] [#:volatile-root? #f] @
26569 [#:linux-modules '()]
26570 Return as a file-like object a generic initrd, with kernel
26571 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
26572 mounted by the initrd, possibly in addition to the root file system specified
26573 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
26574 mappings to realize before @var{file-systems} are mounted.
26576 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26577 the desired console keyboard layout. This is done before @var{mapped-devices}
26578 are set up and before @var{file-systems} are mounted such that, should the
26579 user need to enter a passphrase or use the REPL, this happens using the
26580 intended keyboard layout.
26582 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
26584 The initrd is automatically populated with all the kernel modules necessary
26585 for @var{file-systems} and for the given options. Additional kernel
26586 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
26587 loaded at boot time in the order in which they appear.
26590 Needless to say, the initrds we produce and use embed a
26591 statically-linked Guile, and the initialization program is a Guile
26592 program. That gives a lot of flexibility. The
26593 @code{expression->initrd} procedure builds such an initrd, given the
26594 program to run in that initrd.
26596 @deffn {Scheme Procedure} expression->initrd @var{exp} @
26597 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
26598 Return as a file-like object a Linux initrd (a gzipped cpio archive)
26599 containing @var{guile} and that evaluates @var{exp}, a G-expression,
26600 upon booting. All the derivations referenced by @var{exp} are
26601 automatically copied to the initrd.
26604 @node Bootloader Configuration
26605 @section Bootloader Configuration
26608 @cindex boot loader
26610 The operating system supports multiple bootloaders. The bootloader is
26611 configured using @code{bootloader-configuration} declaration. All the
26612 fields of this structure are bootloader agnostic except for one field,
26613 @code{bootloader} that indicates the bootloader to be configured and
26616 Some of the bootloaders do not honor every field of
26617 @code{bootloader-configuration}. For instance, the extlinux
26618 bootloader does not support themes and thus ignores the @code{theme}
26621 @deftp {Data Type} bootloader-configuration
26622 The type of a bootloader configuration declaration.
26626 @item @code{bootloader}
26627 @cindex EFI, bootloader
26628 @cindex UEFI, bootloader
26629 @cindex BIOS, bootloader
26630 The bootloader to use, as a @code{bootloader} object. For now
26631 @code{grub-bootloader}, @code{grub-efi-bootloader},
26632 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
26634 @vindex grub-efi-bootloader
26635 @code{grub-efi-bootloader} allows to boot on modern systems using the
26636 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
26637 use if the installation image contains a @file{/sys/firmware/efi} directory
26638 when you boot it on your system.
26640 @vindex grub-bootloader
26641 @code{grub-bootloader} allows you to boot in particular Intel-based machines
26642 in ``legacy'' BIOS mode.
26644 @cindex ARM, bootloaders
26645 @cindex AArch64, bootloaders
26646 Available bootloaders are described in @code{(gnu bootloader @dots{})}
26647 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
26648 of bootloaders for a wide range of ARM and AArch64 systems, using the
26649 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
26651 @item @code{target}
26652 This is a string denoting the target onto which to install the
26655 The interpretation depends on the bootloader in question. For
26656 @code{grub-bootloader}, for example, it should be a device name understood by
26657 the bootloader @command{installer} command, such as @code{/dev/sda} or
26658 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
26659 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
26660 system, usually @file{/boot/efi}.
26662 @item @code{menu-entries} (default: @code{()})
26663 A possibly empty list of @code{menu-entry} objects (see below), denoting
26664 entries to appear in the bootloader menu, in addition to the current
26665 system entry and the entry pointing to previous system generations.
26667 @item @code{default-entry} (default: @code{0})
26668 The index of the default boot menu entry. Index 0 is for the entry of the
26671 @item @code{timeout} (default: @code{5})
26672 The number of seconds to wait for keyboard input before booting. Set to
26673 0 to boot immediately, and to -1 to wait indefinitely.
26675 @cindex keyboard layout, for the bootloader
26676 @item @code{keyboard-layout} (default: @code{#f})
26677 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
26678 layout, usually US@tie{}English (``qwerty'').
26680 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
26684 This option is currently ignored by bootloaders other than @code{grub} and
26688 @item @code{theme} (default: @var{#f})
26689 The bootloader theme object describing the theme to use. If no theme
26690 is provided, some bootloaders might use a default theme, that's true
26693 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
26694 The output terminals used for the bootloader boot menu, as a list of
26695 symbols. GRUB accepts the values: @code{console}, @code{serial},
26696 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
26697 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
26698 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
26699 configuration,,, grub,GNU GRUB manual}).
26701 @item @code{terminal-inputs} (default: @code{'()})
26702 The input terminals used for the bootloader boot menu, as a list of
26703 symbols. For GRUB, the default is the native platform terminal as
26704 determined at run-time. GRUB accepts the values: @code{console},
26705 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
26706 @code{usb_keyboard}. This field corresponds to the GRUB variable
26707 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
26710 @item @code{serial-unit} (default: @code{#f})
26711 The serial unit used by the bootloader, as an integer from 0 to 3.
26712 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
26713 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26715 @item @code{serial-speed} (default: @code{#f})
26716 The speed of the serial interface, as an integer. For GRUB, the
26717 default value is chosen at run-time; currently GRUB chooses
26718 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26725 Should you want to list additional boot menu entries @i{via} the
26726 @code{menu-entries} field above, you will need to create them with the
26727 @code{menu-entry} form. For example, imagine you want to be able to
26728 boot another distro (hard to imagine!), you can define a menu entry
26733 (label "The Other Distro")
26734 (linux "/boot/old/vmlinux-2.6.32")
26735 (linux-arguments '("root=/dev/sda2"))
26736 (initrd "/boot/old/initrd"))
26741 @deftp {Data Type} menu-entry
26742 The type of an entry in the bootloader menu.
26747 The label to show in the menu---e.g., @code{"GNU"}.
26750 The Linux kernel image to boot, for example:
26753 (file-append linux-libre "/bzImage")
26756 For GRUB, it is also possible to specify a device explicitly in the
26757 file path using GRUB's device naming convention (@pxref{Naming
26758 convention,,, grub, GNU GRUB manual}), for example:
26761 "(hd0,msdos1)/boot/vmlinuz"
26764 If the device is specified explicitly as above, then the @code{device}
26765 field is ignored entirely.
26767 @item @code{linux-arguments} (default: @code{()})
26768 The list of extra Linux kernel command-line arguments---e.g.,
26769 @code{("console=ttyS0")}.
26771 @item @code{initrd}
26772 A G-Expression or string denoting the file name of the initial RAM disk
26773 to use (@pxref{G-Expressions}).
26774 @item @code{device} (default: @code{#f})
26775 The device where the kernel and initrd are to be found---i.e., for GRUB,
26776 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
26778 This may be a file system label (a string), a file system UUID (a
26779 bytevector, @pxref{File Systems}), or @code{#f}, in which case
26780 the bootloader will search the device containing the file specified by
26781 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
26782 must @emph{not} be an OS device name such as @file{/dev/sda1}.
26790 @c FIXME: Write documentation once it's stable.
26791 For now only GRUB has theme support. GRUB themes are created using
26792 the @code{grub-theme} form, which is not fully documented yet.
26794 @deftp {Data Type} grub-theme
26795 Data type representing the configuration of the GRUB theme.
26798 @item @code{gfxmode} (default: @code{'("auto")})
26799 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
26800 @pxref{gfxmode,,, grub, GNU GRUB manual}).
26804 @defvr {Scheme Variable} %default-theme
26805 This is the default GRUB theme used by the operating system if no
26806 @code{theme} field is specified in @code{bootloader-configuration}
26809 It comes with a fancy background image displaying the GNU and Guix
26813 For example, to override the default resolution, you may use something
26818 (bootloader-configuration
26821 (inherit %default-theme)
26822 (gfxmode '("1024x786x32" "auto"))))))
26825 @node Invoking guix system
26826 @section Invoking @code{guix system}
26828 Once you have written an operating system declaration as seen in the
26829 previous section, it can be @dfn{instantiated} using the @command{guix
26830 system} command. The synopsis is:
26833 guix system @var{options}@dots{} @var{action} @var{file}
26836 @var{file} must be the name of a file containing an
26837 @code{operating-system} declaration. @var{action} specifies how the
26838 operating system is instantiated. Currently the following values are
26843 Display available service type definitions that match the given regular
26844 expressions, sorted by relevance:
26850 $ guix system search console
26851 name: console-fonts
26852 location: gnu/services/base.scm:806:2
26853 extends: shepherd-root
26854 description: Install the given fonts on the specified ttys (fonts are per
26855 + virtual console on GNU/Linux). The value of this service is a list of
26856 + tty/font pairs. The font can be the name of a font provided by the `kbd'
26857 + package or any valid argument to `setfont', as in this example:
26859 + '(("tty1" . "LatGrkCyr-8x16")
26860 + ("tty2" . (file-append
26862 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
26863 + ("tty3" . (file-append
26865 + "/share/consolefonts/ter-132n"))) ; for HDPI
26869 location: gnu/services/base.scm:1190:2
26870 extends: shepherd-root
26871 description: Provide console login using the `mingetty' program.
26875 location: gnu/services/base.scm:860:2
26877 description: Provide a console log-in service as specified by its
26878 + configuration value, a `login-configuration' object.
26884 As for @command{guix package --search}, the result is written in
26885 @code{recutils} format, which makes it easy to filter the output
26886 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
26889 Build the operating system described in @var{file}, activate it, and
26890 switch to it@footnote{This action (and the related actions
26891 @code{switch-generation} and @code{roll-back}) are usable only on
26892 systems already running Guix System.}.
26895 @c The paragraph below refers to the problem discussed at
26896 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
26897 It is highly recommended to run @command{guix pull} once before you run
26898 @command{guix system reconfigure} for the first time (@pxref{Invoking
26899 guix pull}). Failing to do that you would see an older version of Guix
26900 once @command{reconfigure} has completed.
26903 This effects all the configuration specified in @var{file}: user
26904 accounts, system services, global package list, setuid programs, etc.
26905 The command starts system services specified in @var{file} that are not
26906 currently running; if a service is currently running this command will
26907 arrange for it to be upgraded the next time it is stopped (e.g.@: by
26908 @code{herd stop X} or @code{herd restart X}).
26910 This command creates a new generation whose number is one greater than
26911 the current generation (as reported by @command{guix system
26912 list-generations}). If that generation already exists, it will be
26913 overwritten. This behavior mirrors that of @command{guix package}
26914 (@pxref{Invoking guix package}).
26916 It also adds a bootloader menu entry for the new OS configuration,
26917 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
26918 entries for older configurations to a submenu, allowing you to choose
26919 an older system generation at boot time should you need it.
26921 @cindex provenance tracking, of the operating system
26922 Upon completion, the new system is deployed under
26923 @file{/run/current-system}. This directory contains @dfn{provenance
26924 meta-data}: the list of channels in use (@pxref{Channels}) and
26925 @var{file} itself, when available. This information is useful should
26926 you later want to inspect how this particular generation was built.
26928 In fact, assuming @var{file} is self-contained, you can later rebuild
26929 generation @var{n} of your operating system with:
26932 guix time-machine \
26933 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
26934 system reconfigure \
26935 /var/guix/profiles/system-@var{n}-link/configuration.scm
26938 You can think of it as some sort of built-in version control! Your
26939 system is not just a binary artifact: @emph{it carries its own source}.
26940 @xref{Service Reference, @code{provenance-service-type}}, for more
26941 information on provenance tracking.
26943 @item switch-generation
26944 @cindex generations
26945 Switch to an existing system generation. This action atomically
26946 switches the system profile to the specified system generation. It
26947 also rearranges the system's existing bootloader menu entries. It
26948 makes the menu entry for the specified system generation the default,
26949 and it moves the entries for the other generations to a submenu, if
26950 supported by the bootloader being used. The next time the system
26951 boots, it will use the specified system generation.
26953 The bootloader itself is not being reinstalled when using this
26954 command. Thus, the installed bootloader is used with an updated
26955 configuration file.
26957 The target generation can be specified explicitly by its generation
26958 number. For example, the following invocation would switch to system
26962 guix system switch-generation 7
26965 The target generation can also be specified relative to the current
26966 generation with the form @code{+N} or @code{-N}, where @code{+3} means
26967 ``3 generations ahead of the current generation,'' and @code{-1} means
26968 ``1 generation prior to the current generation.'' When specifying a
26969 negative value such as @code{-1}, you must precede it with @code{--} to
26970 prevent it from being parsed as an option. For example:
26973 guix system switch-generation -- -1
26976 Currently, the effect of invoking this action is @emph{only} to switch
26977 the system profile to an existing generation and rearrange the
26978 bootloader menu entries. To actually start using the target system
26979 generation, you must reboot after running this action. In the future,
26980 it will be updated to do the same things as @command{reconfigure},
26981 like activating and deactivating services.
26983 This action will fail if the specified generation does not exist.
26986 @cindex rolling back
26987 Switch to the preceding system generation. The next time the system
26988 boots, it will use the preceding system generation. This is the inverse
26989 of @command{reconfigure}, and it is exactly the same as invoking
26990 @command{switch-generation} with an argument of @code{-1}.
26992 Currently, as with @command{switch-generation}, you must reboot after
26993 running this action to actually start using the preceding system
26996 @item delete-generations
26997 @cindex deleting system generations
26998 @cindex saving space
26999 Delete system generations, making them candidates for garbage collection
27000 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
27003 This works in the same way as @samp{guix package --delete-generations}
27004 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
27005 arguments, all system generations but the current one are deleted:
27008 guix system delete-generations
27011 You can also select the generations you want to delete. The example below
27012 deletes all the system generations that are more than two month old:
27015 guix system delete-generations 2m
27018 Running this command automatically reinstalls the bootloader with an updated
27019 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
27020 longer lists the generations that have been deleted.
27023 Build the derivation of the operating system, which includes all the
27024 configuration files and programs needed to boot and run the system.
27025 This action does not actually install anything.
27028 Populate the given directory with all the files necessary to run the
27029 operating system specified in @var{file}. This is useful for first-time
27030 installations of Guix System. For instance:
27033 guix system init my-os-config.scm /mnt
27036 copies to @file{/mnt} all the store items required by the configuration
27037 specified in @file{my-os-config.scm}. This includes configuration
27038 files, packages, and so on. It also creates other essential files
27039 needed for the system to operate correctly---e.g., the @file{/etc},
27040 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
27042 This command also installs bootloader on the target specified in
27043 @file{my-os-config}, unless the @option{--no-bootloader} option was
27047 @cindex virtual machine
27049 @anchor{guix system vm}
27050 Build a virtual machine that contains the operating system declared in
27051 @var{file}, and return a script to run that virtual machine (VM).
27054 The @code{vm} action and others below
27055 can use KVM support in the Linux-libre kernel. Specifically, if the
27056 machine has hardware virtualization support, the corresponding
27057 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
27058 must exist and be readable and writable by the user and by the
27059 build users of the daemon (@pxref{Build Environment Setup}).
27062 Arguments given to the script are passed to QEMU as in the example
27063 below, which enables networking and requests 1@tie{}GiB of RAM for the
27067 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
27070 The VM shares its store with the host system.
27072 Additional file systems can be shared between the host and the VM using
27073 the @option{--share} and @option{--expose} command-line options: the former
27074 specifies a directory to be shared with write access, while the latter
27075 provides read-only access to the shared directory.
27077 The example below creates a VM in which the user's home directory is
27078 accessible read-only, and where the @file{/exchange} directory is a
27079 read-write mapping of @file{$HOME/tmp} on the host:
27082 guix system vm my-config.scm \
27083 --expose=$HOME --share=$HOME/tmp=/exchange
27086 On GNU/Linux, the default is to boot directly to the kernel; this has
27087 the advantage of requiring only a very tiny root disk image since the
27088 store of the host can then be mounted.
27090 The @option{--full-boot} option forces a complete boot sequence, starting
27091 with the bootloader. This requires more disk space since a root image
27092 containing at least the kernel, initrd, and bootloader data files must
27093 be created. The @option{--image-size} option can be used to specify the
27096 @cindex System images, creation in various formats
27097 @cindex Creating system images in various formats
27100 @itemx docker-image
27101 Return a virtual machine, disk image, or Docker image of the operating
27102 system declared in @var{file} that stands alone. By default,
27103 @command{guix system} estimates the size of the image needed to store
27104 the system, but you can use the @option{--image-size} option to specify
27105 a value. Docker images are built to contain exactly what they need, so
27106 the @option{--image-size} option is ignored in the case of
27107 @code{docker-image}.
27109 You can specify the root file system type by using the
27110 @option{--file-system-type} option. It defaults to @code{ext4}.
27112 When using @code{vm-image}, the returned image is in qcow2 format, which
27113 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
27114 for more information on how to run the image in a virtual machine.
27116 When using @code{disk-image}, a raw disk image is produced; it can be
27117 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
27118 the device corresponding to a USB stick, one can copy the image to it
27119 using the following command:
27122 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
27125 When using @code{docker-image}, a Docker image is produced. Guix builds
27126 the image from scratch, not from a pre-existing Docker base image. As a
27127 result, it contains @emph{exactly} what you define in the operating
27128 system configuration file. You can then load the image and launch a
27129 Docker container using commands like the following:
27132 image_id="`docker load < guix-system-docker-image.tar.gz`"
27133 container_id="`docker create $image_id`"
27134 docker start $container_id
27137 This command starts a new Docker container from the specified image. It
27138 will boot the Guix system in the usual manner, which means it will
27139 start any services you have defined in the operating system
27140 configuration. You can get an interactive shell running in the container
27141 using @command{docker exec}:
27144 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
27147 Depending on what you run in the Docker container, it
27148 may be necessary to give the container additional permissions. For
27149 example, if you intend to build software using Guix inside of the Docker
27150 container, you may need to pass the @option{--privileged} option to
27151 @code{docker create}.
27153 Last, the @option{--network} option applies to @command{guix system
27154 docker-image}: it produces an image where network is supposedly shared
27155 with the host, and thus without services like nscd or NetworkManager.
27158 Return a script to run the operating system declared in @var{file}
27159 within a container. Containers are a set of lightweight isolation
27160 mechanisms provided by the kernel Linux-libre. Containers are
27161 substantially less resource-demanding than full virtual machines since
27162 the kernel, shared objects, and other resources can be shared with the
27163 host system; this also means they provide thinner isolation.
27165 Currently, the script must be run as root in order to support more than
27166 a single user and group. The container shares its store with the host
27169 As with the @code{vm} action (@pxref{guix system vm}), additional file
27170 systems to be shared between the host and container can be specified
27171 using the @option{--share} and @option{--expose} options:
27174 guix system container my-config.scm \
27175 --expose=$HOME --share=$HOME/tmp=/exchange
27179 This option requires Linux-libre 3.19 or newer.
27184 @var{options} can contain any of the common build options (@pxref{Common
27185 Build Options}). In addition, @var{options} can contain one of the
27189 @item --expression=@var{expr}
27190 @itemx -e @var{expr}
27191 Consider the operating-system @var{expr} evaluates to.
27192 This is an alternative to specifying a file which evaluates to an
27194 This is used to generate the Guix system installer @pxref{Building the
27195 Installation Image}).
27197 @item --system=@var{system}
27198 @itemx -s @var{system}
27199 Attempt to build for @var{system} instead of the host system type.
27200 This works as per @command{guix build} (@pxref{Invoking guix build}).
27204 Return the derivation file name of the given operating system without
27207 @cindex provenance tracking, of the operating system
27208 @item --save-provenance
27209 As discussed above, @command{guix system init} and @command{guix system
27210 reconfigure} always save provenance information @i{via} a dedicated
27211 service (@pxref{Service Reference, @code{provenance-service-type}}).
27212 However, other commands don't do that by default. If you wish to, say,
27213 create a virtual machine image that contains provenance information, you
27217 guix system vm-image --save-provenance config.scm
27220 That way, the resulting image will effectively ``embed its own source''
27221 in the form of meta-data in @file{/run/current-system}. With that
27222 information, one can rebuild the image to make sure it really contains
27223 what it pretends to contain; or they could use that to derive a variant
27226 @item --file-system-type=@var{type}
27227 @itemx -t @var{type}
27228 For the @code{disk-image} action, create a file system of the given
27229 @var{type} on the image.
27231 When this option is omitted, @command{guix system} uses @code{ext4}.
27233 @cindex ISO-9660 format
27234 @cindex CD image format
27235 @cindex DVD image format
27236 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
27237 for burning on CDs and DVDs.
27239 @item --image-size=@var{size}
27240 For the @code{vm-image} and @code{disk-image} actions, create an image
27241 of the given @var{size}. @var{size} may be a number of bytes, or it may
27242 include a unit as a suffix (@pxref{Block size, size specifications,,
27243 coreutils, GNU Coreutils}).
27245 When this option is omitted, @command{guix system} computes an estimate
27246 of the image size as a function of the size of the system declared in
27251 For the @code{container} action, allow containers to access the host network,
27252 that is, do not create a network namespace.
27254 @item --root=@var{file}
27255 @itemx -r @var{file}
27256 Make @var{file} a symlink to the result, and register it as a garbage
27259 @item --skip-checks
27260 Skip pre-installation safety checks.
27262 By default, @command{guix system init} and @command{guix system
27263 reconfigure} perform safety checks: they make sure the file systems that
27264 appear in the @code{operating-system} declaration actually exist
27265 (@pxref{File Systems}), and that any Linux kernel modules that may be
27266 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
27267 RAM Disk}). Passing this option skips these tests altogether.
27270 @cindex on-error strategy
27271 @cindex error strategy
27272 @item --on-error=@var{strategy}
27273 Apply @var{strategy} when an error occurs when reading @var{file}.
27274 @var{strategy} may be one of the following:
27277 @item nothing-special
27278 Report the error concisely and exit. This is the default strategy.
27281 Likewise, but also display a backtrace.
27284 Report the error and enter Guile's debugger. From there, you can run
27285 commands such as @code{,bt} to get a backtrace, @code{,locals} to
27286 display local variable values, and more generally inspect the state of the
27287 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
27288 a list of available debugging commands.
27292 Once you have built, configured, re-configured, and re-re-configured
27293 your Guix installation, you may find it useful to list the operating
27294 system generations available on disk---and that you can choose from the
27295 bootloader boot menu:
27300 Describe the current system generation: its file name, the kernel and
27301 bootloader used, etc., as well as provenance information when available.
27303 @item list-generations
27304 List a summary of each generation of the operating system available on
27305 disk, in a human-readable way. This is similar to the
27306 @option{--list-generations} option of @command{guix package}
27307 (@pxref{Invoking guix package}).
27309 Optionally, one can specify a pattern, with the same syntax that is used
27310 in @command{guix package --list-generations}, to restrict the list of
27311 generations displayed. For instance, the following command displays
27312 generations that are up to 10 days old:
27315 $ guix system list-generations 10d
27320 The @command{guix system} command has even more to offer! The following
27321 sub-commands allow you to visualize how your system services relate to
27324 @anchor{system-extension-graph}
27327 @item extension-graph
27328 Emit in Dot/Graphviz format to standard output the @dfn{service
27329 extension graph} of the operating system defined in @var{file}
27330 (@pxref{Service Composition}, for more information on service
27336 $ guix system extension-graph @var{file} | xdot -
27339 shows the extension relations among services.
27341 @anchor{system-shepherd-graph}
27342 @item shepherd-graph
27343 Emit in Dot/Graphviz format to standard output the @dfn{dependency
27344 graph} of shepherd services of the operating system defined in
27345 @var{file}. @xref{Shepherd Services}, for more information and for an
27350 @node Invoking guix deploy
27351 @section Invoking @code{guix deploy}
27353 We've already seen @code{operating-system} declarations used to manage a
27354 machine's configuration locally. Suppose you need to configure multiple
27355 machines, though---perhaps you're managing a service on the web that's
27356 comprised of several servers. @command{guix deploy} enables you to use those
27357 same @code{operating-system} declarations to manage multiple remote hosts at
27358 once as a logical ``deployment''.
27361 The functionality described in this section is still under development
27362 and is subject to change. Get in touch with us on
27363 @email{guix-devel@@gnu.org}!
27367 guix deploy @var{file}
27370 Such an invocation will deploy the machines that the code within @var{file}
27371 evaluates to. As an example, @var{file} might contain a definition like this:
27374 ;; This is a Guix deployment of a "bare bones" setup, with
27375 ;; no X11 display server, to a machine with an SSH daemon
27376 ;; listening on localhost:2222. A configuration such as this
27377 ;; may be appropriate for virtual machine with ports
27378 ;; forwarded to the host's loopback interface.
27380 (use-service-modules networking ssh)
27381 (use-package-modules bootloaders)
27385 (host-name "gnu-deployed")
27386 (timezone "Etc/UTC")
27387 (bootloader (bootloader-configuration
27388 (bootloader grub-bootloader)
27389 (target "/dev/vda")
27390 (terminal-outputs '(console))))
27391 (file-systems (cons (file-system
27393 (device "/dev/vda1")
27395 %base-file-systems))
27397 (append (list (service dhcp-client-service-type)
27398 (service openssh-service-type
27399 (openssh-configuration
27400 (permit-root-login #t)
27401 (allow-empty-passwords? #t))))
27405 (operating-system %system)
27406 (environment managed-host-environment-type)
27407 (configuration (machine-ssh-configuration
27408 (host-name "localhost")
27409 (system "x86_64-linux")
27411 (identity "./id_rsa")
27415 The file should evaluate to a list of @var{machine} objects. This example,
27416 upon being deployed, will create a new generation on the remote system
27417 realizing the @code{operating-system} declaration @code{%system}.
27418 @code{environment} and @code{configuration} specify how the machine should be
27419 provisioned---that is, how the computing resources should be created and
27420 managed. The above example does not create any resources, as a
27421 @code{'managed-host} is a machine that is already running the Guix system and
27422 available over the network. This is a particularly simple case; a more
27423 complex deployment may involve, for example, starting virtual machines through
27424 a Virtual Private Server (VPS) provider. In such a case, a different
27425 @var{environment} type would be used.
27427 Do note that you first need to generate a key pair on the coordinator machine
27428 to allow the daemon to export signed archives of files from the store
27429 (@pxref{Invoking guix archive}).
27432 # guix archive --generate-key
27436 Each target machine must authorize the key of the master machine so that it
27437 accepts store items it receives from the coordinator:
27440 # guix archive --authorize < coordinator-public-key.txt
27443 @code{user}, in this example, specifies the name of the user account to log in
27444 as to perform the deployment. Its default value is @code{root}, but root
27445 login over SSH may be forbidden in some cases. To work around this,
27446 @command{guix deploy} can log in as an unprivileged user and employ
27447 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
27448 currently installed on the remote and can be invoked non-interactively as
27449 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
27450 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
27451 be accomplished with the following operating system configuration snippet:
27455 (gnu system)) ;for %sudoers-specification
27457 (define %user "username")
27462 (plain-file "sudoers"
27463 (string-append (plain-file-content %sudoers-specification)
27464 (format #f "~a ALL = NOPASSWD: ALL~%"
27469 For more information regarding the format of the @file{sudoers} file,
27470 consult @command{man sudoers}.
27472 @deftp {Data Type} machine
27473 This is the data type representing a single machine in a heterogeneous Guix
27477 @item @code{operating-system}
27478 The object of the operating system configuration to deploy.
27480 @item @code{environment}
27481 An @code{environment-type} describing how the machine should be provisioned.
27483 @item @code{configuration} (default: @code{#f})
27484 An object describing the configuration for the machine's @code{environment}.
27485 If the @code{environment} has a default configuration, @code{#f} may be used.
27486 If @code{#f} is used for an environment with no default configuration,
27487 however, an error will be thrown.
27491 @deftp {Data Type} machine-ssh-configuration
27492 This is the data type representing the SSH client parameters for a machine
27493 with an @code{environment} of @code{managed-host-environment-type}.
27496 @item @code{host-name}
27497 @item @code{build-locally?} (default: @code{#t})
27498 If false, system derivations will be built on the machine being deployed to.
27499 @item @code{system}
27500 The system type describing the architecture of the machine being deployed
27501 to---e.g., @code{"x86_64-linux"}.
27502 @item @code{authorize?} (default: @code{#t})
27503 If true, the coordinator's signing key will be added to the remote's ACL
27505 @item @code{port} (default: @code{22})
27506 @item @code{user} (default: @code{"root"})
27507 @item @code{identity} (default: @code{#f})
27508 If specified, the path to the SSH private key to use to authenticate with the
27511 @item @code{host-key} (default: @code{#f})
27512 This should be the SSH host key of the machine, which looks like this:
27515 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
27518 When @code{host-key} is @code{#f}, the server is authenticated against
27519 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
27525 @deftp {Data Type} digital-ocean-configuration
27526 This is the data type describing the Droplet that should be created for a
27527 machine with an @code{environment} of @code{digital-ocean-environment-type}.
27530 @item @code{ssh-key}
27531 The path to the SSH private key to use to authenticate with the remote
27532 host. In the future, this field may not exist.
27534 A list of string ``tags'' that uniquely identify the machine. Must be given
27535 such that no two machines in the deployment have the same set of tags.
27536 @item @code{region}
27537 A Digital Ocean region slug, such as @code{"nyc3"}.
27539 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
27540 @item @code{enable-ipv6?}
27541 Whether or not the droplet should be created with IPv6 networking.
27545 @node Running Guix in a VM
27546 @section Running Guix in a Virtual Machine
27548 @cindex virtual machine
27549 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
27551 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
27552 This image is a compressed image in QCOW format. You will first need to
27553 decompress with @command{xz -d}, and then you can pass it to an emulator such
27554 as QEMU (see below for details).
27556 This image boots the Xfce graphical environment and it contains some
27557 commonly-used tools. You can install more software in the image by running
27558 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
27559 also reconfigure the system based on its initial configuration file available
27560 as @file{/run/current-system/configuration.scm} (@pxref{Using the
27561 Configuration System}).
27563 Instead of using this pre-built image, one can also build their own virtual
27564 machine image using @command{guix system vm-image} (@pxref{Invoking guix
27565 system}). The returned image is in qcow2 format, which the
27566 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
27569 If you built your own image, you must copy it out of the store
27570 (@pxref{The Store}) and give yourself permission to write to the copy
27571 before you can use it. When invoking QEMU, you must choose a system
27572 emulator that is suitable for your hardware platform. Here is a minimal
27573 QEMU invocation that will boot the result of @command{guix system
27574 vm-image} on x86_64 hardware:
27577 $ qemu-system-x86_64 \
27578 -nic user,model=virtio-net-pci \
27579 -enable-kvm -m 1024 \
27580 -device virtio-blk,drive=myhd \
27581 -drive if=none,file=/tmp/qemu-image,id=myhd
27584 Here is what each of these options means:
27587 @item qemu-system-x86_64
27588 This specifies the hardware platform to emulate. This should match the
27591 @item -nic user,model=virtio-net-pci
27592 Enable the unprivileged user-mode network stack. The guest OS can
27593 access the host but not vice versa. This is the simplest way to get the
27594 guest OS online. @code{model} specifies which network device to emulate:
27595 @code{virtio-net-pci} is a special device made for virtualized operating
27596 systems and recommended for most uses. Assuming your hardware platform is
27597 x86_64, you can get a list of available NIC models by running
27598 @command{qemu-system-x86_64 -nic model=help}.
27601 If your system has hardware virtualization extensions, enabling the
27602 virtual machine support (KVM) of the Linux kernel will make things run
27605 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
27607 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
27608 which may be insufficient for some operations.
27610 @item -device virtio-blk,drive=myhd
27611 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
27612 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
27613 better performance than if it were emulating a complete disk drive. See the
27614 QEMU and KVM documentation for more info.
27616 @item -drive if=none,file=/tmp/qemu-image,id=myhd
27617 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
27618 the ``myhd'' drive.
27621 The default @command{run-vm.sh} script that is returned by an invocation of
27622 @command{guix system vm} does not add a @command{-nic user} flag by default.
27623 To get network access from within the vm add the @code{(dhcp-client-service)}
27624 to your system definition and start the VM using
27625 @command{`guix system vm config.scm` -nic user}. An important caveat of using
27626 @command{-nic user} for networking is that @command{ping} will not work, because
27627 it uses the ICMP protocol. You'll have to use a different command to check for
27628 network connectivity, for example @command{guix download}.
27630 @subsection Connecting Through SSH
27634 To enable SSH inside a VM you need to add an SSH server like
27635 @code{openssh-service-type} to your VM (@pxref{Networking Services,
27636 @code{openssh-service-type}}). In addition you need to forward the SSH port,
27637 22 by default, to the host. You can do this with
27640 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
27643 To connect to the VM you can run
27646 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
27649 The @command{-p} tells @command{ssh} the port you want to connect to.
27650 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
27651 every time you modify your @command{config.scm} file and the
27652 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
27653 connection to an unknown host every time you connect.
27655 @subsection Using @command{virt-viewer} with Spice
27657 As an alternative to the default @command{qemu} graphical client you can
27658 use the @command{remote-viewer} from the @command{virt-viewer} package. To
27659 connect pass the @command{-spice port=5930,disable-ticketing} flag to
27660 @command{qemu}. See previous section for further information on how to do this.
27662 Spice also allows you to do some nice stuff like share your clipboard with your
27663 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
27666 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
27667 -chardev spicevmc,name=vdagent,id=vdagent
27668 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
27669 name=com.redhat.spice.0
27672 You'll also need to add the @code{(spice-vdagent-service)} to your
27673 system definition (@pxref{Miscellaneous Services, Spice service}).
27675 @node Defining Services
27676 @section Defining Services
27678 The previous sections show the available services and how one can combine
27679 them in an @code{operating-system} declaration. But how do we define
27680 them in the first place? And what is a service anyway?
27683 * Service Composition:: The model for composing services.
27684 * Service Types and Services:: Types and services.
27685 * Service Reference:: API reference.
27686 * Shepherd Services:: A particular type of service.
27689 @node Service Composition
27690 @subsection Service Composition
27694 Here we define a @dfn{service} as, broadly, something that extends the
27695 functionality of the operating system. Often a service is a process---a
27696 @dfn{daemon}---started when the system boots: a secure shell server, a
27697 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
27698 whose execution can be triggered by another daemon---e.g., an FTP server
27699 started by @command{inetd} or a D-Bus service activated by
27700 @command{dbus-daemon}. Occasionally, a service does not map to a
27701 daemon. For instance, the ``account'' service collects user accounts
27702 and makes sure they exist when the system runs; the ``udev'' service
27703 collects device management rules and makes them available to the eudev
27704 daemon; the @file{/etc} service populates the @file{/etc} directory
27707 @cindex service extensions
27708 Guix system services are connected by @dfn{extensions}. For instance, the
27709 secure shell service @emph{extends} the Shepherd---the
27710 initialization system, running as PID@tie{}1---by giving it the command
27711 lines to start and stop the secure shell daemon (@pxref{Networking
27712 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
27713 service by passing it its @file{.service} specification, and extends the
27714 udev service by passing it device management rules (@pxref{Desktop
27715 Services, @code{upower-service}}); the Guix daemon service extends the
27716 Shepherd by passing it the command lines to start and stop the daemon,
27717 and extends the account service by passing it a list of required build
27718 user accounts (@pxref{Base Services}).
27720 All in all, services and their ``extends'' relations form a directed
27721 acyclic graph (DAG). If we represent services as boxes and extensions
27722 as arrows, a typical system might provide something like this:
27724 @image{images/service-graph,,5in,Typical service extension graph.}
27726 @cindex system service
27727 At the bottom, we see the @dfn{system service}, which produces the
27728 directory containing everything to run and boot the system, as returned
27729 by the @command{guix system build} command. @xref{Service Reference},
27730 to learn about the other service types shown here.
27731 @xref{system-extension-graph, the @command{guix system extension-graph}
27732 command}, for information on how to generate this representation for a
27733 particular operating system definition.
27735 @cindex service types
27736 Technically, developers can define @dfn{service types} to express these
27737 relations. There can be any number of services of a given type on the
27738 system---for instance, a system running two instances of the GNU secure
27739 shell server (lsh) has two instances of @code{lsh-service-type}, with
27740 different parameters.
27742 The following section describes the programming interface for service
27743 types and services.
27745 @node Service Types and Services
27746 @subsection Service Types and Services
27748 A @dfn{service type} is a node in the DAG described above. Let us start
27749 with a simple example, the service type for the Guix build daemon
27750 (@pxref{Invoking guix-daemon}):
27753 (define guix-service-type
27757 (list (service-extension shepherd-root-service-type guix-shepherd-service)
27758 (service-extension account-service-type guix-accounts)
27759 (service-extension activation-service-type guix-activation)))
27760 (default-value (guix-configuration))))
27764 It defines three things:
27768 A name, whose sole purpose is to make inspection and debugging easier.
27771 A list of @dfn{service extensions}, where each extension designates the
27772 target service type and a procedure that, given the parameters of the
27773 service, returns a list of objects to extend the service of that type.
27775 Every service type has at least one service extension. The only
27776 exception is the @dfn{boot service type}, which is the ultimate service.
27779 Optionally, a default value for instances of this type.
27782 In this example, @code{guix-service-type} extends three services:
27785 @item shepherd-root-service-type
27786 The @code{guix-shepherd-service} procedure defines how the Shepherd
27787 service is extended. Namely, it returns a @code{<shepherd-service>}
27788 object that defines how @command{guix-daemon} is started and stopped
27789 (@pxref{Shepherd Services}).
27791 @item account-service-type
27792 This extension for this service is computed by @code{guix-accounts},
27793 which returns a list of @code{user-group} and @code{user-account}
27794 objects representing the build user accounts (@pxref{Invoking
27797 @item activation-service-type
27798 Here @code{guix-activation} is a procedure that returns a gexp, which is
27799 a code snippet to run at ``activation time''---e.g., when the service is
27803 A service of this type is instantiated like this:
27806 (service guix-service-type
27807 (guix-configuration
27809 (use-substitutes? #f)))
27812 The second argument to the @code{service} form is a value representing
27813 the parameters of this specific service instance.
27814 @xref{guix-configuration-type, @code{guix-configuration}}, for
27815 information about the @code{guix-configuration} data type. When the
27816 value is omitted, the default value specified by
27817 @code{guix-service-type} is used:
27820 (service guix-service-type)
27823 @code{guix-service-type} is quite simple because it extends other
27824 services but is not extensible itself.
27826 @c @subsubsubsection Extensible Service Types
27828 The service type for an @emph{extensible} service looks like this:
27831 (define udev-service-type
27832 (service-type (name 'udev)
27834 (list (service-extension shepherd-root-service-type
27835 udev-shepherd-service)))
27837 (compose concatenate) ;concatenate the list of rules
27838 (extend (lambda (config rules)
27840 (($ <udev-configuration> udev initial-rules)
27841 (udev-configuration
27842 (udev udev) ;the udev package to use
27843 (rules (append initial-rules rules)))))))))
27846 This is the service type for the
27847 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
27848 management daemon}. Compared to the previous example, in addition to an
27849 extension of @code{shepherd-root-service-type}, we see two new fields:
27853 This is the procedure to @dfn{compose} the list of extensions to
27854 services of this type.
27856 Services can extend the udev service by passing it lists of rules; we
27857 compose those extensions simply by concatenating them.
27860 This procedure defines how the value of the service is @dfn{extended} with
27861 the composition of the extensions.
27863 Udev extensions are composed into a list of rules, but the udev service
27864 value is itself a @code{<udev-configuration>} record. So here, we
27865 extend that record by appending the list of rules it contains to the
27866 list of contributed rules.
27869 This is a string giving an overview of the service type. The string can
27870 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
27871 @command{guix system search} command searches these strings and displays
27872 them (@pxref{Invoking guix system}).
27875 There can be only one instance of an extensible service type such as
27876 @code{udev-service-type}. If there were more, the
27877 @code{service-extension} specifications would be ambiguous.
27879 Still here? The next section provides a reference of the programming
27880 interface for services.
27882 @node Service Reference
27883 @subsection Service Reference
27885 We have seen an overview of service types (@pxref{Service Types and
27886 Services}). This section provides a reference on how to manipulate
27887 services and service types. This interface is provided by the
27888 @code{(gnu services)} module.
27890 @deffn {Scheme Procedure} service @var{type} [@var{value}]
27891 Return a new service of @var{type}, a @code{<service-type>} object (see
27892 below.) @var{value} can be any object; it represents the parameters of
27893 this particular service instance.
27895 When @var{value} is omitted, the default value specified by @var{type}
27896 is used; if @var{type} does not specify a default value, an error is
27899 For instance, this:
27902 (service openssh-service-type)
27906 is equivalent to this:
27909 (service openssh-service-type
27910 (openssh-configuration))
27913 In both cases the result is an instance of @code{openssh-service-type}
27914 with the default configuration.
27917 @deffn {Scheme Procedure} service? @var{obj}
27918 Return true if @var{obj} is a service.
27921 @deffn {Scheme Procedure} service-kind @var{service}
27922 Return the type of @var{service}---i.e., a @code{<service-type>} object.
27925 @deffn {Scheme Procedure} service-value @var{service}
27926 Return the value associated with @var{service}. It represents its
27930 Here is an example of how a service is created and manipulated:
27934 (service nginx-service-type
27935 (nginx-configuration
27937 (log-directory log-directory)
27938 (run-directory run-directory)
27939 (file config-file))))
27944 (eq? (service-kind s) nginx-service-type)
27948 The @code{modify-services} form provides a handy way to change the
27949 parameters of some of the services of a list such as
27950 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
27951 evaluates to a list of services. Of course, you could always use
27952 standard list combinators such as @code{map} and @code{fold} to do that
27953 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
27954 @code{modify-services} simply provides a more concise form for this
27957 @deffn {Scheme Syntax} modify-services @var{services} @
27958 (@var{type} @var{variable} => @var{body}) @dots{}
27960 Modify the services listed in @var{services} according to the given
27961 clauses. Each clause has the form:
27964 (@var{type} @var{variable} => @var{body})
27967 where @var{type} is a service type---e.g.,
27968 @code{guix-service-type}---and @var{variable} is an identifier that is
27969 bound within the @var{body} to the service parameters---e.g., a
27970 @code{guix-configuration} instance---of the original service of that
27973 The @var{body} should evaluate to the new service parameters, which will
27974 be used to configure the new service. This new service will replace the
27975 original in the resulting list. Because a service's service parameters
27976 are created using @code{define-record-type*}, you can write a succinct
27977 @var{body} that evaluates to the new service parameters by using the
27978 @code{inherit} feature that @code{define-record-type*} provides.
27980 @xref{Using the Configuration System}, for example usage.
27984 Next comes the programming interface for service types. This is
27985 something you want to know when writing new service definitions, but not
27986 necessarily when simply looking for ways to customize your
27987 @code{operating-system} declaration.
27989 @deftp {Data Type} service-type
27990 @cindex service type
27991 This is the representation of a @dfn{service type} (@pxref{Service Types
27996 This is a symbol, used only to simplify inspection and debugging.
27998 @item @code{extensions}
27999 A non-empty list of @code{<service-extension>} objects (see below).
28001 @item @code{compose} (default: @code{#f})
28002 If this is @code{#f}, then the service type denotes services that cannot
28003 be extended---i.e., services that do not receive ``values'' from other
28006 Otherwise, it must be a one-argument procedure. The procedure is called
28007 by @code{fold-services} and is passed a list of values collected from
28008 extensions. It may return any single value.
28010 @item @code{extend} (default: @code{#f})
28011 If this is @code{#f}, services of this type cannot be extended.
28013 Otherwise, it must be a two-argument procedure: @code{fold-services}
28014 calls it, passing it the initial value of the service as the first
28015 argument and the result of applying @code{compose} to the extension
28016 values as the second argument. It must return a value that is a valid
28017 parameter value for the service instance.
28020 @xref{Service Types and Services}, for examples.
28023 @deffn {Scheme Procedure} service-extension @var{target-type} @
28025 Return a new extension for services of type @var{target-type}.
28026 @var{compute} must be a one-argument procedure: @code{fold-services}
28027 calls it, passing it the value associated with the service that provides
28028 the extension; it must return a valid value for the target service.
28031 @deffn {Scheme Procedure} service-extension? @var{obj}
28032 Return true if @var{obj} is a service extension.
28035 Occasionally, you might want to simply extend an existing service. This
28036 involves creating a new service type and specifying the extension of
28037 interest, which can be verbose; the @code{simple-service} procedure
28038 provides a shorthand for this.
28040 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
28041 Return a service that extends @var{target} with @var{value}. This works
28042 by creating a singleton service type @var{name}, of which the returned
28043 service is an instance.
28045 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
28049 (simple-service 'my-mcron-job mcron-service-type
28050 #~(job '(next-hour (3)) "guix gc -F 2G"))
28054 At the core of the service abstraction lies the @code{fold-services}
28055 procedure, which is responsible for ``compiling'' a list of services
28056 down to a single directory that contains everything needed to boot and
28057 run the system---the directory shown by the @command{guix system build}
28058 command (@pxref{Invoking guix system}). In essence, it propagates
28059 service extensions down the service graph, updating each node parameters
28060 on the way, until it reaches the root node.
28062 @deffn {Scheme Procedure} fold-services @var{services} @
28063 [#:target-type @var{system-service-type}]
28064 Fold @var{services} by propagating their extensions down to the root of
28065 type @var{target-type}; return the root service adjusted accordingly.
28068 Lastly, the @code{(gnu services)} module also defines several essential
28069 service types, some of which are listed below.
28071 @defvr {Scheme Variable} system-service-type
28072 This is the root of the service graph. It produces the system directory
28073 as returned by the @command{guix system build} command.
28076 @defvr {Scheme Variable} boot-service-type
28077 The type of the ``boot service'', which produces the @dfn{boot script}.
28078 The boot script is what the initial RAM disk runs when booting.
28081 @defvr {Scheme Variable} etc-service-type
28082 The type of the @file{/etc} service. This service is used to create
28083 files under @file{/etc} and can be extended by
28084 passing it name/file tuples such as:
28087 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
28090 In this example, the effect would be to add an @file{/etc/issue} file
28091 pointing to the given file.
28094 @defvr {Scheme Variable} setuid-program-service-type
28095 Type for the ``setuid-program service''. This service collects lists of
28096 executable file names, passed as gexps, and adds them to the set of
28097 setuid-root programs on the system (@pxref{Setuid Programs}).
28100 @defvr {Scheme Variable} profile-service-type
28101 Type of the service that populates the @dfn{system profile}---i.e., the
28102 programs under @file{/run/current-system/profile}. Other services can
28103 extend it by passing it lists of packages to add to the system profile.
28106 @cindex provenance tracking, of the operating system
28107 @defvr {Scheme Variable} provenance-service-type
28108 This is the type of the service that records @dfn{provenance meta-data}
28109 in the system itself. It creates several files under
28110 @file{/run/current-system}:
28114 This is a ``channel file'' that can be passed to @command{guix pull -C}
28115 or @command{guix time-machine -C}, and which describes the channels used
28116 to build the system, if that information was available
28117 (@pxref{Channels}).
28119 @item configuration.scm
28120 This is the file that was passed as the value for this
28121 @code{provenance-service-type} service. By default, @command{guix
28122 system reconfigure} automatically passes the OS configuration file it
28123 received on the command line.
28126 This contains the same information as the two other files but in a
28127 format that is more readily processable.
28130 In general, these two pieces of information (channels and configuration
28131 file) are enough to reproduce the operating system ``from source''.
28134 This information is necessary to rebuild your operating system, but it
28135 is not always sufficient. In particular, @file{configuration.scm}
28136 itself is insufficient if it is not self-contained---if it refers to
28137 external Guile modules or to extra files. If you want
28138 @file{configuration.scm} to be self-contained, we recommend that modules
28139 or files it refers to be part of a channel.
28141 Besides, provenance meta-data is ``silent'' in the sense that it does
28142 not change the bits contained in your system, @emph{except for the
28143 meta-data bits themselves}. Two different OS configurations or sets of
28144 channels can lead to the same system, bit-for-bit; when
28145 @code{provenance-service-type} is used, these two systems will have
28146 different meta-data and thus different store file names, which makes
28147 comparison less trivial.
28150 This service is automatically added to your operating system
28151 configuration when you use @command{guix system reconfigure},
28152 @command{guix system init}, or @command{guix deploy}.
28155 @node Shepherd Services
28156 @subsection Shepherd Services
28158 @cindex shepherd services
28160 @cindex init system
28161 The @code{(gnu services shepherd)} module provides a way to define
28162 services managed by the GNU@tie{}Shepherd, which is the
28163 initialization system---the first process that is started when the
28164 system boots, also known as PID@tie{}1
28165 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
28167 Services in the Shepherd can depend on each other. For instance, the
28168 SSH daemon may need to be started after the syslog daemon has been
28169 started, which in turn can only happen once all the file systems have
28170 been mounted. The simple operating system defined earlier (@pxref{Using
28171 the Configuration System}) results in a service graph like this:
28173 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
28175 You can actually generate such a graph for any operating system
28176 definition using the @command{guix system shepherd-graph} command
28177 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
28179 The @code{%shepherd-root-service} is a service object representing
28180 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
28181 by passing it lists of @code{<shepherd-service>} objects.
28183 @deftp {Data Type} shepherd-service
28184 The data type representing a service managed by the Shepherd.
28187 @item @code{provision}
28188 This is a list of symbols denoting what the service provides.
28190 These are the names that may be passed to @command{herd start},
28191 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
28192 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
28193 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
28195 @item @code{requirement} (default: @code{'()})
28196 List of symbols denoting the Shepherd services this one depends on.
28198 @cindex one-shot services, for the Shepherd
28199 @item @code{one-shot?} (default: @code{#f})
28200 Whether this service is @dfn{one-shot}. One-shot services stop immediately
28201 after their @code{start} action has completed. @xref{Slots of services,,,
28202 shepherd, The GNU Shepherd Manual}, for more info.
28204 @item @code{respawn?} (default: @code{#t})
28205 Whether to restart the service when it stops, for instance when the
28206 underlying process dies.
28209 @itemx @code{stop} (default: @code{#~(const #f)})
28210 The @code{start} and @code{stop} fields refer to the Shepherd's
28211 facilities to start and stop processes (@pxref{Service De- and
28212 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
28213 G-expressions that get expanded in the Shepherd configuration file
28214 (@pxref{G-Expressions}).
28216 @item @code{actions} (default: @code{'()})
28217 @cindex actions, of Shepherd services
28218 This is a list of @code{shepherd-action} objects (see below) defining
28219 @dfn{actions} supported by the service, in addition to the standard
28220 @code{start} and @code{stop} actions. Actions listed here become available as
28221 @command{herd} sub-commands:
28224 herd @var{action} @var{service} [@var{arguments}@dots{}]
28227 @item @code{auto-start?} (default: @code{#t})
28228 Whether this service should be started automatically by the Shepherd. If it
28229 is @code{#f} the service has to be started manually with @code{herd start}.
28231 @item @code{documentation}
28232 A documentation string, as shown when running:
28235 herd doc @var{service-name}
28238 where @var{service-name} is one of the symbols in @code{provision}
28239 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
28241 @item @code{modules} (default: @code{%default-modules})
28242 This is the list of modules that must be in scope when @code{start} and
28243 @code{stop} are evaluated.
28248 @deftp {Data Type} shepherd-action
28249 This is the data type that defines additional actions implemented by a
28250 Shepherd service (see above).
28254 Symbol naming the action.
28256 @item documentation
28257 This is a documentation string for the action. It can be viewed by running:
28260 herd doc @var{service} action @var{action}
28264 This should be a gexp that evaluates to a procedure of at least one argument,
28265 which is the ``running value'' of the service (@pxref{Slots of services,,,
28266 shepherd, The GNU Shepherd Manual}).
28269 The following example defines an action called @code{say-hello} that kindly
28275 (documentation "Say hi!")
28276 (procedure #~(lambda (running . args)
28277 (format #t "Hello, friend! arguments: ~s\n"
28282 Assuming this action is added to the @code{example} service, then you can do:
28285 # herd say-hello example
28286 Hello, friend! arguments: ()
28287 # herd say-hello example a b c
28288 Hello, friend! arguments: ("a" "b" "c")
28291 This, as you can see, is a fairly sophisticated way to say hello.
28292 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
28296 @defvr {Scheme Variable} shepherd-root-service-type
28297 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
28299 This is the service type that extensions target when they want to create
28300 shepherd services (@pxref{Service Types and Services}, for an example).
28301 Each extension must pass a list of @code{<shepherd-service>}.
28304 @defvr {Scheme Variable} %shepherd-root-service
28305 This service represents PID@tie{}1.
28309 @node Documentation
28310 @chapter Documentation
28312 @cindex documentation, searching for
28313 @cindex searching for documentation
28314 @cindex Info, documentation format
28316 @cindex manual pages
28317 In most cases packages installed with Guix come with documentation.
28318 There are two main documentation formats: ``Info'', a browseable
28319 hypertext format used for GNU software, and ``manual pages'' (or ``man
28320 pages''), the linear documentation format traditionally found on Unix.
28321 Info manuals are accessed with the @command{info} command or with Emacs,
28322 and man pages are accessed using @command{man}.
28324 You can look for documentation of software installed on your system by
28325 keyword. For example, the following command searches for information
28326 about ``TLS'' in Info manuals:
28330 "(emacs)Network Security" -- STARTTLS
28331 "(emacs)Network Security" -- TLS
28332 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
28333 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
28338 The command below searches for the same keyword in man pages:
28342 SSL (7) - OpenSSL SSL/TLS library
28343 certtool (1) - GnuTLS certificate tool
28347 These searches are purely local to your computer so you have the
28348 guarantee that documentation you find corresponds to what you have
28349 actually installed, you can access it off-line, and your privacy is
28352 Once you have these results, you can view the relevant documentation by
28356 $ info "(gnutls)Core TLS API"
28366 Info manuals contain sections and indices as well as hyperlinks like
28367 those found in Web pages. The @command{info} reader (@pxref{Top, Info
28368 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
28369 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
28370 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
28371 Introduction}, for an introduction to Info navigation.
28373 @node Installing Debugging Files
28374 @chapter Installing Debugging Files
28376 @cindex debugging files
28377 Program binaries, as produced by the GCC compilers for instance, are
28378 typically written in the ELF format, with a section containing
28379 @dfn{debugging information}. Debugging information is what allows the
28380 debugger, GDB, to map binary code to source code; it is required to
28381 debug a compiled program in good conditions.
28383 The problem with debugging information is that is takes up a fair amount
28384 of disk space. For example, debugging information for the GNU C Library
28385 weighs in at more than 60 MiB. Thus, as a user, keeping all the
28386 debugging info of all the installed programs is usually not an option.
28387 Yet, space savings should not come at the cost of an impediment to
28388 debugging---especially in the GNU system, which should make it easier
28389 for users to exert their computing freedom (@pxref{GNU Distribution}).
28391 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
28392 mechanism that allows users to get the best of both worlds: debugging
28393 information can be stripped from the binaries and stored in separate
28394 files. GDB is then able to load debugging information from those files,
28395 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
28398 The GNU distribution takes advantage of this by storing debugging
28399 information in the @code{lib/debug} sub-directory of a separate package
28400 output unimaginatively called @code{debug} (@pxref{Packages with
28401 Multiple Outputs}). Users can choose to install the @code{debug} output
28402 of a package when they need it. For instance, the following command
28403 installs the debugging information for the GNU C Library and for GNU
28407 guix install glibc:debug guile:debug
28410 GDB must then be told to look for debug files in the user's profile, by
28411 setting the @code{debug-file-directory} variable (consider setting it
28412 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
28416 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
28419 From there on, GDB will pick up debugging information from the
28420 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
28422 In addition, you will most likely want GDB to be able to show the source
28423 code being debugged. To do that, you will have to unpack the source
28424 code of the package of interest (obtained with @code{guix build
28425 --source}, @pxref{Invoking guix build}), and to point GDB to that source
28426 directory using the @code{directory} command (@pxref{Source Path,
28427 @code{directory},, gdb, Debugging with GDB}).
28429 @c XXX: keep me up-to-date
28430 The @code{debug} output mechanism in Guix is implemented by the
28431 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
28432 opt-in---debugging information is available only for the packages
28433 with definitions explicitly declaring a @code{debug} output. This may be
28434 changed to opt-out in the future if our build farm servers can handle
28435 the load. To check whether a package has a @code{debug} output, use
28436 @command{guix package --list-available} (@pxref{Invoking guix package}).
28439 @node Security Updates
28440 @chapter Security Updates
28442 @cindex security updates
28443 @cindex security vulnerabilities
28444 Occasionally, important security vulnerabilities are discovered in software
28445 packages and must be patched. Guix developers try hard to keep track of
28446 known vulnerabilities and to apply fixes as soon as possible in the
28447 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
28448 containing only security updates.) The @command{guix lint} tool helps
28449 developers find out about vulnerable versions of software packages in the
28454 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
28455 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
28456 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
28460 @xref{Invoking guix lint}, for more information.
28462 Guix follows a functional
28463 package management discipline (@pxref{Introduction}), which implies
28464 that, when a package is changed, @emph{every package that depends on it}
28465 must be rebuilt. This can significantly slow down the deployment of
28466 fixes in core packages such as libc or Bash, since basically the whole
28467 distribution would need to be rebuilt. Using pre-built binaries helps
28468 (@pxref{Substitutes}), but deployment may still take more time than
28472 To address this, Guix implements @dfn{grafts}, a mechanism that allows
28473 for fast deployment of critical updates without the costs associated
28474 with a whole-distribution rebuild. The idea is to rebuild only the
28475 package that needs to be patched, and then to ``graft'' it onto packages
28476 explicitly installed by the user and that were previously referring to
28477 the original package. The cost of grafting is typically very low, and
28478 order of magnitudes lower than a full rebuild of the dependency chain.
28480 @cindex replacements of packages, for grafts
28481 For instance, suppose a security update needs to be applied to Bash.
28482 Guix developers will provide a package definition for the ``fixed''
28483 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
28484 Packages}). Then, the original package definition is augmented with a
28485 @code{replacement} field pointing to the package containing the bug fix:
28492 (replacement bash-fixed)))
28495 From there on, any package depending directly or indirectly on Bash---as
28496 reported by @command{guix gc --requisites} (@pxref{Invoking guix
28497 gc})---that is installed is automatically ``rewritten'' to refer to
28498 @code{bash-fixed} instead of @code{bash}. This grafting process takes
28499 time proportional to the size of the package, usually less than a
28500 minute for an ``average'' package on a recent machine. Grafting is
28501 recursive: when an indirect dependency requires grafting, then grafting
28502 ``propagates'' up to the package that the user is installing.
28504 Currently, the length of the name and version of the graft and that of
28505 the package it replaces (@code{bash-fixed} and @code{bash} in the example
28506 above) must be equal. This restriction mostly comes from the fact that
28507 grafting works by patching files, including binary files, directly.
28508 Other restrictions may apply: for instance, when adding a graft to a
28509 package providing a shared library, the original shared library and its
28510 replacement must have the same @code{SONAME} and be binary-compatible.
28512 The @option{--no-grafts} command-line option allows you to forcefully
28513 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
28517 guix build bash --no-grafts
28521 returns the store file name of the original Bash, whereas:
28528 returns the store file name of the ``fixed'', replacement Bash. This
28529 allows you to distinguish between the two variants of Bash.
28531 To verify which Bash your whole profile refers to, you can run
28532 (@pxref{Invoking guix gc}):
28535 guix gc -R `readlink -f ~/.guix-profile` | grep bash
28539 @dots{} and compare the store file names that you get with those above.
28540 Likewise for a complete Guix system generation:
28543 guix gc -R `guix system build my-config.scm` | grep bash
28546 Lastly, to check which Bash running processes are using, you can use the
28547 @command{lsof} command:
28550 lsof | grep /gnu/store/.*bash
28554 @node Bootstrapping
28555 @chapter Bootstrapping
28557 @c Adapted from the ELS 2013 paper.
28559 @cindex bootstrapping
28561 Bootstrapping in our context refers to how the distribution gets built
28562 ``from nothing''. Remember that the build environment of a derivation
28563 contains nothing but its declared inputs (@pxref{Introduction}). So
28564 there's an obvious chicken-and-egg problem: how does the first package
28565 get built? How does the first compiler get compiled? Note that this is
28566 a question of interest only to the curious hacker, not to the regular
28567 user, so you can shamelessly skip this section if you consider yourself
28568 a ``regular user''.
28570 @cindex bootstrap binaries
28571 The GNU system is primarily made of C code, with libc at its core. The
28572 GNU build system itself assumes the availability of a Bourne shell and
28573 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
28574 `grep'. Furthermore, build programs---programs that run
28575 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
28576 (@pxref{Derivations}). Consequently, to be able to build anything at
28577 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
28578 Binutils, libc, and the other packages mentioned above---the
28579 @dfn{bootstrap binaries}.
28581 These bootstrap binaries are ``taken for granted'', though we can also
28582 re-create them if needed (more on that later).
28584 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
28585 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
28588 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
28589 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
28592 @node Reduced Binary Seed Bootstrap
28593 @section The Reduced Binary Seed Bootstrap
28595 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
28596 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
28597 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
28598 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
28599 ``taken for granted.''
28601 Taking these binaries for granted means that we consider them to be a correct
28602 and trustworthy `seed' for building the complete system. Therein lies a
28603 problem: the current combined size of these bootstrap binaries is about 250MB
28604 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
28605 these is next to impossible.
28607 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
28608 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
28609 Bootstrap'' and while we are working towards that goal it would be hyperbole
28610 to use that term for what we do now.}.
28612 The Reduced Binary Seed bootstrap removes the most critical tools---from a
28613 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
28614 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
28615 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
28616 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
28617 these new binary seeds and a new set of
28619 packages@footnote{@c
28634 gcc-mesboot1-wrapper,
28635 glibc-headers-mesboot,
28639 gcc-mesboot-wrapper.
28642 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
28643 From here on the more traditional bootstrap process resumes. This approach
28644 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
28645 reduce this further. If you are interested, join us on @code{#bootstrappable}
28646 on the Freenode IRC network.
28648 @c ./pre-inst-env guix graph --type=bag -e '(begin (use-modules (guix packages)) (%current-system "i686-linux") (@@ (gnu packages commencement) gcc-mesboot))' > doc/images/gcc-mesboot-bag-graph.dot
28649 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
28651 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
28652 compiler used to build the rest of GuixSD.
28654 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
28656 @node Preparing to Use the Bootstrap Binaries
28657 @section Preparing to Use the Bootstrap Binaries
28659 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
28660 @c large image, it's hard to scroll. Oh well.
28661 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
28663 The figure above shows the very beginning of the dependency graph of the
28664 distribution, corresponding to the package definitions of the @code{(gnu
28665 packages bootstrap)} module. A similar figure can be generated with
28666 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
28669 guix graph -t derivation \
28670 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
28671 | dot -Tps > gcc.ps
28674 or, for the Reduced Binary Seed bootstrap
28677 guix graph -t derivation \
28678 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
28679 | dot -Tps > mes.ps
28682 At this level of detail, things are
28683 slightly complex. First, Guile itself consists of an ELF executable,
28684 along with many source and compiled Scheme files that are dynamically
28685 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
28686 tarball shown in this graph. This tarball is part of Guix's ``source''
28687 distribution, and gets inserted into the store with @code{add-to-store}
28688 (@pxref{The Store}).
28690 But how do we write a derivation that unpacks this tarball and adds it
28691 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
28692 derivation---the first one that gets built---uses @code{bash} as its
28693 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
28694 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
28695 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
28696 the Guix source distribution, whose sole purpose is to allow the Guile
28697 tarball to be unpacked.
28699 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
28700 Guile that can be used to run subsequent build programs. Its first task
28701 is to download tarballs containing the other pre-built binaries---this
28702 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
28703 @code{ftp-client.scm} are used for this purpose. The
28704 @code{module-import.drv} derivations import those modules in a directory
28705 in the store, using the original layout. The
28706 @code{module-import-compiled.drv} derivations compile those modules, and
28707 write them in an output directory with the right layout. This
28708 corresponds to the @code{#:modules} argument of
28709 @code{build-expression->derivation} (@pxref{Derivations}).
28711 Finally, the various tarballs are unpacked by the derivations
28712 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
28713 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
28714 point we have a working C tool chain.
28716 @unnumberedsec Building the Build Tools
28718 Bootstrapping is complete when we have a full tool chain that does not
28719 depend on the pre-built bootstrap tools discussed above. This
28720 no-dependency requirement is verified by checking whether the files of
28721 the final tool chain contain references to the @file{/gnu/store}
28722 directories of the bootstrap inputs. The process that leads to this
28723 ``final'' tool chain is described by the package definitions found in
28724 the @code{(gnu packages commencement)} module.
28726 The @command{guix graph} command allows us to ``zoom out'' compared to
28727 the graph above, by looking at the level of package objects instead of
28728 individual derivations---remember that a package may translate to
28729 several derivations, typically one derivation to download its source,
28730 one to build the Guile modules it needs, and one to actually build the
28731 package from source. The command:
28734 guix graph -t bag \
28735 -e '(@@@@ (gnu packages commencement)
28736 glibc-final-with-bootstrap-bash)' | xdot -
28740 displays the dependency graph leading to the ``final'' C
28741 library@footnote{You may notice the @code{glibc-intermediate} label,
28742 suggesting that it is not @emph{quite} final, but as a good
28743 approximation, we will consider it final.}, depicted below.
28745 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
28747 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
28748 The first tool that gets built with the bootstrap binaries is
28749 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
28750 for all the following packages. From there Findutils and Diffutils get
28753 Then come the first-stage Binutils and GCC, built as pseudo cross
28754 tools---i.e., with @option{--target} equal to @option{--host}. They are
28755 used to build libc. Thanks to this cross-build trick, this libc is
28756 guaranteed not to hold any reference to the initial tool chain.
28758 From there the final Binutils and GCC (not shown above) are built. GCC
28759 uses @command{ld} from the final Binutils, and links programs against
28760 the just-built libc. This tool chain is used to build the other
28761 packages used by Guix and by the GNU Build System: Guile, Bash,
28764 And voilà! At this point we have the complete set of build tools that
28765 the GNU Build System expects. These are in the @code{%final-inputs}
28766 variable of the @code{(gnu packages commencement)} module, and are
28767 implicitly used by any package that uses @code{gnu-build-system}
28768 (@pxref{Build Systems, @code{gnu-build-system}}).
28771 @unnumberedsec Building the Bootstrap Binaries
28773 @cindex bootstrap binaries
28774 Because the final tool chain does not depend on the bootstrap binaries,
28775 those rarely need to be updated. Nevertheless, it is useful to have an
28776 automated way to produce them, should an update occur, and this is what
28777 the @code{(gnu packages make-bootstrap)} module provides.
28779 The following command builds the tarballs containing the bootstrap binaries
28780 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
28781 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
28782 and Guile, and a tarball containing a mixture of Coreutils and other basic
28783 command-line tools):
28786 guix build bootstrap-tarballs
28789 The generated tarballs are those that should be referred to in the
28790 @code{(gnu packages bootstrap)} module mentioned at the beginning of
28793 Still here? Then perhaps by now you've started to wonder: when do we
28794 reach a fixed point? That is an interesting question! The answer is
28795 unknown, but if you would like to investigate further (and have
28796 significant computational and storage resources to do so), then let us
28799 @unnumberedsec Reducing the Set of Bootstrap Binaries
28801 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
28802 binary code! Why is that a problem? It's a problem because these big chunks
28803 of binary code are practically non-auditable, which makes it hard to establish
28804 what source code produced them. Every unauditable binary also leaves us
28805 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
28806 paper @emph{Reflections on Trusting Trust}.
28808 This is mitigated by the fact that our bootstrap binaries were generated
28809 from an earlier Guix revision. Nevertheless it lacks the level of
28810 transparency that we get in the rest of the package dependency graph,
28811 where Guix always gives us a source-to-binary mapping. Thus, our goal
28812 is to reduce the set of bootstrap binaries to the bare minimum.
28814 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
28815 on-going projects to do that. One of these is about replacing the
28816 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
28817 of increasing complexity, which could be built from source starting from
28818 a simple and auditable assembler.
28820 Our first major achievement is the replacement of of GCC, the GNU C Library
28821 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
28822 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
28823 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
28824 bootstrapped yet and thus we inject them as binary seeds. We call this the
28825 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
28826 binaries! Also, it has eliminated the C compiler binary; i686-linux and
28827 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
28829 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
28830 also looking at any other bootstrap binaries. Your help is welcome!
28833 @chapter Porting to a New Platform
28835 As discussed above, the GNU distribution is self-contained, and
28836 self-containment is achieved by relying on pre-built ``bootstrap
28837 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
28838 operating system kernel, CPU architecture, and application binary
28839 interface (ABI). Thus, to port the distribution to a platform that is
28840 not yet supported, one must build those bootstrap binaries, and update
28841 the @code{(gnu packages bootstrap)} module to use them on that platform.
28843 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
28844 When everything goes well, and assuming the GNU tool chain supports the
28845 target platform, this can be as simple as running a command like this
28849 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
28852 For this to work, the @code{glibc-dynamic-linker} procedure in
28853 @code{(gnu packages bootstrap)} must be augmented to return the right
28854 file name for libc's dynamic linker on that platform; likewise,
28855 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
28856 taught about the new platform.
28858 Once these are built, the @code{(gnu packages bootstrap)} module needs
28859 to be updated to refer to these binaries on the target platform. That
28860 is, the hashes and URLs of the bootstrap tarballs for the new platform
28861 must be added alongside those of the currently supported platforms. The
28862 bootstrap Guile tarball is treated specially: it is expected to be
28863 available locally, and @file{gnu/local.mk} has rules to download it for
28864 the supported architectures; a rule for the new platform must be added
28867 In practice, there may be some complications. First, it may be that the
28868 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
28869 above) is not recognized by all the GNU tools. Typically, glibc
28870 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
28871 configure flag (see @code{gcc.scm} for examples of how to handle this).
28872 Second, some of the required packages could fail to build for that
28873 platform. Lastly, the generated binaries could be broken for some
28876 @c *********************************************************************
28877 @include contributing.texi
28879 @c *********************************************************************
28880 @node Acknowledgments
28881 @chapter Acknowledgments
28883 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
28884 which was designed and
28885 implemented by Eelco Dolstra, with contributions from other people (see
28886 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
28887 management, and promoted unprecedented features, such as transactional
28888 package upgrades and rollbacks, per-user profiles, and referentially
28889 transparent build processes. Without this work, Guix would not exist.
28891 The Nix-based software distributions, Nixpkgs and NixOS, have also been
28892 an inspiration for Guix.
28894 GNU@tie{}Guix itself is a collective work with contributions from a
28895 number of people. See the @file{AUTHORS} file in Guix for more
28896 information on these fine people. The @file{THANKS} file lists people
28897 who have helped by reporting bugs, taking care of the infrastructure,
28898 providing artwork and themes, making suggestions, and more---thank you!
28901 @c *********************************************************************
28902 @node GNU Free Documentation License
28903 @appendix GNU Free Documentation License
28904 @cindex license, GNU Free Documentation License
28905 @include fdl-1.3.texi
28907 @c *********************************************************************
28908 @node Concept Index
28909 @unnumbered Concept Index
28912 @node Programming Index
28913 @unnumbered Programming Index
28914 @syncodeindex tp fn
28915 @syncodeindex vr fn
28920 @c Local Variables:
28921 @c ispell-local-dictionary: "american";