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 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 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 @code{--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 @code{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 @code{--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 @code{--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 @code{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 @code{TMPDIR} does not leak inside build
1011 environments, which avoids discrepancies in cases where build processes
1012 capture the name of their build tree.
1015 The daemon also honors the @code{http_proxy} environment variable for
1016 HTTP downloads it performs, be it for fixed-output derivations
1017 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1019 If you are installing Guix as an unprivileged user, it is still possible
1020 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1021 However, build processes will not be isolated from one another, and not
1022 from the rest of the system. Thus, build processes may interfere with
1023 each other, and may access programs, libraries, and other files
1024 available on the system---making it much harder to view them as
1025 @emph{pure} functions.
1028 @node Daemon Offload Setup
1029 @subsection Using the Offload Facility
1033 When desired, the build daemon can @dfn{offload} derivation builds to
1034 other machines running Guix, using the @code{offload} @dfn{build
1035 hook}@footnote{This feature is available only when
1036 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1037 present.}. When that
1038 feature is enabled, a list of user-specified build machines is read from
1039 @file{/etc/guix/machines.scm}; every time a build is requested, for
1040 instance via @code{guix build}, the daemon attempts to offload it to one
1041 of the machines that satisfy the constraints of the derivation, in
1042 particular its system type---e.g., @file{x86_64-linux}. Missing
1043 prerequisites for the build are copied over SSH to the target machine,
1044 which then proceeds with the build; upon success the output(s) of the
1045 build are copied back to the initial machine.
1047 The @file{/etc/guix/machines.scm} file typically looks like this:
1050 (list (build-machine
1051 (name "eightysix.example.org")
1052 (system "x86_64-linux")
1053 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1055 (speed 2.)) ;incredibly fast!
1058 (name "meeps.example.org")
1059 (system "mips64el-linux")
1060 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1063 (string-append (getenv "HOME")
1064 "/.ssh/identity-for-guix"))))
1068 In the example above we specify a list of two build machines, one for
1069 the @code{x86_64} architecture and one for the @code{mips64el}
1072 In fact, this file is---not surprisingly!---a Scheme file that is
1073 evaluated when the @code{offload} hook is started. Its return value
1074 must be a list of @code{build-machine} objects. While this example
1075 shows a fixed list of build machines, one could imagine, say, using
1076 DNS-SD to return a list of potential build machines discovered in the
1077 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1078 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1081 @deftp {Data Type} build-machine
1082 This data type represents build machines to which the daemon may offload
1083 builds. The important fields are:
1088 The host name of the remote machine.
1091 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1094 The user account to use when connecting to the remote machine over SSH.
1095 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1096 allow non-interactive logins.
1099 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1100 This is used to authenticate the machine when we connect to it. It is a
1101 long string that looks like this:
1104 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1107 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1108 key can be found in a file such as
1109 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1111 If the machine is running the SSH daemon of GNU@tie{}lsh,
1112 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1113 similar file. It can be converted to the OpenSSH format using
1114 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1117 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1118 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1123 A number of optional fields may be specified:
1127 @item @code{port} (default: @code{22})
1128 Port number of SSH server on the machine.
1130 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1131 The SSH private key file to use when connecting to the machine, in
1132 OpenSSH format. This key must not be protected with a passphrase.
1134 Note that the default value is the private key @emph{of the root
1135 account}. Make sure it exists if you use the default.
1137 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1138 @itemx @code{compression-level} (default: @code{3})
1139 The SSH-level compression methods and compression level requested.
1141 Note that offloading relies on SSH compression to reduce bandwidth usage
1142 when transferring files to and from build machines.
1144 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1145 File name of the Unix-domain socket @command{guix-daemon} is listening
1148 @item @code{parallel-builds} (default: @code{1})
1149 The number of builds that may run in parallel on the machine.
1151 @item @code{speed} (default: @code{1.0})
1152 A ``relative speed factor''. The offload scheduler will tend to prefer
1153 machines with a higher speed factor.
1155 @item @code{features} (default: @code{'()})
1156 A list of strings denoting specific features supported by the machine.
1157 An example is @code{"kvm"} for machines that have the KVM Linux modules
1158 and corresponding hardware support. Derivations can request features by
1159 name, and they will be scheduled on matching build machines.
1164 The @command{guix} command must be in the search path on the build
1165 machines. You can check whether this is the case by running:
1168 ssh build-machine guix repl --version
1171 There is one last thing to do once @file{machines.scm} is in place. As
1172 explained above, when offloading, files are transferred back and forth
1173 between the machine stores. For this to work, you first need to
1174 generate a key pair on each machine to allow the daemon to export signed
1175 archives of files from the store (@pxref{Invoking guix archive}):
1178 # guix archive --generate-key
1182 Each build machine must authorize the key of the master machine so that
1183 it accepts store items it receives from the master:
1186 # guix archive --authorize < master-public-key.txt
1190 Likewise, the master machine must authorize the key of each build machine.
1192 All the fuss with keys is here to express pairwise mutual trust
1193 relations between the master and the build machines. Concretely, when
1194 the master receives files from a build machine (and @i{vice versa}), its
1195 build daemon can make sure they are genuine, have not been tampered
1196 with, and that they are signed by an authorized key.
1198 @cindex offload test
1199 To test whether your setup is operational, run this command on the
1206 This will attempt to connect to each of the build machines specified in
1207 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1208 available on each machine, attempt to export to the machine and import
1209 from it, and report any error in the process.
1211 If you want to test a different machine file, just specify it on the
1215 # guix offload test machines-qualif.scm
1218 Last, you can test the subset of the machines whose name matches a
1219 regular expression like this:
1222 # guix offload test machines.scm '\.gnu\.org$'
1225 @cindex offload status
1226 To display the current load of all build hosts, run this command on the
1230 # guix offload status
1234 @node SELinux Support
1235 @subsection SELinux Support
1237 @cindex SELinux, daemon policy
1238 @cindex mandatory access control, SELinux
1239 @cindex security, guix-daemon
1240 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1241 can be installed on a system where SELinux is enabled, in order to label
1242 Guix files and to specify the expected behavior of the daemon. Since
1243 Guix System does not provide an SELinux base policy, the daemon policy cannot
1244 be used on Guix System.
1246 @subsubsection Installing the SELinux policy
1247 @cindex SELinux, policy installation
1248 To install the policy run this command as root:
1251 semodule -i etc/guix-daemon.cil
1254 Then relabel the file system with @code{restorecon} or by a different
1255 mechanism provided by your system.
1257 Once the policy is installed, the file system has been relabeled, and
1258 the daemon has been restarted, it should be running in the
1259 @code{guix_daemon_t} context. You can confirm this with the following
1263 ps -Zax | grep guix-daemon
1266 Monitor the SELinux log files as you run a command like @code{guix build
1267 hello} to convince yourself that SELinux permits all necessary
1270 @subsubsection Limitations
1271 @cindex SELinux, limitations
1273 This policy is not perfect. Here is a list of limitations or quirks
1274 that should be considered when deploying the provided SELinux policy for
1279 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1280 operations involve contexts that have anything to do with
1281 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1282 but it would be preferrable to define socket rules for only this label.
1285 @code{guix gc} cannot access arbitrary links to profiles. By design,
1286 the file label of the destination of a symlink is independent of the
1287 file label of the link itself. Although all profiles under
1288 $localstatedir are labelled, the links to these profiles inherit the
1289 label of the directory they are in. For links in the user’s home
1290 directory this will be @code{user_home_t}. But for links from the root
1291 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1292 directory, etc, this won’t work. @code{guix gc} would be prevented from
1293 reading and following these links.
1296 The daemon’s feature to listen for TCP connections might no longer work.
1297 This might require extra rules, because SELinux treats network sockets
1298 differently from files.
1301 Currently all files with a name matching the regular expression
1302 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1303 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1304 that name in any profile would be permitted to run in the
1305 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1306 build a package that provides this executable and convince a user to
1307 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1308 At that point SELinux could not prevent it from accessing files that are
1309 allowed for processes in that domain.
1311 We could generate a much more restrictive policy at installation time,
1312 so that only the @emph{exact} file name of the currently installed
1313 @code{guix-daemon} executable would be labelled with
1314 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1315 The downside is that root would have to install or upgrade the policy at
1316 installation time whenever the Guix package that provides the
1317 effectively running @code{guix-daemon} executable is upgraded.
1320 @node Invoking guix-daemon
1321 @section Invoking @command{guix-daemon}
1323 The @command{guix-daemon} program implements all the functionality to
1324 access the store. This includes launching build processes, running the
1325 garbage collector, querying the availability of a build result, etc. It
1326 is normally run as @code{root} like this:
1329 # guix-daemon --build-users-group=guixbuild
1333 For details on how to set it up, @pxref{Setting Up the Daemon}.
1336 @cindex container, build environment
1337 @cindex build environment
1338 @cindex reproducible builds
1339 By default, @command{guix-daemon} launches build processes under
1340 different UIDs, taken from the build group specified with
1341 @code{--build-users-group}. In addition, each build process is run in a
1342 chroot environment that only contains the subset of the store that the
1343 build process depends on, as specified by its derivation
1344 (@pxref{Programming Interface, derivation}), plus a set of specific
1345 system directories. By default, the latter contains @file{/dev} and
1346 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1347 @dfn{container}: in addition to having its own file system tree, it has
1348 a separate mount name space, its own PID name space, network name space,
1349 etc. This helps achieve reproducible builds (@pxref{Features}).
1351 When the daemon performs a build on behalf of the user, it creates a
1352 build directory under @file{/tmp} or under the directory specified by
1353 its @code{TMPDIR} environment variable. This directory is shared with
1354 the container for the duration of the build, though within the container,
1355 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1357 The build directory is automatically deleted upon completion, unless the
1358 build failed and the client specified @option{--keep-failed}
1359 (@pxref{Invoking guix build, @option{--keep-failed}}).
1361 The daemon listens for connections and spawns one sub-process for each session
1362 started by a client (one of the @command{guix} sub-commands.) The
1363 @command{guix processes} command allows you to get an overview of the activity
1364 on your system by viewing each of the active sessions and clients.
1365 @xref{Invoking guix processes}, for more information.
1367 The following command-line options are supported:
1370 @item --build-users-group=@var{group}
1371 Take users from @var{group} to run build processes (@pxref{Setting Up
1372 the Daemon, build users}).
1374 @item --no-substitutes
1376 Do not use substitutes for build products. That is, always build things
1377 locally instead of allowing downloads of pre-built binaries
1378 (@pxref{Substitutes}).
1380 When the daemon runs with @code{--no-substitutes}, clients can still
1381 explicitly enable substitution @i{via} the @code{set-build-options}
1382 remote procedure call (@pxref{The Store}).
1384 @item --substitute-urls=@var{urls}
1385 @anchor{daemon-substitute-urls}
1386 Consider @var{urls} the default whitespace-separated list of substitute
1387 source URLs. When this option is omitted,
1388 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1390 This means that substitutes may be downloaded from @var{urls}, as long
1391 as they are signed by a trusted signature (@pxref{Substitutes}).
1395 Do not use offload builds to other machines (@pxref{Daemon Offload
1396 Setup}). That is, always build things locally instead of offloading
1397 builds to remote machines.
1399 @item --cache-failures
1400 Cache build failures. By default, only successful builds are cached.
1402 When this option is used, @command{guix gc --list-failures} can be used
1403 to query the set of store items marked as failed; @command{guix gc
1404 --clear-failures} removes store items from the set of cached failures.
1405 @xref{Invoking guix gc}.
1407 @item --cores=@var{n}
1409 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1412 The default value is @code{0}, but it may be overridden by clients, such
1413 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1416 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1417 in the build process, which can then use it to exploit internal
1418 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1420 @item --max-jobs=@var{n}
1422 Allow at most @var{n} build jobs in parallel. The default value is
1423 @code{1}. Setting it to @code{0} means that no builds will be performed
1424 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1425 Setup}), or simply fail.
1427 @item --max-silent-time=@var{seconds}
1428 When the build or substitution process remains silent for more than
1429 @var{seconds}, terminate it and report a build failure.
1431 The default value is @code{0}, which disables the timeout.
1433 The value specified here can be overridden by clients (@pxref{Common
1434 Build Options, @code{--max-silent-time}}).
1436 @item --timeout=@var{seconds}
1437 Likewise, when the build or substitution process lasts for more than
1438 @var{seconds}, terminate it and report a build failure.
1440 The default value is @code{0}, which disables the timeout.
1442 The value specified here can be overridden by clients (@pxref{Common
1443 Build Options, @code{--timeout}}).
1445 @item --rounds=@var{N}
1446 Build each derivation @var{n} times in a row, and raise an error if
1447 consecutive build results are not bit-for-bit identical. Note that this
1448 setting can be overridden by clients such as @command{guix build}
1449 (@pxref{Invoking guix build}).
1451 When used in conjunction with @option{--keep-failed}, the differing
1452 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1453 This makes it easy to look for differences between the two results.
1456 Produce debugging output.
1458 This is useful to debug daemon start-up issues, but then it may be
1459 overridden by clients, for example the @code{--verbosity} option of
1460 @command{guix build} (@pxref{Invoking guix build}).
1462 @item --chroot-directory=@var{dir}
1463 Add @var{dir} to the build chroot.
1465 Doing this may change the result of build processes---for instance if
1466 they use optional dependencies found in @var{dir} when it is available,
1467 and not otherwise. For that reason, it is not recommended to do so.
1468 Instead, make sure that each derivation declares all the inputs that it
1471 @item --disable-chroot
1472 Disable chroot builds.
1474 Using this option is not recommended since, again, it would allow build
1475 processes to gain access to undeclared dependencies. It is necessary,
1476 though, when @command{guix-daemon} is running under an unprivileged user
1479 @item --log-compression=@var{type}
1480 Compress build logs according to @var{type}, one of @code{gzip},
1481 @code{bzip2}, or @code{none}.
1483 Unless @code{--lose-logs} is used, all the build logs are kept in the
1484 @var{localstatedir}. To save space, the daemon automatically compresses
1485 them with bzip2 by default.
1487 @item --disable-deduplication
1488 @cindex deduplication
1489 Disable automatic file ``deduplication'' in the store.
1491 By default, files added to the store are automatically ``deduplicated'':
1492 if a newly added file is identical to another one found in the store,
1493 the daemon makes the new file a hard link to the other file. This can
1494 noticeably reduce disk usage, at the expense of slightly increased
1495 input/output load at the end of a build process. This option disables
1498 @item --gc-keep-outputs[=yes|no]
1499 Tell whether the garbage collector (GC) must keep outputs of live
1503 @cindex garbage collector roots
1504 When set to ``yes'', the GC will keep the outputs of any live derivation
1505 available in the store---the @code{.drv} files. The default is ``no'',
1506 meaning that derivation outputs are kept only if they are reachable from a GC
1507 root. @xref{Invoking guix gc}, for more on GC roots.
1509 @item --gc-keep-derivations[=yes|no]
1510 Tell whether the garbage collector (GC) must keep derivations
1511 corresponding to live outputs.
1513 When set to ``yes'', as is the case by default, the GC keeps
1514 derivations---i.e., @code{.drv} files---as long as at least one of their
1515 outputs is live. This allows users to keep track of the origins of
1516 items in their store. Setting it to ``no'' saves a bit of disk space.
1518 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1519 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1520 ``yes'' causes liveness to flow from derivations to outputs. When both are
1521 set to ``yes'', the effect is to keep all the build prerequisites (the
1522 sources, compiler, libraries, and other build-time tools) of live objects in
1523 the store, regardless of whether these prerequisites are reachable from a GC
1524 root. This is convenient for developers since it saves rebuilds or downloads.
1526 @item --impersonate-linux-2.6
1527 On Linux-based systems, impersonate Linux 2.6. This means that the
1528 kernel's @code{uname} system call will report 2.6 as the release number.
1530 This might be helpful to build programs that (usually wrongfully) depend
1531 on the kernel version number.
1534 Do not keep build logs. By default they are kept under
1535 @code{@var{localstatedir}/guix/log}.
1537 @item --system=@var{system}
1538 Assume @var{system} as the current system type. By default it is the
1539 architecture/kernel pair found at configure time, such as
1540 @code{x86_64-linux}.
1542 @item --listen=@var{endpoint}
1543 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1544 as the file name of a Unix-domain socket if it starts with
1545 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1546 host name or host name and port to listen to. Here are a few examples:
1549 @item --listen=/gnu/var/daemon
1550 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1551 creating it if needed.
1553 @item --listen=localhost
1554 @cindex daemon, remote access
1555 @cindex remote access to the daemon
1556 @cindex daemon, cluster setup
1557 @cindex clusters, daemon setup
1558 Listen for TCP connections on the network interface corresponding to
1559 @code{localhost}, on port 44146.
1561 @item --listen=128.0.0.42:1234
1562 Listen for TCP connections on the network interface corresponding to
1563 @code{128.0.0.42}, on port 1234.
1566 This option can be repeated multiple times, in which case
1567 @command{guix-daemon} accepts connections on all the specified
1568 endpoints. Users can tell client commands what endpoint to connect to
1569 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1570 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1573 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1574 @code{--listen=@var{host}} is suitable on local networks, such as
1575 clusters, where only trusted nodes may connect to the build daemon. In
1576 other cases where remote access to the daemon is needed, we recommend
1577 using Unix-domain sockets along with SSH.
1580 When @code{--listen} is omitted, @command{guix-daemon} listens for
1581 connections on the Unix-domain socket located at
1582 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1586 @node Application Setup
1587 @section Application Setup
1589 @cindex foreign distro
1590 When using Guix on top of GNU/Linux distribution other than Guix System---a
1591 so-called @dfn{foreign distro}---a few additional steps are needed to
1592 get everything in place. Here are some of them.
1596 @anchor{locales-and-locpath}
1597 @cindex locales, when not on Guix System
1599 @vindex GUIX_LOCPATH
1600 Packages installed @i{via} Guix will not use the locale data of the
1601 host system. Instead, you must first install one of the locale packages
1602 available with Guix and then define the @code{GUIX_LOCPATH} environment
1606 $ guix install glibc-locales
1607 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1610 Note that the @code{glibc-locales} package contains data for all the
1611 locales supported by the GNU@tie{}libc and weighs in at around
1612 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1613 limited to a few UTF-8 locales.
1615 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1616 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1617 Manual}). There are two important differences though:
1621 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1622 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1623 to make sure the programs of the foreign distro will not end up loading
1624 incompatible locale data.
1627 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1628 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1629 should your Guix profile contain a mixture of programs linked against
1630 different libc version, each libc version will only try to load locale
1631 data in the right format.
1634 This is important because the locale data format used by different libc
1635 versions may be incompatible.
1637 @subsection Name Service Switch
1639 @cindex name service switch, glibc
1640 @cindex NSS (name service switch), glibc
1641 @cindex nscd (name service caching daemon)
1642 @cindex name service caching daemon (nscd)
1643 When using Guix on a foreign distro, we @emph{strongly recommend} that
1644 the system run the GNU C library's @dfn{name service cache daemon},
1645 @command{nscd}, which should be listening on the
1646 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1647 installed with Guix may fail to look up host names or user accounts, or
1648 may even crash. The next paragraphs explain why.
1650 @cindex @file{nsswitch.conf}
1651 The GNU C library implements a @dfn{name service switch} (NSS), which is
1652 an extensible mechanism for ``name lookups'' in general: host name
1653 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1654 The GNU C Library Reference Manual}).
1656 @cindex Network information service (NIS)
1657 @cindex NIS (Network information service)
1658 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1659 lookup implementations: for example, the @code{nss-mdns} plugin allow
1660 resolution of @code{.local} host names, the @code{nis} plugin allows
1661 user account lookup using the Network information service (NIS), and so
1662 on. These extra ``lookup services'' are configured system-wide in
1663 @file{/etc/nsswitch.conf}, and all the programs running on the system
1664 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1667 When they perform a name lookup---for instance by calling the
1668 @code{getaddrinfo} function in C---applications first try to connect to
1669 the nscd; on success, nscd performs name lookups on their behalf. If
1670 the nscd is not running, then they perform the name lookup by
1671 themselves, by loading the name lookup services into their own address
1672 space and running it. These name lookup services---the
1673 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1674 the host system's C library, rather than from the C library the
1675 application is linked against (the C library coming from Guix).
1677 And this is where the problem is: if your application is linked against
1678 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1679 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1680 likely crash or have its name lookups fail unexpectedly.
1682 Running @command{nscd} on the system, among other advantages, eliminates
1683 this binary incompatibility problem because those @code{libnss_*.so}
1684 files are loaded in the @command{nscd} process, not in applications
1687 @subsection X11 Fonts
1690 The majority of graphical applications use Fontconfig to locate and
1691 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1692 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1693 by default. Thus, to allow graphical applications installed with Guix
1694 to display fonts, you have to install fonts with Guix as well.
1695 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1696 @code{font-gnu-freefont}.
1698 @cindex @code{fc-cache}
1700 Once you have installed or removed fonts, or when you notice an
1701 application that does not find fonts, you may need to install Fontconfig
1702 and to force an update of its font cache by running:
1705 guix install fontconfig
1709 To display text written in Chinese languages, Japanese, or Korean in
1710 graphical applications, consider installing
1711 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1712 has multiple outputs, one per language family (@pxref{Packages with
1713 Multiple Outputs}). For instance, the following command installs fonts
1714 for Chinese languages:
1717 guix install font-adobe-source-han-sans:cn
1720 @cindex @code{xterm}
1721 Older programs such as @command{xterm} do not use Fontconfig and instead
1722 rely on server-side font rendering. Such programs require to specify a
1723 full name of a font using XLFD (X Logical Font Description), like this:
1726 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1729 To be able to use such full names for the TrueType fonts installed in
1730 your Guix profile, you need to extend the font path of the X server:
1732 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1733 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1735 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1738 @cindex @code{xlsfonts}
1739 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1740 to make sure your TrueType fonts are listed there.
1743 @subsection X.509 Certificates
1745 @cindex @code{nss-certs}
1746 The @code{nss-certs} package provides X.509 certificates, which allow
1747 programs to authenticate Web servers accessed over HTTPS.
1749 When using Guix on a foreign distro, you can install this package and
1750 define the relevant environment variables so that packages know where to
1751 look for certificates. @xref{X.509 Certificates}, for detailed
1754 @subsection Emacs Packages
1756 @cindex @code{emacs}
1757 When you install Emacs packages with Guix, the Elisp files are placed
1758 under the @file{share/emacs/site-lisp/} directory of the profile in
1759 which they are installed. The Elisp libraries are made available to
1760 Emacs through the @code{EMACSLOADPATH} environment variable, which is
1761 set when installing Emacs itself.
1763 Additionally, autoload definitions are automatically evaluated at the
1764 initialization of Emacs, by the Guix-specific
1765 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1766 want to avoid auto-loading the Emacs packages installed with Guix, you
1767 can do so by running Emacs with the @code{--no-site-file} option
1768 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1770 @subsection The GCC toolchain
1772 @c XXX: The contents of this section were moved under
1773 @c ``Development'', since it makes more sense there and is not specific
1774 @c foreign distros. Remove it from here eventually?
1775 @xref{Packages for C Development}, for information on packages for C/C++
1778 @node Upgrading Guix
1779 @section Upgrading Guix
1781 @cindex Upgrading Guix, on a foreign distro
1783 To upgrade Guix, run:
1789 @xref{Invoking guix pull}, for more information.
1791 @cindex upgrading Guix for the root user, on a foreign distro
1792 @cindex upgrading the Guix daemon, on a foreign distro
1793 @cindex @command{guix pull} for the root user, on a foreign distro
1795 On a foreign distro, you can upgrade the build daemon by running:
1802 followed by (assuming your distro uses the systemd service management
1806 systemctl restart guix-daemon.service
1809 On Guix System, upgrading the daemon is achieved by reconfiguring the
1810 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1814 @c *********************************************************************
1815 @node System Installation
1816 @chapter System Installation
1818 @cindex installing Guix System
1819 @cindex Guix System, installation
1820 This section explains how to install Guix System
1821 on a machine. Guix, as a package manager, can
1822 also be installed on top of a running GNU/Linux system,
1823 @pxref{Installation}.
1827 @c This paragraph is for people reading this from tty2 of the
1828 @c installation image.
1829 You are reading this documentation with an Info reader. For details on
1830 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1831 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1832 Info}. Hit @kbd{l} afterwards to come back here.
1834 Alternately, run @command{info info} in another tty to keep the manual
1840 * Limitations:: What you can expect.
1841 * Hardware Considerations:: Supported hardware.
1842 * USB Stick and DVD Installation:: Preparing the installation medium.
1843 * Preparing for Installation:: Networking, partitioning, etc.
1844 * Guided Graphical Installation:: Easy graphical installation.
1845 * Manual Installation:: Manual installation for wizards.
1846 * After System Installation:: When installation succeeded.
1847 * Installing Guix in a VM:: Guix System playground.
1848 * Building the Installation Image:: How this comes to be.
1852 @section Limitations
1854 We consider Guix System to be ready for a wide range of ``desktop'' and server
1855 use cases. The reliability guarantees it provides---transactional upgrades
1856 and rollbacks, reproducibility---make it a solid foundation.
1858 Nevertheless, before you proceed with the installation, be aware of the
1859 following noteworthy limitations applicable to version @value{VERSION}:
1863 Support for the Logical Volume Manager (LVM) is missing.
1866 More and more system services are provided (@pxref{Services}), but some
1870 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1871 as well as a number of X11 window managers. However, KDE is currently
1875 More than a disclaimer, this is an invitation to report issues (and success
1876 stories!), and to join us in improving it. @xref{Contributing}, for more
1880 @node Hardware Considerations
1881 @section Hardware Considerations
1883 @cindex hardware support on Guix System
1884 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1885 builds around the kernel Linux-libre, which means that only hardware for
1886 which free software drivers and firmware exist is supported. Nowadays,
1887 a wide range of off-the-shelf hardware is supported on
1888 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1889 Ethernet controllers. Unfortunately, there are still areas where
1890 hardware vendors deny users control over their own computing, and such
1891 hardware is not supported on Guix System.
1893 @cindex WiFi, hardware support
1894 One of the main areas where free drivers or firmware are lacking is WiFi
1895 devices. WiFi devices known to work include those using Atheros chips
1896 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1897 driver, and those using Broadcom/AirForce chips (BCM43xx with
1898 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1899 Linux-libre driver. Free firmware exists for both and is available
1900 out-of-the-box on Guix System, as part of @code{%base-firmware}
1901 (@pxref{operating-system Reference, @code{firmware}}).
1903 @cindex RYF, Respects Your Freedom
1904 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1905 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1906 certification program for hardware products that respect your freedom
1907 and your privacy and ensure that you have control over your device. We
1908 encourage you to check the list of RYF-certified devices.
1910 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1911 web site. It contains a catalog of hardware devices with information
1912 about their support in GNU/Linux.
1915 @node USB Stick and DVD Installation
1916 @section USB Stick and DVD Installation
1918 An ISO-9660 installation image that can be written to a USB stick or
1919 burnt to a DVD can be downloaded from
1920 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1921 where @var{system} is one of:
1925 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1928 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1931 @c start duplication of authentication part from ``Binary Installation''
1932 Make sure to download the associated @file{.sig} file and to verify the
1933 authenticity of the image against it, along these lines:
1936 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1937 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1940 If that command fails because you do not have the required public key,
1941 then run this command to import it:
1944 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1945 -qO - | gpg --import -
1949 and rerun the @code{gpg --verify} command.
1951 Take note that a warning like ``This key is not certified with a trusted
1952 signature!'' is normal.
1956 This image contains the tools necessary for an installation.
1957 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1959 @unnumberedsubsec Copying to a USB Stick
1961 To copy the image to a USB stick, follow these steps:
1965 Decompress the image using the @command{xz} command:
1968 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1972 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1973 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1974 copy the image with:
1977 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1981 Access to @file{/dev/sdX} usually requires root privileges.
1984 @unnumberedsubsec Burning on a DVD
1986 To copy the image to a DVD, follow these steps:
1990 Decompress the image using the @command{xz} command:
1993 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1997 Insert a blank DVD into your machine, and determine
1998 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1999 copy the image with:
2002 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
2005 Access to @file{/dev/srX} usually requires root privileges.
2008 @unnumberedsubsec Booting
2010 Once this is done, you should be able to reboot the system and boot from
2011 the USB stick or DVD. The latter usually requires you to get in the
2012 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2013 In order to boot from Libreboot, switch to the command mode by pressing
2014 the @kbd{c} key and type @command{search_grub usb}.
2016 @xref{Installing Guix in a VM}, if, instead, you would like to install
2017 Guix System in a virtual machine (VM).
2020 @node Preparing for Installation
2021 @section Preparing for Installation
2023 Once you have booted, you can use the guided graphical installer, which makes
2024 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2025 if you are already familiar with GNU/Linux and if you want more control than
2026 what the graphical installer provides, you can choose the ``manual''
2027 installation process (@pxref{Manual Installation}).
2029 The graphical installer is available on TTY1. You can obtain root shells on
2030 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2031 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2032 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2033 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2034 which allows you to select text with the left mouse button and to paste it
2035 with the middle button.
2038 Installation requires access to the Internet so that any missing
2039 dependencies of your system configuration can be downloaded. See the
2040 ``Networking'' section below.
2043 @node Guided Graphical Installation
2044 @section Guided Graphical Installation
2046 The graphical installer is a text-based user interface. It will guide you,
2047 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2049 The first dialog boxes allow you to set up the system as you use it during the
2050 installation: you can choose the language, keyboard layout, and set up
2051 networking, which will be used during the installation. The image below shows
2052 the networking dialog.
2054 @image{images/installer-network,5in,, networking setup with the graphical installer}
2056 Later steps allow you to partition your hard disk, as shown in the image
2057 below, to choose whether or not to use encrypted file systems, to enter the
2058 host name and root password, and to create an additional account, among other
2061 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2063 Note that, at any time, the installer allows you to exit the current
2064 installation step and resume at a previous step, as show in the image below.
2066 @image{images/installer-resume,5in,, resuming the installation process}
2068 Once you're done, the installer produces an operating system configuration and
2069 displays it (@pxref{Using the Configuration System}). At that point you can
2070 hit ``OK'' and installation will proceed. On success, you can reboot into the
2071 new system and enjoy. @xref{After System Installation}, for what's next!
2074 @node Manual Installation
2075 @section Manual Installation
2077 This section describes how you would ``manually'' install GNU@tie{}Guix System
2078 on your machine. This option requires familiarity with GNU/Linux, with the
2079 shell, and with common administration tools. If you think this is not for
2080 you, consider using the guided graphical installer (@pxref{Guided Graphical
2083 The installation system provides root shells on TTYs 3 to 6; press
2084 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2085 many common tools needed to install the system. But it is also a full-blown
2086 Guix System, which means that you can install additional packages, should you
2087 need it, using @command{guix package} (@pxref{Invoking guix package}).
2090 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2091 * Proceeding with the Installation:: Installing.
2094 @node Keyboard Layout and Networking and Partitioning
2095 @subsection Keyboard Layout, Networking, and Partitioning
2097 Before you can install the system, you may want to adjust the keyboard layout,
2098 set up networking, and partition your target hard disk. This section will
2099 guide you through this.
2101 @subsubsection Keyboard Layout
2103 @cindex keyboard layout
2104 The installation image uses the US qwerty keyboard layout. If you want
2105 to change it, you can use the @command{loadkeys} command. For example,
2106 the following command selects the Dvorak keyboard layout:
2112 See the files under @file{/run/current-system/profile/share/keymaps} for
2113 a list of available keyboard layouts. Run @command{man loadkeys} for
2116 @subsubsection Networking
2118 Run the following command to see what your network interfaces are called:
2125 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2131 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2132 Wired interfaces have a name starting with @samp{e}; for example, the
2133 interface corresponding to the first on-board Ethernet controller is
2134 called @samp{eno1}. Wireless interfaces have a name starting with
2135 @samp{w}, like @samp{w1p2s0}.
2138 @item Wired connection
2139 To configure a wired network run the following command, substituting
2140 @var{interface} with the name of the wired interface you want to use.
2143 ifconfig @var{interface} up
2147 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2150 ip link set @var{interface} up
2153 @item Wireless connection
2156 To configure wireless networking, you can create a configuration file
2157 for the @command{wpa_supplicant} configuration tool (its location is not
2158 important) using one of the available text editors such as
2162 nano wpa_supplicant.conf
2165 As an example, the following stanza can go to this file and will work
2166 for many wireless networks, provided you give the actual SSID and
2167 passphrase for the network you are connecting to:
2171 ssid="@var{my-ssid}"
2173 psk="the network's secret passphrase"
2177 Start the wireless service and run it in the background with the
2178 following command (substitute @var{interface} with the name of the
2179 network interface you want to use):
2182 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2185 Run @command{man wpa_supplicant} for more information.
2189 At this point, you need to acquire an IP address. On a network where IP
2190 addresses are automatically assigned @i{via} DHCP, you can run:
2193 dhclient -v @var{interface}
2196 Try to ping a server to see if networking is up and running:
2202 Setting up network access is almost always a requirement because the
2203 image does not contain all the software and tools that may be needed.
2205 @cindex proxy, during system installation
2206 If you need HTTP and HTTPS access to go through a proxy, run the
2210 herd set-http-proxy guix-daemon @var{URL}
2214 where @var{URL} is the proxy URL, for example
2215 @code{http://example.org:8118}.
2217 @cindex installing over SSH
2218 If you want to, you can continue the installation remotely by starting
2222 herd start ssh-daemon
2225 Make sure to either set a password with @command{passwd}, or configure
2226 OpenSSH public key authentication before logging in.
2228 @subsubsection Disk Partitioning
2230 Unless this has already been done, the next step is to partition, and
2231 then format the target partition(s).
2233 The installation image includes several partitioning tools, including
2234 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2235 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2236 the partition layout you want:
2242 If your disk uses the GUID Partition Table (GPT) format and you plan to
2243 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2244 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2247 @cindex EFI, installation
2248 @cindex UEFI, installation
2249 @cindex ESP, EFI system partition
2250 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2251 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2252 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2255 parted /dev/sda set 1 esp on
2259 @vindex grub-bootloader
2260 @vindex grub-efi-bootloader
2261 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2262 @file{/sys/firmware/efi} exists in the installation image, then you should
2263 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2264 Otherwise you should use the BIOS-based GRUB, known as
2265 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2269 Once you are done partitioning the target hard disk drive, you have to
2270 create a file system on the relevant partition(s)@footnote{Currently
2271 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2272 code that reads file system UUIDs and labels only works for these file system
2273 types.}. For the ESP, if you have one and assuming it is
2274 @file{/dev/sda1}, run:
2277 mkfs.fat -F32 /dev/sda1
2280 Preferably, assign file systems a label so that you can easily and
2281 reliably refer to them in @code{file-system} declarations (@pxref{File
2282 Systems}). This is typically done using the @code{-L} option of
2283 @command{mkfs.ext4} and related commands. So, assuming the target root
2284 partition lives at @file{/dev/sda2}, a file system with the label
2285 @code{my-root} can be created with:
2288 mkfs.ext4 -L my-root /dev/sda2
2291 @cindex encrypted disk
2292 If you are instead planning to encrypt the root partition, you can use
2293 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2294 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2295 @code{man cryptsetup}} for more information.) Assuming you want to
2296 store the root partition on @file{/dev/sda2}, the command sequence would
2297 be along these lines:
2300 cryptsetup luksFormat /dev/sda2
2301 cryptsetup open --type luks /dev/sda2 my-partition
2302 mkfs.ext4 -L my-root /dev/mapper/my-partition
2305 Once that is done, mount the target file system under @file{/mnt}
2306 with a command like (again, assuming @code{my-root} is the label of the
2310 mount LABEL=my-root /mnt
2313 Also mount any other file systems you would like to use on the target
2314 system relative to this path. If you have opted for @file{/boot/efi} as an
2315 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2316 found by @code{guix system init} afterwards.
2318 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2319 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2320 sure to initialize them with @command{mkswap}. Assuming you have one
2321 swap partition on @file{/dev/sda3}, you would run:
2328 Alternatively, you may use a swap file. For example, assuming that in
2329 the new system you want to use the file @file{/swapfile} as a swap file,
2330 you would run@footnote{This example will work for many types of file
2331 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2332 btrfs), the required steps may be different. For details, see the
2333 manual pages for @command{mkswap} and @command{swapon}.}:
2336 # This is 10 GiB of swap space. Adjust "count" to change the size.
2337 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2338 # For security, make the file readable and writable only by root.
2339 chmod 600 /mnt/swapfile
2340 mkswap /mnt/swapfile
2341 swapon /mnt/swapfile
2344 Note that if you have encrypted the root partition and created a swap
2345 file in its file system as described above, then the encryption also
2346 protects the swap file, just like any other file in that file system.
2348 @node Proceeding with the Installation
2349 @subsection Proceeding with the Installation
2351 With the target partitions ready and the target root mounted on
2352 @file{/mnt}, we're ready to go. First, run:
2355 herd start cow-store /mnt
2358 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2359 during the installation phase are written to the target disk on @file{/mnt}
2360 rather than kept in memory. This is necessary because the first phase of
2361 the @command{guix system init} command (see below) entails downloads or
2362 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2364 Next, you have to edit a file and
2365 provide the declaration of the operating system to be installed. To
2366 that end, the installation system comes with three text editors. We
2367 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2368 supports syntax highlighting and parentheses matching; other editors
2369 include GNU Zile (an Emacs clone), and
2370 nvi (a clone of the original BSD @command{vi} editor).
2371 We strongly recommend storing that file on the target root file system, say,
2372 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2373 configuration file once you have rebooted into the newly-installed system.
2375 @xref{Using the Configuration System}, for an overview of the
2376 configuration file. The example configurations discussed in that
2377 section are available under @file{/etc/configuration} in the
2378 installation image. Thus, to get started with a system configuration
2379 providing a graphical display server (a ``desktop'' system), you can run
2380 something along these lines:
2384 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2385 # nano /mnt/etc/config.scm
2388 You should pay attention to what your configuration file contains, and
2393 Make sure the @code{bootloader-configuration} form refers to the target
2394 you want to install GRUB on. It should mention @code{grub-bootloader} if
2395 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2396 for newer UEFI systems. For legacy systems, the @code{target} field
2397 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2398 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2399 currently mounted and a @code{file-system} entry is specified in your
2403 Be sure that your file system labels match the value of their respective
2404 @code{device} fields in your @code{file-system} configuration, assuming
2405 your @code{file-system} configuration uses the @code{file-system-label}
2406 procedure in its @code{device} field.
2409 If there are encrypted or RAID partitions, make sure to add a
2410 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2413 Once you are done preparing the configuration file, the new system must
2414 be initialized (remember that the target root file system is mounted
2418 guix system init /mnt/etc/config.scm /mnt
2422 This copies all the necessary files and installs GRUB on
2423 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2424 more information, @pxref{Invoking guix system}. This command may trigger
2425 downloads or builds of missing packages, which can take some time.
2427 Once that command has completed---and hopefully succeeded!---you can run
2428 @command{reboot} and boot into the new system. The @code{root} password
2429 in the new system is initially empty; other users' passwords need to be
2430 initialized by running the @command{passwd} command as @code{root},
2431 unless your configuration specifies otherwise
2432 (@pxref{user-account-password, user account passwords}).
2433 @xref{After System Installation}, for what's next!
2436 @node After System Installation
2437 @section After System Installation
2439 Success, you've now booted into Guix System! From then on, you can update the
2440 system whenever you want by running, say:
2444 sudo guix system reconfigure /etc/config.scm
2448 This builds a new system generation with the latest packages and services
2449 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2450 your system includes the latest security updates (@pxref{Security Updates}).
2452 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2454 @cindex sudo vs. @command{guix pull}
2455 Note that @command{sudo guix} runs your user's @command{guix} command and
2456 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2457 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2459 The difference matters here, because @command{guix pull} updates
2460 the @command{guix} command and package definitions only for the user it is ran
2461 as. This means that if you choose to use @command{guix system reconfigure} in
2462 root's login shell, you'll need to @command{guix pull} separately.
2465 Join us on @code{#guix} on the Freenode IRC network or on
2466 @email{guix-devel@@gnu.org} to share your experience!
2469 @node Installing Guix in a VM
2470 @section Installing Guix in a Virtual Machine
2472 @cindex virtual machine, Guix System installation
2473 @cindex virtual private server (VPS)
2474 @cindex VPS (virtual private server)
2475 If you'd like to install Guix System in a virtual machine (VM) or on a
2476 virtual private server (VPS) rather than on your beloved machine, this
2479 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2480 disk image, follow these steps:
2484 First, retrieve and decompress the Guix system installation image as
2485 described previously (@pxref{USB Stick and DVD Installation}).
2488 Create a disk image that will hold the installed system. To make a
2489 qcow2-formatted disk image, use the @command{qemu-img} command:
2492 qemu-img create -f qcow2 guix-system.img 50G
2495 The resulting file will be much smaller than 50 GB (typically less than
2496 1 MB), but it will grow as the virtualized storage device is filled up.
2499 Boot the USB installation image in an VM:
2502 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2503 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2504 -drive file=guix-system.img \
2505 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2508 @code{-enable-kvm} is optional, but significantly improves performance,
2509 @pxref{Running Guix in a VM}.
2512 You're now root in the VM, proceed with the installation process.
2513 @xref{Preparing for Installation}, and follow the instructions.
2516 Once installation is complete, you can boot the system that's on your
2517 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2520 @node Building the Installation Image
2521 @section Building the Installation Image
2523 @cindex installation image
2524 The installation image described above was built using the @command{guix
2525 system} command, specifically:
2528 guix system disk-image --file-system-type=iso9660 \
2529 gnu/system/install.scm
2532 Have a look at @file{gnu/system/install.scm} in the source tree,
2533 and see also @ref{Invoking guix system} for more information
2534 about the installation image.
2536 @section Building the Installation Image for ARM Boards
2538 Many ARM boards require a specific variant of the
2539 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2541 If you build a disk image and the bootloader is not available otherwise
2542 (on another boot drive etc), it's advisable to build an image that
2543 includes the bootloader, specifically:
2546 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2549 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2550 board, a list of possible boards will be printed.
2552 @c *********************************************************************
2553 @node Package Management
2554 @chapter Package Management
2557 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2558 remove software packages, without having to know about their build
2559 procedures or dependencies. Guix also goes beyond this obvious set of
2562 This chapter describes the main features of Guix, as well as the
2563 package management tools it provides. Along with the command-line
2564 interface described below (@pxref{Invoking guix package, @code{guix
2565 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2566 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2567 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2571 guix install emacs-guix
2575 * Features:: How Guix will make your life brighter.
2576 * Invoking guix package:: Package installation, removal, etc.
2577 * Substitutes:: Downloading pre-built binaries.
2578 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2579 * Invoking guix gc:: Running the garbage collector.
2580 * Invoking guix pull:: Fetching the latest Guix and distribution.
2581 * Channels:: Customizing the package collection.
2582 * Invoking guix time-machine:: Running an older revision of Guix.
2583 * Inferiors:: Interacting with another revision of Guix.
2584 * Invoking guix describe:: Display information about your Guix revision.
2585 * Invoking guix archive:: Exporting and importing store files.
2591 When using Guix, each package ends up in the @dfn{package store}, in its
2592 own directory---something that resembles
2593 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2595 Instead of referring to these directories, users have their own
2596 @dfn{profile}, which points to the packages that they actually want to
2597 use. These profiles are stored within each user's home directory, at
2598 @code{$HOME/.guix-profile}.
2600 For example, @code{alice} installs GCC 4.7.2. As a result,
2601 @file{/home/alice/.guix-profile/bin/gcc} points to
2602 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2603 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2604 simply continues to point to
2605 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2606 coexist on the same system without any interference.
2608 The @command{guix package} command is the central tool to manage
2609 packages (@pxref{Invoking guix package}). It operates on the per-user
2610 profiles, and can be used @emph{with normal user privileges}.
2612 @cindex transactions
2613 The command provides the obvious install, remove, and upgrade
2614 operations. Each invocation is actually a @emph{transaction}: either
2615 the specified operation succeeds, or nothing happens. Thus, if the
2616 @command{guix package} process is terminated during the transaction,
2617 or if a power outage occurs during the transaction, then the user's
2618 profile remains in its previous state, and remains usable.
2620 In addition, any package transaction may be @emph{rolled back}. So, if,
2621 for example, an upgrade installs a new version of a package that turns
2622 out to have a serious bug, users may roll back to the previous instance
2623 of their profile, which was known to work well. Similarly, the global
2624 system configuration on Guix is subject to
2625 transactional upgrades and roll-back
2626 (@pxref{Using the Configuration System}).
2628 All packages in the package store may be @emph{garbage-collected}.
2629 Guix can determine which packages are still referenced by user
2630 profiles, and remove those that are provably no longer referenced
2631 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2632 generations of their profile so that the packages they refer to can be
2635 @cindex reproducibility
2636 @cindex reproducible builds
2637 Guix takes a @dfn{purely functional} approach to package
2638 management, as described in the introduction (@pxref{Introduction}).
2639 Each @file{/gnu/store} package directory name contains a hash of all the
2640 inputs that were used to build that package---compiler, libraries, build
2641 scripts, etc. This direct correspondence allows users to make sure a
2642 given package installation matches the current state of their
2643 distribution. It also helps maximize @dfn{build reproducibility}:
2644 thanks to the isolated build environments that are used, a given build
2645 is likely to yield bit-identical files when performed on different
2646 machines (@pxref{Invoking guix-daemon, container}).
2649 This foundation allows Guix to support @dfn{transparent binary/source
2650 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2651 available from an external source---a @dfn{substitute}, Guix just
2652 downloads it and unpacks it;
2653 otherwise, it builds the package from source, locally
2654 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2655 reproducible, users do not have to trust servers that provide
2656 substitutes: they can force a local build and @emph{challenge} providers
2657 (@pxref{Invoking guix challenge}).
2659 Control over the build environment is a feature that is also useful for
2660 developers. The @command{guix environment} command allows developers of
2661 a package to quickly set up the right development environment for their
2662 package, without having to manually install the dependencies of the
2663 package into their profile (@pxref{Invoking guix environment}).
2665 @cindex replication, of software environments
2666 @cindex provenance tracking, of software artifacts
2667 All of Guix and its package definitions is version-controlled, and
2668 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2669 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2670 Guix instance on a different machine or at a later point in time, which in
2671 turn allows you to @emph{replicate complete software environments}, while
2672 retaining precise @dfn{provenance tracking} of the software.
2674 @node Invoking guix package
2675 @section Invoking @command{guix package}
2677 @cindex installing packages
2678 @cindex removing packages
2679 @cindex package installation
2680 @cindex package removal
2681 The @command{guix package} command is the tool that allows users to
2682 install, upgrade, and remove packages, as well as rolling back to
2683 previous configurations. It operates only on the user's own profile,
2684 and works with normal user privileges (@pxref{Features}). Its syntax
2688 guix package @var{options}
2691 @cindex transactions
2692 Primarily, @var{options} specifies the operations to be performed during
2693 the transaction. Upon completion, a new profile is created, but
2694 previous @dfn{generations} of the profile remain available, should the user
2697 For example, to remove @code{lua} and install @code{guile} and
2698 @code{guile-cairo} in a single transaction:
2701 guix package -r lua -i guile guile-cairo
2704 @cindex aliases, for @command{guix package}
2705 For your convenience, we also provide the following aliases:
2709 @command{guix search} is an alias for @command{guix package -s},
2711 @command{guix install} is an alias for @command{guix package -i},
2713 @command{guix remove} is an alias for @command{guix package -r},
2715 @command{guix upgrade} is an alias for @command{guix package -u},
2717 and @command{guix show} is an alias for @command{guix package --show=}.
2720 These aliases are less expressive than @command{guix package} and provide
2721 fewer options, so in some cases you'll probably want to use @command{guix
2724 @command{guix package} also supports a @dfn{declarative approach}
2725 whereby the user specifies the exact set of packages to be available and
2726 passes it @i{via} the @option{--manifest} option
2727 (@pxref{profile-manifest, @option{--manifest}}).
2730 For each user, a symlink to the user's default profile is automatically
2731 created in @file{$HOME/.guix-profile}. This symlink always points to the
2732 current generation of the user's default profile. Thus, users can add
2733 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2734 variable, and so on.
2735 @cindex search paths
2736 If you are not using Guix System, consider adding the
2737 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2738 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2739 shells get all the right environment variable definitions:
2742 GUIX_PROFILE="$HOME/.guix-profile" ; \
2743 source "$HOME/.guix-profile/etc/profile"
2746 In a multi-user setup, user profiles are stored in a place registered as
2747 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2748 to (@pxref{Invoking guix gc}). That directory is normally
2749 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2750 @var{localstatedir} is the value passed to @code{configure} as
2751 @code{--localstatedir}, and @var{user} is the user name. The
2752 @file{per-user} directory is created when @command{guix-daemon} is
2753 started, and the @var{user} sub-directory is created by @command{guix
2756 The @var{options} can be among the following:
2760 @item --install=@var{package} @dots{}
2761 @itemx -i @var{package} @dots{}
2762 Install the specified @var{package}s.
2764 Each @var{package} may specify either a simple package name, such as
2765 @code{guile}, or a package name followed by an at-sign and version number,
2766 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2767 case, the newest version prefixed by @code{1.8} is selected.)
2769 If no version number is specified, the
2770 newest available version will be selected. In addition, @var{package}
2771 may contain a colon, followed by the name of one of the outputs of the
2772 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2773 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2774 name (and optionally version) are searched for among the GNU
2775 distribution modules (@pxref{Package Modules}).
2777 @cindex propagated inputs
2778 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2779 that automatically get installed along with the required package
2780 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2781 @code{package} objects}, for information about propagated inputs in
2782 package definitions).
2784 @anchor{package-cmd-propagated-inputs}
2785 An example is the GNU MPC library: its C header files refer to those of
2786 the GNU MPFR library, which in turn refer to those of the GMP library.
2787 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2788 in the profile; removing MPC also removes MPFR and GMP---unless they had
2789 also been explicitly installed by the user.
2791 Besides, packages sometimes rely on the definition of environment
2792 variables for their search paths (see explanation of
2793 @code{--search-paths} below). Any missing or possibly incorrect
2794 environment variable definitions are reported here.
2796 @item --install-from-expression=@var{exp}
2798 Install the package @var{exp} evaluates to.
2800 @var{exp} must be a Scheme expression that evaluates to a
2801 @code{<package>} object. This option is notably useful to disambiguate
2802 between same-named variants of a package, with expressions such as
2803 @code{(@@ (gnu packages base) guile-final)}.
2805 Note that this option installs the first output of the specified
2806 package, which may be insufficient when needing a specific output of a
2807 multiple-output package.
2809 @item --install-from-file=@var{file}
2810 @itemx -f @var{file}
2811 Install the package that the code within @var{file} evaluates to.
2813 As an example, @var{file} might contain a definition like this
2814 (@pxref{Defining Packages}):
2817 @include package-hello.scm
2820 Developers may find it useful to include such a @file{guix.scm} file
2821 in the root of their project source tree that can be used to test
2822 development snapshots and create reproducible development environments
2823 (@pxref{Invoking guix environment}).
2825 The @var{file} may also contain a JSON representation of one or more
2826 package definitions. Running @code{guix package -f} on
2827 @file{hello.json} with the following contents would result in installing
2828 the package @code{greeter} after building @code{myhello}:
2831 @verbatiminclude package-hello.json
2834 @item --remove=@var{package} @dots{}
2835 @itemx -r @var{package} @dots{}
2836 Remove the specified @var{package}s.
2838 As for @code{--install}, each @var{package} may specify a version number
2839 and/or output name in addition to the package name. For instance,
2840 @code{-r glibc:debug} would remove the @code{debug} output of
2843 @item --upgrade[=@var{regexp} @dots{}]
2844 @itemx -u [@var{regexp} @dots{}]
2845 @cindex upgrading packages
2846 Upgrade all the installed packages. If one or more @var{regexp}s are
2847 specified, upgrade only installed packages whose name matches a
2848 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2850 Note that this upgrades package to the latest version of packages found
2851 in the distribution currently installed. To update your distribution,
2852 you should regularly run @command{guix pull} (@pxref{Invoking guix
2855 @item --do-not-upgrade[=@var{regexp} @dots{}]
2856 When used together with the @code{--upgrade} option, do @emph{not}
2857 upgrade any packages whose name matches a @var{regexp}. For example, to
2858 upgrade all packages in the current profile except those containing the
2859 substring ``emacs'':
2862 $ guix package --upgrade . --do-not-upgrade emacs
2865 @item @anchor{profile-manifest}--manifest=@var{file}
2866 @itemx -m @var{file}
2867 @cindex profile declaration
2868 @cindex profile manifest
2869 Create a new generation of the profile from the manifest object
2870 returned by the Scheme code in @var{file}. This option can be repeated
2871 several times, in which case the manifests are concatenated.
2873 This allows you to @emph{declare} the profile's contents rather than
2874 constructing it through a sequence of @code{--install} and similar
2875 commands. The advantage is that @var{file} can be put under version
2876 control, copied to different machines to reproduce the same profile, and
2879 @c FIXME: Add reference to (guix profile) documentation when available.
2880 @var{file} must return a @dfn{manifest} object, which is roughly a list
2883 @findex packages->manifest
2885 (use-package-modules guile emacs)
2890 ;; Use a specific package output.
2891 (list guile-2.0 "debug")))
2894 @findex specifications->manifest
2895 In this example we have to know which modules define the @code{emacs}
2896 and @code{guile-2.0} variables to provide the right
2897 @code{use-package-modules} line, which can be cumbersome. We can
2898 instead provide regular package specifications and let
2899 @code{specifications->manifest} look up the corresponding package
2903 (specifications->manifest
2904 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2908 @cindex rolling back
2909 @cindex undoing transactions
2910 @cindex transactions, undoing
2911 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2912 the last transaction.
2914 When combined with options such as @code{--install}, roll back occurs
2915 before any other actions.
2917 When rolling back from the first generation that actually contains
2918 installed packages, the profile is made to point to the @dfn{zeroth
2919 generation}, which contains no files apart from its own metadata.
2921 After having rolled back, installing, removing, or upgrading packages
2922 overwrites previous future generations. Thus, the history of the
2923 generations in a profile is always linear.
2925 @item --switch-generation=@var{pattern}
2926 @itemx -S @var{pattern}
2928 Switch to a particular generation defined by @var{pattern}.
2930 @var{pattern} may be either a generation number or a number prefixed
2931 with ``+'' or ``-''. The latter means: move forward/backward by a
2932 specified number of generations. For example, if you want to return to
2933 the latest generation after @code{--roll-back}, use
2934 @code{--switch-generation=+1}.
2936 The difference between @code{--roll-back} and
2937 @code{--switch-generation=-1} is that @code{--switch-generation} will
2938 not make a zeroth generation, so if a specified generation does not
2939 exist, the current generation will not be changed.
2941 @item --search-paths[=@var{kind}]
2942 @cindex search paths
2943 Report environment variable definitions, in Bash syntax, that may be
2944 needed in order to use the set of installed packages. These environment
2945 variables are used to specify @dfn{search paths} for files used by some
2946 of the installed packages.
2948 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2949 environment variables to be defined so it can look for headers and
2950 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2951 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2952 library are installed in the profile, then @code{--search-paths} will
2953 suggest setting these variables to @code{@var{profile}/include} and
2954 @code{@var{profile}/lib}, respectively.
2956 The typical use case is to define these environment variables in the
2960 $ eval `guix package --search-paths`
2963 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2964 meaning that the returned environment variable definitions will either
2965 be exact settings, or prefixes or suffixes of the current value of these
2966 variables. When omitted, @var{kind} defaults to @code{exact}.
2968 This option can also be used to compute the @emph{combined} search paths
2969 of several profiles. Consider this example:
2972 $ guix package -p foo -i guile
2973 $ guix package -p bar -i guile-json
2974 $ guix package -p foo -p bar --search-paths
2977 The last command above reports about the @code{GUILE_LOAD_PATH}
2978 variable, even though, taken individually, neither @file{foo} nor
2979 @file{bar} would lead to that recommendation.
2982 @item --profile=@var{profile}
2983 @itemx -p @var{profile}
2984 Use @var{profile} instead of the user's default profile.
2986 @var{profile} must be the name of a file that will be created upon
2987 completion. Concretely, @var{profile} will be a mere symbolic link
2988 (``symlink'') pointing to the actual profile where packages are
2992 $ guix install hello -p ~/code/my-profile
2994 $ ~/code/my-profile/bin/hello
2998 All it takes to get rid of the profile is to remove this symlink and its
2999 siblings that point to specific generations:
3002 $ rm ~/code/my-profile ~/code/my-profile-*-link
3005 @item --list-profiles
3006 List all the user's profiles:
3009 $ guix package --list-profiles
3010 /home/charlie/.guix-profile
3011 /home/charlie/code/my-profile
3012 /home/charlie/code/devel-profile
3013 /home/charlie/tmp/test
3016 When running as root, list all the profiles of all the users.
3018 @cindex collisions, in a profile
3019 @cindex colliding packages in profiles
3020 @cindex profile collisions
3021 @item --allow-collisions
3022 Allow colliding packages in the new profile. Use at your own risk!
3024 By default, @command{guix package} reports as an error @dfn{collisions}
3025 in the profile. Collisions happen when two or more different versions
3026 or variants of a given package end up in the profile.
3029 Use the bootstrap Guile to build the profile. This option is only
3030 useful to distribution developers.
3034 In addition to these actions, @command{guix package} supports the
3035 following options to query the current state of a profile, or the
3036 availability of packages:
3040 @item --search=@var{regexp}
3041 @itemx -s @var{regexp}
3042 @cindex searching for packages
3043 List the available packages whose name, synopsis, or description matches
3044 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3045 Print all the metadata of matching packages in
3046 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3047 GNU recutils manual}).
3049 This allows specific fields to be extracted using the @command{recsel}
3050 command, for instance:
3053 $ guix package -s malloc | recsel -p name,version,relevance
3067 Similarly, to show the name of all the packages available under the
3068 terms of the GNU@tie{}LGPL version 3:
3071 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3078 It is also possible to refine search results using several @code{-s} flags to
3079 @command{guix package}, or several arguments to @command{guix search}. For
3080 example, the following command returns a list of board games (this time using
3081 the @command{guix search} alias):
3084 $ guix search '\<board\>' game | recsel -p name
3089 If we were to omit @code{-s game}, we would also get software packages
3090 that deal with printed circuit boards; removing the angle brackets
3091 around @code{board} would further add packages that have to do with
3094 And now for a more elaborate example. The following command searches
3095 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3096 libraries, and prints the name and synopsis of the matching packages:
3099 $ guix search crypto library | \
3100 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3104 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3105 information on @dfn{selection expressions} for @code{recsel -e}.
3107 @item --show=@var{package}
3108 Show details about @var{package}, taken from the list of available packages, in
3109 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3113 $ guix package --show=python | recsel -p name,version
3121 You may also specify the full name of a package to only get details about a
3122 specific version of it (this time using the @command{guix show} alias):
3124 $ guix show python@@3.4 | recsel -p name,version
3131 @item --list-installed[=@var{regexp}]
3132 @itemx -I [@var{regexp}]
3133 List the currently installed packages in the specified profile, with the
3134 most recently installed packages shown last. When @var{regexp} is
3135 specified, list only installed packages whose name matches @var{regexp}.
3137 For each installed package, print the following items, separated by
3138 tabs: the package name, its version string, the part of the package that
3139 is installed (for instance, @code{out} for the default output,
3140 @code{include} for its headers, etc.), and the path of this package in
3143 @item --list-available[=@var{regexp}]
3144 @itemx -A [@var{regexp}]
3145 List packages currently available in the distribution for this system
3146 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3147 available packages whose name matches @var{regexp}.
3149 For each package, print the following items separated by tabs: its name,
3150 its version string, the parts of the package (@pxref{Packages with
3151 Multiple Outputs}), and the source location of its definition.
3153 @item --list-generations[=@var{pattern}]
3154 @itemx -l [@var{pattern}]
3156 Return a list of generations along with their creation dates; for each
3157 generation, show the installed packages, with the most recently
3158 installed packages shown last. Note that the zeroth generation is never
3161 For each installed package, print the following items, separated by
3162 tabs: the name of a package, its version string, the part of the package
3163 that is installed (@pxref{Packages with Multiple Outputs}), and the
3164 location of this package in the store.
3166 When @var{pattern} is used, the command returns only matching
3167 generations. Valid patterns include:
3170 @item @emph{Integers and comma-separated integers}. Both patterns denote
3171 generation numbers. For instance, @code{--list-generations=1} returns
3174 And @code{--list-generations=1,8,2} outputs three generations in the
3175 specified order. Neither spaces nor trailing commas are allowed.
3177 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3178 specified generations and everything in between. Note that the start of
3179 a range must be smaller than its end.
3181 It is also possible to omit the endpoint. For example,
3182 @code{--list-generations=2..}, returns all generations starting from the
3185 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3186 or months by passing an integer along with the first letter of the
3187 duration. For example, @code{--list-generations=20d} lists generations
3188 that are up to 20 days old.
3191 @item --delete-generations[=@var{pattern}]
3192 @itemx -d [@var{pattern}]
3193 When @var{pattern} is omitted, delete all generations except the current
3196 This command accepts the same patterns as @option{--list-generations}.
3197 When @var{pattern} is specified, delete the matching generations. When
3198 @var{pattern} specifies a duration, generations @emph{older} than the
3199 specified duration match. For instance, @code{--delete-generations=1m}
3200 deletes generations that are more than one month old.
3202 If the current generation matches, it is @emph{not} deleted. Also, the
3203 zeroth generation is never deleted.
3205 Note that deleting generations prevents rolling back to them.
3206 Consequently, this command must be used with care.
3210 Finally, since @command{guix package} may actually start build
3211 processes, it supports all the common build options (@pxref{Common Build
3212 Options}). It also supports package transformation options, such as
3213 @option{--with-source} (@pxref{Package Transformation Options}).
3214 However, note that package transformations are lost when upgrading; to
3215 preserve transformations across upgrades, you should define your own
3216 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3217 (@pxref{Defining Packages}).
3220 @section Substitutes
3223 @cindex pre-built binaries
3224 Guix supports transparent source/binary deployment, which means that it
3225 can either build things locally, or download pre-built items from a
3226 server, or both. We call these pre-built items @dfn{substitutes}---they
3227 are substitutes for local build results. In many cases, downloading a
3228 substitute is much faster than building things locally.
3230 Substitutes can be anything resulting from a derivation build
3231 (@pxref{Derivations}). Of course, in the common case, they are
3232 pre-built package binaries, but source tarballs, for instance, which
3233 also result from derivation builds, can be available as substitutes.
3236 * Official Substitute Server:: One particular source of substitutes.
3237 * Substitute Server Authorization:: How to enable or disable substitutes.
3238 * Substitute Authentication:: How Guix verifies substitutes.
3239 * Proxy Settings:: How to get substitutes via proxy.
3240 * Substitution Failure:: What happens when substitution fails.
3241 * On Trusting Binaries:: How can you trust that binary blob?
3244 @node Official Substitute Server
3245 @subsection Official Substitute Server
3248 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3249 that builds packages from Guix continuously for some
3250 architectures, and makes them available as substitutes. This is the
3251 default source of substitutes; it can be overridden by passing the
3252 @option{--substitute-urls} option either to @command{guix-daemon}
3253 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3254 or to client tools such as @command{guix package}
3255 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3258 Substitute URLs can be either HTTP or HTTPS.
3259 HTTPS is recommended because communications are encrypted; conversely,
3260 using HTTP makes all communications visible to an eavesdropper, who
3261 could use the information gathered to determine, for instance, whether
3262 your system has unpatched security vulnerabilities.
3264 Substitutes from the official build farm are enabled by default when
3265 using Guix System (@pxref{GNU Distribution}). However,
3266 they are disabled by default when using Guix on a foreign distribution,
3267 unless you have explicitly enabled them via one of the recommended
3268 installation steps (@pxref{Installation}). The following paragraphs
3269 describe how to enable or disable substitutes for the official build
3270 farm; the same procedure can also be used to enable substitutes for any
3271 other substitute server.
3273 @node Substitute Server Authorization
3274 @subsection Substitute Server Authorization
3277 @cindex substitutes, authorization thereof
3278 @cindex access control list (ACL), for substitutes
3279 @cindex ACL (access control list), for substitutes
3280 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3282 must add its public key to the access control list (ACL) of archive
3283 imports, using the @command{guix archive} command (@pxref{Invoking guix
3284 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3285 be compromised and to serve genuine substitutes.
3287 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3288 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3289 the installation prefix of Guix. If you installed Guix from source,
3290 make sure you checked the GPG signature of
3291 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3292 Then, you can run something like this:
3295 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3298 Once this is in place, the output of a command like @code{guix build}
3299 should change from something like:
3302 $ guix build emacs --dry-run
3303 The following derivations would be built:
3304 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3305 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3306 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3307 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3315 $ guix build emacs --dry-run
3316 112.3 MB would be downloaded:
3317 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3318 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3319 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3320 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3325 The text changed from ``The following derivations would be built'' to
3326 ``112.3 MB would be downloaded''. This indicates that substitutes from
3327 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3328 possible, for future builds.
3330 @cindex substitutes, how to disable
3331 The substitute mechanism can be disabled globally by running
3332 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3333 guix-daemon}). It can also be disabled temporarily by passing the
3334 @code{--no-substitutes} option to @command{guix package}, @command{guix
3335 build}, and other command-line tools.
3337 @node Substitute Authentication
3338 @subsection Substitute Authentication
3340 @cindex digital signatures
3341 Guix detects and raises an error when attempting to use a substitute
3342 that has been tampered with. Likewise, it ignores substitutes that are
3343 not signed, or that are not signed by one of the keys listed in the ACL.
3345 There is one exception though: if an unauthorized server provides
3346 substitutes that are @emph{bit-for-bit identical} to those provided by
3347 an authorized server, then the unauthorized server becomes eligible for
3348 downloads. For example, assume we have chosen two substitute servers
3352 --substitute-urls="https://a.example.org https://b.example.org"
3356 @cindex reproducible builds
3357 If the ACL contains only the key for @code{b.example.org}, and if
3358 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3359 then Guix will download substitutes from @code{a.example.org} because it
3360 comes first in the list and can be considered a mirror of
3361 @code{b.example.org}. In practice, independent build machines usually
3362 produce the same binaries, thanks to bit-reproducible builds (see
3365 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3366 (in other words, the server is not authenticated), contrary to what
3367 HTTPS clients such as Web browsers usually do. This is because Guix
3368 authenticates substitute information itself, as explained above, which
3369 is what we care about (whereas X.509 certificates are about
3370 authenticating bindings between domain names and public keys.)
3372 @node Proxy Settings
3373 @subsection Proxy Settings
3376 Substitutes are downloaded over HTTP or HTTPS.
3377 The @code{http_proxy} environment
3378 variable can be set in the environment of @command{guix-daemon} and is
3379 honored for downloads of substitutes. Note that the value of
3380 @code{http_proxy} in the environment where @command{guix build},
3381 @command{guix package}, and other client commands are run has
3382 @emph{absolutely no effect}.
3384 @node Substitution Failure
3385 @subsection Substitution Failure
3387 Even when a substitute for a derivation is available, sometimes the
3388 substitution attempt will fail. This can happen for a variety of
3389 reasons: the substitute server might be offline, the substitute may
3390 recently have been deleted, the connection might have been interrupted,
3393 When substitutes are enabled and a substitute for a derivation is
3394 available, but the substitution attempt fails, Guix will attempt to
3395 build the derivation locally depending on whether or not
3396 @code{--fallback} was given (@pxref{fallback-option,, common build
3397 option @code{--fallback}}). Specifically, if @code{--fallback} was
3398 omitted, then no local build will be performed, and the derivation is
3399 considered to have failed. However, if @code{--fallback} was given,
3400 then Guix will attempt to build the derivation locally, and the success
3401 or failure of the derivation depends on the success or failure of the
3402 local build. Note that when substitutes are disabled or no substitute
3403 is available for the derivation in question, a local build will
3404 @emph{always} be performed, regardless of whether or not
3405 @code{--fallback} was given.
3407 To get an idea of how many substitutes are available right now, you can
3408 try running the @command{guix weather} command (@pxref{Invoking guix
3409 weather}). This command provides statistics on the substitutes provided
3412 @node On Trusting Binaries
3413 @subsection On Trusting Binaries
3415 @cindex trust, of pre-built binaries
3416 Today, each individual's control over their own computing is at the
3417 mercy of institutions, corporations, and groups with enough power and
3418 determination to subvert the computing infrastructure and exploit its
3419 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3420 convenient, we encourage users to also build on their own, or even run
3421 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3422 interesting target. One way to help is by publishing the software you
3423 build using @command{guix publish} so that others have one more choice
3424 of server to download substitutes from (@pxref{Invoking guix publish}).
3426 Guix has the foundations to maximize build reproducibility
3427 (@pxref{Features}). In most cases, independent builds of a given
3428 package or derivation should yield bit-identical results. Thus, through
3429 a diverse set of independent package builds, we can strengthen the
3430 integrity of our systems. The @command{guix challenge} command aims to
3431 help users assess substitute servers, and to assist developers in
3432 finding out about non-deterministic package builds (@pxref{Invoking guix
3433 challenge}). Similarly, the @option{--check} option of @command{guix
3434 build} allows users to check whether previously-installed substitutes
3435 are genuine by rebuilding them locally (@pxref{build-check,
3436 @command{guix build --check}}).
3438 In the future, we want Guix to have support to publish and retrieve
3439 binaries to/from other users, in a peer-to-peer fashion. If you would
3440 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3442 @node Packages with Multiple Outputs
3443 @section Packages with Multiple Outputs
3445 @cindex multiple-output packages
3446 @cindex package outputs
3449 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3450 source package leads to exactly one directory in the store. When running
3451 @command{guix install glibc}, one installs the default output of the
3452 GNU libc package; the default output is called @code{out}, but its name
3453 can be omitted as shown in this command. In this particular case, the
3454 default output of @code{glibc} contains all the C header files, shared
3455 libraries, static libraries, Info documentation, and other supporting
3458 Sometimes it is more appropriate to separate the various types of files
3459 produced from a single source package into separate outputs. For
3460 instance, the GLib C library (used by GTK+ and related packages)
3461 installs more than 20 MiB of reference documentation as HTML pages.
3462 To save space for users who do not need it, the documentation goes to a
3463 separate output, called @code{doc}. To install the main GLib output,
3464 which contains everything but the documentation, one would run:
3470 @cindex documentation
3471 The command to install its documentation is:
3474 guix install glib:doc
3477 Some packages install programs with different ``dependency footprints''.
3478 For instance, the WordNet package installs both command-line tools and
3479 graphical user interfaces (GUIs). The former depend solely on the C
3480 library, whereas the latter depend on Tcl/Tk and the underlying X
3481 libraries. In this case, we leave the command-line tools in the default
3482 output, whereas the GUIs are in a separate output. This allows users
3483 who do not need the GUIs to save space. The @command{guix size} command
3484 can help find out about such situations (@pxref{Invoking guix size}).
3485 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3487 There are several such multiple-output packages in the GNU distribution.
3488 Other conventional output names include @code{lib} for libraries and
3489 possibly header files, @code{bin} for stand-alone programs, and
3490 @code{debug} for debugging information (@pxref{Installing Debugging
3491 Files}). The outputs of a packages are listed in the third column of
3492 the output of @command{guix package --list-available} (@pxref{Invoking
3496 @node Invoking guix gc
3497 @section Invoking @command{guix gc}
3499 @cindex garbage collector
3501 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3502 The @command{guix gc} command allows users to explicitly run the garbage
3503 collector to reclaim space from the @file{/gnu/store} directory. It is
3504 the @emph{only} way to remove files from @file{/gnu/store}---removing
3505 files or directories manually may break it beyond repair!
3508 @cindex garbage collector roots
3509 The garbage collector has a set of known @dfn{roots}: any file under
3510 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3511 cannot be deleted; any other file is considered @dfn{dead} and may be
3512 deleted. The set of garbage collector roots (``GC roots'' for short)
3513 includes default user profiles; by default, the symlinks under
3514 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3515 added with @command{guix build --root}, for example (@pxref{Invoking
3516 guix build}). The @command{guix gc --list-roots} command lists them.
3518 Prior to running @code{guix gc --collect-garbage} to make space, it is
3519 often useful to remove old generations from user profiles; that way, old
3520 package builds referenced by those generations can be reclaimed. This
3521 is achieved by running @code{guix package --delete-generations}
3522 (@pxref{Invoking guix package}).
3524 Our recommendation is to run a garbage collection periodically, or when
3525 you are short on disk space. For instance, to guarantee that at least
3526 5@tie{}GB are available on your disk, simply run:
3532 It is perfectly safe to run as a non-interactive periodic job
3533 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3534 Running @command{guix gc} with no arguments will collect as
3535 much garbage as it can, but that is often inconvenient: you may find
3536 yourself having to rebuild or re-download software that is ``dead'' from
3537 the GC viewpoint but that is necessary to build other pieces of
3538 software---e.g., the compiler tool chain.
3540 The @command{guix gc} command has three modes of operation: it can be
3541 used to garbage-collect any dead files (the default), to delete specific
3542 files (the @code{--delete} option), to print garbage-collector
3543 information, or for more advanced queries. The garbage collection
3544 options are as follows:
3547 @item --collect-garbage[=@var{min}]
3548 @itemx -C [@var{min}]
3549 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3550 sub-directories. This is the default operation when no option is
3553 When @var{min} is given, stop once @var{min} bytes have been collected.
3554 @var{min} may be a number of bytes, or it may include a unit as a
3555 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3556 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3558 When @var{min} is omitted, collect all the garbage.
3560 @item --free-space=@var{free}
3561 @itemx -F @var{free}
3562 Collect garbage until @var{free} space is available under
3563 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3564 as @code{500MiB}, as described above.
3566 When @var{free} or more is already available in @file{/gnu/store}, do
3567 nothing and exit immediately.
3569 @item --delete-generations[=@var{duration}]
3570 @itemx -d [@var{duration}]
3571 Before starting the garbage collection process, delete all the generations
3572 older than @var{duration}, for all the user profiles; when run as root, this
3573 applies to all the profiles @emph{of all the users}.
3575 For example, this command deletes all the generations of all your profiles
3576 that are older than 2 months (except generations that are current), and then
3577 proceeds to free space until at least 10 GiB are available:
3580 guix gc -d 2m -F 10G
3585 Attempt to delete all the store files and directories specified as
3586 arguments. This fails if some of the files are not in the store, or if
3587 they are still live.
3589 @item --list-failures
3590 List store items corresponding to cached build failures.
3592 This prints nothing unless the daemon was started with
3593 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3594 @option{--cache-failures}}).
3597 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3601 List store items in use by currently running processes. These store
3602 items are effectively considered GC roots: they cannot be deleted.
3604 @item --clear-failures
3605 Remove the specified store items from the failed-build cache.
3607 Again, this option only makes sense when the daemon is started with
3608 @option{--cache-failures}. Otherwise, it does nothing.
3611 Show the list of dead files and directories still present in the
3612 store---i.e., files and directories no longer reachable from any root.
3615 Show the list of live store files and directories.
3619 In addition, the references among existing store files can be queried:
3625 @cindex package dependencies
3626 List the references (respectively, the referrers) of store files given
3632 List the requisites of the store files passed as arguments. Requisites
3633 include the store files themselves, their references, and the references
3634 of these, recursively. In other words, the returned list is the
3635 @dfn{transitive closure} of the store files.
3637 @xref{Invoking guix size}, for a tool to profile the size of the closure
3638 of an element. @xref{Invoking guix graph}, for a tool to visualize
3639 the graph of references.
3643 Return the derivation(s) leading to the given store items
3644 (@pxref{Derivations}).
3646 For example, this command:
3649 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3653 returns the @file{.drv} file(s) leading to the @code{emacs} package
3654 installed in your profile.
3656 Note that there may be zero matching @file{.drv} files, for instance
3657 because these files have been garbage-collected. There can also be more
3658 than one matching @file{.drv} due to fixed-output derivations.
3661 Lastly, the following options allow you to check the integrity of the
3662 store and to control disk usage.
3666 @item --verify[=@var{options}]
3667 @cindex integrity, of the store
3668 @cindex integrity checking
3669 Verify the integrity of the store.
3671 By default, make sure that all the store items marked as valid in the
3672 database of the daemon actually exist in @file{/gnu/store}.
3674 When provided, @var{options} must be a comma-separated list containing one
3675 or more of @code{contents} and @code{repair}.
3677 When passing @option{--verify=contents}, the daemon computes the
3678 content hash of each store item and compares it against its hash in the
3679 database. Hash mismatches are reported as data corruptions. Because it
3680 traverses @emph{all the files in the store}, this command can take a
3681 long time, especially on systems with a slow disk drive.
3683 @cindex repairing the store
3684 @cindex corruption, recovering from
3685 Using @option{--verify=repair} or @option{--verify=contents,repair}
3686 causes the daemon to try to repair corrupt store items by fetching
3687 substitutes for them (@pxref{Substitutes}). Because repairing is not
3688 atomic, and thus potentially dangerous, it is available only to the
3689 system administrator. A lightweight alternative, when you know exactly
3690 which items in the store are corrupt, is @command{guix build --repair}
3691 (@pxref{Invoking guix build}).
3694 @cindex deduplication
3695 Optimize the store by hard-linking identical files---this is
3696 @dfn{deduplication}.
3698 The daemon performs deduplication after each successful build or archive
3699 import, unless it was started with @code{--disable-deduplication}
3700 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3701 this option is primarily useful when the daemon was running with
3702 @code{--disable-deduplication}.
3706 @node Invoking guix pull
3707 @section Invoking @command{guix pull}
3709 @cindex upgrading Guix
3710 @cindex updating Guix
3711 @cindex @command{guix pull}
3713 Packages are installed or upgraded to the latest version available in
3714 the distribution currently available on your local machine. To update
3715 that distribution, along with the Guix tools, you must run @command{guix
3716 pull}: the command downloads the latest Guix source code and package
3717 descriptions, and deploys it. Source code is downloaded from a
3718 @uref{https://git-scm.com, Git} repository, by default the official
3719 GNU@tie{}Guix repository, though this can be customized.
3721 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3722 (@pxref{Channels}) specified by one of the followings, in this order:
3726 the @option{--channels} option;
3728 the user's @file{~/.config/guix/channels.scm} file;
3730 the system-wide @file{/etc/guix/channels.scm} file;
3732 the built-in default channels specified in the @code{%default-channels}
3736 On completion, @command{guix package} will use packages and package
3737 versions from this just-retrieved copy of Guix. Not only that, but all
3738 the Guix commands and Scheme modules will also be taken from that latest
3739 version. New @command{guix} sub-commands added by the update also
3742 Any user can update their Guix copy using @command{guix pull}, and the
3743 effect is limited to the user who ran @command{guix pull}. For
3744 instance, when user @code{root} runs @command{guix pull}, this has no
3745 effect on the version of Guix that user @code{alice} sees, and vice
3748 The result of running @command{guix pull} is a @dfn{profile} available
3749 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3750 make sure to add it to the beginning of your search path so that you use
3751 the latest version, and similarly for the Info manual
3752 (@pxref{Documentation}):
3755 export PATH="$HOME/.config/guix/current/bin:$PATH"
3756 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3759 The @code{--list-generations} or @code{-l} option lists past generations
3760 produced by @command{guix pull}, along with details about their provenance:
3764 Generation 1 Jun 10 2018 00:18:18
3766 repository URL: https://git.savannah.gnu.org/git/guix.git
3767 branch: origin/master
3768 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3770 Generation 2 Jun 11 2018 11:02:49
3772 repository URL: https://git.savannah.gnu.org/git/guix.git
3773 branch: origin/master
3774 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3775 2 new packages: keepalived, libnfnetlink
3776 6 packages upgraded: emacs-nix-mode@@2.0.4,
3777 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3778 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3780 Generation 3 Jun 13 2018 23:31:07 (current)
3782 repository URL: https://git.savannah.gnu.org/git/guix.git
3783 branch: origin/master
3784 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3785 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3786 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3789 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3790 describe the current status of Guix.
3792 This @code{~/.config/guix/current} profile works exactly like the profiles
3793 created by @command{guix package} (@pxref{Invoking guix package}). That
3794 is, you can list generations, roll back to the previous
3795 generation---i.e., the previous Guix---and so on:
3798 $ guix pull --roll-back
3799 switched from generation 3 to 2
3800 $ guix pull --delete-generations=1
3801 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3804 You can also use @command{guix package} (@pxref{Invoking guix package})
3805 to manage the profile by naming it explicitly:
3807 $ guix package -p ~/.config/guix/current --roll-back
3808 switched from generation 3 to 2
3809 $ guix package -p ~/.config/guix/current --delete-generations=1
3810 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3813 The @command{guix pull} command is usually invoked with no arguments,
3814 but it supports the following options:
3817 @item --url=@var{url}
3818 @itemx --commit=@var{commit}
3819 @itemx --branch=@var{branch}
3820 Download code for the @code{guix} channel from the specified @var{url}, at the
3821 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3822 string), or @var{branch}.
3824 @cindex @file{channels.scm}, configuration file
3825 @cindex configuration file for channels
3826 These options are provided for convenience, but you can also specify your
3827 configuration in the @file{~/.config/guix/channels.scm} file or using the
3828 @option{--channels} option (see below).
3830 @item --channels=@var{file}
3831 @itemx -C @var{file}
3832 Read the list of channels from @var{file} instead of
3833 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3834 @var{file} must contain Scheme code that
3835 evaluates to a list of channel objects. @xref{Channels}, for more
3838 @cindex channel news
3841 Display the list of packages added or upgraded since the previous
3842 generation, as well as, occasionally, news written by channel authors
3843 for their users (@pxref{Channels, Writing Channel News}).
3845 The package information is the same as displayed upon @command{guix
3846 pull} completion, but without ellipses; it is also similar to the output
3847 of @command{guix pull -l} for the last generation (see below).
3849 @item --list-generations[=@var{pattern}]
3850 @itemx -l [@var{pattern}]
3851 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3852 is provided, the subset of generations that match @var{pattern}.
3853 The syntax of @var{pattern} is the same as with @code{guix package
3854 --list-generations} (@pxref{Invoking guix package}).
3857 @cindex rolling back
3858 @cindex undoing transactions
3859 @cindex transactions, undoing
3860 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3861 undo the last transaction.
3863 @item --switch-generation=@var{pattern}
3864 @itemx -S @var{pattern}
3866 Switch to a particular generation defined by @var{pattern}.
3868 @var{pattern} may be either a generation number or a number prefixed
3869 with ``+'' or ``-''. The latter means: move forward/backward by a
3870 specified number of generations. For example, if you want to return to
3871 the latest generation after @code{--roll-back}, use
3872 @code{--switch-generation=+1}.
3874 @item --delete-generations[=@var{pattern}]
3875 @itemx -d [@var{pattern}]
3876 When @var{pattern} is omitted, delete all generations except the current
3879 This command accepts the same patterns as @option{--list-generations}.
3880 When @var{pattern} is specified, delete the matching generations. When
3881 @var{pattern} specifies a duration, generations @emph{older} than the
3882 specified duration match. For instance, @code{--delete-generations=1m}
3883 deletes generations that are more than one month old.
3885 If the current generation matches, it is @emph{not} deleted.
3887 Note that deleting generations prevents rolling back to them.
3888 Consequently, this command must be used with care.
3890 @xref{Invoking guix describe}, for a way to display information about the
3891 current generation only.
3893 @item --profile=@var{profile}
3894 @itemx -p @var{profile}
3895 Use @var{profile} instead of @file{~/.config/guix/current}.
3899 Show which channel commit(s) would be used and what would be built or
3900 substituted but do not actually do it.
3902 @item --system=@var{system}
3903 @itemx -s @var{system}
3904 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3905 the system type of the build host.
3908 Produce verbose output, writing build logs to the standard error output.
3911 Use the bootstrap Guile to build the latest Guix. This option is only
3912 useful to Guix developers.
3915 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3916 repository and branch to pull from, as well as @emph{additional} repositories
3917 containing package modules that should be deployed. @xref{Channels}, for more
3920 In addition, @command{guix pull} supports all the common build options
3921 (@pxref{Common Build Options}).
3927 @cindex @file{channels.scm}, configuration file
3928 @cindex configuration file for channels
3929 @cindex @command{guix pull}, configuration file
3930 @cindex configuration of @command{guix pull}
3931 Guix and its package collection are updated by running @command{guix pull}
3932 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3933 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3934 customized by defining @dfn{channels} in the
3935 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3936 of a Git repository to be deployed, and @command{guix pull} can be instructed
3937 to pull from one or more channels. In other words, channels can be used to
3938 @emph{customize} and to @emph{extend} Guix, as we will see below.
3940 @subsection Using a Custom Guix Channel
3942 The channel called @code{guix} specifies where Guix itself---its command-line
3943 tools as well as its package collection---should be downloaded. For instance,
3944 suppose you want to update from your own copy of the Guix repository at
3945 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3946 write in @code{~/.config/guix/channels.scm} this specification:
3949 ;; Tell 'guix pull' to use my own repo.
3952 (url "https://example.org/my-guix.git")
3953 (branch "super-hacks")))
3957 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3958 branch of the repository at @code{example.org}.
3960 @subsection Specifying Additional Channels
3962 @cindex extending the package collection (channels)
3963 @cindex personal packages (channels)
3964 @cindex channels, for personal packages
3965 You can also specify @emph{additional channels} to pull from. Let's say you
3966 have a bunch of custom package variants or personal packages that you think
3967 would make little sense to contribute to the Guix project, but would like to
3968 have these packages transparently available to you at the command line. You
3969 would first write modules containing those package definitions (@pxref{Package
3970 Modules}), maintain them in a Git repository, and then you and anyone else can
3971 use it as an additional channel to get packages from. Neat, no?
3973 @c What follows stems from discussions at
3974 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3975 @c earlier discussions on guix-devel@gnu.org.
3977 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3978 publish your personal channel to the world, we would like to share a few words
3983 Before publishing a channel, please consider contributing your package
3984 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3985 to free software of all sorts, and packages in Guix proper are readily
3986 available to all Guix users and benefit from the project's quality assurance
3990 When you maintain package definitions outside Guix, we, Guix developers,
3991 consider that @emph{the compatibility burden is on you}. Remember that
3992 package modules and package definitions are just Scheme code that uses various
3993 programming interfaces (APIs). We want to remain free to change these APIs to
3994 keep improving Guix, possibly in ways that break your channel. We never
3995 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3999 Corollary: if you're using an external channel and that channel breaks, please
4000 @emph{report the issue to the channel authors}, not to the Guix project.
4003 You've been warned! Having said this, we believe external channels are a
4004 practical way to exert your freedom to augment Guix' package collection and to
4005 share your improvements, which are basic tenets of
4006 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4007 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4010 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4011 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4014 @vindex %default-channels
4016 ;; Add my personal packages to those Guix provides.
4018 (name 'my-personal-packages)
4019 (url "https://example.org/personal-packages.git"))
4024 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4025 add a channel the list of channels that the variable @code{%default-channels}
4026 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4027 Manual}). With this file in place, @command{guix pull} builds not only Guix
4028 but also the package modules from your own repository. The result in
4029 @file{~/.config/guix/current} is the union of Guix with your own package
4033 $ guix pull --list-generations
4035 Generation 19 Aug 27 2018 16:20:48
4037 repository URL: https://git.savannah.gnu.org/git/guix.git
4039 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4040 my-personal-packages dd3df5e
4041 repository URL: https://example.org/personal-packages.git
4043 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4044 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4045 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4049 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4050 both Guix and packages from the @code{my-personal-packages} channel. Among
4051 the new and upgraded packages that are listed, some like @code{my-gimp} and
4052 @code{my-emacs-with-cool-features} might come from
4053 @code{my-personal-packages}, while others come from the Guix default channel.
4055 To create a channel, create a Git repository containing your own package
4056 modules and make it available. The repository can contain anything, but a
4057 useful channel will contain Guile modules that export packages. Once you
4058 start using a channel, Guix will behave as if the root directory of that
4059 channel's Git repository has been added to the Guile load path (@pxref{Load
4060 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4061 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4062 module, then the module will be available under the name @code{(my-packages
4063 my-tools)}, and you will be able to use it like any other module
4064 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4066 @cindex dependencies, channels
4067 @cindex meta-data, channels
4068 @subsection Declaring Channel Dependencies
4070 Channel authors may decide to augment a package collection provided by other
4071 channels. They can declare their channel to be dependent on other channels in
4072 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4073 the channel repository.
4075 The meta-data file should contain a simple S-expression like this:
4082 (name some-collection)
4083 (url "https://example.org/first-collection.git"))
4085 (name some-other-collection)
4086 (url "https://example.org/second-collection.git")
4087 (branch "testing"))))
4090 In the above example this channel is declared to depend on two other channels,
4091 which will both be fetched automatically. The modules provided by the channel
4092 will be compiled in an environment where the modules of all these declared
4093 channels are available.
4095 For the sake of reliability and maintainability, you should avoid dependencies
4096 on channels that you don't control, and you should aim to keep the number of
4097 dependencies to a minimum.
4099 @cindex subdirectory, channels
4100 @subsection Package Modules in a Sub-directory
4102 As a channel author, you may want to keep your channel modules in a
4103 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4104 add a meta-data file @file{.guix-channel} that contains:
4112 @cindex news, for channels
4113 @subsection Writing Channel News
4115 Channel authors may occasionally want to communicate to their users
4116 information about important changes in the channel. You'd send them all
4117 an email, but that's not convenient.
4119 Instead, channels can provide a @dfn{news file}; when the channel users
4120 run @command{guix pull}, that news file is automatically read and
4121 @command{guix pull --news} can display the announcements that correspond
4122 to the new commits that have been pulled, if any.
4124 To do that, channel authors must first declare the name of the news file
4125 in their @file{.guix-channel} file:
4130 (news-file "etc/news.txt"))
4133 The news file itself, @file{etc/news.txt} in this example, must look
4134 something like this:
4139 (entry (tag "the-bug-fix")
4140 (title (en "Fixed terrible bug")
4142 (body (en "@@emph@{Good news@}! It's fixed!")
4143 (eo "Certe ĝi pli bone funkcias nun!")))
4144 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4145 (title (en "Added a great package")
4146 (ca "Què vol dir guix?"))
4147 (body (en "Don't miss the @@code@{hello@} package!"))))
4150 The file consists of a list of @dfn{news entries}. Each entry is
4151 associated with a commit or tag: it describes changes made in this
4152 commit, possibly in preceding commits as well. Users see entries only
4153 the first time they obtain the commit the entry refers to.
4155 The @code{title} field should be a one-line summary while @code{body}
4156 can be arbitrarily long, and both can contain Texinfo markup
4157 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4158 a list of language tag/message tuples, which allows @command{guix pull}
4159 to display news in the language that corresponds to the user's locale.
4161 If you want to translate news using a gettext-based workflow, you can
4162 extract translatable strings with @command{xgettext} (@pxref{xgettext
4163 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4164 you write news entries in English first, the command below creates a PO
4165 file containing the strings to translate:
4168 xgettext -o news.po -l scheme -ken etc/news.scm
4171 To sum up, yes, you could use your channel as a blog. But beware, this
4172 is @emph{not quite} what your users might expect.
4174 @subsection Replicating Guix
4176 @cindex pinning, channels
4177 @cindex replicating Guix
4178 @cindex reproducibility, of Guix
4179 The @command{guix pull --list-generations} output above shows precisely which
4180 commits were used to build this instance of Guix. We can thus replicate it,
4181 say, on another machine, by providing a channel specification in
4182 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4185 ;; Deploy specific commits of my channels of interest.
4188 (url "https://git.savannah.gnu.org/git/guix.git")
4189 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4191 (name 'my-personal-packages)
4192 (url "https://example.org/personal-packages.git")
4193 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4196 The @command{guix describe --format=channels} command can even generate this
4197 list of channels directly (@pxref{Invoking guix describe}). The resulting
4198 file can be used with the -C options of @command{guix pull}
4199 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4200 (@pxref{Invoking guix time-machine}).
4202 At this point the two machines run the @emph{exact same Guix}, with access to
4203 the @emph{exact same packages}. The output of @command{guix build gimp} on
4204 one machine will be exactly the same, bit for bit, as the output of the same
4205 command on the other machine. It also means both machines have access to all
4206 the source code of Guix and, transitively, to all the source code of every
4209 This gives you super powers, allowing you to track the provenance of binary
4210 artifacts with very fine grain, and to reproduce software environments at
4211 will---some sort of ``meta reproducibility'' capabilities, if you will.
4212 @xref{Inferiors}, for another way to take advantage of these super powers.
4214 @node Invoking guix time-machine
4215 @section Invoking @command{guix time-machine}
4217 @cindex @command{guix time-machine}
4218 @cindex pinning, channels
4219 @cindex replicating Guix
4220 @cindex reproducibility, of Guix
4222 The @command{guix time-machine} command provides access to other
4223 revisions of Guix, for example to install older versions of packages,
4224 or to reproduce a computation in an identical environment. The revision
4225 of Guix to be used is defined by a commit or by a channel
4226 description file created by @command{guix describe}
4227 (@pxref{Invoking guix describe}).
4229 The general syntax is:
4232 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4235 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4236 @command{guix} command of the specified revision. The @var{options} that define
4237 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4240 @item --url=@var{url}
4241 @itemx --commit=@var{commit}
4242 @itemx --branch=@var{branch}
4243 Use the @code{guix} channel from the specified @var{url}, at the
4244 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4245 string), or @var{branch}.
4247 @item --channels=@var{file}
4248 @itemx -C @var{file}
4249 Read the list of channels from @var{file}. @var{file} must contain
4250 Scheme code that evaluates to a list of channel objects.
4251 @xref{Channels} for more information.
4254 As for @command{guix pull}, the absence of any options means that the
4255 the latest commit on the master branch will be used. The command
4258 guix time-machine -- build hello
4261 will thus build the package @code{hello} as defined in the master branch,
4262 which is in general a newer revision of Guix than you have installed.
4263 Time travel works in both directions!
4265 Note that @command{guix time-machine} can trigger builds of channels and
4266 their dependencies, and these are controlled by the standard build
4267 options (@pxref{Common Build Options}).
4272 @c TODO: Remove this once we're more confident about API stability.
4274 The functionality described here is a ``technology preview'' as of version
4275 @value{VERSION}. As such, the interface is subject to change.
4279 @cindex composition of Guix revisions
4280 Sometimes you might need to mix packages from the revision of Guix you're
4281 currently running with packages available in a different revision of Guix.
4282 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4283 revisions in arbitrary ways.
4285 @cindex inferior packages
4286 Technically, an ``inferior'' is essentially a separate Guix process connected
4287 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4288 @code{(guix inferior)} module allows you to create inferiors and to
4289 communicate with them. It also provides a high-level interface to browse and
4290 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4292 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4293 to interact with a separate revision of Guix. For example, let's assume you
4294 want to install in your profile the current @code{guile} package, along with
4295 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4296 because the newer @code{guile-json} has an incompatible API and you want to
4297 run your code against the old API@. To do that, you could write a manifest for
4298 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4299 manifest, you would create an inferior for that old Guix revision you care
4300 about, and you would look up the @code{guile-json} package in the inferior:
4303 (use-modules (guix inferior) (guix channels)
4304 (srfi srfi-1)) ;for 'first'
4307 ;; This is the old revision from which we want to
4308 ;; extract guile-json.
4311 (url "https://git.savannah.gnu.org/git/guix.git")
4313 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4316 ;; An inferior representing the above revision.
4317 (inferior-for-channels channels))
4319 ;; Now create a manifest with the current "guile" package
4320 ;; and the old "guile-json" package.
4322 (list (first (lookup-inferior-packages inferior "guile-json"))
4323 (specification->package "guile")))
4326 On its first run, @command{guix package --manifest} might have to build the
4327 channel you specified before it can create the inferior; subsequent runs will
4328 be much faster because the Guix revision will be cached.
4330 The @code{(guix inferior)} module provides the following procedures to open an
4333 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4334 [#:cache-directory] [#:ttl]
4335 Return an inferior for @var{channels}, a list of channels. Use the cache at
4336 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4337 This procedure opens a new connection to the build daemon.
4339 As a side effect, this procedure may build or substitute binaries for
4340 @var{channels}, which can take time.
4343 @deffn {Scheme Procedure} open-inferior @var{directory} @
4344 [#:command "bin/guix"]
4345 Open the inferior Guix in @var{directory}, running
4346 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4347 the inferior could not be launched.
4350 @cindex inferior packages
4351 The procedures listed below allow you to obtain and manipulate inferior
4354 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4355 Return the list of packages known to @var{inferior}.
4358 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4360 Return the sorted list of inferior packages matching @var{name} in
4361 @var{inferior}, with highest version numbers first. If @var{version} is true,
4362 return only packages with a version number prefixed by @var{version}.
4365 @deffn {Scheme Procedure} inferior-package? @var{obj}
4366 Return true if @var{obj} is an inferior package.
4369 @deffn {Scheme Procedure} inferior-package-name @var{package}
4370 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4371 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4372 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4373 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4374 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4375 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4376 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4377 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4378 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4379 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4380 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4381 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4382 These procedures are the counterpart of package record accessors
4383 (@pxref{package Reference}). Most of them work by querying the inferior
4384 @var{package} comes from, so the inferior must still be live when you call
4388 Inferior packages can be used transparently like any other package or
4389 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4390 transparently handled by the @code{packages->manifest} procedure, which is
4391 commonly use in manifests (@pxref{Invoking guix package, the
4392 @option{--manifest} option of @command{guix package}}). Thus you can insert
4393 an inferior package pretty much anywhere you would insert a regular package:
4394 in manifests, in the @code{packages} field of your @code{operating-system}
4395 declaration, and so on.
4397 @node Invoking guix describe
4398 @section Invoking @command{guix describe}
4400 @cindex reproducibility
4401 @cindex replicating Guix
4402 Often you may want to answer questions like: ``Which revision of Guix am I
4403 using?'' or ``Which channels am I using?'' This is useful information in many
4404 situations: if you want to @emph{replicate} an environment on a different
4405 machine or user account, if you want to report a bug or to determine what
4406 change in the channels you are using caused it, or if you want to record your
4407 system state for reproducibility purposes. The @command{guix describe}
4408 command answers these questions.
4410 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4411 displays the channel(s) that it was built from, including their repository URL
4412 and commit IDs (@pxref{Channels}):
4416 Generation 10 Sep 03 2018 17:32:44 (current)
4418 repository URL: https://git.savannah.gnu.org/git/guix.git
4420 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4423 If you're familiar with the Git version control system, this is similar in
4424 spirit to @command{git describe}; the output is also similar to that of
4425 @command{guix pull --list-generations}, but limited to the current generation
4426 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4427 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4428 information is all it takes to describe the revision of Guix you're using, and
4429 also to replicate it.
4431 To make it easier to replicate Guix, @command{guix describe} can also be asked
4432 to return a list of channels instead of the human-readable description above:
4435 $ guix describe -f channels
4438 (url "https://git.savannah.gnu.org/git/guix.git")
4440 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4444 You can save this to a file and feed it to @command{guix pull -C} on some
4445 other machine or at a later point in time, which will instantiate @emph{this
4446 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4447 From there on, since you're able to deploy the same revision of Guix, you can
4448 just as well @emph{replicate a complete software environment}. We humbly
4449 think that this is @emph{awesome}, and we hope you'll like it too!
4451 The details of the options supported by @command{guix describe} are as
4455 @item --format=@var{format}
4456 @itemx -f @var{format}
4457 Produce output in the specified @var{format}, one of:
4461 produce human-readable output;
4463 produce a list of channel specifications that can be passed to @command{guix
4464 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4468 produce a list of channel specifications in JSON format;
4470 produce a list of channel specifications in Recutils format.
4473 @item --profile=@var{profile}
4474 @itemx -p @var{profile}
4475 Display information about @var{profile}.
4478 @node Invoking guix archive
4479 @section Invoking @command{guix archive}
4481 @cindex @command{guix archive}
4483 The @command{guix archive} command allows users to @dfn{export} files
4484 from the store into a single archive, and to later @dfn{import} them on
4485 a machine that runs Guix.
4486 In particular, it allows store files to be transferred from one machine
4487 to the store on another machine.
4490 If you're looking for a way to produce archives in a format suitable for
4491 tools other than Guix, @pxref{Invoking guix pack}.
4494 @cindex exporting store items
4495 To export store files as an archive to standard output, run:
4498 guix archive --export @var{options} @var{specifications}...
4501 @var{specifications} may be either store file names or package
4502 specifications, as for @command{guix package} (@pxref{Invoking guix
4503 package}). For instance, the following command creates an archive
4504 containing the @code{gui} output of the @code{git} package and the main
4505 output of @code{emacs}:
4508 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4511 If the specified packages are not built yet, @command{guix archive}
4512 automatically builds them. The build process may be controlled with the
4513 common build options (@pxref{Common Build Options}).
4515 To transfer the @code{emacs} package to a machine connected over SSH,
4519 guix archive --export -r emacs | ssh the-machine guix archive --import
4523 Similarly, a complete user profile may be transferred from one machine
4524 to another like this:
4527 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4528 ssh the-machine guix archive --import
4532 However, note that, in both examples, all of @code{emacs} and the
4533 profile as well as all of their dependencies are transferred (due to
4534 @code{-r}), regardless of what is already available in the store on the
4535 target machine. The @code{--missing} option can help figure out which
4536 items are missing from the target store. The @command{guix copy}
4537 command simplifies and optimizes this whole process, so this is probably
4538 what you should use in this case (@pxref{Invoking guix copy}).
4540 @cindex nar, archive format
4541 @cindex normalized archive (nar)
4542 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4543 comparable in spirit to `tar', but with differences
4544 that make it more appropriate for our purposes. First, rather than
4545 recording all Unix metadata for each file, the nar format only mentions
4546 the file type (regular, directory, or symbolic link); Unix permissions
4547 and owner/group are dismissed. Second, the order in which directory
4548 entries are stored always follows the order of file names according to
4549 the C locale collation order. This makes archive production fully
4552 When exporting, the daemon digitally signs the contents of the archive,
4553 and that digital signature is appended. When importing, the daemon
4554 verifies the signature and rejects the import in case of an invalid
4555 signature or if the signing key is not authorized.
4556 @c FIXME: Add xref to daemon doc about signatures.
4558 The main options are:
4562 Export the specified store files or packages (see below.) Write the
4563 resulting archive to the standard output.
4565 Dependencies are @emph{not} included in the output, unless
4566 @code{--recursive} is passed.
4570 When combined with @code{--export}, this instructs @command{guix
4571 archive} to include dependencies of the given items in the archive.
4572 Thus, the resulting archive is self-contained: it contains the closure
4573 of the exported store items.
4576 Read an archive from the standard input, and import the files listed
4577 therein into the store. Abort if the archive has an invalid digital
4578 signature, or if it is signed by a public key not among the authorized
4579 keys (see @code{--authorize} below.)
4582 Read a list of store file names from the standard input, one per line,
4583 and write on the standard output the subset of these files missing from
4586 @item --generate-key[=@var{parameters}]
4587 @cindex signing, archives
4588 Generate a new key pair for the daemon. This is a prerequisite before
4589 archives can be exported with @code{--export}. Note that this operation
4590 usually takes time, because it needs to gather enough entropy to
4591 generate the key pair.
4593 The generated key pair is typically stored under @file{/etc/guix}, in
4594 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4595 key, which must be kept secret.) When @var{parameters} is omitted,
4596 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4597 versions before 1.6.0, it is a 4096-bit RSA key.
4598 Alternatively, @var{parameters} can specify
4599 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4600 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4601 Libgcrypt Reference Manual}).
4604 @cindex authorizing, archives
4605 Authorize imports signed by the public key passed on standard input.
4606 The public key must be in ``s-expression advanced format''---i.e., the
4607 same format as the @file{signing-key.pub} file.
4609 The list of authorized keys is kept in the human-editable file
4610 @file{/etc/guix/acl}. The file contains
4611 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4612 s-expressions''} and is structured as an access-control list in the
4613 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4616 @item --extract=@var{directory}
4617 @itemx -x @var{directory}
4618 Read a single-item archive as served by substitute servers
4619 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4620 low-level operation needed in only very narrow use cases; see below.
4622 For example, the following command extracts the substitute for Emacs
4623 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4627 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4628 | gunzip | guix archive -x /tmp/emacs
4631 Single-item archives are different from multiple-item archives produced
4632 by @command{guix archive --export}; they contain a single store item,
4633 and they do @emph{not} embed a signature. Thus this operation does
4634 @emph{no} signature verification and its output should be considered
4637 The primary purpose of this operation is to facilitate inspection of
4638 archive contents coming from possibly untrusted substitute servers
4639 (@pxref{Invoking guix challenge}).
4643 Read a single-item archive as served by substitute servers
4644 (@pxref{Substitutes}) and print the list of files it contains, as in
4649 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4650 | lzip -d | guix archive -t
4656 @c *********************************************************************
4658 @chapter Development
4660 @cindex software development
4661 If you are a software developer, Guix provides tools that you should find
4662 helpful---independently of the language you're developing in. This is what
4663 this chapter is about.
4665 The @command{guix environment} command provides a convenient way to set up
4666 @dfn{development environments} containing all the dependencies and tools
4667 necessary to work on the software package of your choice. The @command{guix
4668 pack} command allows you to create @dfn{application bundles} that can be
4669 easily distributed to users who do not run Guix.
4672 * Invoking guix environment:: Setting up development environments.
4673 * Invoking guix pack:: Creating software bundles.
4674 * Packages for C Development:: Working with C code with Guix.
4677 @node Invoking guix environment
4678 @section Invoking @command{guix environment}
4680 @cindex reproducible build environments
4681 @cindex development environments
4682 @cindex @command{guix environment}
4683 @cindex environment, package build environment
4684 The purpose of @command{guix environment} is to assist hackers in
4685 creating reproducible development environments without polluting their
4686 package profile. The @command{guix environment} tool takes one or more
4687 packages, builds all of their inputs, and creates a shell
4688 environment to use them.
4690 The general syntax is:
4693 guix environment @var{options} @var{package}@dots{}
4696 The following example spawns a new shell set up for the development of
4700 guix environment guile
4703 If the needed dependencies are not built yet, @command{guix environment}
4704 automatically builds them. The environment of the new shell is an augmented
4705 version of the environment that @command{guix environment} was run in.
4706 It contains the necessary search paths for building the given package
4707 added to the existing environment variables. To create a ``pure''
4708 environment, in which the original environment variables have been unset,
4709 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4710 environment variables such as @code{PATH} in their @file{~/.bashrc}
4711 file. As a consequence, when @code{guix environment} launches it, Bash
4712 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4713 environment variables. It is an error to define such environment
4714 variables in @file{.bashrc}; instead, they should be defined in
4715 @file{.bash_profile}, which is sourced only by log-in shells.
4716 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4717 details on Bash start-up files.}.
4719 @vindex GUIX_ENVIRONMENT
4720 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4721 variable in the shell it spawns; its value is the file name of the
4722 profile of this environment. This allows users to, say, define a
4723 specific prompt for development environments in their @file{.bashrc}
4724 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4727 if [ -n "$GUIX_ENVIRONMENT" ]
4729 export PS1="\u@@\h \w [dev]\$ "
4734 ...@: or to browse the profile:
4737 $ ls "$GUIX_ENVIRONMENT/bin"
4740 Additionally, more than one package may be specified, in which case the
4741 union of the inputs for the given packages are used. For example, the
4742 command below spawns a shell where all of the dependencies of both Guile
4743 and Emacs are available:
4746 guix environment guile emacs
4749 Sometimes an interactive shell session is not desired. An arbitrary
4750 command may be invoked by placing the @code{--} token to separate the
4751 command from the rest of the arguments:
4754 guix environment guile -- make -j4
4757 In other situations, it is more convenient to specify the list of
4758 packages needed in the environment. For example, the following command
4759 runs @command{python} from an environment containing Python@tie{}2.7 and
4763 guix environment --ad-hoc python2-numpy python-2.7 -- python
4766 Furthermore, one might want the dependencies of a package and also some
4767 additional packages that are not build-time or runtime dependencies, but
4768 are useful when developing nonetheless. Because of this, the
4769 @code{--ad-hoc} flag is positional. Packages appearing before
4770 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4771 added to the environment. Packages appearing after are interpreted as
4772 packages that will be added to the environment directly. For example,
4773 the following command creates a Guix development environment that
4774 additionally includes Git and strace:
4777 guix environment --pure guix --ad-hoc git strace
4780 Sometimes it is desirable to isolate the environment as much as
4781 possible, for maximal purity and reproducibility. In particular, when
4782 using Guix on a host distro that is not Guix System, it is desirable to
4783 prevent access to @file{/usr/bin} and other system-wide resources from
4784 the development environment. For example, the following command spawns
4785 a Guile REPL in a ``container'' where only the store and the current
4786 working directory are mounted:
4789 guix environment --ad-hoc --container guile -- guile
4793 The @code{--container} option requires Linux-libre 3.19 or newer.
4796 The available options are summarized below.
4799 @item --root=@var{file}
4800 @itemx -r @var{file}
4801 @cindex persistent environment
4802 @cindex garbage collector root, for environments
4803 Make @var{file} a symlink to the profile for this environment, and
4804 register it as a garbage collector root.
4806 This is useful if you want to protect your environment from garbage
4807 collection, to make it ``persistent''.
4809 When this option is omitted, the environment is protected from garbage
4810 collection only for the duration of the @command{guix environment}
4811 session. This means that next time you recreate the same environment,
4812 you could have to rebuild or re-download packages. @xref{Invoking guix
4813 gc}, for more on GC roots.
4815 @item --expression=@var{expr}
4816 @itemx -e @var{expr}
4817 Create an environment for the package or list of packages that
4818 @var{expr} evaluates to.
4820 For example, running:
4823 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4826 starts a shell with the environment for this specific variant of the
4832 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4835 starts a shell with all the base system packages available.
4837 The above commands only use the default output of the given packages.
4838 To select other outputs, two element tuples can be specified:
4841 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4844 @item --load=@var{file}
4845 @itemx -l @var{file}
4846 Create an environment for the package or list of packages that the code
4847 within @var{file} evaluates to.
4849 As an example, @var{file} might contain a definition like this
4850 (@pxref{Defining Packages}):
4853 @verbatiminclude environment-gdb.scm
4856 @item --manifest=@var{file}
4857 @itemx -m @var{file}
4858 Create an environment for the packages contained in the manifest object
4859 returned by the Scheme code in @var{file}. This option can be repeated
4860 several times, in which case the manifests are concatenated.
4862 This is similar to the same-named option in @command{guix package}
4863 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4867 Include all specified packages in the resulting environment, as if an
4868 @i{ad hoc} package were defined with them as inputs. This option is
4869 useful for quickly creating an environment without having to write a
4870 package expression to contain the desired inputs.
4872 For instance, the command:
4875 guix environment --ad-hoc guile guile-sdl -- guile
4878 runs @command{guile} in an environment where Guile and Guile-SDL are
4881 Note that this example implicitly asks for the default output of
4882 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4883 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4884 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4886 This option may be composed with the default behavior of @command{guix
4887 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4888 as packages whose dependencies will be added to the environment, the
4889 default behavior. Packages appearing after are interpreted as packages
4890 that will be added to the environment directly.
4893 Unset existing environment variables when building the new environment, except
4894 those specified with @option{--preserve} (see below.) This has the effect of
4895 creating an environment in which search paths only contain package inputs.
4897 @item --preserve=@var{regexp}
4898 @itemx -E @var{regexp}
4899 When used alongside @option{--pure}, preserve the environment variables
4900 matching @var{regexp}---in other words, put them on a ``white list'' of
4901 environment variables that must be preserved. This option can be repeated
4905 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4909 This example runs @command{mpirun} in a context where the only environment
4910 variables defined are @code{PATH}, environment variables whose name starts
4911 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4914 @item --search-paths
4915 Display the environment variable definitions that make up the
4918 @item --system=@var{system}
4919 @itemx -s @var{system}
4920 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4925 Run @var{command} within an isolated container. The current working
4926 directory outside the container is mapped inside the container.
4927 Additionally, unless overridden with @code{--user}, a dummy home
4928 directory is created that matches the current user's home directory, and
4929 @file{/etc/passwd} is configured accordingly.
4931 The spawned process runs as the current user outside the container. Inside
4932 the container, it has the same UID and GID as the current user, unless
4933 @option{--user} is passed (see below.)
4937 For containers, share the network namespace with the host system.
4938 Containers created without this flag only have access to the loopback
4941 @item --link-profile
4943 For containers, link the environment profile to
4944 @file{~/.guix-profile} within the container. This is equivalent to
4945 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4946 within the container. Linking will fail and abort the environment if
4947 the directory already exists, which will certainly be the case if
4948 @command{guix environment} was invoked in the user's home directory.
4950 Certain packages are configured to look in
4951 @code{~/.guix-profile} for configuration files and data;@footnote{For
4952 example, the @code{fontconfig} package inspects
4953 @file{~/.guix-profile/share/fonts} for additional fonts.}
4954 @code{--link-profile} allows these programs to behave as expected within
4957 @item --user=@var{user}
4958 @itemx -u @var{user}
4959 For containers, use the username @var{user} in place of the current
4960 user. The generated @file{/etc/passwd} entry within the container will
4961 contain the name @var{user}, the home directory will be
4962 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4963 the UID and GID inside the container are 1000. @var{user}
4964 need not exist on the system.
4966 Additionally, any shared or exposed path (see @code{--share} and
4967 @code{--expose} respectively) whose target is within the current user's
4968 home directory will be remapped relative to @file{/home/USER}; this
4969 includes the automatic mapping of the current working directory.
4972 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4974 guix environment --container --user=foo \
4975 --expose=$HOME/test \
4976 --expose=/tmp/target=$HOME/target
4979 While this will limit the leaking of user identity through home paths
4980 and each of the user fields, this is only one useful component of a
4981 broader privacy/anonymity solution---not one in and of itself.
4984 For containers, the default behavior is to share the current working
4985 directory with the isolated container and immediately change to that
4986 directory within the container. If this is undesirable, @code{--no-cwd}
4987 will cause the current working directory to @emph{not} be automatically
4988 shared and will change to the user's home directory within the container
4989 instead. See also @code{--user}.
4991 @item --expose=@var{source}[=@var{target}]
4992 @itemx --share=@var{source}[=@var{target}]
4993 For containers, @code{--expose} (resp. @code{--share}) exposes the file
4994 system @var{source} from the host system as the read-only
4995 (resp. writable) file system @var{target} within the container. If
4996 @var{target} is not specified, @var{source} is used as the target mount
4997 point in the container.
4999 The example below spawns a Guile REPL in a container in which the user's
5000 home directory is accessible read-only via the @file{/exchange}
5004 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5009 @command{guix environment}
5010 also supports all of the common build options that @command{guix
5011 build} supports (@pxref{Common Build Options}) as well as package
5012 transformation options (@pxref{Package Transformation Options}).
5014 @node Invoking guix pack
5015 @section Invoking @command{guix pack}
5017 Occasionally you want to pass software to people who are not (yet!)
5018 lucky enough to be using Guix. You'd tell them to run @command{guix
5019 package -i @var{something}}, but that's not possible in this case. This
5020 is where @command{guix pack} comes in.
5023 If you are looking for ways to exchange binaries among machines that
5024 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5025 publish}, and @ref{Invoking guix archive}.
5030 @cindex application bundle
5031 @cindex software bundle
5032 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5033 @dfn{software bundle}: it creates a tarball or some other archive
5034 containing the binaries of the software you're interested in, and all
5035 its dependencies. The resulting archive can be used on any machine that
5036 does not have Guix, and people can run the exact same binaries as those
5037 you have with Guix. The pack itself is created in a bit-reproducible
5038 fashion, so anyone can verify that it really contains the build results
5039 that you pretend to be shipping.
5041 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5042 their dependencies, you can run:
5045 $ guix pack guile emacs geiser
5047 /gnu/store/@dots{}-pack.tar.gz
5050 The result here is a tarball containing a @file{/gnu/store} directory
5051 with all the relevant packages. The resulting tarball contains a
5052 @dfn{profile} with the three packages of interest; the profile is the
5053 same as would be created by @command{guix package -i}. It is this
5054 mechanism that is used to create Guix's own standalone binary tarball
5055 (@pxref{Binary Installation}).
5057 Users of this pack would have to run
5058 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5059 find inconvenient. To work around it, you can create, say, a
5060 @file{/opt/gnu/bin} symlink to the profile:
5063 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5067 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5069 @cindex relocatable binaries, with @command{guix pack}
5070 What if the recipient of your pack does not have root privileges on
5071 their machine, and thus cannot unpack it in the root file system? In
5072 that case, you will want to use the @code{--relocatable} option (see
5073 below). This option produces @dfn{relocatable binaries}, meaning they
5074 they can be placed anywhere in the file system hierarchy: in the example
5075 above, users can unpack your tarball in their home directory and
5076 directly run @file{./opt/gnu/bin/guile}.
5078 @cindex Docker, build an image with guix pack
5079 Alternatively, you can produce a pack in the Docker image format using
5080 the following command:
5083 guix pack -f docker -S /bin=bin guile guile-readline
5087 The result is a tarball that can be passed to the @command{docker load}
5088 command, followed by @code{docker run}:
5091 docker load < @var{file}
5092 docker run -ti guile-guile-readline /bin/guile
5096 where @var{file} is the image returned by @var{guix pack}, and
5097 @code{guile-guile-readline} is its ``image tag''. See the
5098 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5099 documentation} for more information.
5101 @cindex Singularity, build an image with guix pack
5102 @cindex SquashFS, build an image with guix pack
5103 Yet another option is to produce a SquashFS image with the following
5107 guix pack -f squashfs bash guile emacs geiser
5111 The result is a SquashFS file system image that can either be mounted or
5112 directly be used as a file system container image with the
5113 @uref{https://www.sylabs.io/docs/, Singularity container execution
5114 environment}, using commands like @command{singularity shell} or
5115 @command{singularity exec}.
5117 Several command-line options allow you to customize your pack:
5120 @item --format=@var{format}
5121 @itemx -f @var{format}
5122 Produce a pack in the given @var{format}.
5124 The available formats are:
5128 This is the default format. It produces a tarball containing all the
5129 specified binaries and symlinks.
5132 This produces a tarball that follows the
5133 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5134 Docker Image Specification}. The ``repository name'' as it appears in
5135 the output of the @command{docker images} command is computed from
5136 package names passed on the command line or in the manifest file.
5139 This produces a SquashFS image containing all the specified binaries and
5140 symlinks, as well as empty mount points for virtual file systems like
5144 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5145 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5146 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5147 with something like:
5150 guix pack -f squashfs bash @dots{}
5153 If you forget the @code{bash} (or similar) package, @command{singularity
5154 run} and @command{singularity exec} will fail with an unhelpful ``no
5155 such file or directory'' message.
5159 @cindex relocatable binaries
5162 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5163 anywhere in the file system hierarchy and run from there.
5165 When this option is passed once, the resulting binaries require support for
5166 @dfn{user namespaces} in the kernel Linux; when passed
5167 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5168 PRoot support, can be thought of as the abbreviation of ``Really
5169 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5170 if user namespaces are unavailable, and essentially work anywhere---see below
5171 for the implications.
5173 For example, if you create a pack containing Bash with:
5176 guix pack -RR -S /mybin=bin bash
5180 ...@: you can copy that pack to a machine that lacks Guix, and from your
5181 home directory as a normal user, run:
5189 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5190 @file{/gnu/store} shows up and contains all the dependencies of
5191 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5192 altogether! That is probably the simplest way to deploy Guix-built
5193 software on a non-Guix machine.
5196 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5197 the kernel Linux, which allows unprivileged users to mount or change root.
5198 Old versions of Linux did not support it, and some GNU/Linux distributions
5201 To produce relocatable binaries that work even in the absence of user
5202 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5203 case, binaries will try user namespace support and fall back to PRoot if user
5204 namespaces are not supported.
5206 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5207 support for file system virtualization. It achieves that by using the
5208 @code{ptrace} system call on the running program. This approach has the
5209 advantage to work without requiring special kernel support, but it incurs
5210 run-time overhead every time a system call is made.
5213 @cindex entry point, for Docker images
5214 @item --entry-point=@var{command}
5215 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5216 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5217 support it. @var{command} must be relative to the profile contained in the
5220 The entry point specifies the command that tools like @code{docker run} or
5221 @code{singularity run} automatically start by default. For example, you can
5225 guix pack -f docker --entry-point=bin/guile guile
5228 The resulting pack can easily be loaded and @code{docker run} with no extra
5229 arguments will spawn @code{bin/guile}:
5232 docker load -i pack.tar.gz
5233 docker run @var{image-id}
5236 @item --expression=@var{expr}
5237 @itemx -e @var{expr}
5238 Consider the package @var{expr} evaluates to.
5240 This has the same purpose as the same-named option in @command{guix
5241 build} (@pxref{Additional Build Options, @code{--expression} in
5242 @command{guix build}}).
5244 @item --manifest=@var{file}
5245 @itemx -m @var{file}
5246 Use the packages contained in the manifest object returned by the Scheme
5247 code in @var{file}. This option can be repeated several times, in which
5248 case the manifests are concatenated.
5250 This has a similar purpose as the same-named option in @command{guix
5251 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5252 same manifest files. It allows you to define a collection of packages
5253 once and use it both for creating profiles and for creating archives
5254 for use on machines that do not have Guix installed. Note that you can
5255 specify @emph{either} a manifest file @emph{or} a list of packages,
5258 @item --system=@var{system}
5259 @itemx -s @var{system}
5260 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5261 the system type of the build host.
5263 @item --target=@var{triplet}
5264 @cindex cross-compilation
5265 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5266 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5267 configuration triplets,, autoconf, Autoconf}).
5269 @item --compression=@var{tool}
5270 @itemx -C @var{tool}
5271 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5272 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5274 @item --symlink=@var{spec}
5275 @itemx -S @var{spec}
5276 Add the symlinks specified by @var{spec} to the pack. This option can
5277 appear several times.
5279 @var{spec} has the form @code{@var{source}=@var{target}}, where
5280 @var{source} is the symlink that will be created and @var{target} is the
5283 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5284 symlink pointing to the @file{bin} sub-directory of the profile.
5286 @item --save-provenance
5287 Save provenance information for the packages passed on the command line.
5288 Provenance information includes the URL and commit of the channels in use
5291 Provenance information is saved in the
5292 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5293 usual package metadata---the name and version of each package, their
5294 propagated inputs, and so on. It is useful information to the recipient of
5295 the pack, who then knows how the pack was (supposedly) obtained.
5297 This option is not enabled by default because, like timestamps, provenance
5298 information contributes nothing to the build process. In other words, there
5299 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5300 Recording such ``silent'' metadata in the output thus potentially breaks the
5301 source-to-binary bitwise reproducibility property.
5303 @item --root=@var{file}
5304 @itemx -r @var{file}
5305 @cindex garbage collector root, for packs
5306 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5309 @item --localstatedir
5310 @itemx --profile-name=@var{name}
5311 Include the ``local state directory'', @file{/var/guix}, in the resulting
5312 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5313 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5314 @file{~root/.guix-profile}.
5316 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5317 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5318 the pack means that the store is ``complete'' and manageable by Guix;
5319 not providing it pack means that the store is ``dead'': items cannot be
5320 added to it or removed from it after extraction of the pack.
5322 One use case for this is the Guix self-contained binary tarball
5323 (@pxref{Binary Installation}).
5327 Print the name of the derivation that builds the pack.
5330 Use the bootstrap binaries to build the pack. This option is only
5331 useful to Guix developers.
5334 In addition, @command{guix pack} supports all the common build options
5335 (@pxref{Common Build Options}) and all the package transformation
5336 options (@pxref{Package Transformation Options}).
5338 @node Packages for C Development
5339 @section Packages for C Development
5343 @cindex linker wrapper
5344 @cindex toolchain, for C development
5346 If you need a complete toolchain for compiling and linking C or C++
5347 source code, use the @code{gcc-toolchain} package. This package
5348 provides a complete GCC toolchain for C/C++ development, including GCC
5349 itself, the GNU C Library (headers and binaries, plus debugging symbols
5350 in the @code{debug} output), Binutils, and a linker wrapper.
5352 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5353 passed to the linker, add corresponding @code{-rpath} arguments, and
5354 invoke the actual linker with this new set of arguments. You can instruct the
5355 wrapper to refuse to link against libraries not in the store by setting the
5356 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5360 @c *********************************************************************
5361 @node Programming Interface
5362 @chapter Programming Interface
5364 GNU Guix provides several Scheme programming interfaces (APIs) to
5365 define, build, and query packages. The first interface allows users to
5366 write high-level package definitions. These definitions refer to
5367 familiar packaging concepts, such as the name and version of a package,
5368 its build system, and its dependencies. These definitions can then be
5369 turned into concrete build actions.
5371 Build actions are performed by the Guix daemon, on behalf of users. In a
5372 standard setup, the daemon has write access to the store---the
5373 @file{/gnu/store} directory---whereas users do not. The recommended
5374 setup also has the daemon perform builds in chroots, under a specific
5375 build users, to minimize interference with the rest of the system.
5378 Lower-level APIs are available to interact with the daemon and the
5379 store. To instruct the daemon to perform a build action, users actually
5380 provide it with a @dfn{derivation}. A derivation is a low-level
5381 representation of the build actions to be taken, and the environment in
5382 which they should occur---derivations are to package definitions what
5383 assembly is to C programs. The term ``derivation'' comes from the fact
5384 that build results @emph{derive} from them.
5386 This chapter describes all these APIs in turn, starting from high-level
5387 package definitions.
5390 * Package Modules:: Packages from the programmer's viewpoint.
5391 * Defining Packages:: Defining new packages.
5392 * Build Systems:: Specifying how packages are built.
5393 * The Store:: Manipulating the package store.
5394 * Derivations:: Low-level interface to package derivations.
5395 * The Store Monad:: Purely functional interface to the store.
5396 * G-Expressions:: Manipulating build expressions.
5397 * Invoking guix repl:: Fiddling with Guix interactively.
5400 @node Package Modules
5401 @section Package Modules
5403 From a programming viewpoint, the package definitions of the
5404 GNU distribution are provided by Guile modules in the @code{(gnu packages
5405 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5406 packages @dots{})} module name space are not necessarily ``GNU
5407 packages''. This module naming scheme follows the usual Guile module
5408 naming convention: @code{gnu} means that these modules are distributed
5409 as part of the GNU system, and @code{packages} identifies modules that
5410 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5411 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5412 module exports a variable named @code{emacs}, which is bound to a
5413 @code{<package>} object (@pxref{Defining Packages}).
5415 The @code{(gnu packages @dots{})} module name space is
5416 automatically scanned for packages by the command-line tools. For
5417 instance, when running @code{guix install emacs}, all the @code{(gnu
5418 packages @dots{})} modules are scanned until one that exports a package
5419 object whose name is @code{emacs} is found. This package search
5420 facility is implemented in the @code{(gnu packages)} module.
5422 @cindex customization, of packages
5423 @cindex package module search path
5424 Users can store package definitions in modules with different
5425 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5426 name and module name must match. For instance, the @code{(my-packages
5427 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5428 relative to the load path specified with @option{--load-path} or
5429 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5430 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5431 these package definitions visible to the user interfaces:
5435 By adding the directory containing your package modules to the search path
5436 with the @code{-L} flag of @command{guix package} and other commands
5437 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5438 environment variable described below.
5441 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5442 pulls from it. A channel is essentially a Git repository containing package
5443 modules. @xref{Channels}, for more information on how to define and use
5447 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5449 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5450 This is a colon-separated list of directories to search for additional
5451 package modules. Directories listed in this variable take precedence
5452 over the own modules of the distribution.
5455 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5456 each package is built based solely on other packages in the
5457 distribution. The root of this dependency graph is a small set of
5458 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5459 bootstrap)} module. For more information on bootstrapping,
5460 @pxref{Bootstrapping}.
5462 @node Defining Packages
5463 @section Defining Packages
5465 The high-level interface to package definitions is implemented in the
5466 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5467 example, the package definition, or @dfn{recipe}, for the GNU Hello
5468 package looks like this:
5471 (define-module (gnu packages hello)
5472 #:use-module (guix packages)
5473 #:use-module (guix download)
5474 #:use-module (guix build-system gnu)
5475 #:use-module (guix licenses)
5476 #:use-module (gnu packages gawk))
5478 (define-public hello
5484 (uri (string-append "mirror://gnu/hello/hello-" version
5488 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5489 (build-system gnu-build-system)
5490 (arguments '(#:configure-flags '("--enable-silent-rules")))
5491 (inputs `(("gawk" ,gawk)))
5492 (synopsis "Hello, GNU world: An example GNU package")
5493 (description "Guess what GNU Hello prints!")
5494 (home-page "https://www.gnu.org/software/hello/")
5499 Without being a Scheme expert, the reader may have guessed the meaning
5500 of the various fields here. This expression binds the variable
5501 @code{hello} to a @code{<package>} object, which is essentially a record
5502 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5503 This package object can be inspected using procedures found in the
5504 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5505 returns---surprise!---@code{"hello"}.
5507 With luck, you may be able to import part or all of the definition of
5508 the package you are interested in from another repository, using the
5509 @code{guix import} command (@pxref{Invoking guix import}).
5511 In the example above, @var{hello} is defined in a module of its own,
5512 @code{(gnu packages hello)}. Technically, this is not strictly
5513 necessary, but it is convenient to do so: all the packages defined in
5514 modules under @code{(gnu packages @dots{})} are automatically known to
5515 the command-line tools (@pxref{Package Modules}).
5517 There are a few points worth noting in the above package definition:
5521 The @code{source} field of the package is an @code{<origin>} object
5522 (@pxref{origin Reference}, for the complete reference).
5523 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5524 meaning that the source is a file to be downloaded over FTP or HTTP.
5526 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5527 the GNU mirrors defined in @code{(guix download)}.
5529 The @code{sha256} field specifies the expected SHA256 hash of the file
5530 being downloaded. It is mandatory, and allows Guix to check the
5531 integrity of the file. The @code{(base32 @dots{})} form introduces the
5532 base32 representation of the hash. You can obtain this information with
5533 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5534 hash} (@pxref{Invoking guix hash}).
5537 When needed, the @code{origin} form can also have a @code{patches} field
5538 listing patches to be applied, and a @code{snippet} field giving a
5539 Scheme expression to modify the source code.
5542 @cindex GNU Build System
5543 The @code{build-system} field specifies the procedure to build the
5544 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5545 represents the familiar GNU Build System, where packages may be
5546 configured, built, and installed with the usual @code{./configure &&
5547 make && make check && make install} command sequence.
5550 The @code{arguments} field specifies options for the build system
5551 (@pxref{Build Systems}). Here it is interpreted by
5552 @var{gnu-build-system} as a request run @file{configure} with the
5553 @code{--enable-silent-rules} flag.
5559 What about these quote (@code{'}) characters? They are Scheme syntax to
5560 introduce a literal list; @code{'} is synonymous with @code{quote}.
5561 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5562 for details. Here the value of the @code{arguments} field is a list of
5563 arguments passed to the build system down the road, as with @code{apply}
5564 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5567 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5568 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5569 @code{#:configure-flags} is a keyword used to pass a keyword argument
5570 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5574 The @code{inputs} field specifies inputs to the build process---i.e.,
5575 build-time or run-time dependencies of the package. Here, we define an
5576 input called @code{"gawk"} whose value is that of the @var{gawk}
5577 variable; @var{gawk} is itself bound to a @code{<package>} object.
5579 @cindex backquote (quasiquote)
5582 @cindex comma (unquote)
5586 @findex unquote-splicing
5587 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5588 us to introduce a literal list in the @code{inputs} field, while
5589 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5590 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5593 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5594 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5595 of ensuring that they are present (@pxref{Build Systems}).
5597 However, any other dependencies need to be specified in the
5598 @code{inputs} field. Any dependency not specified here will simply be
5599 unavailable to the build process, possibly leading to a build failure.
5602 @xref{package Reference}, for a full description of possible fields.
5604 Once a package definition is in place, the
5605 package may actually be built using the @code{guix build} command-line
5606 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5607 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5608 package definition using the @command{guix edit} command
5609 (@pxref{Invoking guix edit}).
5610 @xref{Packaging Guidelines}, for
5611 more information on how to test package definitions, and
5612 @ref{Invoking guix lint}, for information on how to check a definition
5613 for style conformance.
5614 @vindex GUIX_PACKAGE_PATH
5615 Lastly, @pxref{Channels}, for information
5616 on how to extend the distribution by adding your own package definitions
5619 Finally, updating the package definition to a new upstream version
5620 can be partly automated by the @command{guix refresh} command
5621 (@pxref{Invoking guix refresh}).
5623 Behind the scenes, a derivation corresponding to the @code{<package>}
5624 object is first computed by the @code{package-derivation} procedure.
5625 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5626 The build actions it prescribes may then be realized by using the
5627 @code{build-derivations} procedure (@pxref{The Store}).
5629 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5630 Return the @code{<derivation>} object of @var{package} for @var{system}
5631 (@pxref{Derivations}).
5633 @var{package} must be a valid @code{<package>} object, and @var{system}
5634 must be a string denoting the target system type---e.g.,
5635 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5636 must be a connection to the daemon, which operates on the store
5637 (@pxref{The Store}).
5641 @cindex cross-compilation
5642 Similarly, it is possible to compute a derivation that cross-builds a
5643 package for some other system:
5645 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5646 @var{package} @var{target} [@var{system}]
5647 Return the @code{<derivation>} object of @var{package} cross-built from
5648 @var{system} to @var{target}.
5650 @var{target} must be a valid GNU triplet denoting the target hardware
5651 and operating system, such as @code{"mips64el-linux-gnu"}
5652 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5655 @cindex package transformations
5656 @cindex input rewriting
5657 @cindex dependency tree rewriting
5658 Packages can be manipulated in arbitrary ways. An example of a useful
5659 transformation is @dfn{input rewriting}, whereby the dependency tree of
5660 a package is rewritten by replacing specific inputs by others:
5662 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5663 [@var{rewrite-name}]
5664 Return a procedure that, when passed a package, replaces its direct and
5665 indirect dependencies (but not its implicit inputs) according to
5666 @var{replacements}. @var{replacements} is a list of package pairs; the
5667 first element of each pair is the package to replace, and the second one
5670 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5671 the name of a package and returns its new name after rewrite.
5675 Consider this example:
5678 (define libressl-instead-of-openssl
5679 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5681 (package-input-rewriting `((,openssl . ,libressl))))
5683 (define git-with-libressl
5684 (libressl-instead-of-openssl git))
5688 Here we first define a rewriting procedure that replaces @var{openssl}
5689 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5690 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5691 This is exactly what the @option{--with-input} command-line option does
5692 (@pxref{Package Transformation Options, @option{--with-input}}).
5694 The following variant of @code{package-input-rewriting} can match packages to
5695 be replaced by name rather than by identity.
5697 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5698 Return a procedure that, given a package, applies the given @var{replacements} to
5699 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5700 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5701 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5702 replacement for that package.
5705 The example above could be rewritten this way:
5708 (define libressl-instead-of-openssl
5709 ;; Replace all the packages called "openssl" with LibreSSL.
5710 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5713 The key difference here is that, this time, packages are matched by spec and
5714 not by identity. In other words, any package in the graph that is called
5715 @code{openssl} will be replaced.
5717 A more generic procedure to rewrite a package dependency graph is
5718 @code{package-mapping}: it supports arbitrary changes to nodes in the
5721 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5722 Return a procedure that, given a package, applies @var{proc} to all the packages
5723 depended on and returns the resulting package. The procedure stops recursion
5724 when @var{cut?} returns true for a given package.
5728 * package Reference:: The package data type.
5729 * origin Reference:: The origin data type.
5733 @node package Reference
5734 @subsection @code{package} Reference
5736 This section summarizes all the options available in @code{package}
5737 declarations (@pxref{Defining Packages}).
5739 @deftp {Data Type} package
5740 This is the data type representing a package recipe.
5744 The name of the package, as a string.
5746 @item @code{version}
5747 The version of the package, as a string.
5750 An object telling how the source code for the package should be
5751 acquired. Most of the time, this is an @code{origin} object, which
5752 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5753 can also be any other ``file-like'' object such as a @code{local-file},
5754 which denotes a file from the local file system (@pxref{G-Expressions,
5755 @code{local-file}}).
5757 @item @code{build-system}
5758 The build system that should be used to build the package (@pxref{Build
5761 @item @code{arguments} (default: @code{'()})
5762 The arguments that should be passed to the build system. This is a
5763 list, typically containing sequential keyword-value pairs.
5765 @item @code{inputs} (default: @code{'()})
5766 @itemx @code{native-inputs} (default: @code{'()})
5767 @itemx @code{propagated-inputs} (default: @code{'()})
5768 @cindex inputs, of packages
5769 These fields list dependencies of the package. Each one is a list of
5770 tuples, where each tuple has a label for the input (a string) as its
5771 first element, a package, origin, or derivation as its second element,
5772 and optionally the name of the output thereof that should be used, which
5773 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5774 more on package outputs). For example, the list below specifies three
5778 `(("libffi" ,libffi)
5779 ("libunistring" ,libunistring)
5780 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5783 @cindex cross compilation, package dependencies
5784 The distinction between @code{native-inputs} and @code{inputs} is
5785 necessary when considering cross-compilation. When cross-compiling,
5786 dependencies listed in @code{inputs} are built for the @emph{target}
5787 architecture; conversely, dependencies listed in @code{native-inputs}
5788 are built for the architecture of the @emph{build} machine.
5790 @code{native-inputs} is typically used to list tools needed at
5791 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5792 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5793 this area (@pxref{Invoking guix lint}).
5795 @anchor{package-propagated-inputs}
5796 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5797 specified packages will be automatically installed alongside the package
5798 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5799 package}}, for information on how @command{guix package} deals with
5802 For example this is necessary when a C/C++ library needs headers of
5803 another library to compile, or when a pkg-config file refers to another
5804 one @i{via} its @code{Requires} field.
5806 Another example where @code{propagated-inputs} is useful is for languages
5807 that lack a facility to record the run-time search path akin to the
5808 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5809 more. To ensure that libraries written in those languages can find
5810 library code they depend on at run time, run-time dependencies must be
5811 listed in @code{propagated-inputs} rather than @code{inputs}.
5813 @item @code{outputs} (default: @code{'("out")})
5814 The list of output names of the package. @xref{Packages with Multiple
5815 Outputs}, for typical uses of additional outputs.
5817 @item @code{native-search-paths} (default: @code{'()})
5818 @itemx @code{search-paths} (default: @code{'()})
5819 A list of @code{search-path-specification} objects describing
5820 search-path environment variables honored by the package.
5822 @item @code{replacement} (default: @code{#f})
5823 This must be either @code{#f} or a package object that will be used as a
5824 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5827 @item @code{synopsis}
5828 A one-line description of the package.
5830 @item @code{description}
5831 A more elaborate description of the package.
5833 @item @code{license}
5834 @cindex license, of packages
5835 The license of the package; a value from @code{(guix licenses)},
5836 or a list of such values.
5838 @item @code{home-page}
5839 The URL to the home-page of the package, as a string.
5841 @item @code{supported-systems} (default: @code{%supported-systems})
5842 The list of systems supported by the package, as strings of the form
5843 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5845 @item @code{location} (default: source location of the @code{package} form)
5846 The source location of the package. It is useful to override this when
5847 inheriting from another package, in which case this field is not
5848 automatically corrected.
5852 @deffn {Scheme Syntax} this-package
5853 When used in the @emph{lexical scope} of a package field definition, this
5854 identifier resolves to the package being defined.
5856 The example below shows how to add a package as a native input of itself when
5864 ;; When cross-compiled, Guile, for example, depends on
5865 ;; a native version of itself. Add it here.
5866 (native-inputs (if (%current-target-system)
5867 `(("self" ,this-package))
5871 It is an error to refer to @code{this-package} outside a package definition.
5874 @node origin Reference
5875 @subsection @code{origin} Reference
5877 This section summarizes all the options available in @code{origin}
5878 declarations (@pxref{Defining Packages}).
5880 @deftp {Data Type} origin
5881 This is the data type representing a source code origin.
5885 An object containing the URI of the source. The object type depends on
5886 the @code{method} (see below). For example, when using the
5887 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5888 values are: a URL represented as a string, or a list thereof.
5891 A procedure that handles the URI.
5896 @item @var{url-fetch} from @code{(guix download)}
5897 download a file from the HTTP, HTTPS, or FTP URL specified in the
5901 @item @var{git-fetch} from @code{(guix git-download)}
5902 clone the Git version control repository, and check out the revision
5903 specified in the @code{uri} field as a @code{git-reference} object; a
5904 @code{git-reference} looks like this:
5908 (url "https://git.savannah.gnu.org/git/hello.git")
5914 A bytevector containing the SHA-256 hash of the source. Typically the
5915 @code{base32} form is used here to generate the bytevector from a
5918 You can obtain this information using @code{guix download}
5919 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5922 @item @code{file-name} (default: @code{#f})
5923 The file name under which the source code should be saved. When this is
5924 @code{#f}, a sensible default value will be used in most cases. In case
5925 the source is fetched from a URL, the file name from the URL will be
5926 used. For version control checkouts, it is recommended to provide the
5927 file name explicitly because the default is not very descriptive.
5929 @item @code{patches} (default: @code{'()})
5930 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5931 file-like objects}) pointing to patches to be applied to the source.
5933 This list of patches must be unconditional. In particular, it cannot
5934 depend on the value of @code{%current-system} or
5935 @code{%current-target-system}.
5937 @item @code{snippet} (default: @code{#f})
5938 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5939 in the source directory. This is a convenient way to modify the source,
5940 sometimes more convenient than a patch.
5942 @item @code{patch-flags} (default: @code{'("-p1")})
5943 A list of command-line flags that should be passed to the @code{patch}
5946 @item @code{patch-inputs} (default: @code{#f})
5947 Input packages or derivations to the patching process. When this is
5948 @code{#f}, the usual set of inputs necessary for patching are provided,
5949 such as GNU@tie{}Patch.
5951 @item @code{modules} (default: @code{'()})
5952 A list of Guile modules that should be loaded during the patching
5953 process and while running the code in the @code{snippet} field.
5955 @item @code{patch-guile} (default: @code{#f})
5956 The Guile package that should be used in the patching process. When
5957 this is @code{#f}, a sensible default is used.
5963 @section Build Systems
5965 @cindex build system
5966 Each package definition specifies a @dfn{build system} and arguments for
5967 that build system (@pxref{Defining Packages}). This @code{build-system}
5968 field represents the build procedure of the package, as well as implicit
5969 dependencies of that build procedure.
5971 Build systems are @code{<build-system>} objects. The interface to
5972 create and manipulate them is provided by the @code{(guix build-system)}
5973 module, and actual build systems are exported by specific modules.
5975 @cindex bag (low-level package representation)
5976 Under the hood, build systems first compile package objects to
5977 @dfn{bags}. A @dfn{bag} is like a package, but with less
5978 ornamentation---in other words, a bag is a lower-level representation of
5979 a package, which includes all the inputs of that package, including some
5980 that were implicitly added by the build system. This intermediate
5981 representation is then compiled to a derivation (@pxref{Derivations}).
5983 Build systems accept an optional list of @dfn{arguments}. In package
5984 definitions, these are passed @i{via} the @code{arguments} field
5985 (@pxref{Defining Packages}). They are typically keyword arguments
5986 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5987 Guile Reference Manual}). The value of these arguments is usually
5988 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5989 by the daemon (@pxref{Derivations}).
5991 The main build system is @code{gnu-build-system}, which implements the
5992 standard build procedure for GNU and many other packages. It
5993 is provided by the @code{(guix build-system gnu)} module.
5995 @defvr {Scheme Variable} gnu-build-system
5996 @code{gnu-build-system} represents the GNU Build System, and variants
5997 thereof (@pxref{Configuration, configuration and makefile conventions,,
5998 standards, GNU Coding Standards}).
6000 @cindex build phases
6001 In a nutshell, packages using it are configured, built, and installed with
6002 the usual @code{./configure && make && make check && make install}
6003 command sequence. In practice, a few additional steps are often needed.
6004 All these steps are split up in separate @dfn{phases},
6005 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6006 modules for more details about the build phases.}:
6010 Unpack the source tarball, and change the current directory to the
6011 extracted source tree. If the source is actually a directory, copy it
6012 to the build tree, and enter that directory.
6014 @item patch-source-shebangs
6015 Patch shebangs encountered in source files so they refer to the right
6016 store file names. For instance, this changes @code{#!/bin/sh} to
6017 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6020 Run the @file{configure} script with a number of default options, such
6021 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
6022 by the @code{#:configure-flags} argument.
6025 Run @code{make} with the list of flags specified with
6026 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6027 (the default), build with @code{make -j}.
6030 Run @code{make check}, or some other target specified with
6031 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6032 @code{#:parallel-tests?} argument is true (the default), run @code{make
6036 Run @code{make install} with the flags listed in @code{#:make-flags}.
6038 @item patch-shebangs
6039 Patch shebangs on the installed executable files.
6042 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6043 is false), copying them to the @code{debug} output when available
6044 (@pxref{Installing Debugging Files}).
6047 @vindex %standard-phases
6048 The build-side module @code{(guix build gnu-build-system)} defines
6049 @code{%standard-phases} as the default list of build phases.
6050 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6051 procedure implements the actual phase.
6053 The list of phases used for a particular package can be changed with the
6054 @code{#:phases} parameter. For instance, passing:
6057 #:phases (modify-phases %standard-phases (delete 'configure))
6060 means that all the phases described above will be used, except the
6061 @code{configure} phase.
6063 In addition, this build system ensures that the ``standard'' environment
6064 for GNU packages is available. This includes tools such as GCC, libc,
6065 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6066 build-system gnu)} module for a complete list). We call these the
6067 @dfn{implicit inputs} of a package, because package definitions do not
6068 have to mention them.
6071 Other @code{<build-system>} objects are defined to support other
6072 conventions and tools used by free software packages. They inherit most
6073 of @code{gnu-build-system}, and differ mainly in the set of inputs
6074 implicitly added to the build process, and in the list of phases
6075 executed. Some of these build systems are listed below.
6077 @defvr {Scheme Variable} ant-build-system
6078 This variable is exported by @code{(guix build-system ant)}. It
6079 implements the build procedure for Java packages that can be built with
6080 @url{https://ant.apache.org/, Ant build tool}.
6082 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6083 provided by the @code{icedtea} package to the set of inputs. Different
6084 packages can be specified with the @code{#:ant} and @code{#:jdk}
6085 parameters, respectively.
6087 When the original package does not provide a suitable Ant build file,
6088 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6089 build file @file{build.xml} with tasks to build the specified jar
6090 archive. In this case the parameter @code{#:source-dir} can be used to
6091 specify the source sub-directory, defaulting to ``src''.
6093 The @code{#:main-class} parameter can be used with the minimal ant
6094 buildfile to specify the main class of the resulting jar. This makes the
6095 jar file executable. The @code{#:test-include} parameter can be used to
6096 specify the list of junit tests to run. It defaults to
6097 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6098 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6099 because abstract classes cannot be run as tests.
6101 The parameter @code{#:build-target} can be used to specify the Ant task
6102 that should be run during the @code{build} phase. By default the
6103 ``jar'' task will be run.
6107 @defvr {Scheme Variable} android-ndk-build-system
6108 @cindex Android distribution
6109 @cindex Android NDK build system
6110 This variable is exported by @code{(guix build-system android-ndk)}. It
6111 implements a build procedure for Android NDK (native development kit)
6112 packages using a Guix-specific build process.
6114 The build system assumes that packages install their public interface
6115 (header) files to the subdirectory @file{include} of the @code{out} output and
6116 their libraries to the subdirectory @file{lib} the @code{out} output.
6118 It's also assumed that the union of all the dependencies of a package
6119 has no conflicting files.
6121 For the time being, cross-compilation is not supported - so right now
6122 the libraries and header files are assumed to be host tools.
6126 @defvr {Scheme Variable} asdf-build-system/source
6127 @defvrx {Scheme Variable} asdf-build-system/sbcl
6128 @defvrx {Scheme Variable} asdf-build-system/ecl
6130 These variables, exported by @code{(guix build-system asdf)}, implement
6131 build procedures for Common Lisp packages using
6132 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6133 definition facility for Common Lisp programs and libraries.
6135 The @code{asdf-build-system/source} system installs the packages in
6136 source form, and can be loaded using any common lisp implementation, via
6137 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6138 systems in the format which a particular implementation understands.
6139 These build systems can also be used to produce executable programs, or
6140 lisp images which contain a set of packages pre-loaded.
6142 The build system uses naming conventions. For binary packages, the
6143 package name should be prefixed with the lisp implementation, such as
6144 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6146 Additionally, the corresponding source package should be labeled using
6147 the same convention as python packages (see @ref{Python Modules}), using
6148 the @code{cl-} prefix.
6150 For binary packages, each system should be defined as a Guix package.
6151 If one package @code{origin} contains several systems, package variants
6152 can be created in order to build all the systems. Source packages,
6153 which use @code{asdf-build-system/source}, may contain several systems.
6155 In order to create executable programs and images, the build-side
6156 procedures @code{build-program} and @code{build-image} can be used.
6157 They should be called in a build phase after the @code{create-symlinks}
6158 phase, so that the system which was just built can be used within the
6159 resulting image. @code{build-program} requires a list of Common Lisp
6160 expressions to be passed as the @code{#:entry-program} argument.
6162 If the system is not defined within its own @code{.asd} file of the same
6163 name, then the @code{#:asd-file} parameter should be used to specify
6164 which file the system is defined in. Furthermore, if the package
6165 defines a system for its tests in a separate file, it will be loaded
6166 before the tests are run if it is specified by the
6167 @code{#:test-asd-file} parameter. If it is not set, the files
6168 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6169 and @code{test.asd} will be tried if they exist.
6171 If for some reason the package must be named in a different way than the
6172 naming conventions suggest, the @code{#:asd-system-name} parameter can
6173 be used to specify the name of the system.
6177 @defvr {Scheme Variable} cargo-build-system
6178 @cindex Rust programming language
6179 @cindex Cargo (Rust build system)
6180 This variable is exported by @code{(guix build-system cargo)}. It
6181 supports builds of packages using Cargo, the build tool of the
6182 @uref{https://www.rust-lang.org, Rust programming language}.
6184 It adds @code{rustc} and @code{cargo} to the set of inputs.
6185 A different Rust package can be specified with the @code{#:rust} parameter.
6187 Regular cargo dependencies should be added to the package definition via the
6188 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6189 spec can be a package or a source definition. Note that the spec must
6190 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6191 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6192 should be added to the package definition via the
6193 @code{#:cargo-development-inputs} parameter.
6195 In its @code{configure} phase, this build system will make any source inputs
6196 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6197 parameters available to cargo. It will also remove an included
6198 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6199 @code{build} phase. The @code{install} phase installs any crate the binaries
6200 if they are defined by the crate.
6204 @defvr {Scheme Variable} copy-build-system
6205 This variable is exported by @code{(guix build-system copy)}. It
6206 supports builds of simple packages that don't require much compiling,
6207 mostly just moving files around.
6209 It adds much of the @code{gnu-build-system} packages to the set of
6210 inputs. Because of this, the @code{copy-build-system} does not require
6211 all the boilerplate code often needed for the
6212 @code{trivial-build-system}.
6214 To further simplify the file installation process, an
6215 @code{#:install-plan} argument is exposed to let the packager specify
6216 which files go where. The install plan is a list of @code{(@var{source}
6217 @var{target} [@var{filters}])}. @var{filters} are optional.
6220 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6222 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6223 @item Otherwise install @var{source} as @var{target}.
6226 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6227 the trailing slash of @var{target} is implied with the same meaning
6230 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6231 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6232 @code{#:exclude-regexp}, only select files are installed depending on
6233 the filters. Each filters is specified by a list of strings.
6235 @item With @code{#:include}, install all the files which the path suffix matches
6236 at least one of the elements in the given list.
6237 @item With @code{#:include-regexp}, install all the files which the
6238 subpaths match at least one of the regular expressions in the given
6240 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6241 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6242 install all files but those matching the exclusion filters.
6243 If both inclusions and exclusions are specified, the exclusions are done
6244 on top of the inclusions.
6247 In all cases, the paths relative to @var{source} are preserved within
6254 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6255 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6256 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6257 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6258 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6259 @file{share/my-app/sub/file}.
6260 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6261 @file{share/my-app/file}.
6266 @cindex Clojure (programming language)
6267 @cindex simple Clojure build system
6268 @defvr {Scheme Variable} clojure-build-system
6269 This variable is exported by @code{(guix build-system clojure)}. It implements
6270 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6271 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6274 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6275 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6276 @code{#:zip} parameters, respectively.
6278 A list of source directories, test directories and jar names can be specified
6279 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6280 parameters, respectively. Compile directory and main class can be specified
6281 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6282 Other parameters are documented below.
6284 This build system is an extension of @code{ant-build-system}, but with the
6285 following phases changed:
6290 This phase calls @code{compile} in Clojure to compile source files and runs
6291 @command{jar} to create jars from both source files and compiled files
6292 according to the include list and exclude list specified in
6293 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6294 has priority over the include list. These lists consist of symbols
6295 representing Clojure libraries or the special keyword @code{#:all} representing
6296 all Clojure libraries found under the source directories. The parameter
6297 @code{#:omit-source?} decides if source should be included into the jars.
6300 This phase runs tests according to the include list and exclude list specified
6301 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6302 meanings are analogous to that of @code{#:aot-include} and
6303 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6304 stands for all Clojure libraries found under the test directories. The
6305 parameter @code{#:tests?} decides if tests should be run.
6308 This phase installs all jars built previously.
6311 Apart from the above, this build system also contains an additional phase:
6316 This phase installs all top-level files with base name matching
6317 @code{%doc-regex}. A different regex can be specified with the
6318 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6319 directories specified in @code{#:doc-dirs} are installed as well.
6323 @defvr {Scheme Variable} cmake-build-system
6324 This variable is exported by @code{(guix build-system cmake)}. It
6325 implements the build procedure for packages using the
6326 @url{https://www.cmake.org, CMake build tool}.
6328 It automatically adds the @code{cmake} package to the set of inputs.
6329 Which package is used can be specified with the @code{#:cmake}
6332 The @code{#:configure-flags} parameter is taken as a list of flags
6333 passed to the @command{cmake} command. The @code{#:build-type}
6334 parameter specifies in abstract terms the flags passed to the compiler;
6335 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6336 debugging information''), which roughly means that code is compiled with
6337 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6340 @defvr {Scheme Variable} dune-build-system
6341 This variable is exported by @code{(guix build-system dune)}. It
6342 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6343 tool for the OCaml programming language. It is implemented as an extension
6344 of the @code{ocaml-build-system} which is described below. As such, the
6345 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6348 It automatically adds the @code{dune} package to the set of inputs.
6349 Which package is used can be specified with the @code{#:dune}
6352 There is no @code{configure} phase because dune packages typically don't
6353 need to be configured. The @code{#:build-flags} parameter is taken as a
6354 list of flags passed to the @code{dune} command during the build.
6356 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6357 command instead of the more recent @code{dune} command while building
6358 a package. Its default value is @code{#f}.
6360 The @code{#:package} parameter can be passed to specify a package name, which
6361 is useful when a package contains multiple packages and you want to build
6362 only one of them. This is equivalent to passing the @code{-p} argument to
6366 @defvr {Scheme Variable} go-build-system
6367 This variable is exported by @code{(guix build-system go)}. It
6368 implements a build procedure for Go packages using the standard
6369 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6370 Go build mechanisms}.
6372 The user is expected to provide a value for the key @code{#:import-path}
6373 and, in some cases, @code{#:unpack-path}. The
6374 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6375 corresponds to the file system path expected by the package's build
6376 scripts and any referring packages, and provides a unique way to
6377 refer to a Go package. It is typically based on a combination of the
6378 package source code's remote URI and file system hierarchy structure. In
6379 some cases, you will need to unpack the package's source code to a
6380 different directory structure than the one indicated by the import path,
6381 and @code{#:unpack-path} should be used in such cases.
6383 Packages that provide Go libraries should install their source code into
6384 the built output. The key @code{#:install-source?}, which defaults to
6385 @code{#t}, controls whether or not the source code is installed. It can
6386 be set to @code{#f} for packages that only provide executable files.
6389 @defvr {Scheme Variable} glib-or-gtk-build-system
6390 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6391 is intended for use with packages making use of GLib or GTK+.
6393 This build system adds the following two phases to the ones defined by
6394 @code{gnu-build-system}:
6397 @item glib-or-gtk-wrap
6398 The phase @code{glib-or-gtk-wrap} ensures that programs in
6399 @file{bin/} are able to find GLib ``schemas'' and
6400 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6401 modules}. This is achieved by wrapping the programs in launch scripts
6402 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6403 environment variables.
6405 It is possible to exclude specific package outputs from that wrapping
6406 process by listing their names in the
6407 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6408 when an output is known not to contain any GLib or GTK+ binaries, and
6409 where wrapping would gratuitously add a dependency of that output on
6412 @item glib-or-gtk-compile-schemas
6413 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6414 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6415 GSettings schemas} of GLib are compiled. Compilation is performed by the
6416 @command{glib-compile-schemas} program. It is provided by the package
6417 @code{glib:bin} which is automatically imported by the build system.
6418 The @code{glib} package providing @command{glib-compile-schemas} can be
6419 specified with the @code{#:glib} parameter.
6422 Both phases are executed after the @code{install} phase.
6425 @defvr {Scheme Variable} guile-build-system
6426 This build system is for Guile packages that consist exclusively of Scheme
6427 code and that are so lean that they don't even have a makefile, let alone a
6428 @file{configure} script. It compiles Scheme code using @command{guild
6429 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6430 installs the @file{.scm} and @file{.go} files in the right place. It also
6431 installs documentation.
6433 This build system supports cross-compilation by using the @code{--target}
6434 option of @command{guild compile}.
6436 Packages built with @code{guile-build-system} must provide a Guile package in
6437 their @code{native-inputs} field.
6440 @defvr {Scheme Variable} julia-build-system
6441 This variable is exported by @code{(guix build-system julia)}. It implements
6442 the build procedure used by @uref{https://julialang.org/, julia} packages,
6443 which essentially is similar to running @command{julia -e 'using Pkg;
6444 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6445 paths to all Julia package inputs. Tests are run not run.
6447 Julia packages require the source @code{file-name} to be the real name of the
6448 package, correctly capitalized.
6450 For packages requiring shared library dependencies, you may need to write the
6451 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6452 variable = /gnu/store/library.so} for each dependency, plus a void function
6453 @code{check_deps() = nothing}.
6455 Some older packages that aren't using @file{Package.toml} yet, will require
6456 this file to be created, too. The function @code{julia-create-package-toml}
6457 helps creating the file. You need to pass the outputs and the source of the
6458 package, it's name (the same as the @code{file-name} parameter), the package
6459 uuid, the package version, and a list of dependencies specified by their name
6463 @defvr {Scheme Variable} minify-build-system
6464 This variable is exported by @code{(guix build-system minify)}. It
6465 implements a minification procedure for simple JavaScript packages.
6467 It adds @code{uglify-js} to the set of inputs and uses it to compress
6468 all JavaScript files in the @file{src} directory. A different minifier
6469 package can be specified with the @code{#:uglify-js} parameter, but it
6470 is expected that the package writes the minified code to the standard
6473 When the input JavaScript files are not all located in the @file{src}
6474 directory, the parameter @code{#:javascript-files} can be used to
6475 specify a list of file names to feed to the minifier.
6478 @defvr {Scheme Variable} ocaml-build-system
6479 This variable is exported by @code{(guix build-system ocaml)}. It implements
6480 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6481 of choosing the correct set of commands to run for each package. OCaml
6482 packages can expect many different commands to be run. This build system will
6485 When the package has a @file{setup.ml} file present at the top-level, it will
6486 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6487 @code{ocaml setup.ml -install}. The build system will assume that this file
6488 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6489 care of setting the prefix and enabling tests if they are not disabled. You
6490 can pass configure and build flags with the @code{#:configure-flags} and
6491 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6492 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6493 bypass this system in the build and install phases.
6495 When the package has a @file{configure} file, it is assumed that it is a
6496 hand-made configure script that requires a different argument format than
6497 in the @code{gnu-build-system}. You can add more flags with the
6498 @code{#:configure-flags} key.
6500 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6501 @code{#t}), it will be used and more flags can be passed to the build and
6502 install phases with the @code{#:make-flags} key.
6504 Finally, some packages do not have these files and use a somewhat standard
6505 location for its build system. In that case, the build system will run
6506 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6507 providing the path to the required findlib module. Additional flags can
6508 be passed via the @code{#:build-flags} key. Install is taken care of by
6509 @command{opam-installer}. In this case, the @code{opam} package must
6510 be added to the @code{native-inputs} field of the package definition.
6512 Note that most OCaml packages assume they will be installed in the same
6513 directory as OCaml, which is not what we want in guix. In particular, they
6514 will install @file{.so} files in their module's directory, which is usually
6515 fine because it is in the OCaml compiler directory. In guix though, these
6516 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6517 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6518 @file{.so} libraries should be installed.
6521 @defvr {Scheme Variable} python-build-system
6522 This variable is exported by @code{(guix build-system python)}. It
6523 implements the more or less standard build procedure used by Python
6524 packages, which consists in running @code{python setup.py build} and
6525 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6527 For packages that install stand-alone Python programs under @code{bin/},
6528 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6529 environment variable points to all the Python libraries they depend on.
6531 Which Python package is used to perform the build can be specified with
6532 the @code{#:python} parameter. This is a useful way to force a package
6533 to be built for a specific version of the Python interpreter, which
6534 might be necessary if the package is only compatible with a single
6535 interpreter version.
6537 By default guix calls @code{setup.py} under control of
6538 @code{setuptools}, much like @command{pip} does. Some packages are not
6539 compatible with setuptools (and pip), thus you can disable this by
6540 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6543 @defvr {Scheme Variable} perl-build-system
6544 This variable is exported by @code{(guix build-system perl)}. It
6545 implements the standard build procedure for Perl packages, which either
6546 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6547 followed by @code{Build} and @code{Build install}; or in running
6548 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6549 @code{make} and @code{make install}, depending on which of
6550 @code{Build.PL} or @code{Makefile.PL} is present in the package
6551 distribution. Preference is given to the former if both @code{Build.PL}
6552 and @code{Makefile.PL} exist in the package distribution. This
6553 preference can be reversed by specifying @code{#t} for the
6554 @code{#:make-maker?} parameter.
6556 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6557 passes flags specified by the @code{#:make-maker-flags} or
6558 @code{#:module-build-flags} parameter, respectively.
6560 Which Perl package is used can be specified with @code{#:perl}.
6563 @defvr {Scheme Variable} qt-build-system
6564 This variable is exported by @code{(guix build-system qt)}. It
6565 is intended for use with applications using Qt or KDE.
6567 This build system adds the following two phases to the ones defined by
6568 @code{cmake-build-system}:
6572 The phase @code{check-setup} prepares the environment for running
6573 the checks as commonly used by Qt test programs.
6574 For now this only sets some environment variables:
6575 @code{QT_QPA_PLATFORM=offscreen},
6576 @code{DBUS_FATAL_WARNINGS=0} and
6577 @code{CTEST_OUTPUT_ON_FAILURE=1}.
6579 This phase is added before the @code{check} phase.
6580 It's a separate phase to ease adjusting if necessary.
6583 The phase @code{qt-wrap}
6584 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
6585 and output. In case some path is found, all programs in the output's
6586 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
6587 are wrapped in scripts defining the necessary environment variables.
6589 It is possible to exclude specific package outputs from that wrapping process
6590 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
6591 This is useful when an output is known not to contain any Qt binaries, and
6592 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
6595 This phase is added after the @code{install} phase.
6599 @defvr {Scheme Variable} r-build-system
6600 This variable is exported by @code{(guix build-system r)}. It
6601 implements the build procedure used by @uref{https://r-project.org, R}
6602 packages, which essentially is little more than running @code{R CMD
6603 INSTALL --library=/gnu/store/@dots{}} in an environment where
6604 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6605 are run after installation using the R function
6606 @code{tools::testInstalledPackage}.
6609 @defvr {Scheme Variable} rakudo-build-system
6610 This variable is exported by @code{(guix build-system rakudo)}. It
6611 implements the build procedure used by @uref{https://rakudo.org/,
6612 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6613 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6614 installs the binaries, library files and the resources, as well as wrap
6615 the files under the @code{bin/} directory. Tests can be skipped by
6616 passing @code{#f} to the @code{tests?} parameter.
6618 Which rakudo package is used can be specified with @code{rakudo}.
6619 Which perl6-tap-harness package used for the tests can be specified with
6620 @code{#:prove6} or removed by passing @code{#f} to the
6621 @code{with-prove6?} parameter.
6622 Which perl6-zef package used for tests and installing can be specified
6623 with @code{#:zef} or removed by passing @code{#f} to the
6624 @code{with-zef?} parameter.
6627 @defvr {Scheme Variable} texlive-build-system
6628 This variable is exported by @code{(guix build-system texlive)}. It is
6629 used to build TeX packages in batch mode with a specified engine. The
6630 build system sets the @code{TEXINPUTS} variable to find all TeX source
6631 files in the inputs.
6633 By default it runs @code{luatex} on all files ending on @code{ins}. A
6634 different engine and format can be specified with the
6635 @code{#:tex-format} argument. Different build targets can be specified
6636 with the @code{#:build-targets} argument, which expects a list of file
6637 names. The build system adds only @code{texlive-bin} and
6638 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6639 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6640 and @code{#:texlive-latex-base}, respectively.
6642 The @code{#:tex-directory} parameter tells the build system where to
6643 install the built files under the texmf tree.
6646 @defvr {Scheme Variable} ruby-build-system
6647 This variable is exported by @code{(guix build-system ruby)}. It
6648 implements the RubyGems build procedure used by Ruby packages, which
6649 involves running @code{gem build} followed by @code{gem install}.
6651 The @code{source} field of a package that uses this build system
6652 typically references a gem archive, since this is the format that Ruby
6653 developers use when releasing their software. The build system unpacks
6654 the gem archive, potentially patches the source, runs the test suite,
6655 repackages the gem, and installs it. Additionally, directories and
6656 tarballs may be referenced to allow building unreleased gems from Git or
6657 a traditional source release tarball.
6659 Which Ruby package is used can be specified with the @code{#:ruby}
6660 parameter. A list of additional flags to be passed to the @command{gem}
6661 command can be specified with the @code{#:gem-flags} parameter.
6664 @defvr {Scheme Variable} waf-build-system
6665 This variable is exported by @code{(guix build-system waf)}. It
6666 implements a build procedure around the @code{waf} script. The common
6667 phases---@code{configure}, @code{build}, and @code{install}---are
6668 implemented by passing their names as arguments to the @code{waf}
6671 The @code{waf} script is executed by the Python interpreter. Which
6672 Python package is used to run the script can be specified with the
6673 @code{#:python} parameter.
6676 @defvr {Scheme Variable} scons-build-system
6677 This variable is exported by @code{(guix build-system scons)}. It
6678 implements the build procedure used by the SCons software construction
6679 tool. This build system runs @code{scons} to build the package,
6680 @code{scons test} to run tests, and then @code{scons install} to install
6683 Additional flags to be passed to @code{scons} can be specified with the
6684 @code{#:scons-flags} parameter. The default build and install targets
6685 can be overridden with @code{#:build-targets} and
6686 @code{#:install-targets} respectively. The version of Python used to
6687 run SCons can be specified by selecting the appropriate SCons package
6688 with the @code{#:scons} parameter.
6691 @defvr {Scheme Variable} haskell-build-system
6692 This variable is exported by @code{(guix build-system haskell)}. It
6693 implements the Cabal build procedure used by Haskell packages, which
6694 involves running @code{runhaskell Setup.hs configure
6695 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6696 Instead of installing the package by running @code{runhaskell Setup.hs
6697 install}, to avoid trying to register libraries in the read-only
6698 compiler store directory, the build system uses @code{runhaskell
6699 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6700 addition, the build system generates the package documentation by
6701 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6702 is passed. Optional Haddock parameters can be passed with the help of
6703 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6704 not found, the build system looks for @code{Setup.lhs} instead.
6706 Which Haskell compiler is used can be specified with the @code{#:haskell}
6707 parameter which defaults to @code{ghc}.
6710 @defvr {Scheme Variable} dub-build-system
6711 This variable is exported by @code{(guix build-system dub)}. It
6712 implements the Dub build procedure used by D packages, which
6713 involves running @code{dub build} and @code{dub run}.
6714 Installation is done by copying the files manually.
6716 Which D compiler is used can be specified with the @code{#:ldc}
6717 parameter which defaults to @code{ldc}.
6720 @defvr {Scheme Variable} emacs-build-system
6721 This variable is exported by @code{(guix build-system emacs)}. It
6722 implements an installation procedure similar to the packaging system
6723 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6725 It first creates the @code{@code{package}-autoloads.el} file, then it
6726 byte compiles all Emacs Lisp files. Differently from the Emacs
6727 packaging system, the Info documentation files are moved to the standard
6728 documentation directory and the @file{dir} file is deleted. The Elisp
6729 package files are installed directly under @file{share/emacs/site-lisp}.
6732 @defvr {Scheme Variable} font-build-system
6733 This variable is exported by @code{(guix build-system font)}. It
6734 implements an installation procedure for font packages where upstream
6735 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6736 need to be copied into place. It copies font files to standard
6737 locations in the output directory.
6740 @defvr {Scheme Variable} meson-build-system
6741 This variable is exported by @code{(guix build-system meson)}. It
6742 implements the build procedure for packages that use
6743 @url{https://mesonbuild.com, Meson} as their build system.
6745 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6746 of inputs, and they can be changed with the parameters @code{#:meson}
6747 and @code{#:ninja} if needed. The default Meson is
6748 @code{meson-for-build}, which is special because it doesn't clear the
6749 @code{RUNPATH} of binaries and libraries when they are installed.
6751 This build system is an extension of @code{gnu-build-system}, but with the
6752 following phases changed to some specific for Meson:
6757 The phase runs @code{meson} with the flags specified in
6758 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6759 @code{plain} unless something else is specified in @code{#:build-type}.
6762 The phase runs @code{ninja} to build the package in parallel by default, but
6763 this can be changed with @code{#:parallel-build?}.
6766 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6767 which is @code{"test"} by default.
6770 The phase runs @code{ninja install} and can not be changed.
6773 Apart from that, the build system also adds the following phases:
6778 This phase ensures that all binaries can find the libraries they need.
6779 It searches for required libraries in subdirectories of the package being
6780 built, and adds those to @code{RUNPATH} where needed. It also removes
6781 references to libraries left over from the build phase by
6782 @code{meson-for-build}, such as test dependencies, that aren't actually
6783 required for the program to run.
6785 @item glib-or-gtk-wrap
6786 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6787 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6789 @item glib-or-gtk-compile-schemas
6790 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6791 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6795 @defvr {Scheme Variable} linux-module-build-system
6796 @code{linux-module-build-system} allows building Linux kernel modules.
6798 @cindex build phases
6799 This build system is an extension of @code{gnu-build-system}, but with the
6800 following phases changed:
6805 This phase configures the environment so that the Linux kernel's Makefile
6806 can be used to build the external kernel module.
6809 This phase uses the Linux kernel's Makefile in order to build the external
6813 This phase uses the Linux kernel's Makefile in order to install the external
6817 It is possible and useful to specify the Linux kernel to use for building
6818 the module (in the @code{arguments} form of a package using the
6819 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
6822 @defvr {Scheme Variable} node-build-system
6823 This variable is exported by @code{(guix build-system node)}. It
6824 implements the build procedure used by @uref{https://nodejs.org,
6825 Node.js}, which implements an approximation of the @code{npm install}
6826 command, followed by an @code{npm test} command.
6828 Which Node.js package is used to interpret the @code{npm} commands can
6829 be specified with the @code{#:node} parameter which defaults to
6833 Lastly, for packages that do not need anything as sophisticated, a
6834 ``trivial'' build system is provided. It is trivial in the sense that
6835 it provides basically no support: it does not pull any implicit inputs,
6836 and does not have a notion of build phases.
6838 @defvr {Scheme Variable} trivial-build-system
6839 This variable is exported by @code{(guix build-system trivial)}.
6841 This build system requires a @code{#:builder} argument. This argument
6842 must be a Scheme expression that builds the package output(s)---as
6843 with @code{build-expression->derivation} (@pxref{Derivations,
6844 @code{build-expression->derivation}}).
6854 Conceptually, the @dfn{store} is the place where derivations that have
6855 been built successfully are stored---by default, @file{/gnu/store}.
6856 Sub-directories in the store are referred to as @dfn{store items} or
6857 sometimes @dfn{store paths}. The store has an associated database that
6858 contains information such as the store paths referred to by each store
6859 path, and the list of @emph{valid} store items---results of successful
6860 builds. This database resides in @file{@var{localstatedir}/guix/db},
6861 where @var{localstatedir} is the state directory specified @i{via}
6862 @option{--localstatedir} at configure time, usually @file{/var}.
6864 The store is @emph{always} accessed by the daemon on behalf of its clients
6865 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6866 connect to the daemon over a Unix-domain socket, send requests to it,
6867 and read the result---these are remote procedure calls, or RPCs.
6870 Users must @emph{never} modify files under @file{/gnu/store} directly.
6871 This would lead to inconsistencies and break the immutability
6872 assumptions of Guix's functional model (@pxref{Introduction}).
6874 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6875 how to check the integrity of the store and attempt recovery from
6876 accidental modifications.
6879 The @code{(guix store)} module provides procedures to connect to the
6880 daemon, and to perform RPCs. These are described below. By default,
6881 @code{open-connection}, and thus all the @command{guix} commands,
6882 connect to the local daemon or to the URI specified by the
6883 @code{GUIX_DAEMON_SOCKET} environment variable.
6885 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6886 When set, the value of this variable should be a file name or a URI
6887 designating the daemon endpoint. When it is a file name, it denotes a
6888 Unix-domain socket to connect to. In addition to file names, the
6889 supported URI schemes are:
6894 These are for Unix-domain sockets.
6895 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6896 @file{/var/guix/daemon-socket/socket}.
6899 @cindex daemon, remote access
6900 @cindex remote access to the daemon
6901 @cindex daemon, cluster setup
6902 @cindex clusters, daemon setup
6903 These URIs denote connections over TCP/IP, without encryption nor
6904 authentication of the remote host. The URI must specify the host name
6905 and optionally a port number (by default port 44146 is used):
6908 guix://master.guix.example.org:1234
6911 This setup is suitable on local networks, such as clusters, where only
6912 trusted nodes may connect to the build daemon at
6913 @code{master.guix.example.org}.
6915 The @code{--listen} option of @command{guix-daemon} can be used to
6916 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6920 @cindex SSH access to build daemons
6921 These URIs allow you to connect to a remote daemon over SSH. This
6922 feature requires Guile-SSH (@pxref{Requirements}) and a working
6923 @code{guile} binary in @code{PATH} on the destination machine. It
6924 supports public key and GSSAPI authentication. A typical URL might look
6928 ssh://charlie@@guix.example.org:22
6931 As for @command{guix copy}, the usual OpenSSH client configuration files
6932 are honored (@pxref{Invoking guix copy}).
6935 Additional URI schemes may be supported in the future.
6937 @c XXX: Remove this note when the protocol incurs fewer round trips
6938 @c and when (guix derivations) no longer relies on file system access.
6940 The ability to connect to remote build daemons is considered
6941 experimental as of @value{VERSION}. Please get in touch with us to
6942 share any problems or suggestions you may have (@pxref{Contributing}).
6946 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6947 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6948 @var{reserve-space?} is true, instruct it to reserve a little bit of
6949 extra space on the file system so that the garbage collector can still
6950 operate should the disk become full. Return a server object.
6952 @var{file} defaults to @code{%default-socket-path}, which is the normal
6953 location given the options that were passed to @command{configure}.
6956 @deffn {Scheme Procedure} close-connection @var{server}
6957 Close the connection to @var{server}.
6960 @defvr {Scheme Variable} current-build-output-port
6961 This variable is bound to a SRFI-39 parameter, which refers to the port
6962 where build and error logs sent by the daemon should be written.
6965 Procedures that make RPCs all take a server object as their first
6968 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6969 @cindex invalid store items
6970 Return @code{#t} when @var{path} designates a valid store item and
6971 @code{#f} otherwise (an invalid item may exist on disk but still be
6972 invalid, for instance because it is the result of an aborted or failed
6975 A @code{&store-protocol-error} condition is raised if @var{path} is not
6976 prefixed by the store directory (@file{/gnu/store}).
6979 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6980 Add @var{text} under file @var{name} in the store, and return its store
6981 path. @var{references} is the list of store paths referred to by the
6982 resulting store path.
6985 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6987 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6988 file names, or derivation/output pairs, using the specified
6989 @var{mode}---@code{(build-mode normal)} by default.
6992 Note that the @code{(guix monads)} module provides a monad as well as
6993 monadic versions of the above procedures, with the goal of making it
6994 more convenient to work with code that accesses the store (@pxref{The
6998 @i{This section is currently incomplete.}
7001 @section Derivations
7004 Low-level build actions and the environment in which they are performed
7005 are represented by @dfn{derivations}. A derivation contains the
7006 following pieces of information:
7010 The outputs of the derivation---derivations produce at least one file or
7011 directory in the store, but may produce more.
7014 @cindex build-time dependencies
7015 @cindex dependencies, build-time
7016 The inputs of the derivations---i.e., its build-time dependencies---which may
7017 be other derivations or plain files in the store (patches, build scripts,
7021 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7024 The file name of a build script in the store, along with the arguments
7028 A list of environment variables to be defined.
7032 @cindex derivation path
7033 Derivations allow clients of the daemon to communicate build actions to
7034 the store. They exist in two forms: as an in-memory representation,
7035 both on the client- and daemon-side, and as files in the store whose
7036 name end in @code{.drv}---these files are referred to as @dfn{derivation
7037 paths}. Derivations paths can be passed to the @code{build-derivations}
7038 procedure to perform the build actions they prescribe (@pxref{The
7041 @cindex fixed-output derivations
7042 Operations such as file downloads and version-control checkouts for
7043 which the expected content hash is known in advance are modeled as
7044 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7045 of a fixed-output derivation are independent of its inputs---e.g., a
7046 source code download produces the same result regardless of the download
7047 method and tools being used.
7050 @cindex run-time dependencies
7051 @cindex dependencies, run-time
7052 The outputs of derivations---i.e., the build results---have a set of
7053 @dfn{references}, as reported by the @code{references} RPC or the
7054 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7055 are the set of run-time dependencies of the build results. References are a
7056 subset of the inputs of the derivation; this subset is automatically computed
7057 by the build daemon by scanning all the files in the outputs.
7059 The @code{(guix derivations)} module provides a representation of
7060 derivations as Scheme objects, along with procedures to create and
7061 otherwise manipulate derivations. The lowest-level primitive to create
7062 a derivation is the @code{derivation} procedure:
7064 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7065 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7066 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7067 [#:system (%current-system)] [#:references-graphs #f] @
7068 [#:allowed-references #f] [#:disallowed-references #f] @
7069 [#:leaked-env-vars #f] [#:local-build? #f] @
7070 [#:substitutable? #t] [#:properties '()]
7071 Build a derivation with the given arguments, and return the resulting
7072 @code{<derivation>} object.
7074 When @var{hash} and @var{hash-algo} are given, a
7075 @dfn{fixed-output derivation} is created---i.e., one whose result is
7076 known in advance, such as a file download. If, in addition,
7077 @var{recursive?} is true, then that fixed output may be an executable
7078 file or a directory and @var{hash} must be the hash of an archive
7079 containing this output.
7081 When @var{references-graphs} is true, it must be a list of file
7082 name/store path pairs. In that case, the reference graph of each store
7083 path is exported in the build environment in the corresponding file, in
7084 a simple text format.
7086 When @var{allowed-references} is true, it must be a list of store items
7087 or outputs that the derivation's output may refer to. Likewise,
7088 @var{disallowed-references}, if true, must be a list of things the
7089 outputs may @emph{not} refer to.
7091 When @var{leaked-env-vars} is true, it must be a list of strings
7092 denoting environment variables that are allowed to ``leak'' from the
7093 daemon's environment to the build environment. This is only applicable
7094 to fixed-output derivations---i.e., when @var{hash} is true. The main
7095 use is to allow variables such as @code{http_proxy} to be passed to
7096 derivations that download files.
7098 When @var{local-build?} is true, declare that the derivation is not a
7099 good candidate for offloading and should rather be built locally
7100 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7101 where the costs of data transfers would outweigh the benefits.
7103 When @var{substitutable?} is false, declare that substitutes of the
7104 derivation's output should not be used (@pxref{Substitutes}). This is
7105 useful, for instance, when building packages that capture details of the
7106 host CPU instruction set.
7108 @var{properties} must be an association list describing ``properties'' of the
7109 derivation. It is kept as-is, uninterpreted, in the derivation.
7113 Here's an example with a shell script as its builder, assuming
7114 @var{store} is an open connection to the daemon, and @var{bash} points
7115 to a Bash executable in the store:
7118 (use-modules (guix utils)
7122 (let ((builder ; add the Bash script to the store
7123 (add-text-to-store store "my-builder.sh"
7124 "echo hello world > $out\n" '())))
7125 (derivation store "foo"
7126 bash `("-e" ,builder)
7127 #:inputs `((,bash) (,builder))
7128 #:env-vars '(("HOME" . "/homeless"))))
7129 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7132 As can be guessed, this primitive is cumbersome to use directly. A
7133 better approach is to write build scripts in Scheme, of course! The
7134 best course of action for that is to write the build code as a
7135 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7136 information, @pxref{G-Expressions}.
7138 Once upon a time, @code{gexp->derivation} did not exist and constructing
7139 derivations with build code written in Scheme was achieved with
7140 @code{build-expression->derivation}, documented below. This procedure
7141 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7143 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7144 @var{name} @var{exp} @
7145 [#:system (%current-system)] [#:inputs '()] @
7146 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7147 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7148 [#:references-graphs #f] [#:allowed-references #f] @
7149 [#:disallowed-references #f] @
7150 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7151 Return a derivation that executes Scheme expression @var{exp} as a
7152 builder for derivation @var{name}. @var{inputs} must be a list of
7153 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7154 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7155 modules from the current search path to be copied in the store,
7156 compiled, and made available in the load path during the execution of
7157 @var{exp}---e.g., @code{((guix build utils) (guix build
7158 gnu-build-system))}.
7160 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7161 to a list of output/path pairs, and where @code{%build-inputs} is bound
7162 to a list of string/output-path pairs made from @var{inputs}.
7163 Optionally, @var{env-vars} is a list of string pairs specifying the name
7164 and value of environment variables visible to the builder. The builder
7165 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7166 @var{exp} returns @code{#f}, the build is considered to have failed.
7168 @var{exp} is built using @var{guile-for-build} (a derivation). When
7169 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7170 @code{%guile-for-build} fluid is used instead.
7172 See the @code{derivation} procedure for the meaning of
7173 @var{references-graphs}, @var{allowed-references},
7174 @var{disallowed-references}, @var{local-build?}, and
7175 @var{substitutable?}.
7179 Here's an example of a single-output derivation that creates a directory
7180 containing one file:
7183 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7184 (mkdir out) ; create /gnu/store/@dots{}-goo
7185 (call-with-output-file (string-append out "/test")
7187 (display '(hello guix) p))))))
7188 (build-expression->derivation store "goo" builder))
7190 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7194 @node The Store Monad
7195 @section The Store Monad
7199 The procedures that operate on the store described in the previous
7200 sections all take an open connection to the build daemon as their first
7201 argument. Although the underlying model is functional, they either have
7202 side effects or depend on the current state of the store.
7204 The former is inconvenient: the connection to the build daemon has to be
7205 carried around in all those functions, making it impossible to compose
7206 functions that do not take that parameter with functions that do. The
7207 latter can be problematic: since store operations have side effects
7208 and/or depend on external state, they have to be properly sequenced.
7210 @cindex monadic values
7211 @cindex monadic functions
7212 This is where the @code{(guix monads)} module comes in. This module
7213 provides a framework for working with @dfn{monads}, and a particularly
7214 useful monad for our uses, the @dfn{store monad}. Monads are a
7215 construct that allows two things: associating ``context'' with values
7216 (in our case, the context is the store), and building sequences of
7217 computations (here computations include accesses to the store). Values
7218 in a monad---values that carry this additional context---are called
7219 @dfn{monadic values}; procedures that return such values are called
7220 @dfn{monadic procedures}.
7222 Consider this ``normal'' procedure:
7225 (define (sh-symlink store)
7226 ;; Return a derivation that symlinks the 'bash' executable.
7227 (let* ((drv (package-derivation store bash))
7228 (out (derivation->output-path drv))
7229 (sh (string-append out "/bin/bash")))
7230 (build-expression->derivation store "sh"
7231 `(symlink ,sh %output))))
7234 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7235 as a monadic function:
7238 (define (sh-symlink)
7239 ;; Same, but return a monadic value.
7240 (mlet %store-monad ((drv (package->derivation bash)))
7241 (gexp->derivation "sh"
7242 #~(symlink (string-append #$drv "/bin/bash")
7246 There are several things to note in the second version: the @code{store}
7247 parameter is now implicit and is ``threaded'' in the calls to the
7248 @code{package->derivation} and @code{gexp->derivation} monadic
7249 procedures, and the monadic value returned by @code{package->derivation}
7250 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7252 As it turns out, the call to @code{package->derivation} can even be
7253 omitted since it will take place implicitly, as we will see later
7254 (@pxref{G-Expressions}):
7257 (define (sh-symlink)
7258 (gexp->derivation "sh"
7259 #~(symlink (string-append #$bash "/bin/bash")
7264 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7265 @c for the funny quote.
7266 Calling the monadic @code{sh-symlink} has no effect. As someone once
7267 said, ``you exit a monad like you exit a building on fire: by running''.
7268 So, to exit the monad and get the desired effect, one must use
7269 @code{run-with-store}:
7272 (run-with-store (open-connection) (sh-symlink))
7273 @result{} /gnu/store/...-sh-symlink
7276 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7277 new ``meta-commands'' to make it easier to deal with monadic procedures:
7278 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7279 to ``run'' a single monadic value through the store:
7282 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7283 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7286 The latter enters a recursive REPL, where all the return values are
7287 automatically run through the store:
7290 scheme@@(guile-user)> ,enter-store-monad
7291 store-monad@@(guile-user) [1]> (package->derivation hello)
7292 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7293 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7294 $3 = "/gnu/store/@dots{}-foo"
7295 store-monad@@(guile-user) [1]> ,q
7296 scheme@@(guile-user)>
7300 Note that non-monadic values cannot be returned in the
7301 @code{store-monad} REPL.
7303 The main syntactic forms to deal with monads in general are provided by
7304 the @code{(guix monads)} module and are described below.
7306 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7307 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7311 @deffn {Scheme Syntax} return @var{val}
7312 Return a monadic value that encapsulates @var{val}.
7315 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7316 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7317 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7318 referred to as ``bind'', but that name denotes an unrelated procedure in
7319 Guile. Thus we use this somewhat cryptic symbol inherited from the
7320 Haskell language.}. There can be one @var{mproc} or several of them, as
7325 (with-monad %state-monad
7327 (lambda (x) (return (+ 1 x)))
7328 (lambda (x) (return (* 2 x)))))
7332 @result{} some-state
7336 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7338 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7340 Bind the variables @var{var} to the monadic values @var{mval} in
7341 @var{body}, which is a sequence of expressions. As with the bind
7342 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7343 value ``contained'' in @var{mval} and making @var{var} refer to that
7344 raw, non-monadic value within the scope of the @var{body}. The form
7345 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7346 @var{val}, as per @code{let}. The binding operations occur in sequence
7347 from left to right. The last expression of @var{body} must be a monadic
7348 expression, and its result will become the result of the @code{mlet} or
7349 @code{mlet*} when run in the @var{monad}.
7351 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7352 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7355 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7356 Bind @var{mexp} and the following monadic expressions in sequence,
7357 returning the result of the last expression. Every expression in the
7358 sequence must be a monadic expression.
7360 This is akin to @code{mlet}, except that the return values of the
7361 monadic expressions are ignored. In that sense, it is analogous to
7362 @code{begin}, but applied to monadic expressions.
7365 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7366 When @var{condition} is true, evaluate the sequence of monadic
7367 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7368 @var{condition} is false, return @code{*unspecified*} in the current
7369 monad. Every expression in the sequence must be a monadic expression.
7372 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7373 When @var{condition} is false, evaluate the sequence of monadic
7374 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7375 @var{condition} is true, return @code{*unspecified*} in the current
7376 monad. Every expression in the sequence must be a monadic expression.
7380 The @code{(guix monads)} module provides the @dfn{state monad}, which
7381 allows an additional value---the state---to be @emph{threaded} through
7382 monadic procedure calls.
7384 @defvr {Scheme Variable} %state-monad
7385 The state monad. Procedures in the state monad can access and change
7386 the state that is threaded.
7388 Consider the example below. The @code{square} procedure returns a value
7389 in the state monad. It returns the square of its argument, but also
7390 increments the current state value:
7394 (mlet %state-monad ((count (current-state)))
7395 (mbegin %state-monad
7396 (set-current-state (+ 1 count))
7399 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7404 When ``run'' through @code{%state-monad}, we obtain that additional state
7405 value, which is the number of @code{square} calls.
7408 @deffn {Monadic Procedure} current-state
7409 Return the current state as a monadic value.
7412 @deffn {Monadic Procedure} set-current-state @var{value}
7413 Set the current state to @var{value} and return the previous state as a
7417 @deffn {Monadic Procedure} state-push @var{value}
7418 Push @var{value} to the current state, which is assumed to be a list,
7419 and return the previous state as a monadic value.
7422 @deffn {Monadic Procedure} state-pop
7423 Pop a value from the current state and return it as a monadic value.
7424 The state is assumed to be a list.
7427 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7428 Run monadic value @var{mval} starting with @var{state} as the initial
7429 state. Return two values: the resulting value, and the resulting state.
7432 The main interface to the store monad, provided by the @code{(guix
7433 store)} module, is as follows.
7435 @defvr {Scheme Variable} %store-monad
7436 The store monad---an alias for @code{%state-monad}.
7438 Values in the store monad encapsulate accesses to the store. When its
7439 effect is needed, a value of the store monad must be ``evaluated'' by
7440 passing it to the @code{run-with-store} procedure (see below.)
7443 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7444 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7445 open store connection.
7448 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7449 Return as a monadic value the absolute file name in the store of the file
7450 containing @var{text}, a string. @var{references} is a list of store items that the
7451 resulting text file refers to; it defaults to the empty list.
7454 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7455 Return as a monadic value the absolute file name in the store of the file
7456 containing @var{data}, a bytevector. @var{references} is a list of store
7457 items that the resulting binary file refers to; it defaults to the empty list.
7460 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7461 [#:recursive? #t] [#:select? (const #t)]
7462 Return the name of @var{file} once interned in the store. Use
7463 @var{name} as its store name, or the basename of @var{file} if
7464 @var{name} is omitted.
7466 When @var{recursive?} is true, the contents of @var{file} are added
7467 recursively; if @var{file} designates a flat file and @var{recursive?}
7468 is true, its contents are added, and its permission bits are kept.
7470 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7471 @var{stat})} for each directory entry, where @var{file} is the entry's
7472 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7473 entries for which @var{select?} does not return true.
7475 The example below adds a file to the store, under two different names:
7478 (run-with-store (open-connection)
7479 (mlet %store-monad ((a (interned-file "README"))
7480 (b (interned-file "README" "LEGU-MIN")))
7481 (return (list a b))))
7483 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7488 The @code{(guix packages)} module exports the following package-related
7491 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7492 [#:system (%current-system)] [#:target #f] @
7495 value in the absolute file name of @var{file} within the @var{output}
7496 directory of @var{package}. When @var{file} is omitted, return the name
7497 of the @var{output} directory of @var{package}. When @var{target} is
7498 true, use it as a cross-compilation target triplet.
7500 Note that this procedure does @emph{not} build @var{package}. Thus, the
7501 result might or might not designate an existing file. We recommend not
7502 using this procedure unless you know what you are doing.
7505 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7506 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7507 @var{target} [@var{system}]
7508 Monadic version of @code{package-derivation} and
7509 @code{package-cross-derivation} (@pxref{Defining Packages}).
7514 @section G-Expressions
7516 @cindex G-expression
7517 @cindex build code quoting
7518 So we have ``derivations'', which represent a sequence of build actions
7519 to be performed to produce an item in the store (@pxref{Derivations}).
7520 These build actions are performed when asking the daemon to actually
7521 build the derivations; they are run by the daemon in a container
7522 (@pxref{Invoking guix-daemon}).
7524 @cindex strata of code
7525 It should come as no surprise that we like to write these build actions
7526 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7527 code@footnote{The term @dfn{stratum} in this context was coined by
7528 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7529 Kiselyov, who has written insightful
7530 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7531 on this topic}, refers to this kind of code generation as
7532 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7533 to the daemon, etc.---and the ``build code''---code that actually
7534 performs build actions, such as making directories, invoking
7535 @command{make}, etc.
7537 To describe a derivation and its build actions, one typically needs to
7538 embed build code inside host code. It boils down to manipulating build
7539 code as data, and the homoiconicity of Scheme---code has a direct
7540 representation as data---comes in handy for that. But we need more than
7541 the normal @code{quasiquote} mechanism in Scheme to construct build
7544 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7545 S-expressions adapted to build expressions. G-expressions, or
7546 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7547 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7548 @code{#$}, and @code{#$@@}), which are comparable to
7549 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7550 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7551 GNU Guile Reference Manual}). However, there are major differences:
7555 Gexps are meant to be written to a file and run or manipulated by other
7559 When a high-level object such as a package or derivation is unquoted
7560 inside a gexp, the result is as if its output file name had been
7564 Gexps carry information about the packages or derivations they refer to,
7565 and these dependencies are automatically added as inputs to the build
7566 processes that use them.
7569 @cindex lowering, of high-level objects in gexps
7570 This mechanism is not limited to package and derivation
7571 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7572 derivations or files in the store can be defined,
7573 such that these objects can also be inserted
7574 into gexps. For example, a useful type of high-level objects that can be
7575 inserted in a gexp is ``file-like objects'', which make it easy to
7576 add files to the store and to refer to them in
7577 derivations and such (see @code{local-file} and @code{plain-file}
7580 To illustrate the idea, here is an example of a gexp:
7587 (symlink (string-append #$coreutils "/bin/ls")
7591 This gexp can be passed to @code{gexp->derivation}; we obtain a
7592 derivation that builds a directory containing exactly one symlink to
7593 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7596 (gexp->derivation "the-thing" build-exp)
7599 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7600 substituted to the reference to the @var{coreutils} package in the
7601 actual build code, and @var{coreutils} is automatically made an input to
7602 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7603 output)}) is replaced by a string containing the directory name of the
7604 output of the derivation.
7606 @cindex cross compilation
7607 In a cross-compilation context, it is useful to distinguish between
7608 references to the @emph{native} build of a package---that can run on the
7609 host---versus references to cross builds of a package. To that end, the
7610 @code{#+} plays the same role as @code{#$}, but is a reference to a
7611 native package build:
7614 (gexp->derivation "vi"
7617 (mkdir (string-append #$output "/bin"))
7618 (system* (string-append #+coreutils "/bin/ln")
7620 (string-append #$emacs "/bin/emacs")
7621 (string-append #$output "/bin/vi")))
7622 #:target "mips64el-linux-gnu")
7626 In the example above, the native build of @var{coreutils} is used, so
7627 that @command{ln} can actually run on the host; but then the
7628 cross-compiled build of @var{emacs} is referenced.
7630 @cindex imported modules, for gexps
7631 @findex with-imported-modules
7632 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7633 able to use certain Guile modules from the ``host environment'' in the
7634 gexp, so those modules should be imported in the ``build environment''.
7635 The @code{with-imported-modules} form allows you to express that:
7638 (let ((build (with-imported-modules '((guix build utils))
7640 (use-modules (guix build utils))
7641 (mkdir-p (string-append #$output "/bin"))))))
7642 (gexp->derivation "empty-dir"
7645 (display "success!\n")
7650 In this example, the @code{(guix build utils)} module is automatically
7651 pulled into the isolated build environment of our gexp, such that
7652 @code{(use-modules (guix build utils))} works as expected.
7654 @cindex module closure
7655 @findex source-module-closure
7656 Usually you want the @emph{closure} of the module to be imported---i.e.,
7657 the module itself and all the modules it depends on---rather than just
7658 the module; failing to do that, attempts to use the module will fail
7659 because of missing dependent modules. The @code{source-module-closure}
7660 procedure computes the closure of a module by looking at its source file
7661 headers, which comes in handy in this case:
7664 (use-modules (guix modules)) ;for 'source-module-closure'
7666 (with-imported-modules (source-module-closure
7667 '((guix build utils)
7669 (gexp->derivation "something-with-vms"
7671 (use-modules (guix build utils)
7676 @cindex extensions, for gexps
7677 @findex with-extensions
7678 In the same vein, sometimes you want to import not just pure-Scheme
7679 modules, but also ``extensions'' such as Guile bindings to C libraries
7680 or other ``full-blown'' packages. Say you need the @code{guile-json}
7681 package available on the build side, here's how you would do it:
7684 (use-modules (gnu packages guile)) ;for 'guile-json'
7686 (with-extensions (list guile-json)
7687 (gexp->derivation "something-with-json"
7689 (use-modules (json))
7693 The syntactic form to construct gexps is summarized below.
7695 @deffn {Scheme Syntax} #~@var{exp}
7696 @deffnx {Scheme Syntax} (gexp @var{exp})
7697 Return a G-expression containing @var{exp}. @var{exp} may contain one
7698 or more of the following forms:
7702 @itemx (ungexp @var{obj})
7703 Introduce a reference to @var{obj}. @var{obj} may have one of the
7704 supported types, for example a package or a
7705 derivation, in which case the @code{ungexp} form is replaced by its
7706 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7708 If @var{obj} is a list, it is traversed and references to supported
7709 objects are substituted similarly.
7711 If @var{obj} is another gexp, its contents are inserted and its
7712 dependencies are added to those of the containing gexp.
7714 If @var{obj} is another kind of object, it is inserted as is.
7716 @item #$@var{obj}:@var{output}
7717 @itemx (ungexp @var{obj} @var{output})
7718 This is like the form above, but referring explicitly to the
7719 @var{output} of @var{obj}---this is useful when @var{obj} produces
7720 multiple outputs (@pxref{Packages with Multiple Outputs}).
7723 @itemx #+@var{obj}:output
7724 @itemx (ungexp-native @var{obj})
7725 @itemx (ungexp-native @var{obj} @var{output})
7726 Same as @code{ungexp}, but produces a reference to the @emph{native}
7727 build of @var{obj} when used in a cross compilation context.
7729 @item #$output[:@var{output}]
7730 @itemx (ungexp output [@var{output}])
7731 Insert a reference to derivation output @var{output}, or to the main
7732 output when @var{output} is omitted.
7734 This only makes sense for gexps passed to @code{gexp->derivation}.
7737 @itemx (ungexp-splicing @var{lst})
7738 Like the above, but splices the contents of @var{lst} inside the
7742 @itemx (ungexp-native-splicing @var{lst})
7743 Like the above, but refers to native builds of the objects listed in
7748 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7749 of the @code{gexp?} type (see below.)
7752 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7753 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7754 in their execution environment.
7756 Each item in @var{modules} can be the name of a module, such as
7757 @code{(guix build utils)}, or it can be a module name, followed by an
7758 arrow, followed by a file-like object:
7761 `((guix build utils)
7763 ((guix config) => ,(scheme-file "config.scm"
7764 #~(define-module @dots{}))))
7768 In the example above, the first two modules are taken from the search
7769 path, and the last one is created from the given file-like object.
7771 This form has @emph{lexical} scope: it has an effect on the gexps
7772 directly defined in @var{body}@dots{}, but not on those defined, say, in
7773 procedures called from @var{body}@dots{}.
7776 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7777 Mark the gexps defined in @var{body}@dots{} as requiring
7778 @var{extensions} in their build and execution environment.
7779 @var{extensions} is typically a list of package objects such as those
7780 defined in the @code{(gnu packages guile)} module.
7782 Concretely, the packages listed in @var{extensions} are added to the
7783 load path while compiling imported modules in @var{body}@dots{}; they
7784 are also added to the load path of the gexp returned by
7788 @deffn {Scheme Procedure} gexp? @var{obj}
7789 Return @code{#t} if @var{obj} is a G-expression.
7792 G-expressions are meant to be written to disk, either as code building
7793 some derivation, or as plain files in the store. The monadic procedures
7794 below allow you to do that (@pxref{The Store Monad}, for more
7795 information about monads.)
7797 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7798 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7799 [#:hash #f] [#:hash-algo #f] @
7800 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7801 [#:module-path @code{%load-path}] @
7802 [#:effective-version "2.2"] @
7803 [#:references-graphs #f] [#:allowed-references #f] @
7804 [#:disallowed-references #f] @
7805 [#:leaked-env-vars #f] @
7806 [#:script-name (string-append @var{name} "-builder")] @
7807 [#:deprecation-warnings #f] @
7808 [#:local-build? #f] [#:substitutable? #t] @
7809 [#:properties '()] [#:guile-for-build #f]
7810 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7811 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7812 stored in a file called @var{script-name}. When @var{target} is true,
7813 it is used as the cross-compilation target triplet for packages referred
7816 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7818 make @var{modules} available in the evaluation context of @var{exp};
7819 @var{modules} is a list of names of Guile modules searched in
7820 @var{module-path} to be copied in the store, compiled, and made available in
7821 the load path during the execution of @var{exp}---e.g., @code{((guix
7822 build utils) (guix build gnu-build-system))}.
7824 @var{effective-version} determines the string to use when adding extensions of
7825 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7827 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7830 When @var{references-graphs} is true, it must be a list of tuples of one of the
7834 (@var{file-name} @var{package})
7835 (@var{file-name} @var{package} @var{output})
7836 (@var{file-name} @var{derivation})
7837 (@var{file-name} @var{derivation} @var{output})
7838 (@var{file-name} @var{store-item})
7841 The right-hand-side of each element of @var{references-graphs} is automatically made
7842 an input of the build process of @var{exp}. In the build environment, each
7843 @var{file-name} contains the reference graph of the corresponding item, in a simple
7846 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7847 In the latter case, the list denotes store items that the result is allowed to
7848 refer to. Any reference to another store item will lead to a build error.
7849 Similarly for @var{disallowed-references}, which can list items that must not be
7850 referenced by the outputs.
7852 @var{deprecation-warnings} determines whether to show deprecation warnings while
7853 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7855 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7858 @cindex file-like objects
7859 The @code{local-file}, @code{plain-file}, @code{computed-file},
7860 @code{program-file}, and @code{scheme-file} procedures below return
7861 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7862 these objects lead to a file in the store. Consider this G-expression:
7865 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7866 #$(local-file "/tmp/my-nscd.conf"))
7869 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7870 to the store. Once expanded, for instance @i{via}
7871 @code{gexp->derivation}, the G-expression refers to that copy under
7872 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7873 does not have any effect on what the G-expression does.
7874 @code{plain-file} can be used similarly; it differs in that the file
7875 content is directly passed as a string.
7877 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7878 [#:recursive? #f] [#:select? (const #t)]
7879 Return an object representing local file @var{file} to add to the store;
7880 this object can be used in a gexp. If @var{file} is a literal string
7881 denoting a relative file name, it is looked up relative to the source
7882 file where it appears; if @var{file} is not a literal string, it is
7883 looked up relative to the current working directory at run time.
7884 @var{file} will be added to the store under @var{name}--by default the
7885 base name of @var{file}.
7887 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7888 designates a flat file and @var{recursive?} is true, its contents are added, and its
7889 permission bits are kept.
7891 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7892 @var{stat})} for each directory entry, where @var{file} is the entry's
7893 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7894 entries for which @var{select?} does not return true.
7896 This is the declarative counterpart of the @code{interned-file} monadic
7897 procedure (@pxref{The Store Monad, @code{interned-file}}).
7900 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7901 Return an object representing a text file called @var{name} with the given
7902 @var{content} (a string or a bytevector) to be added to the store.
7904 This is the declarative counterpart of @code{text-file}.
7907 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7908 [#:options '(#:local-build? #t)]
7909 Return an object representing the store item @var{name}, a file or
7910 directory computed by @var{gexp}. @var{options}
7911 is a list of additional arguments to pass to @code{gexp->derivation}.
7913 This is the declarative counterpart of @code{gexp->derivation}.
7916 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7917 [#:guile (default-guile)] [#:module-path %load-path] @
7918 [#:system (%current-system)] [#:target #f]
7919 Return an executable script @var{name} that runs @var{exp} using
7920 @var{guile}, with @var{exp}'s imported modules in its search path.
7921 Look up @var{exp}'s modules in @var{module-path}.
7923 The example below builds a script that simply invokes the @command{ls}
7927 (use-modules (guix gexp) (gnu packages base))
7929 (gexp->script "list-files"
7930 #~(execl #$(file-append coreutils "/bin/ls")
7934 When ``running'' it through the store (@pxref{The Store Monad,
7935 @code{run-with-store}}), we obtain a derivation that produces an
7936 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7939 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7941 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7945 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7946 [#:guile #f] [#:module-path %load-path]
7947 Return an object representing the executable store item @var{name} that
7948 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7949 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7951 This is the declarative counterpart of @code{gexp->script}.
7954 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7955 [#:set-load-path? #t] [#:module-path %load-path] @
7957 [#:guile (default-guile)]
7958 Return a derivation that builds a file @var{name} containing @var{exp}.
7959 When @var{splice?} is true, @var{exp} is considered to be a list of
7960 expressions that will be spliced in the resulting file.
7962 When @var{set-load-path?} is true, emit code in the resulting file to
7963 set @code{%load-path} and @code{%load-compiled-path} to honor
7964 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7967 The resulting file holds references to all the dependencies of @var{exp}
7968 or a subset thereof.
7971 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
7972 [#:splice? #f] [#:set-load-path? #t]
7973 Return an object representing the Scheme file @var{name} that contains
7976 This is the declarative counterpart of @code{gexp->file}.
7979 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7980 Return as a monadic value a derivation that builds a text file
7981 containing all of @var{text}. @var{text} may list, in addition to
7982 strings, objects of any type that can be used in a gexp: packages,
7983 derivations, local file objects, etc. The resulting store file holds
7984 references to all these.
7986 This variant should be preferred over @code{text-file} anytime the file
7987 to create will reference items from the store. This is typically the
7988 case when building a configuration file that embeds store file names,
7992 (define (profile.sh)
7993 ;; Return the name of a shell script in the store that
7994 ;; initializes the 'PATH' environment variable.
7995 (text-file* "profile.sh"
7996 "export PATH=" coreutils "/bin:"
7997 grep "/bin:" sed "/bin\n"))
8000 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8001 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8002 preventing them from being garbage-collected during its lifetime.
8005 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8006 Return an object representing store file @var{name} containing
8007 @var{text}. @var{text} is a sequence of strings and file-like objects,
8011 (mixed-text-file "profile"
8012 "export PATH=" coreutils "/bin:" grep "/bin")
8015 This is the declarative counterpart of @code{text-file*}.
8018 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8019 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8020 Each item in @var{files} must be a two-element list where the first element is the
8021 file name to use in the new directory, and the second element is a gexp
8022 denoting the target file. Here's an example:
8026 `(("hosts" ,(plain-file "hosts"
8027 "127.0.0.1 localhost"))
8028 ("bashrc" ,(plain-file "bashrc"
8029 "alias ls='ls --color=auto'"))))
8032 This yields an @code{etc} directory containing these two files.
8035 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8036 Return a directory that is the union of @var{things}, where @var{things} is a list of
8037 file-like objects denoting directories. For example:
8040 (directory-union "guile+emacs" (list guile emacs))
8043 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8046 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8047 Return a file-like object that expands to the concatenation of @var{obj}
8048 and @var{suffix}, where @var{obj} is a lowerable object and each
8049 @var{suffix} is a string.
8051 As an example, consider this gexp:
8054 (gexp->script "run-uname"
8055 #~(system* #$(file-append coreutils
8059 The same effect could be achieved with:
8062 (gexp->script "run-uname"
8063 #~(system* (string-append #$coreutils
8067 There is one difference though: in the @code{file-append} case, the
8068 resulting script contains the absolute file name as a string, whereas in
8069 the second case, the resulting script contains a @code{(string-append
8070 @dots{})} expression to construct the file name @emph{at run time}.
8073 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8074 This macro is similar to the @code{parameterize} form for
8075 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8076 Guile Reference Manual}). The key difference is that it takes effect
8077 when the file-like object returned by @var{exp} is lowered to a
8078 derivation or store item.
8080 A typical use of @code{with-parameters} is to force the system in effect
8084 (with-parameters ((%current-system "i686-linux"))
8088 The example above returns an object that corresponds to the i686 build
8089 of Coreutils, regardless of the current value of @code{%current-system}.
8093 Of course, in addition to gexps embedded in ``host'' code, there are
8094 also modules containing build tools. To make it clear that they are
8095 meant to be used in the build stratum, these modules are kept in the
8096 @code{(guix build @dots{})} name space.
8098 @cindex lowering, of high-level objects in gexps
8099 Internally, high-level objects are @dfn{lowered}, using their compiler,
8100 to either derivations or store items. For instance, lowering a package
8101 yields a derivation, and lowering a @code{plain-file} yields a store
8102 item. This is achieved using the @code{lower-object} monadic procedure.
8104 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8106 Return as a value in @code{%store-monad} the derivation or store item
8107 corresponding to @var{obj} for @var{system}, cross-compiling for
8108 @var{target} if @var{target} is true. @var{obj} must be an object that
8109 has an associated gexp compiler, such as a @code{<package>}.
8112 @node Invoking guix repl
8113 @section Invoking @command{guix repl}
8115 @cindex REPL, read-eval-print loop
8116 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
8117 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
8118 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
8119 command, @command{guix repl} guarantees that all the Guix modules and all its
8120 dependencies are available in the search path. You can use it this way:
8124 scheme@@(guile-user)> ,use (gnu packages base)
8125 scheme@@(guile-user)> coreutils
8126 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8130 In addition, @command{guix repl} implements a simple machine-readable REPL
8131 protocol for use by @code{(guix inferior)}, a facility to interact with
8132 @dfn{inferiors}, separate processes running a potentially different revision
8135 The available options are as follows:
8138 @item --type=@var{type}
8139 @itemx -t @var{type}
8140 Start a REPL of the given @var{TYPE}, which can be one of the following:
8144 This is default, and it spawns a standard full-featured Guile REPL.
8146 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8147 that the @code{(guix inferior)} module speaks.
8150 @item --listen=@var{endpoint}
8151 By default, @command{guix repl} reads from standard input and writes to
8152 standard output. When this option is passed, it will instead listen for
8153 connections on @var{endpoint}. Here are examples of valid options:
8156 @item --listen=tcp:37146
8157 Accept connections on localhost on port 37146.
8159 @item --listen=unix:/tmp/socket
8160 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8163 @item --load-path=@var{directory}
8164 @itemx -L @var{directory}
8165 Add @var{directory} to the front of the package module search path
8166 (@pxref{Package Modules}).
8168 This allows users to define their own packages and make them visible to
8169 the command-line tool.
8172 Inhibit loading of the @file{~/.guile} file. By default, that
8173 configuration file is loaded when spawning a @code{guile} REPL.
8176 @c *********************************************************************
8180 This section describes Guix command-line utilities. Some of them are
8181 primarily targeted at developers and users who write new package
8182 definitions, while others are more generally useful. They complement
8183 the Scheme programming interface of Guix in a convenient way.
8186 * Invoking guix build:: Building packages from the command line.
8187 * Invoking guix edit:: Editing package definitions.
8188 * Invoking guix download:: Downloading a file and printing its hash.
8189 * Invoking guix hash:: Computing the cryptographic hash of a file.
8190 * Invoking guix import:: Importing package definitions.
8191 * Invoking guix refresh:: Updating package definitions.
8192 * Invoking guix lint:: Finding errors in package definitions.
8193 * Invoking guix size:: Profiling disk usage.
8194 * Invoking guix graph:: Visualizing the graph of packages.
8195 * Invoking guix publish:: Sharing substitutes.
8196 * Invoking guix challenge:: Challenging substitute servers.
8197 * Invoking guix copy:: Copying to and from a remote store.
8198 * Invoking guix container:: Process isolation.
8199 * Invoking guix weather:: Assessing substitute availability.
8200 * Invoking guix processes:: Listing client processes.
8203 @node Invoking guix build
8204 @section Invoking @command{guix build}
8206 @cindex package building
8207 @cindex @command{guix build}
8208 The @command{guix build} command builds packages or derivations and
8209 their dependencies, and prints the resulting store paths. Note that it
8210 does not modify the user's profile---this is the job of the
8211 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8212 it is mainly useful for distribution developers.
8214 The general syntax is:
8217 guix build @var{options} @var{package-or-derivation}@dots{}
8220 As an example, the following command builds the latest versions of Emacs
8221 and of Guile, displays their build logs, and finally displays the
8222 resulting directories:
8225 guix build emacs guile
8228 Similarly, the following command builds all the available packages:
8231 guix build --quiet --keep-going \
8232 `guix package -A | cut -f1,2 --output-delimiter=@@`
8235 @var{package-or-derivation} may be either the name of a package found in
8236 the software distribution such as @code{coreutils} or
8237 @code{coreutils@@8.20}, or a derivation such as
8238 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8239 package with the corresponding name (and optionally version) is searched
8240 for among the GNU distribution modules (@pxref{Package Modules}).
8242 Alternatively, the @code{--expression} option may be used to specify a
8243 Scheme expression that evaluates to a package; this is useful when
8244 disambiguating among several same-named packages or package variants is
8247 There may be zero or more @var{options}. The available options are
8248 described in the subsections below.
8251 * Common Build Options:: Build options for most commands.
8252 * Package Transformation Options:: Creating variants of packages.
8253 * Additional Build Options:: Options specific to 'guix build'.
8254 * Debugging Build Failures:: Real life packaging experience.
8257 @node Common Build Options
8258 @subsection Common Build Options
8260 A number of options that control the build process are common to
8261 @command{guix build} and other commands that can spawn builds, such as
8262 @command{guix package} or @command{guix archive}. These are the
8267 @item --load-path=@var{directory}
8268 @itemx -L @var{directory}
8269 Add @var{directory} to the front of the package module search path
8270 (@pxref{Package Modules}).
8272 This allows users to define their own packages and make them visible to
8273 the command-line tools.
8277 Keep the build tree of failed builds. Thus, if a build fails, its build
8278 tree is kept under @file{/tmp}, in a directory whose name is shown at
8279 the end of the build log. This is useful when debugging build issues.
8280 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8283 This option implies @option{--no-offload}, and it has no effect when
8284 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8285 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8289 Keep going when some of the derivations fail to build; return only once
8290 all the builds have either completed or failed.
8292 The default behavior is to stop as soon as one of the specified
8293 derivations has failed.
8297 Do not build the derivations.
8299 @anchor{fallback-option}
8301 When substituting a pre-built binary fails, fall back to building
8302 packages locally (@pxref{Substitution Failure}).
8304 @item --substitute-urls=@var{urls}
8305 @anchor{client-substitute-urls}
8306 Consider @var{urls} the whitespace-separated list of substitute source
8307 URLs, overriding the default list of URLs of @command{guix-daemon}
8308 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8310 This means that substitutes may be downloaded from @var{urls}, provided
8311 they are signed by a key authorized by the system administrator
8312 (@pxref{Substitutes}).
8314 When @var{urls} is the empty string, substitutes are effectively
8317 @item --no-substitutes
8318 Do not use substitutes for build products. That is, always build things
8319 locally instead of allowing downloads of pre-built binaries
8320 (@pxref{Substitutes}).
8323 Do not ``graft'' packages. In practice, this means that package updates
8324 available as grafts are not applied. @xref{Security Updates}, for more
8325 information on grafts.
8327 @item --rounds=@var{n}
8328 Build each derivation @var{n} times in a row, and raise an error if
8329 consecutive build results are not bit-for-bit identical.
8331 This is a useful way to detect non-deterministic builds processes.
8332 Non-deterministic build processes are a problem because they make it
8333 practically impossible for users to @emph{verify} whether third-party
8334 binaries are genuine. @xref{Invoking guix challenge}, for more.
8336 Note that, currently, the differing build results are not kept around,
8337 so you will have to manually investigate in case of an error---e.g., by
8338 stashing one of the build results with @code{guix archive --export}
8339 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8343 Do not use offload builds to other machines (@pxref{Daemon Offload
8344 Setup}). That is, always build things locally instead of offloading
8345 builds to remote machines.
8347 @item --max-silent-time=@var{seconds}
8348 When the build or substitution process remains silent for more than
8349 @var{seconds}, terminate it and report a build failure.
8351 By default, the daemon's setting is honored (@pxref{Invoking
8352 guix-daemon, @code{--max-silent-time}}).
8354 @item --timeout=@var{seconds}
8355 Likewise, when the build or substitution process lasts for more than
8356 @var{seconds}, terminate it and report a build failure.
8358 By default, the daemon's setting is honored (@pxref{Invoking
8359 guix-daemon, @code{--timeout}}).
8361 @c Note: This option is actually not part of %standard-build-options but
8362 @c most programs honor it.
8363 @cindex verbosity, of the command-line tools
8364 @cindex build logs, verbosity
8365 @item -v @var{level}
8366 @itemx --verbosity=@var{level}
8367 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8368 output is produced, 1 is for quiet output, and 2 shows all the build log
8369 output on standard error.
8371 @item --cores=@var{n}
8373 Allow the use of up to @var{n} CPU cores for the build. The special
8374 value @code{0} means to use as many CPU cores as available.
8376 @item --max-jobs=@var{n}
8378 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8379 guix-daemon, @code{--max-jobs}}, for details about this option and the
8380 equivalent @command{guix-daemon} option.
8382 @item --debug=@var{level}
8383 Produce debugging output coming from the build daemon. @var{level} must be an
8384 integer between 0 and 5; higher means more verbose output. Setting a level of
8385 4 or more may be helpful when debugging setup issues with the build daemon.
8389 Behind the scenes, @command{guix build} is essentially an interface to
8390 the @code{package-derivation} procedure of the @code{(guix packages)}
8391 module, and to the @code{build-derivations} procedure of the @code{(guix
8392 derivations)} module.
8394 In addition to options explicitly passed on the command line,
8395 @command{guix build} and other @command{guix} commands that support
8396 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8398 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8399 Users can define this variable to a list of command line options that
8400 will automatically be used by @command{guix build} and other
8401 @command{guix} commands that can perform builds, as in the example
8405 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8408 These options are parsed independently, and the result is appended to
8409 the parsed command-line options.
8413 @node Package Transformation Options
8414 @subsection Package Transformation Options
8416 @cindex package variants
8417 Another set of command-line options supported by @command{guix build}
8418 and also @command{guix package} are @dfn{package transformation
8419 options}. These are options that make it possible to define @dfn{package
8420 variants}---for instance, packages built from different source code.
8421 This is a convenient way to create customized packages on the fly
8422 without having to type in the definitions of package variants
8423 (@pxref{Defining Packages}).
8427 @item --with-source=@var{source}
8428 @itemx --with-source=@var{package}=@var{source}
8429 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8430 Use @var{source} as the source of @var{package}, and @var{version} as
8432 @var{source} must be a file name or a URL, as for @command{guix
8433 download} (@pxref{Invoking guix download}).
8435 When @var{package} is omitted,
8436 it is taken to be the package name specified on the
8437 command line that matches the base of @var{source}---e.g.,
8438 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8439 package is @code{guile}.
8441 Likewise, when @var{version} is omitted, the version string is inferred from
8442 @var{source}; in the previous example, it is @code{2.0.10}.
8444 This option allows users to try out versions of packages other than the
8445 one provided by the distribution. The example below downloads
8446 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8447 the @code{ed} package:
8450 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8453 As a developer, @code{--with-source} makes it easy to test release
8457 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8460 @dots{} or to build from a checkout in a pristine environment:
8463 $ git clone git://git.sv.gnu.org/guix.git
8464 $ guix build guix --with-source=guix@@1.0=./guix
8467 @item --with-input=@var{package}=@var{replacement}
8468 Replace dependency on @var{package} by a dependency on
8469 @var{replacement}. @var{package} must be a package name, and
8470 @var{replacement} must be a package specification such as @code{guile}
8471 or @code{guile@@1.8}.
8473 For instance, the following command builds Guix, but replaces its
8474 dependency on the current stable version of Guile with a dependency on
8475 the legacy version of Guile, @code{guile@@2.0}:
8478 guix build --with-input=guile=guile@@2.0 guix
8481 This is a recursive, deep replacement. So in this example, both
8482 @code{guix} and its dependency @code{guile-json} (which also depends on
8483 @code{guile}) get rebuilt against @code{guile@@2.0}.
8485 This is implemented using the @code{package-input-rewriting} Scheme
8486 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8488 @item --with-graft=@var{package}=@var{replacement}
8489 This is similar to @code{--with-input} but with an important difference:
8490 instead of rebuilding the whole dependency chain, @var{replacement} is
8491 built and then @dfn{grafted} onto the binaries that were initially
8492 referring to @var{package}. @xref{Security Updates}, for more
8493 information on grafts.
8495 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8496 and all its dependencies, replacing references to the version of GnuTLS
8497 they currently refer to:
8500 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8503 This has the advantage of being much faster than rebuilding everything.
8504 But there is a caveat: it works if and only if @var{package} and
8505 @var{replacement} are strictly compatible---for example, if they provide
8506 a library, the application binary interface (ABI) of those libraries
8507 must be compatible. If @var{replacement} is somehow incompatible with
8508 @var{package}, then the resulting package may be unusable. Use with
8511 @item --with-git-url=@var{package}=@var{url}
8512 @cindex Git, using the latest commit
8513 @cindex latest commit, building
8514 Build @var{package} from the latest commit of the @code{master} branch of the
8515 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8518 For example, the following command builds the NumPy Python library against the
8519 latest commit of the master branch of Python itself:
8522 guix build python-numpy \
8523 --with-git-url=python=https://github.com/python/cpython
8526 This option can also be combined with @code{--with-branch} or
8527 @code{--with-commit} (see below).
8529 @cindex continuous integration
8530 Obviously, since it uses the latest commit of the given branch, the result of
8531 such a command varies over time. Nevertheless it is a convenient way to
8532 rebuild entire software stacks against the latest commit of one or more
8533 packages. This is particularly useful in the context of continuous
8536 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8537 consecutive accesses to the same repository. You may want to clean it up once
8538 in a while to save disk space.
8540 @item --with-branch=@var{package}=@var{branch}
8541 Build @var{package} from the latest commit of @var{branch}. If the
8542 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8543 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8544 repository URL is taken from that @code{source}. Otherwise you have to use
8545 @code{--with-git-url} to specify the URL of the Git repository.
8547 For instance, the following command builds @code{guile-sqlite3} from the
8548 latest commit of its @code{master} branch, and then builds @code{guix} (which
8549 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8550 specific @code{guile-sqlite3} build:
8553 guix build --with-branch=guile-sqlite3=master cuirass
8556 @item --with-commit=@var{package}=@var{commit}
8557 This is similar to @code{--with-branch}, except that it builds from
8558 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8559 Git commit SHA1 identifier or a tag.
8562 @node Additional Build Options
8563 @subsection Additional Build Options
8565 The command-line options presented below are specific to @command{guix
8572 Build quietly, without displaying the build log; this is equivalent to
8573 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8574 (or similar) and can always be retrieved using the @option{--log-file} option.
8576 @item --file=@var{file}
8577 @itemx -f @var{file}
8578 Build the package, derivation, or other file-like object that the code within
8579 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8581 As an example, @var{file} might contain a package definition like this
8582 (@pxref{Defining Packages}):
8585 @include package-hello.scm
8588 The @var{file} may also contain a JSON representation of one or more
8589 package definitions. Running @code{guix build -f} on @file{hello.json}
8590 with the following contents would result in building the packages
8591 @code{myhello} and @code{greeter}:
8594 @verbatiminclude package-hello.json
8597 @item --manifest=@var{manifest}
8598 @itemx -m @var{manifest}
8599 Build all packages listed in the given @var{manifest}
8600 (@pxref{profile-manifest, @option{--manifest}}).
8602 @item --expression=@var{expr}
8603 @itemx -e @var{expr}
8604 Build the package or derivation @var{expr} evaluates to.
8606 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8607 guile-1.8)}, which unambiguously designates this specific variant of
8608 version 1.8 of Guile.
8610 Alternatively, @var{expr} may be a G-expression, in which case it is used
8611 as a build program passed to @code{gexp->derivation}
8612 (@pxref{G-Expressions}).
8614 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8615 (@pxref{The Store Monad}). The procedure must return a derivation as a
8616 monadic value, which is then passed through @code{run-with-store}.
8620 Build the source derivations of the packages, rather than the packages
8623 For instance, @code{guix build -S gcc} returns something like
8624 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8627 The returned source tarball is the result of applying any patches and
8628 code snippets specified in the package @code{origin} (@pxref{Defining
8631 Note that @command{guix build -S} compiles the sources only of the
8632 specified packages. They do not include the sources of statically
8633 linked dependencies and by themselves are insufficient for reproducing
8637 Fetch and return the source of @var{package-or-derivation} and all their
8638 dependencies, recursively. This is a handy way to obtain a local copy
8639 of all the source code needed to build @var{packages}, allowing you to
8640 eventually build them even without network access. It is an extension
8641 of the @code{--source} option and can accept one of the following
8642 optional argument values:
8646 This value causes the @code{--sources} option to behave in the same way
8647 as the @code{--source} option.
8650 Build the source derivations of all packages, including any source that
8651 might be listed as @code{inputs}. This is the default value.
8654 $ guix build --sources tzdata
8655 The following derivations will be built:
8656 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8657 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8661 Build the source derivations of all packages, as well of all transitive
8662 inputs to the packages. This can be used e.g.@: to
8663 prefetch package source for later offline building.
8666 $ guix build --sources=transitive tzdata
8667 The following derivations will be built:
8668 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8669 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8670 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8671 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8672 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8673 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8679 @item --system=@var{system}
8680 @itemx -s @var{system}
8681 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8682 the system type of the build host. The @command{guix build} command allows
8683 you to repeat this option several times, in which case it builds for all the
8684 specified systems; other commands ignore extraneous @option{-s} options.
8687 The @code{--system} flag is for @emph{native} compilation and must not
8688 be confused with cross-compilation. See @code{--target} below for
8689 information on cross-compilation.
8692 An example use of this is on Linux-based systems, which can emulate
8693 different personalities. For instance, passing
8694 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8695 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8696 to build packages in a complete 32-bit environment.
8699 Building for an @code{armhf-linux} system is unconditionally enabled on
8700 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8701 allow for this functionality, notably the ThunderX.
8704 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8705 is enabled (@pxref{Virtualization Services,
8706 @code{qemu-binfmt-service-type}}), you can build for any system for
8707 which a QEMU @code{binfmt_misc} handler is installed.
8709 Builds for a system other than that of the machine you are using can
8710 also be offloaded to a remote machine of the right architecture.
8711 @xref{Daemon Offload Setup}, for more information on offloading.
8713 @item --target=@var{triplet}
8714 @cindex cross-compilation
8715 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8716 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8717 configuration triplets,, autoconf, Autoconf}).
8719 @anchor{build-check}
8721 @cindex determinism, checking
8722 @cindex reproducibility, checking
8723 Rebuild @var{package-or-derivation}, which are already available in the
8724 store, and raise an error if the build results are not bit-for-bit
8727 This mechanism allows you to check whether previously installed
8728 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8729 of a package is deterministic. @xref{Invoking guix challenge}, for more
8730 background information and tools.
8732 When used in conjunction with @option{--keep-failed}, the differing
8733 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8734 This makes it easy to look for differences between the two results.
8737 @cindex repairing store items
8738 @cindex corruption, recovering from
8739 Attempt to repair the specified store items, if they are corrupt, by
8740 re-downloading or rebuilding them.
8742 This operation is not atomic and thus restricted to @code{root}.
8746 Return the derivation paths, not the output paths, of the given
8749 @item --root=@var{file}
8750 @itemx -r @var{file}
8751 @cindex GC roots, adding
8752 @cindex garbage collector roots, adding
8753 Make @var{file} a symlink to the result, and register it as a garbage
8756 Consequently, the results of this @command{guix build} invocation are
8757 protected from garbage collection until @var{file} is removed. When
8758 that option is omitted, build results are eligible for garbage
8759 collection as soon as the build completes. @xref{Invoking guix gc}, for
8763 @cindex build logs, access
8764 Return the build log file names or URLs for the given
8765 @var{package-or-derivation}, or raise an error if build logs are
8768 This works regardless of how packages or derivations are specified. For
8769 instance, the following invocations are equivalent:
8772 guix build --log-file `guix build -d guile`
8773 guix build --log-file `guix build guile`
8774 guix build --log-file guile
8775 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8778 If a log is unavailable locally, and unless @code{--no-substitutes} is
8779 passed, the command looks for a corresponding log on one of the
8780 substitute servers (as specified with @code{--substitute-urls}.)
8782 So for instance, imagine you want to see the build log of GDB on MIPS,
8783 but you are actually on an @code{x86_64} machine:
8786 $ guix build --log-file gdb -s mips64el-linux
8787 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8790 You can freely access a huge library of build logs!
8793 @node Debugging Build Failures
8794 @subsection Debugging Build Failures
8796 @cindex build failures, debugging
8797 When defining a new package (@pxref{Defining Packages}), you will
8798 probably find yourself spending some time debugging and tweaking the
8799 build until it succeeds. To do that, you need to operate the build
8800 commands yourself in an environment as close as possible to the one the
8803 To that end, the first thing to do is to use the @option{--keep-failed}
8804 or @option{-K} option of @command{guix build}, which will keep the
8805 failed build tree in @file{/tmp} or whatever directory you specified as
8806 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8808 From there on, you can @command{cd} to the failed build tree and source
8809 the @file{environment-variables} file, which contains all the
8810 environment variable definitions that were in place when the build
8811 failed. So let's say you're debugging a build failure in package
8812 @code{foo}; a typical session would look like this:
8816 @dots{} @i{build fails}
8817 $ cd /tmp/guix-build-foo.drv-0
8818 $ source ./environment-variables
8822 Now, you can invoke commands as if you were the daemon (almost) and
8823 troubleshoot your build process.
8825 Sometimes it happens that, for example, a package's tests pass when you
8826 run them manually but they fail when the daemon runs them. This can
8827 happen because the daemon runs builds in containers where, unlike in our
8828 environment above, network access is missing, @file{/bin/sh} does not
8829 exist, etc. (@pxref{Build Environment Setup}).
8831 In such cases, you may need to run inspect the build process from within
8832 a container similar to the one the build daemon creates:
8837 $ cd /tmp/guix-build-foo.drv-0
8838 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8839 [env]# source ./environment-variables
8843 Here, @command{guix environment -C} creates a container and spawns a new
8844 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8845 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8846 the container, which you may find handy while debugging. The
8847 @option{--no-grafts} option makes sure we get the exact same
8848 environment, with ungrafted packages (@pxref{Security Updates}, for more
8851 To get closer to a container like that used by the build daemon, we can
8852 remove @file{/bin/sh}:
8858 (Don't worry, this is harmless: this is all happening in the throw-away
8859 container created by @command{guix environment}.)
8861 The @command{strace} command is probably not in the search path, but we
8865 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8868 In this way, not only you will have reproduced the environment variables
8869 the daemon uses, you will also be running the build process in a container
8870 similar to the one the daemon uses.
8873 @node Invoking guix edit
8874 @section Invoking @command{guix edit}
8876 @cindex @command{guix edit}
8877 @cindex package definition, editing
8878 So many packages, so many source files! The @command{guix edit} command
8879 facilitates the life of users and packagers by pointing their editor at
8880 the source file containing the definition of the specified packages.
8884 guix edit gcc@@4.9 vim
8888 launches the program specified in the @code{VISUAL} or in the
8889 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8892 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8893 have created your own packages on @code{GUIX_PACKAGE_PATH}
8894 (@pxref{Package Modules}), you will be able to edit the package
8895 recipes. In other cases, you will be able to examine the read-only recipes
8896 for packages currently in the store.
8898 Instead of @code{GUIX_PACKAGE_PATH}, the command-line option
8899 @code{--load-path=@var{directory}} (or in short @code{-L
8900 @var{directory}}) allows you to add @var{directory} to the front of the
8901 package module search path and so make your own packages visible.
8903 @node Invoking guix download
8904 @section Invoking @command{guix download}
8906 @cindex @command{guix download}
8907 @cindex downloading package sources
8908 When writing a package definition, developers typically need to download
8909 a source tarball, compute its SHA256 hash, and write that
8910 hash in the package definition (@pxref{Defining Packages}). The
8911 @command{guix download} tool helps with this task: it downloads a file
8912 from the given URI, adds it to the store, and prints both its file name
8913 in the store and its SHA256 hash.
8915 The fact that the downloaded file is added to the store saves bandwidth:
8916 when the developer eventually tries to build the newly defined package
8917 with @command{guix build}, the source tarball will not have to be
8918 downloaded again because it is already in the store. It is also a
8919 convenient way to temporarily stash files, which may be deleted
8920 eventually (@pxref{Invoking guix gc}).
8922 The @command{guix download} command supports the same URIs as used in
8923 package definitions. In particular, it supports @code{mirror://} URIs.
8924 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8925 Guile bindings for GnuTLS are available in the user's environment; when
8926 they are not available, an error is raised. @xref{Guile Preparations,
8927 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8928 GnuTLS-Guile}, for more information.
8930 @command{guix download} verifies HTTPS server certificates by loading
8931 the certificates of X.509 authorities from the directory pointed to by
8932 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8933 Certificates}), unless @option{--no-check-certificate} is used.
8935 The following options are available:
8938 @item --format=@var{fmt}
8940 Write the hash in the format specified by @var{fmt}. For more
8941 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8943 @item --no-check-certificate
8944 Do not validate the X.509 certificates of HTTPS servers.
8946 When using this option, you have @emph{absolutely no guarantee} that you
8947 are communicating with the authentic server responsible for the given
8948 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8950 @item --output=@var{file}
8951 @itemx -o @var{file}
8952 Save the downloaded file to @var{file} instead of adding it to the
8956 @node Invoking guix hash
8957 @section Invoking @command{guix hash}
8959 @cindex @command{guix hash}
8960 The @command{guix hash} command computes the SHA256 hash of a file.
8961 It is primarily a convenience tool for anyone contributing to the
8962 distribution: it computes the cryptographic hash of a file, which can be
8963 used in the definition of a package (@pxref{Defining Packages}).
8965 The general syntax is:
8968 guix hash @var{option} @var{file}
8971 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8972 hash of data read from standard input. @command{guix hash} has the
8977 @item --format=@var{fmt}
8979 Write the hash in the format specified by @var{fmt}.
8981 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8982 (@code{hex} and @code{hexadecimal} can be used as well).
8984 If the @option{--format} option is not specified, @command{guix hash}
8985 will output the hash in @code{nix-base32}. This representation is used
8986 in the definitions of packages.
8990 Compute the hash on @var{file} recursively.
8992 In this case, the hash is computed on an archive containing @var{file},
8993 including its children if it is a directory. Some of the metadata of
8994 @var{file} is part of the archive; for instance, when @var{file} is a
8995 regular file, the hash is different depending on whether @var{file} is
8996 executable or not. Metadata such as time stamps has no impact on the
8997 hash (@pxref{Invoking guix archive}).
8998 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9003 When combined with @option{--recursive}, exclude version control system
9004 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
9007 As an example, here is how you would compute the hash of a Git checkout,
9008 which is useful when using the @code{git-fetch} method (@pxref{origin
9012 $ git clone http://example.org/foo.git
9018 @node Invoking guix import
9019 @section Invoking @command{guix import}
9021 @cindex importing packages
9022 @cindex package import
9023 @cindex package conversion
9024 @cindex Invoking @command{guix import}
9025 The @command{guix import} command is useful for people who would like to
9026 add a package to the distribution with as little work as
9027 possible---a legitimate demand. The command knows of a few
9028 repositories from which it can ``import'' package metadata. The result
9029 is a package definition, or a template thereof, in the format we know
9030 (@pxref{Defining Packages}).
9032 The general syntax is:
9035 guix import @var{importer} @var{options}@dots{}
9038 @var{importer} specifies the source from which to import package
9039 metadata, and @var{options} specifies a package identifier and other
9040 options specific to @var{importer}.
9042 Some of the importers rely on the ability to run the @command{gpgv} command.
9043 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9046 Currently, the available ``importers'' are:
9050 Import metadata for the given GNU package. This provides a template
9051 for the latest version of that GNU package, including the hash of its
9052 source tarball, and its canonical synopsis and description.
9054 Additional information such as the package dependencies and its
9055 license needs to be figured out manually.
9057 For example, the following command returns a package definition for
9061 guix import gnu hello
9064 Specific command-line options are:
9067 @item --key-download=@var{policy}
9068 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
9069 keys when verifying the package signature. @xref{Invoking guix
9070 refresh, @code{--key-download}}.
9075 Import metadata from the @uref{https://pypi.python.org/, Python Package
9076 Index}. Information is taken from the JSON-formatted description
9077 available at @code{pypi.python.org} and usually includes all the relevant
9078 information, including package dependencies. For maximum efficiency, it
9079 is recommended to install the @command{unzip} utility, so that the
9080 importer can unzip Python wheels and gather data from them.
9082 The command below imports metadata for the @code{itsdangerous} Python
9086 guix import pypi itsdangerous
9092 Traverse the dependency graph of the given upstream package recursively
9093 and generate package expressions for all those packages that are not yet
9099 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9100 is taken from the JSON-formatted description available at
9101 @code{rubygems.org} and includes most relevant information, including
9102 runtime dependencies. There are some caveats, however. The metadata
9103 doesn't distinguish between synopses and descriptions, so the same string
9104 is used for both fields. Additionally, the details of non-Ruby
9105 dependencies required to build native extensions is unavailable and left
9106 as an exercise to the packager.
9108 The command below imports metadata for the @code{rails} Ruby package:
9111 guix import gem rails
9117 Traverse the dependency graph of the given upstream package recursively
9118 and generate package expressions for all those packages that are not yet
9124 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9125 Information is taken from the JSON-formatted metadata provided through
9126 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9127 relevant information, such as module dependencies. License information
9128 should be checked closely. If Perl is available in the store, then the
9129 @code{corelist} utility will be used to filter core modules out of the
9130 list of dependencies.
9132 The command command below imports metadata for the @code{Acme::Boolean}
9136 guix import cpan Acme::Boolean
9141 @cindex Bioconductor
9142 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9143 central repository for the @uref{https://r-project.org, GNU@tie{}R
9144 statistical and graphical environment}.
9146 Information is extracted from the @code{DESCRIPTION} file of the package.
9148 The command command below imports metadata for the @code{Cairo}
9152 guix import cran Cairo
9155 When @code{--recursive} is added, the importer will traverse the
9156 dependency graph of the given upstream package recursively and generate
9157 package expressions for all those packages that are not yet in Guix.
9159 When @code{--archive=bioconductor} is added, metadata is imported from
9160 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9161 packages for for the analysis and comprehension of high-throughput
9162 genomic data in bioinformatics.
9164 Information is extracted from the @code{DESCRIPTION} file contained in the
9167 The command below imports metadata for the @code{GenomicRanges}
9171 guix import cran --archive=bioconductor GenomicRanges
9174 Finally, you can also import R packages that have not yet been published on
9175 CRAN or Bioconductor as long as they are in a git repository. Use
9176 @code{--archive=git} followed by the URL of the git repository:
9179 guix import cran --archive=git https://github.com/immunogenomics/harmony
9185 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9186 comprehensive TeX archive network for TeX packages that are part of the
9187 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9189 Information about the package is obtained through the XML API provided
9190 by CTAN, while the source code is downloaded from the SVN repository of
9191 the Tex Live project. This is done because the CTAN does not keep
9194 The command command below imports metadata for the @code{fontspec}
9198 guix import texlive fontspec
9201 When @code{--archive=DIRECTORY} is added, the source code is downloaded
9202 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
9203 tree in the TeX Live SVN repository, but from the specified sibling
9204 directory under the same root.
9206 The command below imports metadata for the @code{ifxetex} package from
9207 CTAN while fetching the sources from the directory
9208 @file{texmf/source/generic}:
9211 guix import texlive --archive=generic ifxetex
9215 @cindex JSON, import
9216 Import package metadata from a local JSON file. Consider the following
9217 example package definition in JSON format:
9223 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9224 "build-system": "gnu",
9225 "home-page": "https://www.gnu.org/software/hello/",
9226 "synopsis": "Hello, GNU world: An example GNU package",
9227 "description": "GNU Hello prints a greeting.",
9228 "license": "GPL-3.0+",
9229 "native-inputs": ["gettext"]
9233 The field names are the same as for the @code{<package>} record
9234 (@xref{Defining Packages}). References to other packages are provided
9235 as JSON lists of quoted package specification strings such as
9236 @code{guile} or @code{guile@@2.0}.
9238 The importer also supports a more explicit source definition using the
9239 common fields for @code{<origin>} records:
9245 "method": "url-fetch",
9246 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9248 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9255 The command below reads metadata from the JSON file @code{hello.json}
9256 and outputs a package expression:
9259 guix import json hello.json
9263 Import metadata from a local copy of the source of the
9264 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9265 relies on the @command{nix-instantiate} command of
9266 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9267 typically written in a mixture of Nix-language and Bash code. This
9268 command only imports the high-level package structure that is written in
9269 the Nix language. It normally includes all the basic fields of a
9272 When importing a GNU package, the synopsis and descriptions are replaced
9273 by their canonical upstream variant.
9275 Usually, you will first need to do:
9278 export NIX_REMOTE=daemon
9282 so that @command{nix-instantiate} does not try to open the Nix database.
9284 As an example, the command below imports the package definition of
9285 LibreOffice (more precisely, it imports the definition of the package
9286 bound to the @code{libreoffice} top-level attribute):
9289 guix import nix ~/path/to/nixpkgs libreoffice
9294 Import metadata from the Haskell community's central package archive
9295 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9296 Cabal files and includes all the relevant information, including package
9299 Specific command-line options are:
9304 Read a Cabal file from standard input.
9305 @item --no-test-dependencies
9307 Do not include dependencies required only by the test suites.
9308 @item --cabal-environment=@var{alist}
9309 @itemx -e @var{alist}
9310 @var{alist} is a Scheme alist defining the environment in which the
9311 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9312 @code{arch}, @code{impl} and a string representing the name of a flag.
9313 The value associated with a flag has to be either the symbol
9314 @code{true} or @code{false}. The value associated with other keys
9315 has to conform to the Cabal file format definition. The default value
9316 associated with the keys @code{os}, @code{arch} and @code{impl} is
9317 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9320 Traverse the dependency graph of the given upstream package recursively
9321 and generate package expressions for all those packages that are not yet
9325 The command below imports metadata for the latest version of the
9326 @code{HTTP} Haskell package without including test dependencies and
9327 specifying the value of the flag @samp{network-uri} as @code{false}:
9330 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9333 A specific package version may optionally be specified by following the
9334 package name by an at-sign and a version number as in the following example:
9337 guix import hackage mtl@@2.1.3.1
9342 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9343 It takes a package name, looks up the package version included in a
9344 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9345 release and uses the @code{hackage} importer to retrieve its metadata.
9346 Note that it is up to you to select an LTS release compatible with the
9347 GHC compiler used by Guix.
9349 Specific command-line options are:
9352 @item --no-test-dependencies
9354 Do not include dependencies required only by the test suites.
9355 @item --lts-version=@var{version}
9356 @itemx -l @var{version}
9357 @var{version} is the desired LTS release version. If omitted the latest
9361 Traverse the dependency graph of the given upstream package recursively
9362 and generate package expressions for all those packages that are not yet
9366 The command below imports metadata for the @code{HTTP} Haskell package
9367 included in the LTS Stackage release version 7.18:
9370 guix import stackage --lts-version=7.18 HTTP
9375 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9376 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9378 Specific command-line options are:
9381 @item --archive=@var{repo}
9382 @itemx -a @var{repo}
9383 @var{repo} identifies the archive repository from which to retrieve the
9384 information. Currently the supported repositories and their identifiers
9388 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9389 identifier. This is the default.
9391 Packages from @code{elpa.gnu.org} are signed with one of the keys
9392 contained in the GnuPG keyring at
9393 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9394 @code{emacs} package (@pxref{Package Installation, ELPA package
9395 signatures,, emacs, The GNU Emacs Manual}).
9398 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9399 @code{melpa-stable} identifier.
9402 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9408 Traverse the dependency graph of the given upstream package recursively
9409 and generate package expressions for all those packages that are not yet
9415 Import metadata from the crates.io Rust package repository
9416 @uref{https://crates.io, crates.io}, as in this example:
9419 guix import crate blake2-rfc
9422 The crate importer also allows you to specify a version string:
9425 guix import crate constant-time-eq@@0.1.0
9428 Additional options include:
9433 Traverse the dependency graph of the given upstream package recursively
9434 and generate package expressions for all those packages that are not yet
9441 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9442 repository used by the OCaml community.
9445 The structure of the @command{guix import} code is modular. It would be
9446 useful to have more importers for other package formats, and your help
9447 is welcome here (@pxref{Contributing}).
9449 @node Invoking guix refresh
9450 @section Invoking @command{guix refresh}
9452 @cindex @command {guix refresh}
9453 The primary audience of the @command{guix refresh} command is developers
9454 of the GNU software distribution. By default, it reports any packages
9455 provided by the distribution that are outdated compared to the latest
9456 upstream version, like this:
9460 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9461 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9464 Alternately, one can specify packages to consider, in which case a
9465 warning is emitted for packages that lack an updater:
9468 $ guix refresh coreutils guile guile-ssh
9469 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9470 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9473 @command{guix refresh} browses the upstream repository of each package and determines
9474 the highest version number of the releases therein. The command
9475 knows how to update specific types of packages: GNU packages, ELPA
9476 packages, etc.---see the documentation for @option{--type} below. There
9477 are many packages, though, for which it lacks a method to determine
9478 whether a new upstream release is available. However, the mechanism is
9479 extensible, so feel free to get in touch with us to add a new method!
9484 Consider the packages specified, and all the packages upon which they depend.
9487 $ guix refresh --recursive coreutils
9488 gnu/packages/acl.scm:35:2: warning: no updater for acl
9489 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9490 gnu/packages/xml.scm:68:2: warning: no updater for expat
9491 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9497 Sometimes the upstream name differs from the package name used in Guix,
9498 and @command{guix refresh} needs a little help. Most updaters honor the
9499 @code{upstream-name} property in package definitions, which can be used
9503 (define-public network-manager
9505 (name "network-manager")
9507 (properties '((upstream-name . "NetworkManager")))))
9510 When passed @code{--update}, it modifies distribution source files to
9511 update the version numbers and source tarball hashes of those package
9512 recipes (@pxref{Defining Packages}). This is achieved by downloading
9513 each package's latest source tarball and its associated OpenPGP
9514 signature, authenticating the downloaded tarball against its signature
9515 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9516 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9519 key used to sign the tarball is missing from the user's keyring, an
9520 attempt is made to automatically retrieve it from a public key server;
9521 when this is successful, the key is added to the user's keyring; otherwise,
9522 @command{guix refresh} reports an error.
9524 The following options are supported:
9528 @item --expression=@var{expr}
9529 @itemx -e @var{expr}
9530 Consider the package @var{expr} evaluates to.
9532 This is useful to precisely refer to a package, as in this example:
9535 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9538 This command lists the dependents of the ``final'' libc (essentially all
9543 Update distribution source files (package recipes) in place. This is
9544 usually run from a checkout of the Guix source tree (@pxref{Running
9545 Guix Before It Is Installed}):
9548 $ ./pre-inst-env guix refresh -s non-core -u
9551 @xref{Defining Packages}, for more information on package definitions.
9553 @item --select=[@var{subset}]
9554 @itemx -s @var{subset}
9555 Select all the packages in @var{subset}, one of @code{core} or
9558 The @code{core} subset refers to all the packages at the core of the
9559 distribution---i.e., packages that are used to build ``everything
9560 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9561 changing one of these packages in the distribution entails a rebuild of
9562 all the others. Thus, such updates are an inconvenience to users in
9563 terms of build time or bandwidth used to achieve the upgrade.
9565 The @code{non-core} subset refers to the remaining packages. It is
9566 typically useful in cases where an update of the core packages would be
9569 @item --manifest=@var{file}
9570 @itemx -m @var{file}
9571 Select all the packages from the manifest in @var{file}. This is useful to
9572 check if any packages of the user manifest can be updated.
9574 @item --type=@var{updater}
9575 @itemx -t @var{updater}
9576 Select only packages handled by @var{updater} (may be a comma-separated
9577 list of updaters). Currently, @var{updater} may be one of:
9581 the updater for GNU packages;
9583 the updater for GNOME packages;
9585 the updater for KDE packages;
9587 the updater for X.org packages;
9589 the updater for packages hosted on kernel.org;
9591 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9593 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9595 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9597 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9599 the updater for @uref{https://pypi.python.org, PyPI} packages.
9601 the updater for @uref{https://rubygems.org, RubyGems} packages.
9603 the updater for @uref{https://github.com, GitHub} packages.
9605 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9607 the updater for @uref{https://www.stackage.org, Stackage} packages.
9609 the updater for @uref{https://crates.io, Crates} packages.
9611 the updater for @uref{https://launchpad.net, Launchpad} packages.
9614 For instance, the following command only checks for updates of Emacs
9615 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9618 $ guix refresh --type=elpa,cran
9619 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9620 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9625 In addition, @command{guix refresh} can be passed one or more package
9626 names, as in this example:
9629 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9633 The command above specifically updates the @code{emacs} and
9634 @code{idutils} packages. The @code{--select} option would have no
9635 effect in this case.
9637 When considering whether to upgrade a package, it is sometimes
9638 convenient to know which packages would be affected by the upgrade and
9639 should be checked for compatibility. For this the following option may
9640 be used when passing @command{guix refresh} one or more package names:
9644 @item --list-updaters
9646 List available updaters and exit (see @option{--type} above.)
9648 For each updater, display the fraction of packages it covers; at the
9649 end, display the fraction of packages covered by all these updaters.
9651 @item --list-dependent
9653 List top-level dependent packages that would need to be rebuilt as a
9654 result of upgrading one or more packages.
9656 @xref{Invoking guix graph, the @code{reverse-package} type of
9657 @command{guix graph}}, for information on how to visualize the list of
9658 dependents of a package.
9662 Be aware that the @code{--list-dependent} option only
9663 @emph{approximates} the rebuilds that would be required as a result of
9664 an upgrade. More rebuilds might be required under some circumstances.
9667 $ guix refresh --list-dependent flex
9668 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9669 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9672 The command above lists a set of packages that could be built to check
9673 for compatibility with an upgraded @code{flex} package.
9677 @item --list-transitive
9678 List all the packages which one or more packages depend upon.
9681 $ guix refresh --list-transitive flex
9682 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9683 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{}
9688 The command above lists a set of packages which, when changed, would cause
9689 @code{flex} to be rebuilt.
9691 The following options can be used to customize GnuPG operation:
9695 @item --gpg=@var{command}
9696 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9697 for in @code{$PATH}.
9699 @item --keyring=@var{file}
9700 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9701 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9702 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9703 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9704 information on a tool to manipulate keybox files).
9706 When this option is omitted, @command{guix refresh} uses
9707 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9708 signing keys. OpenPGP signatures are checked against keys from this keyring;
9709 missing keys are downloaded to this keyring as well (see
9710 @option{--key-download} below.)
9712 You can export keys from your default GPG keyring into a keybox file using
9713 commands like this one:
9716 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9719 Likewise, you can fetch keys to a specific keybox file like this:
9722 gpg --no-default-keyring --keyring mykeyring.kbx \
9723 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9726 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9727 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9729 @item --key-download=@var{policy}
9730 Handle missing OpenPGP keys according to @var{policy}, which may be one
9735 Always download missing OpenPGP keys from the key server, and add them
9736 to the user's GnuPG keyring.
9739 Never try to download missing OpenPGP keys. Instead just bail out.
9742 When a package signed with an unknown OpenPGP key is encountered, ask
9743 the user whether to download it or not. This is the default behavior.
9746 @item --key-server=@var{host}
9747 Use @var{host} as the OpenPGP key server when importing a public key.
9749 @item --load-path=@var{directory}
9750 Add @var{directory} to the front of the package module search path
9751 (@pxref{Package Modules}).
9753 This allows users to define their own packages and make them visible to
9754 the command-line tools.
9758 The @code{github} updater uses the
9759 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9760 releases. When used repeatedly e.g.@: when refreshing all packages,
9761 GitHub will eventually refuse to answer any further API requests. By
9762 default 60 API requests per hour are allowed, and a full refresh on all
9763 GitHub packages in Guix requires more than this. Authentication with
9764 GitHub through the use of an API token alleviates these limits. To use
9765 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9766 token procured from @uref{https://github.com/settings/tokens} or
9770 @node Invoking guix lint
9771 @section Invoking @command{guix lint}
9773 @cindex @command{guix lint}
9774 @cindex package, checking for errors
9775 The @command{guix lint} command is meant to help package developers avoid
9776 common errors and use a consistent style. It runs a number of checks on
9777 a given set of packages in order to find common mistakes in their
9778 definitions. Available @dfn{checkers} include (see
9779 @code{--list-checkers} for a complete list):
9784 Validate certain typographical and stylistic rules about package
9785 descriptions and synopses.
9787 @item inputs-should-be-native
9788 Identify inputs that should most likely be native inputs.
9794 @itemx source-file-name
9795 Probe @code{home-page} and @code{source} URLs and report those that are
9796 invalid. Suggest a @code{mirror://} URL when applicable. If the
9797 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9798 URL. Check that the source file name is meaningful, e.g.@: is not just a
9799 version number or ``git-checkout'', without a declared @code{file-name}
9800 (@pxref{origin Reference}).
9802 @item source-unstable-tarball
9803 Parse the @code{source} URL to determine if a tarball from GitHub is
9804 autogenerated or if it is a release tarball. Unfortunately GitHub's
9805 autogenerated tarballs are sometimes regenerated.
9808 @cindex Software Heritage, source code archive
9809 @cindex archival of source code, Software Heritage
9810 Checks whether the package's source code is archived at
9811 @uref{https://www.softwareheritage.org, Software Heritage}.
9813 When the source code that is not archived comes from a version-control system
9814 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9815 ``save'' request so that it eventually archives it. This ensures that the
9816 source will remain available in the long term, and that Guix can fall back to
9817 Software Heritage should the source code disappear from its original host.
9818 The status of recent ``save'' requests can be
9819 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9821 When source code is a tarball obtained with @code{url-fetch}, simply print a
9822 message when it is not archived. As of this writing, Software Heritage does
9823 not allow requests to save arbitrary tarballs; we are working on ways to
9824 ensure that non-VCS source code is also archived.
9827 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9828 request rate per IP address}. When the limit is reached, @command{guix lint}
9829 prints a message and the @code{archival} checker stops doing anything until
9830 that limit has been reset.
9833 @cindex security vulnerabilities
9834 @cindex CVE, Common Vulnerabilities and Exposures
9835 Report known vulnerabilities found in the Common Vulnerabilities and
9836 Exposures (CVE) databases of the current and past year
9837 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9840 To view information about a particular vulnerability, visit pages such as:
9844 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9846 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9850 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9851 @code{CVE-2015-7554}.
9853 Package developers can specify in package recipes the
9854 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9855 name and version of the package when they differ from the name or version
9856 that Guix uses, as in this example:
9862 ;; CPE calls this package "grub2".
9863 (properties '((cpe-name . "grub2")
9864 (cpe-version . "2.3"))))
9867 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9868 Some entries in the CVE database do not specify which version of a
9869 package they apply to, and would thus ``stick around'' forever. Package
9870 developers who found CVE alerts and verified they can be ignored can
9871 declare them as in this example:
9877 ;; These CVEs no longer apply and can be safely ignored.
9878 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9881 "CVE-2011-5244")))))
9885 Warn about obvious source code formatting issues: trailing white space,
9886 use of tabulations, etc.
9889 The general syntax is:
9892 guix lint @var{options} @var{package}@dots{}
9895 If no package is given on the command line, then all packages are checked.
9896 The @var{options} may be zero or more of the following:
9899 @item --list-checkers
9901 List and describe all the available checkers that will be run on packages
9906 Only enable the checkers specified in a comma-separated list using the
9907 names returned by @code{--list-checkers}.
9909 @item --load-path=@var{directory}
9910 @itemx -L @var{directory}
9911 Add @var{directory} to the front of the package module search path
9912 (@pxref{Package Modules}).
9914 This allows users to define their own packages and make them visible to
9915 the command-line tools.
9919 @node Invoking guix size
9920 @section Invoking @command{guix size}
9923 @cindex package size
9925 @cindex @command{guix size}
9926 The @command{guix size} command helps package developers profile the
9927 disk usage of packages. It is easy to overlook the impact of an
9928 additional dependency added to a package, or the impact of using a
9929 single output for a package that could easily be split (@pxref{Packages
9930 with Multiple Outputs}). Such are the typical issues that
9931 @command{guix size} can highlight.
9933 The command can be passed one or more package specifications
9934 such as @code{gcc@@4.8}
9935 or @code{guile:debug}, or a file name in the store. Consider this
9939 $ guix size coreutils
9940 store item total self
9941 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9942 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9943 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9944 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9945 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9946 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9947 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9948 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9953 The store items listed here constitute the @dfn{transitive closure} of
9954 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9955 would be returned by:
9958 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9961 Here the output shows three columns next to store items. The first column,
9962 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9963 the store item---that is, its own size plus the size of all its
9964 dependencies. The next column, labeled ``self'', shows the size of the
9965 item itself. The last column shows the ratio of the size of the item
9966 itself to the space occupied by all the items listed here.
9968 In this example, we see that the closure of Coreutils weighs in at
9969 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9970 libraries. (That libc and GCC's libraries represent a large fraction of
9971 the closure is not a problem @i{per se} because they are always available
9972 on the system anyway.)
9974 When the package(s) passed to @command{guix size} are available in the
9975 store@footnote{More precisely, @command{guix size} looks for the
9976 @emph{ungrafted} variant of the given package(s), as returned by
9977 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9978 for information on grafts.}, @command{guix size} queries the daemon to determine its
9979 dependencies, and measures its size in the store, similar to @command{du
9980 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9983 When the given packages are @emph{not} in the store, @command{guix size}
9984 reports information based on the available substitutes
9985 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9986 store items that are not even on disk, only available remotely.
9988 You can also specify several package names:
9991 $ guix size coreutils grep sed bash
9992 store item total self
9993 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9994 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9995 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9996 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10002 In this example we see that the combination of the four packages takes
10003 102.3@tie{}MiB in total, which is much less than the sum of each closure
10004 since they have a lot of dependencies in common.
10006 The available options are:
10010 @item --substitute-urls=@var{urls}
10011 Use substitute information from @var{urls}.
10012 @xref{client-substitute-urls, the same option for @code{guix build}}.
10014 @item --sort=@var{key}
10015 Sort lines according to @var{key}, one of the following options:
10019 the size of each item (the default);
10021 the total size of the item's closure.
10024 @item --map-file=@var{file}
10025 Write a graphical map of disk usage in PNG format to @var{file}.
10027 For the example above, the map looks like this:
10029 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10030 produced by @command{guix size}}
10032 This option requires that
10033 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10034 installed and visible in Guile's module search path. When that is not
10035 the case, @command{guix size} fails as it tries to load it.
10037 @item --system=@var{system}
10038 @itemx -s @var{system}
10039 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10041 @item --load-path=@var{directory}
10042 @itemx -L @var{directory}
10043 Add @var{directory} to the front of the package module search path
10044 (@pxref{Package Modules}).
10046 This allows users to define their own packages and make them visible to
10047 the command-line tools.
10050 @node Invoking guix graph
10051 @section Invoking @command{guix graph}
10054 @cindex @command{guix graph}
10055 @cindex package dependencies
10056 Packages and their dependencies form a @dfn{graph}, specifically a
10057 directed acyclic graph (DAG). It can quickly become difficult to have a
10058 mental model of the package DAG, so the @command{guix graph} command
10059 provides a visual representation of the DAG. By default,
10060 @command{guix graph} emits a DAG representation in the input format of
10061 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10062 directly to the @command{dot} command of Graphviz. It can also emit an
10063 HTML page with embedded JavaScript code to display a ``chord diagram''
10064 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10065 emit Cypher queries to construct a graph in a graph database supporting
10066 the @uref{https://www.opencypher.org/, openCypher} query language.
10067 The general syntax is:
10070 guix graph @var{options} @var{package}@dots{}
10073 For example, the following command generates a PDF file representing the
10074 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10078 guix graph coreutils | dot -Tpdf > dag.pdf
10081 The output looks like this:
10083 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10085 Nice little graph, no?
10087 But there is more than one graph! The one above is concise: it is the
10088 graph of package objects, omitting implicit inputs such as GCC, libc,
10089 grep, etc. It is often useful to have such a concise graph, but
10090 sometimes one may want to see more details. @command{guix graph} supports
10091 several types of graphs, allowing you to choose the level of detail:
10095 This is the default type used in the example above. It shows the DAG of
10096 package objects, excluding implicit dependencies. It is concise, but
10097 filters out many details.
10099 @item reverse-package
10100 This shows the @emph{reverse} DAG of packages. For example:
10103 guix graph --type=reverse-package ocaml
10106 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10107 you are also interested in cases where OCaml is an implicit dependency, see
10108 @code{reverse-bag} below.)
10110 Note that for core packages this can yield huge graphs. If all you want
10111 is to know the number of packages that depend on a given package, use
10112 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10113 @option{--list-dependent}}).
10116 This is the package DAG, @emph{including} implicit inputs.
10118 For instance, the following command:
10121 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
10124 ...@: yields this bigger graph:
10126 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10128 At the bottom of the graph, we see all the implicit inputs of
10129 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10131 Now, note that the dependencies of these implicit inputs---that is, the
10132 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10133 here, for conciseness.
10136 Similar to @code{bag-emerged}, but this time including all the bootstrap
10139 @item bag-with-origins
10140 Similar to @code{bag}, but also showing origins and their dependencies.
10143 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10144 it also takes implicit dependencies into account. For example:
10147 guix graph -t reverse-bag dune
10151 ...@: yields the graph of all packages that depend on Dune, directly or
10152 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10153 @i{via} @code{dune-build-system}, this shows a large number of packages,
10154 whereas @code{reverse-package} would show very few if any.
10157 This is the most detailed representation: It shows the DAG of
10158 derivations (@pxref{Derivations}) and plain store items. Compared to
10159 the above representation, many additional nodes are visible, including
10160 build scripts, patches, Guile modules, etc.
10162 For this type of graph, it is also possible to pass a @file{.drv} file
10163 name instead of a package name, as in:
10166 guix graph -t derivation `guix system build -d my-config.scm`
10170 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10171 For example, the following command shows the graph for the package
10172 module that defines the @code{guile} package:
10175 guix graph -t module guile | dot -Tpdf > module-graph.pdf
10179 All the types above correspond to @emph{build-time dependencies}. The
10180 following graph type represents the @emph{run-time dependencies}:
10184 This is the graph of @dfn{references} of a package output, as returned
10185 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10187 If the given package output is not available in the store, @command{guix
10188 graph} attempts to obtain dependency information from substitutes.
10190 Here you can also pass a store file name instead of a package name. For
10191 example, the command below produces the reference graph of your profile
10192 (which can be big!):
10195 guix graph -t references `readlink -f ~/.guix-profile`
10199 This is the graph of the @dfn{referrers} of a store item, as returned by
10200 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10202 This relies exclusively on local information from your store. For
10203 instance, let us suppose that the current Inkscape is available in 10
10204 profiles on your machine; @command{guix graph -t referrers inkscape}
10205 will show a graph rooted at Inkscape and with those 10 profiles linked
10208 It can help determine what is preventing a store item from being garbage
10213 The available options are the following:
10216 @item --type=@var{type}
10217 @itemx -t @var{type}
10218 Produce a graph output of @var{type}, where @var{type} must be one of
10219 the values listed above.
10222 List the supported graph types.
10224 @item --backend=@var{backend}
10225 @itemx -b @var{backend}
10226 Produce a graph using the selected @var{backend}.
10228 @item --list-backends
10229 List the supported graph backends.
10231 Currently, the available backends are Graphviz and d3.js.
10233 @item --expression=@var{expr}
10234 @itemx -e @var{expr}
10235 Consider the package @var{expr} evaluates to.
10237 This is useful to precisely refer to a package, as in this example:
10240 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
10243 @item --system=@var{system}
10244 @itemx -s @var{system}
10245 Display the graph for @var{system}---e.g., @code{i686-linux}.
10247 The package dependency graph is largely architecture-independent, but there
10248 are some architecture-dependent bits that this option allows you to visualize.
10250 @item --load-path=@var{directory}
10251 @itemx -L @var{directory}
10252 Add @var{directory} to the front of the package module search path
10253 (@pxref{Package Modules}).
10255 This allows users to define their own packages and make them visible to
10256 the command-line tools.
10259 On top of that, @command{guix graph} supports all the usual package
10260 transformation options (@pxref{Package Transformation Options}). This
10261 makes it easy to view the effect of a graph-rewriting transformation
10262 such as @option{--with-input}. For example, the command below outputs
10263 the graph of @code{git} once @code{openssl} has been replaced by
10264 @code{libressl} everywhere in the graph:
10267 guix graph git --with-input=openssl=libressl
10270 So many possibilities, so much fun!
10272 @node Invoking guix publish
10273 @section Invoking @command{guix publish}
10275 @cindex @command{guix publish}
10276 The purpose of @command{guix publish} is to enable users to easily share
10277 their store with others, who can then use it as a substitute server
10278 (@pxref{Substitutes}).
10280 When @command{guix publish} runs, it spawns an HTTP server which allows
10281 anyone with network access to obtain substitutes from it. This means
10282 that any machine running Guix can also act as if it were a build farm,
10283 since the HTTP interface is compatible with Cuirass, the software behind
10284 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10286 For security, each substitute is signed, allowing recipients to check
10287 their authenticity and integrity (@pxref{Substitutes}). Because
10288 @command{guix publish} uses the signing key of the system, which is only
10289 readable by the system administrator, it must be started as root; the
10290 @code{--user} option makes it drop root privileges early on.
10292 The signing key pair must be generated before @command{guix publish} is
10293 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10296 The general syntax is:
10299 guix publish @var{options}@dots{}
10302 Running @command{guix publish} without any additional arguments will
10303 spawn an HTTP server on port 8080:
10309 Once a publishing server has been authorized (@pxref{Invoking guix
10310 archive}), the daemon may download substitutes from it:
10313 guix-daemon --substitute-urls=http://example.org:8080
10316 By default, @command{guix publish} compresses archives on the fly as it
10317 serves them. This ``on-the-fly'' mode is convenient in that it requires
10318 no setup and is immediately available. However, when serving lots of
10319 clients, we recommend using the @option{--cache} option, which enables
10320 caching of the archives before they are sent to clients---see below for
10321 details. The @command{guix weather} command provides a handy way to
10322 check what a server provides (@pxref{Invoking guix weather}).
10324 As a bonus, @command{guix publish} also serves as a content-addressed
10325 mirror for source files referenced in @code{origin} records
10326 (@pxref{origin Reference}). For instance, assuming @command{guix
10327 publish} is running on @code{example.org}, the following URL returns the
10328 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10329 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10332 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10335 Obviously, these URLs only work for files that are in the store; in
10336 other cases, they return 404 (``Not Found'').
10338 @cindex build logs, publication
10339 Build logs are available from @code{/log} URLs like:
10342 http://example.org/log/gwspk@dots{}-guile-2.2.3
10346 When @command{guix-daemon} is configured to save compressed build logs,
10347 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10348 URLs return the compressed log as-is, with an appropriate
10349 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10350 running @command{guix-daemon} with @code{--log-compression=gzip} since
10351 Web browsers can automatically decompress it, which is not the case with
10354 The following options are available:
10357 @item --port=@var{port}
10358 @itemx -p @var{port}
10359 Listen for HTTP requests on @var{port}.
10361 @item --listen=@var{host}
10362 Listen on the network interface for @var{host}. The default is to
10363 accept connections from any interface.
10365 @item --user=@var{user}
10366 @itemx -u @var{user}
10367 Change privileges to @var{user} as soon as possible---i.e., once the
10368 server socket is open and the signing key has been read.
10370 @item --compression[=@var{method}[:@var{level}]]
10371 @itemx -C [@var{method}[:@var{level}]]
10372 Compress data using the given @var{method} and @var{level}. @var{method} is
10373 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10376 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10377 to different compression levels: 1 is the fastest, and 9 is the best
10378 (CPU-intensive). The default is 3.
10380 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10381 increase in CPU usage; see
10382 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10385 Unless @option{--cache} is used, compression occurs on the fly and
10386 the compressed streams are not
10387 cached. Thus, to reduce load on the machine that runs @command{guix
10388 publish}, it may be a good idea to choose a low compression level, to
10389 run @command{guix publish} behind a caching proxy, or to use
10390 @option{--cache}. Using @option{--cache} has the advantage that it
10391 allows @command{guix publish} to add @code{Content-Length} HTTP header
10394 This option can be repeated, in which case every substitute gets compressed
10395 using all the selected methods, and all of them are advertised. This is
10396 useful when users may not support all the compression methods: they can select
10397 the one they support.
10399 @item --cache=@var{directory}
10400 @itemx -c @var{directory}
10401 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10402 and only serve archives that are in cache.
10404 When this option is omitted, archives and meta-data are created
10405 on-the-fly. This can reduce the available bandwidth, especially when
10406 compression is enabled, since this may become CPU-bound. Another
10407 drawback of the default mode is that the length of archives is not known
10408 in advance, so @command{guix publish} does not add a
10409 @code{Content-Length} HTTP header to its responses, which in turn
10410 prevents clients from knowing the amount of data being downloaded.
10412 Conversely, when @option{--cache} is used, the first request for a store
10413 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10414 background process to @dfn{bake} the archive---computing its
10415 @code{.narinfo} and compressing the archive, if needed. Once the
10416 archive is cached in @var{directory}, subsequent requests succeed and
10417 are served directly from the cache, which guarantees that clients get
10418 the best possible bandwidth.
10420 The ``baking'' process is performed by worker threads. By default, one
10421 thread per CPU core is created, but this can be customized. See
10422 @option{--workers} below.
10424 When @option{--ttl} is used, cached entries are automatically deleted
10425 when they have expired.
10427 @item --workers=@var{N}
10428 When @option{--cache} is used, request the allocation of @var{N} worker
10429 threads to ``bake'' archives.
10431 @item --ttl=@var{ttl}
10432 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10433 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10434 days, @code{1m} means 1 month, and so on.
10436 This allows the user's Guix to keep substitute information in cache for
10437 @var{ttl}. However, note that @code{guix publish} does not itself
10438 guarantee that the store items it provides will indeed remain available
10439 for as long as @var{ttl}.
10441 Additionally, when @option{--cache} is used, cached entries that have
10442 not been accessed for @var{ttl} and that no longer have a corresponding
10443 item in the store, may be deleted.
10445 @item --nar-path=@var{path}
10446 Use @var{path} as the prefix for the URLs of ``nar'' files
10447 (@pxref{Invoking guix archive, normalized archives}).
10449 By default, nars are served at a URL such as
10450 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10451 change the @code{/nar} part to @var{path}.
10453 @item --public-key=@var{file}
10454 @itemx --private-key=@var{file}
10455 Use the specific @var{file}s as the public/private key pair used to sign
10456 the store items being published.
10458 The files must correspond to the same key pair (the private key is used
10459 for signing and the public key is merely advertised in the signature
10460 metadata). They must contain keys in the canonical s-expression format
10461 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10462 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10463 @file{/etc/guix/signing-key.sec} are used.
10465 @item --repl[=@var{port}]
10466 @itemx -r [@var{port}]
10467 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10468 Reference Manual}) on @var{port} (37146 by default). This is used
10469 primarily for debugging a running @command{guix publish} server.
10472 Enabling @command{guix publish} on Guix System is a one-liner: just
10473 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10474 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10475 @code{guix-publish-service-type}}).
10477 If you are instead running Guix on a ``foreign distro'', follow these
10482 If your host distro uses the systemd init system:
10485 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10486 /etc/systemd/system/
10487 # systemctl start guix-publish && systemctl enable guix-publish
10491 If your host distro uses the Upstart init system:
10494 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10495 # start guix-publish
10499 Otherwise, proceed similarly with your distro's init system.
10502 @node Invoking guix challenge
10503 @section Invoking @command{guix challenge}
10505 @cindex reproducible builds
10506 @cindex verifiable builds
10507 @cindex @command{guix challenge}
10509 Do the binaries provided by this server really correspond to the source
10510 code it claims to build? Is a package build process deterministic?
10511 These are the questions the @command{guix challenge} command attempts to
10514 The former is obviously an important question: Before using a substitute
10515 server (@pxref{Substitutes}), one had better @emph{verify} that it
10516 provides the right binaries, and thus @emph{challenge} it. The latter
10517 is what enables the former: If package builds are deterministic, then
10518 independent builds of the package should yield the exact same result,
10519 bit for bit; if a server provides a binary different from the one
10520 obtained locally, it may be either corrupt or malicious.
10522 We know that the hash that shows up in @file{/gnu/store} file names is
10523 the hash of all the inputs of the process that built the file or
10524 directory---compilers, libraries, build scripts,
10525 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10526 one store file name should map to exactly one build output.
10527 @command{guix challenge} checks whether there is, indeed, a single
10528 mapping by comparing the build outputs of several independent builds of
10529 any given store item.
10531 The command output looks like this:
10534 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10535 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10536 updating list of substitutes from 'https://guix.example.org'... 100.0%
10537 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10538 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10539 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10540 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10542 /lib/libcrypto.so.1.1
10545 /gnu/store/@dots{}-git-2.5.0 contents differ:
10546 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10547 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10548 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10550 /libexec/git-core/git-fsck
10552 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10553 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10554 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10555 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10557 /share/man/man1/pius.1.gz
10561 6,406 store items were analyzed:
10562 - 4,749 (74.1%) were identical
10563 - 525 (8.2%) differed
10564 - 1,132 (17.7%) were inconclusive
10568 In this example, @command{guix challenge} first scans the store to
10569 determine the set of locally-built derivations---as opposed to store
10570 items that were downloaded from a substitute server---and then queries
10571 all the substitute servers. It then reports those store items for which
10572 the servers obtained a result different from the local build.
10574 @cindex non-determinism, in package builds
10575 As an example, @code{guix.example.org} always gets a different answer.
10576 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10577 case of Git. This might indicate that the build process of Git is
10578 non-deterministic, meaning that its output varies as a function of
10579 various things that Guix does not fully control, in spite of building
10580 packages in isolated environments (@pxref{Features}). Most common
10581 sources of non-determinism include the addition of timestamps in build
10582 results, the inclusion of random numbers, and directory listings sorted
10583 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10586 To find out what is wrong with this Git binary, the easiest approach is
10590 guix challenge git \
10591 --diff=diffoscope \
10592 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10595 This automatically invokes @command{diffoscope}, which displays detailed
10596 information about files that differ.
10598 Alternately, we can do something along these lines (@pxref{Invoking guix
10602 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
10603 | lzip -d | guix archive -x /tmp/git
10604 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10607 This command shows the difference between the files resulting from the
10608 local build, and the files resulting from the build on
10609 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10610 diffutils, Comparing and Merging Files}). The @command{diff} command
10611 works great for text files. When binary files differ, a better option
10612 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10613 visualize differences for all kinds of files.
10615 Once you have done that work, you can tell whether the differences are due
10616 to a non-deterministic build process or to a malicious server. We try
10617 hard to remove sources of non-determinism in packages to make it easier
10618 to verify substitutes, but of course, this is a process that
10619 involves not just Guix, but a large part of the free software community.
10620 In the meantime, @command{guix challenge} is one tool to help address
10623 If you are writing packages for Guix, you are encouraged to check
10624 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10625 same build result as you did with:
10628 $ guix challenge @var{package}
10632 where @var{package} is a package specification such as
10633 @code{guile@@2.0} or @code{glibc:debug}.
10635 The general syntax is:
10638 guix challenge @var{options} [@var{packages}@dots{}]
10641 When a difference is found between the hash of a locally-built item and
10642 that of a server-provided substitute, or among substitutes provided by
10643 different servers, the command displays it as in the example above and
10644 its exit code is 2 (other non-zero exit codes denote other kinds of
10647 The one option that matters is:
10651 @item --substitute-urls=@var{urls}
10652 Consider @var{urls} the whitespace-separated list of substitute source
10653 URLs to compare to.
10655 @item --diff=@var{mode}
10656 Upon mismatches, show differences according to @var{mode}, one of:
10659 @item @code{simple} (the default)
10660 Show the list of files that differ.
10662 @item @code{diffoscope}
10663 @itemx @var{command}
10664 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
10665 two directories whose contents do not match.
10667 When @var{command} is an absolute file name, run @var{command} instead
10671 Do not show further details about the differences.
10674 Thus, unless @code{--diff=none} is passed, @command{guix challenge}
10675 downloads the store items from the given substitute servers so that it
10680 Show details about matches (identical contents) in addition to
10681 information about mismatches.
10685 @node Invoking guix copy
10686 @section Invoking @command{guix copy}
10688 @cindex copy, of store items, over SSH
10689 @cindex SSH, copy of store items
10690 @cindex sharing store items across machines
10691 @cindex transferring store items across machines
10692 The @command{guix copy} command copies items from the store of one
10693 machine to that of another machine over a secure shell (SSH)
10694 connection@footnote{This command is available only when Guile-SSH was
10695 found. @xref{Requirements}, for details.}. For example, the following
10696 command copies the @code{coreutils} package, the user's profile, and all
10697 their dependencies over to @var{host}, logged in as @var{user}:
10700 guix copy --to=@var{user}@@@var{host} \
10701 coreutils `readlink -f ~/.guix-profile`
10704 If some of the items to be copied are already present on @var{host},
10705 they are not actually sent.
10707 The command below retrieves @code{libreoffice} and @code{gimp} from
10708 @var{host}, assuming they are available there:
10711 guix copy --from=@var{host} libreoffice gimp
10714 The SSH connection is established using the Guile-SSH client, which is
10715 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10716 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10718 The key used to sign items that are sent must be accepted by the remote
10719 machine. Likewise, the key used by the remote machine to sign items you
10720 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10721 own daemon. @xref{Invoking guix archive}, for more information about
10722 store item authentication.
10724 The general syntax is:
10727 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10730 You must always specify one of the following options:
10733 @item --to=@var{spec}
10734 @itemx --from=@var{spec}
10735 Specify the host to send to or receive from. @var{spec} must be an SSH
10736 spec such as @code{example.org}, @code{charlie@@example.org}, or
10737 @code{charlie@@example.org:2222}.
10740 The @var{items} can be either package names, such as @code{gimp}, or
10741 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10743 When specifying the name of a package to send, it is first built if
10744 needed, unless @option{--dry-run} was specified. Common build options
10745 are supported (@pxref{Common Build Options}).
10748 @node Invoking guix container
10749 @section Invoking @command{guix container}
10751 @cindex @command{guix container}
10753 As of version @value{VERSION}, this tool is experimental. The interface
10754 is subject to radical change in the future.
10757 The purpose of @command{guix container} is to manipulate processes
10758 running within an isolated environment, commonly known as a
10759 ``container'', typically created by the @command{guix environment}
10760 (@pxref{Invoking guix environment}) and @command{guix system container}
10761 (@pxref{Invoking guix system}) commands.
10763 The general syntax is:
10766 guix container @var{action} @var{options}@dots{}
10769 @var{action} specifies the operation to perform with a container, and
10770 @var{options} specifies the context-specific arguments for the action.
10772 The following actions are available:
10776 Execute a command within the context of a running container.
10781 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10784 @var{pid} specifies the process ID of the running container.
10785 @var{program} specifies an executable file name within the root file
10786 system of the container. @var{arguments} are the additional options that
10787 will be passed to @var{program}.
10789 The following command launches an interactive login shell inside a
10790 Guix system container, started by @command{guix system container}, and whose
10791 process ID is 9001:
10794 guix container exec 9001 /run/current-system/profile/bin/bash --login
10797 Note that the @var{pid} cannot be the parent process of a container. It
10798 must be PID 1 of the container or one of its child processes.
10802 @node Invoking guix weather
10803 @section Invoking @command{guix weather}
10805 Occasionally you're grumpy because substitutes are lacking and you end
10806 up building packages by yourself (@pxref{Substitutes}). The
10807 @command{guix weather} command reports on substitute availability on the
10808 specified servers so you can have an idea of whether you'll be grumpy
10809 today. It can sometimes be useful info as a user, but it is primarily
10810 useful to people running @command{guix publish} (@pxref{Invoking guix
10813 @cindex statistics, for substitutes
10814 @cindex availability of substitutes
10815 @cindex substitute availability
10816 @cindex weather, substitute availability
10817 Here's a sample run:
10820 $ guix weather --substitute-urls=https://guix.example.org
10821 computing 5,872 package derivations for x86_64-linux...
10822 looking for 6,128 store items on https://guix.example.org..
10823 updating list of substitutes from 'https://guix.example.org'... 100.0%
10824 https://guix.example.org
10825 43.4% substitutes available (2,658 out of 6,128)
10826 7,032.5 MiB of nars (compressed)
10827 19,824.2 MiB on disk (uncompressed)
10828 0.030 seconds per request (182.9 seconds in total)
10829 33.5 requests per second
10831 9.8% (342 out of 3,470) of the missing items are queued
10833 x86_64-linux: 518 (59.7%)
10834 i686-linux: 221 (25.5%)
10835 aarch64-linux: 128 (14.8%)
10836 build rate: 23.41 builds per hour
10837 x86_64-linux: 11.16 builds per hour
10838 i686-linux: 6.03 builds per hour
10839 aarch64-linux: 6.41 builds per hour
10842 @cindex continuous integration, statistics
10843 As you can see, it reports the fraction of all the packages for which
10844 substitutes are available on the server---regardless of whether
10845 substitutes are enabled, and regardless of whether this server's signing
10846 key is authorized. It also reports the size of the compressed archives
10847 (``nars'') provided by the server, the size the corresponding store
10848 items occupy in the store (assuming deduplication is turned off), and
10849 the server's throughput. The second part gives continuous integration
10850 (CI) statistics, if the server supports it. In addition, using the
10851 @option{--coverage} option, @command{guix weather} can list ``important''
10852 package substitutes missing on the server (see below).
10854 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10855 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10856 challenge}, it ignores signatures on those substitutes, which is
10857 innocuous since the command only gathers statistics and cannot install
10860 The general syntax is:
10863 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10866 When @var{packages} is omitted, @command{guix weather} checks the availability
10867 of substitutes for @emph{all} the packages, or for those specified with
10868 @option{--manifest}; otherwise it only considers the specified packages. It
10869 is also possible to query specific system types with @option{--system}.
10870 @command{guix weather} exits with a non-zero code when the fraction of
10871 available substitutes is below 100%.
10873 The available options are listed below.
10876 @item --substitute-urls=@var{urls}
10877 @var{urls} is the space-separated list of substitute server URLs to
10878 query. When this option is omitted, the default set of substitute
10879 servers is queried.
10881 @item --system=@var{system}
10882 @itemx -s @var{system}
10883 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10884 option can be repeated, in which case @command{guix weather} will query
10885 substitutes for several system types.
10887 @item --manifest=@var{file}
10888 Instead of querying substitutes for all the packages, only ask for those
10889 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10890 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10893 This option can be repeated several times, in which case the manifests
10896 @item --coverage[=@var{count}]
10897 @itemx -c [@var{count}]
10898 Report on substitute coverage for packages: list packages with at least
10899 @var{count} dependents (zero by default) for which substitutes are
10900 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10901 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10902 @var{b} usually lacks substitutes as well. The result looks like this:
10905 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10906 computing 8,983 package derivations for x86_64-linux...
10907 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10908 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10909 @value{SUBSTITUTE-URL}
10910 64.7% substitutes available (6,047 out of 9,343)
10912 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10913 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10914 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10915 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10919 What this example shows is that @code{kcoreaddons} and presumably the 58
10920 packages that depend on it have no substitutes at @code{ci.guix.info};
10921 likewise for @code{qgpgme} and the 46 packages that depend on it.
10923 If you are a Guix developer, or if you are taking care of this build farm,
10924 you'll probably want to have a closer look at these packages: they may simply
10927 @item --display-missing
10928 Display the list of store items for which substitutes are missing.
10931 @node Invoking guix processes
10932 @section Invoking @command{guix processes}
10934 The @command{guix processes} command can be useful to developers and system
10935 administrators, especially on multi-user machines and on build farms: it lists
10936 the current sessions (connections to the daemon), as well as information about
10937 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10938 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10939 listed.}. Here's an example of the information it returns:
10942 $ sudo guix processes
10945 ClientCommand: guix environment --ad-hoc python
10949 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10953 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10954 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10955 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10956 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10957 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10958 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10959 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10962 In this example we see that @command{guix-daemon} has three clients:
10963 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10964 integration tool; their process identifier (PID) is given by the
10965 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10966 @command{guix-daemon} sub-process of this particular session.
10968 The @code{LockHeld} fields show which store items are currently locked by this
10969 session, which corresponds to store items being built or substituted (the
10970 @code{LockHeld} field is not displayed when @command{guix processes} is not
10971 running as root.) Last, by looking at the @code{ChildProcess} field, we
10972 understand that these three builds are being offloaded (@pxref{Daemon Offload
10975 The output is in Recutils format so we can use the handy @command{recsel}
10976 command to select sessions of interest (@pxref{Selection Expressions,,,
10977 recutils, GNU recutils manual}). As an example, the command shows the command
10978 line and PID of the client that triggered the build of a Perl package:
10981 $ sudo guix processes | \
10982 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10984 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10987 @node System Configuration
10988 @chapter System Configuration
10990 @cindex system configuration
10991 Guix System supports a consistent whole-system configuration
10992 mechanism. By that we mean that all aspects of the global system
10993 configuration---such as the available system services, timezone and
10994 locale settings, user accounts---are declared in a single place. Such
10995 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10997 One of the advantages of putting all the system configuration under the
10998 control of Guix is that it supports transactional system upgrades, and
10999 makes it possible to roll back to a previous system instantiation,
11000 should something go wrong with the new one (@pxref{Features}). Another
11001 advantage is that it makes it easy to replicate the exact same configuration
11002 across different machines, or at different points in time, without
11003 having to resort to additional administration tools layered on top of
11004 the own tools of the system.
11005 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11007 This section describes this mechanism. First we focus on the system
11008 administrator's viewpoint---explaining how the system is configured and
11009 instantiated. Then we show how this mechanism can be extended, for
11010 instance to support new system services.
11013 * Using the Configuration System:: Customizing your GNU system.
11014 * operating-system Reference:: Detail of operating-system declarations.
11015 * File Systems:: Configuring file system mounts.
11016 * Mapped Devices:: Block device extra processing.
11017 * User Accounts:: Specifying user accounts.
11018 * Keyboard Layout:: How the system interprets key strokes.
11019 * Locales:: Language and cultural convention settings.
11020 * Services:: Specifying system services.
11021 * Setuid Programs:: Programs running with root privileges.
11022 * X.509 Certificates:: Authenticating HTTPS servers.
11023 * Name Service Switch:: Configuring libc's name service switch.
11024 * Initial RAM Disk:: Linux-Libre bootstrapping.
11025 * Bootloader Configuration:: Configuring the boot loader.
11026 * Invoking guix system:: Instantiating a system configuration.
11027 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11028 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11029 * Defining Services:: Adding new service definitions.
11032 @node Using the Configuration System
11033 @section Using the Configuration System
11035 The operating system is configured by providing an
11036 @code{operating-system} declaration in a file that can then be passed to
11037 the @command{guix system} command (@pxref{Invoking guix system}). A
11038 simple setup, with the default system services, the default Linux-Libre
11039 kernel, initial RAM disk, and boot loader looks like this:
11041 @findex operating-system
11043 @include os-config-bare-bones.texi
11046 This example should be self-describing. Some of the fields defined
11047 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11048 Others, such as @code{packages} and @code{services}, can be omitted, in
11049 which case they get a default value.
11051 Below we discuss the effect of some of the most important fields
11052 (@pxref{operating-system Reference}, for details about all the available
11053 fields), and how to @dfn{instantiate} the operating system using
11054 @command{guix system}.
11056 @unnumberedsubsec Bootloader
11058 @cindex legacy boot, on Intel machines
11059 @cindex BIOS boot, on Intel machines
11062 The @code{bootloader} field describes the method that will be used to boot
11063 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11064 mode, as in the example above. However, more recent machines rely instead on
11065 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11066 the @code{bootloader} field should contain something along these lines:
11069 (bootloader-configuration
11070 (bootloader grub-efi-bootloader)
11071 (target "/boot/efi"))
11074 @xref{Bootloader Configuration}, for more information on the available
11075 configuration options.
11077 @unnumberedsubsec Globally-Visible Packages
11079 @vindex %base-packages
11080 The @code{packages} field lists packages that will be globally visible
11081 on the system, for all user accounts---i.e., in every user's @code{PATH}
11082 environment variable---in addition to the per-user profiles
11083 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11084 provides all the tools one would expect for basic user and administrator
11085 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11086 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11087 etc. The example above adds GNU@tie{}Screen to those,
11088 taken from the @code{(gnu packages screen)}
11089 module (@pxref{Package Modules}). The
11090 @code{(list package output)} syntax can be used to add a specific output
11094 (use-modules (gnu packages))
11095 (use-modules (gnu packages dns))
11099 (packages (cons (list bind "utils")
11103 @findex specification->package
11104 Referring to packages by variable name, like @code{bind} above, has
11105 the advantage of being unambiguous; it also allows typos and such to be
11106 diagnosed right away as ``unbound variables''. The downside is that one
11107 needs to know which module defines which package, and to augment the
11108 @code{use-package-modules} line accordingly. To avoid that, one can use
11109 the @code{specification->package} procedure of the @code{(gnu packages)}
11110 module, which returns the best package for a given name or name and
11114 (use-modules (gnu packages))
11118 (packages (append (map specification->package
11119 '("tcpdump" "htop" "gnupg@@2.0"))
11123 @unnumberedsubsec System Services
11126 @vindex %base-services
11127 The @code{services} field lists @dfn{system services} to be made
11128 available when the system starts (@pxref{Services}).
11129 The @code{operating-system} declaration above specifies that, in
11130 addition to the basic services, we want the OpenSSH secure shell
11131 daemon listening on port 2222 (@pxref{Networking Services,
11132 @code{openssh-service-type}}). Under the hood,
11133 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11134 right command-line options, possibly with supporting configuration files
11135 generated as needed (@pxref{Defining Services}).
11137 @cindex customization, of services
11138 @findex modify-services
11139 Occasionally, instead of using the base services as is, you will want to
11140 customize them. To do this, use @code{modify-services} (@pxref{Service
11141 Reference, @code{modify-services}}) to modify the list.
11143 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11144 (the console log-in) in the @code{%base-services} list (@pxref{Base
11145 Services, @code{%base-services}}). To do that, you can write the
11146 following in your operating system declaration:
11149 (define %my-services
11150 ;; My very own list of services.
11151 (modify-services %base-services
11152 (guix-service-type config =>
11153 (guix-configuration
11155 (use-substitutes? #f)
11156 (extra-options '("--gc-keep-derivations"))))
11157 (mingetty-service-type config =>
11158 (mingetty-configuration
11159 (inherit config)))))
11163 (services %my-services))
11166 This changes the configuration---i.e., the service parameters---of the
11167 @code{guix-service-type} instance, and that of all the
11168 @code{mingetty-service-type} instances in the @code{%base-services} list.
11169 Observe how this is accomplished: first, we arrange for the original
11170 configuration to be bound to the identifier @code{config} in the
11171 @var{body}, and then we write the @var{body} so that it evaluates to the
11172 desired configuration. In particular, notice how we use @code{inherit}
11173 to create a new configuration which has the same values as the old
11174 configuration, but with a few modifications.
11176 @cindex encrypted disk
11177 The configuration for a typical ``desktop'' usage, with an encrypted
11178 root partition, the X11 display
11179 server, GNOME and Xfce (users can choose which of these desktop
11180 environments to use at the log-in screen by pressing @kbd{F1}), network
11181 management, power management, and more, would look like this:
11184 @include os-config-desktop.texi
11187 A graphical system with a choice of lightweight window managers
11188 instead of full-blown desktop environments would look like this:
11191 @include os-config-lightweight-desktop.texi
11194 This example refers to the @file{/boot/efi} file system by its UUID,
11195 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11196 as returned by the @command{blkid} command.
11198 @xref{Desktop Services}, for the exact list of services provided by
11199 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11200 information about the @code{nss-certs} package that is used here.
11202 Again, @code{%desktop-services} is just a list of service objects. If
11203 you want to remove services from there, you can do so using the
11204 procedures for list filtering (@pxref{SRFI-1 Filtering and
11205 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
11206 following expression returns a list that contains all the services in
11207 @code{%desktop-services} minus the Avahi service:
11210 (remove (lambda (service)
11211 (eq? (service-kind service) avahi-service-type))
11215 @unnumberedsubsec Instantiating the System
11217 Assuming the @code{operating-system} declaration
11218 is stored in the @file{my-system-config.scm}
11219 file, the @command{guix system reconfigure my-system-config.scm} command
11220 instantiates that configuration, and makes it the default GRUB boot
11221 entry (@pxref{Invoking guix system}).
11223 The normal way to change the system configuration is by updating this
11224 file and re-running @command{guix system reconfigure}. One should never
11225 have to touch files in @file{/etc} or to run commands that modify the
11226 system state such as @command{useradd} or @command{grub-install}. In
11227 fact, you must avoid that since that would not only void your warranty
11228 but also prevent you from rolling back to previous versions of your
11229 system, should you ever need to.
11231 @cindex roll-back, of the operating system
11232 Speaking of roll-back, each time you run @command{guix system
11233 reconfigure}, a new @dfn{generation} of the system is created---without
11234 modifying or deleting previous generations. Old system generations get
11235 an entry in the bootloader boot menu, allowing you to boot them in case
11236 something went wrong with the latest generation. Reassuring, no? The
11237 @command{guix system list-generations} command lists the system
11238 generations available on disk. It is also possible to roll back the
11239 system via the commands @command{guix system roll-back} and
11240 @command{guix system switch-generation}.
11242 Although the @command{guix system reconfigure} command will not modify
11243 previous generations, you must take care when the current generation is not
11244 the latest (e.g., after invoking @command{guix system roll-back}), since
11245 the operation might overwrite a later generation (@pxref{Invoking guix
11248 @unnumberedsubsec The Programming Interface
11250 At the Scheme level, the bulk of an @code{operating-system} declaration
11251 is instantiated with the following monadic procedure (@pxref{The Store
11254 @deffn {Monadic Procedure} operating-system-derivation os
11255 Return a derivation that builds @var{os}, an @code{operating-system}
11256 object (@pxref{Derivations}).
11258 The output of the derivation is a single directory that refers to all
11259 the packages, configuration files, and other supporting files needed to
11260 instantiate @var{os}.
11263 This procedure is provided by the @code{(gnu system)} module. Along
11264 with @code{(gnu services)} (@pxref{Services}), this module contains the
11265 guts of Guix System. Make sure to visit it!
11268 @node operating-system Reference
11269 @section @code{operating-system} Reference
11271 This section summarizes all the options available in
11272 @code{operating-system} declarations (@pxref{Using the Configuration
11275 @deftp {Data Type} operating-system
11276 This is the data type representing an operating system configuration.
11277 By that, we mean all the global system configuration, not per-user
11278 configuration (@pxref{Using the Configuration System}).
11281 @item @code{kernel} (default: @code{linux-libre})
11282 The package object of the operating system kernel to use@footnote{Currently
11283 only the Linux-libre kernel is supported. In the future, it will be
11284 possible to use the GNU@tie{}Hurd.}.
11286 @item @code{kernel-loadable-modules} (default: '())
11287 A list of objects (usually packages) to collect loadable kernel modules
11288 from--e.g. @code{(list ddcci-driver-linux)}.
11290 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
11291 List of strings or gexps representing additional arguments to pass on
11292 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
11294 @item @code{bootloader}
11295 The system bootloader configuration object. @xref{Bootloader Configuration}.
11298 This is the label (a string) as it appears in the bootloader's menu entry.
11299 The default label includes the kernel name and version.
11301 @item @code{keyboard-layout} (default: @code{#f})
11302 This field specifies the keyboard layout to use in the console. It can be
11303 either @code{#f}, in which case the default keyboard layout is used (usually
11304 US English), or a @code{<keyboard-layout>} record.
11306 This keyboard layout is in effect as soon as the kernel has booted. For
11307 instance, it is the keyboard layout in effect when you type a passphrase if
11308 your root file system is on a @code{luks-device-mapping} mapped device
11309 (@pxref{Mapped Devices}).
11312 This does @emph{not} specify the keyboard layout used by the bootloader, nor
11313 that used by the graphical display server. @xref{Bootloader Configuration},
11314 for information on how to specify the bootloader's keyboard layout. @xref{X
11315 Window}, for information on how to specify the keyboard layout used by the X
11319 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
11321 @cindex initial RAM disk
11322 The list of Linux kernel modules that need to be available in the
11323 initial RAM disk. @xref{Initial RAM Disk}.
11325 @item @code{initrd} (default: @code{base-initrd})
11326 A procedure that returns an initial RAM disk for the Linux
11327 kernel. This field is provided to support low-level customization and
11328 should rarely be needed for casual use. @xref{Initial RAM Disk}.
11330 @item @code{firmware} (default: @code{%base-firmware})
11332 List of firmware packages loadable by the operating system kernel.
11334 The default includes firmware needed for Atheros- and Broadcom-based
11335 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11336 respectively). @xref{Hardware Considerations}, for more info on
11337 supported hardware.
11339 @item @code{host-name}
11342 @item @code{hosts-file}
11344 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11345 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11346 Reference Manual}). The default is a file with entries for
11347 @code{localhost} and @var{host-name}.
11349 @item @code{mapped-devices} (default: @code{'()})
11350 A list of mapped devices. @xref{Mapped Devices}.
11352 @item @code{file-systems}
11353 A list of file systems. @xref{File Systems}.
11355 @item @code{swap-devices} (default: @code{'()})
11356 @cindex swap devices
11357 A list of strings identifying devices or files to be used for ``swap
11358 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11359 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11360 It is possible to specify a swap file in a file system on a mapped
11361 device, provided that the necessary device mapping and file system are
11362 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11364 @item @code{users} (default: @code{%base-user-accounts})
11365 @itemx @code{groups} (default: @code{%base-groups})
11366 List of user accounts and groups. @xref{User Accounts}.
11368 If the @code{users} list lacks a user account with UID@tie{}0, a
11369 ``root'' account with UID@tie{}0 is automatically added.
11371 @item @code{skeletons} (default: @code{(default-skeletons)})
11372 A list target file name/file-like object tuples (@pxref{G-Expressions,
11373 file-like objects}). These are the skeleton files that will be added to
11374 the home directory of newly-created user accounts.
11376 For instance, a valid value may look like this:
11379 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11380 (".guile" ,(plain-file "guile"
11381 "(use-modules (ice-9 readline))
11382 (activate-readline)")))
11385 @item @code{issue} (default: @code{%default-issue})
11386 A string denoting the contents of the @file{/etc/issue} file, which is
11387 displayed when users log in on a text console.
11389 @item @code{packages} (default: @code{%base-packages})
11390 The set of packages installed in the global profile, which is accessible
11391 at @file{/run/current-system/profile}.
11393 The default set includes core utilities and it is good practice to
11394 install non-core utilities in user profiles (@pxref{Invoking guix
11397 @item @code{timezone}
11398 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11400 You can run the @command{tzselect} command to find out which timezone
11401 string corresponds to your region. Choosing an invalid timezone name
11402 causes @command{guix system} to fail.
11404 @item @code{locale} (default: @code{"en_US.utf8"})
11405 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11406 Library Reference Manual}). @xref{Locales}, for more information.
11408 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11409 The list of locale definitions to be compiled and that may be used at
11410 run time. @xref{Locales}.
11412 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11413 The list of GNU@tie{}libc packages whose locale data and tools are used
11414 to build the locale definitions. @xref{Locales}, for compatibility
11415 considerations that justify this option.
11417 @item @code{name-service-switch} (default: @code{%default-nss})
11418 Configuration of the libc name service switch (NSS)---a
11419 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11422 @item @code{services} (default: @code{%base-services})
11423 A list of service objects denoting system services. @xref{Services}.
11425 @cindex essential services
11426 @item @code{essential-services} (default: ...)
11427 The list of ``essential services''---i.e., things like instances of
11428 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11429 Reference}), which are derived from the operating system definition itself.
11430 As a user you should @emph{never} need to touch this field.
11432 @item @code{pam-services} (default: @code{(base-pam-services)})
11434 @cindex pluggable authentication modules
11435 Linux @dfn{pluggable authentication module} (PAM) services.
11436 @c FIXME: Add xref to PAM services section.
11438 @item @code{setuid-programs} (default: @code{%setuid-programs})
11439 List of string-valued G-expressions denoting setuid programs.
11440 @xref{Setuid Programs}.
11442 @item @code{sudoers-file} (default: @code{%sudoers-specification})
11443 @cindex sudoers file
11444 The contents of the @file{/etc/sudoers} file as a file-like object
11445 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11447 This file specifies which users can use the @command{sudo} command, what
11448 they are allowed to do, and what privileges they may gain. The default
11449 is that only @code{root} and members of the @code{wheel} group may use
11454 @deffn {Scheme Syntax} this-operating-system
11455 When used in the @emph{lexical scope} of an operating system field definition,
11456 this identifier resolves to the operating system being defined.
11458 The example below shows how to refer to the operating system being defined in
11459 the definition of the @code{label} field:
11462 (use-modules (gnu) (guix))
11466 (label (package-full-name
11467 (operating-system-kernel this-operating-system))))
11470 It is an error to refer to @code{this-operating-system} outside an operating
11477 @section File Systems
11479 The list of file systems to be mounted is specified in the
11480 @code{file-systems} field of the operating system declaration
11481 (@pxref{Using the Configuration System}). Each file system is declared
11482 using the @code{file-system} form, like this:
11486 (mount-point "/home")
11487 (device "/dev/sda3")
11491 As usual, some of the fields are mandatory---those shown in the example
11492 above---while others can be omitted. These are described below.
11494 @deftp {Data Type} file-system
11495 Objects of this type represent file systems to be mounted. They
11496 contain the following members:
11500 This is a string specifying the type of the file system---e.g.,
11503 @item @code{mount-point}
11504 This designates the place where the file system is to be mounted.
11506 @item @code{device}
11507 This names the ``source'' of the file system. It can be one of three
11508 things: a file system label, a file system UUID, or the name of a
11509 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11510 systems without having to hard-code their actual device
11511 name@footnote{Note that, while it is tempting to use
11512 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11513 result, this is not recommended: These special device nodes are created
11514 by the udev daemon and may be unavailable at the time the device is
11517 @findex file-system-label
11518 File system labels are created using the @code{file-system-label}
11519 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11520 plain strings. Here's an example of a file system referred to by its
11521 label, as shown by the @command{e2label} command:
11525 (mount-point "/home")
11527 (device (file-system-label "my-home")))
11531 UUIDs are converted from their string representation (as shown by the
11532 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11533 @code{uuid} form expects 16-byte UUIDs as defined in
11534 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11535 form of UUID used by the ext2 family of file systems and others, but it
11536 is different from ``UUIDs'' found in FAT file systems, for instance.},
11541 (mount-point "/home")
11543 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11546 When the source of a file system is a mapped device (@pxref{Mapped
11547 Devices}), its @code{device} field @emph{must} refer to the mapped
11548 device name---e.g., @file{"/dev/mapper/root-partition"}.
11549 This is required so that
11550 the system knows that mounting the file system depends on having the
11551 corresponding device mapping established.
11553 @item @code{flags} (default: @code{'()})
11554 This is a list of symbols denoting mount flags. Recognized flags
11555 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11556 access to special files), @code{no-suid} (ignore setuid and setgid
11557 bits), @code{no-atime} (do not update file access times),
11558 @code{strict-atime} (update file access time), @code{lazy-time} (only
11559 update time on the in-memory version of the file inode), and
11560 @code{no-exec} (disallow program execution).
11561 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
11562 Manual}, for more information on these flags.
11564 @item @code{options} (default: @code{#f})
11565 This is either @code{#f}, or a string denoting mount options passed to the
11566 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11567 Reference Manual}, for details and run @command{man 8 mount} for options for
11568 various file systems.
11570 @item @code{mount?} (default: @code{#t})
11571 This value indicates whether to automatically mount the file system when
11572 the system is brought up. When set to @code{#f}, the file system gets
11573 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11574 is not automatically mounted.
11576 @item @code{needed-for-boot?} (default: @code{#f})
11577 This Boolean value indicates whether the file system is needed when
11578 booting. If that is true, then the file system is mounted when the
11579 initial RAM disk (initrd) is loaded. This is always the case, for
11580 instance, for the root file system.
11582 @item @code{check?} (default: @code{#t})
11583 This Boolean indicates whether the file system needs to be checked for
11584 errors before being mounted.
11586 @item @code{create-mount-point?} (default: @code{#f})
11587 When true, the mount point is created if it does not exist yet.
11589 @item @code{dependencies} (default: @code{'()})
11590 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11591 representing file systems that must be mounted or mapped devices that
11592 must be opened before (and unmounted or closed after) this one.
11594 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11595 a dependency of @file{/sys/fs/cgroup/cpu} and
11596 @file{/sys/fs/cgroup/memory}.
11598 Another example is a file system that depends on a mapped device, for
11599 example for an encrypted partition (@pxref{Mapped Devices}).
11603 The @code{(gnu system file-systems)} exports the following useful
11606 @defvr {Scheme Variable} %base-file-systems
11607 These are essential file systems that are required on normal systems,
11608 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
11609 below.) Operating system declarations should always contain at least
11613 @defvr {Scheme Variable} %pseudo-terminal-file-system
11614 This is the file system to be mounted as @file{/dev/pts}. It supports
11615 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11616 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11617 Manual}). Pseudo-terminals are used by terminal emulators such as
11621 @defvr {Scheme Variable} %shared-memory-file-system
11622 This file system is mounted as @file{/dev/shm} and is used to support
11623 memory sharing across processes (@pxref{Memory-mapped I/O,
11624 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11627 @defvr {Scheme Variable} %immutable-store
11628 This file system performs a read-only ``bind mount'' of
11629 @file{/gnu/store}, making it read-only for all the users including
11630 @code{root}. This prevents against accidental modification by software
11631 running as @code{root} or by system administrators.
11633 The daemon itself is still able to write to the store: it remounts it
11634 read-write in its own ``name space.''
11637 @defvr {Scheme Variable} %binary-format-file-system
11638 The @code{binfmt_misc} file system, which allows handling of arbitrary
11639 executable file types to be delegated to user space. This requires the
11640 @code{binfmt.ko} kernel module to be loaded.
11643 @defvr {Scheme Variable} %fuse-control-file-system
11644 The @code{fusectl} file system, which allows unprivileged users to mount
11645 and unmount user-space FUSE file systems. This requires the
11646 @code{fuse.ko} kernel module to be loaded.
11649 @node Mapped Devices
11650 @section Mapped Devices
11652 @cindex device mapping
11653 @cindex mapped devices
11654 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11655 such as a hard disk partition, can be @dfn{mapped} into another device,
11656 usually in @code{/dev/mapper/},
11657 with additional processing over the data that flows through
11658 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11659 concept of a ``mapped device'' and that of a file system: both boil down
11660 to @emph{translating} input/output operations made on a file to
11661 operations on its backing store. Thus, the Hurd implements mapped
11662 devices, like file systems, using the generic @dfn{translator} mechanism
11663 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11664 typical example is encryption device mapping: all writes to the mapped
11665 device are encrypted, and all reads are deciphered, transparently.
11666 Guix extends this notion by considering any device or set of devices that
11667 are @dfn{transformed} in some way to create a new device; for instance,
11668 RAID devices are obtained by @dfn{assembling} several other devices, such
11669 as hard disks or partitions, into a new one that behaves as one partition.
11670 Other examples, not yet implemented, are LVM logical volumes.
11672 Mapped devices are declared using the @code{mapped-device} form,
11673 defined as follows; for examples, see below.
11675 @deftp {Data Type} mapped-device
11676 Objects of this type represent device mappings that will be made when
11677 the system boots up.
11681 This is either a string specifying the name of the block device to be mapped,
11682 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11683 need to be assembled for creating a new one.
11686 This string specifies the name of the resulting mapped device. For
11687 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11688 specifying @code{"my-partition"} leads to the creation of
11689 the @code{"/dev/mapper/my-partition"} device.
11690 For RAID devices of type @code{raid-device-mapping}, the full device name
11691 such as @code{"/dev/md0"} needs to be given.
11694 This must be a @code{mapped-device-kind} object, which specifies how
11695 @var{source} is mapped to @var{target}.
11699 @defvr {Scheme Variable} luks-device-mapping
11700 This defines LUKS block device encryption using the @command{cryptsetup}
11701 command from the package with the same name. It relies on the
11702 @code{dm-crypt} Linux kernel module.
11705 @defvr {Scheme Variable} raid-device-mapping
11706 This defines a RAID device, which is assembled using the @code{mdadm}
11707 command from the package with the same name. It requires a Linux kernel
11708 module for the appropriate RAID level to be loaded, such as @code{raid456}
11709 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11712 @cindex disk encryption
11714 The following example specifies a mapping from @file{/dev/sda3} to
11715 @file{/dev/mapper/home} using LUKS---the
11716 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11717 standard mechanism for disk encryption.
11718 The @file{/dev/mapper/home}
11719 device can then be used as the @code{device} of a @code{file-system}
11720 declaration (@pxref{File Systems}).
11724 (source "/dev/sda3")
11726 (type luks-device-mapping))
11729 Alternatively, to become independent of device numbering, one may obtain
11730 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11734 cryptsetup luksUUID /dev/sda3
11737 and use it as follows:
11741 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11743 (type luks-device-mapping))
11746 @cindex swap encryption
11747 It is also desirable to encrypt swap space, since swap space may contain
11748 sensitive data. One way to accomplish that is to use a swap file in a
11749 file system on a device mapped via LUKS encryption. In this way, the
11750 swap file is encrypted because the entire device is encrypted.
11751 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11753 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11754 may be declared as follows:
11758 (source (list "/dev/sda1" "/dev/sdb1"))
11759 (target "/dev/md0")
11760 (type raid-device-mapping))
11763 The @file{/dev/md0} device can then be used as the @code{device} of a
11764 @code{file-system} declaration (@pxref{File Systems}).
11765 Note that the RAID level need not be given; it is chosen during the
11766 initial creation and formatting of the RAID device and is determined
11767 automatically later.
11770 @node User Accounts
11771 @section User Accounts
11775 @cindex user accounts
11776 User accounts and groups are entirely managed through the
11777 @code{operating-system} declaration. They are specified with the
11778 @code{user-account} and @code{user-group} forms:
11784 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11785 "audio" ;sound card
11786 "video" ;video devices such as webcams
11787 "cdrom")) ;the good ol' CD-ROM
11788 (comment "Bob's sister")
11789 (home-directory "/home/alice"))
11792 When booting or upon completion of @command{guix system reconfigure},
11793 the system ensures that only the user accounts and groups specified in
11794 the @code{operating-system} declaration exist, and with the specified
11795 properties. Thus, account or group creations or modifications made by
11796 directly invoking commands such as @command{useradd} are lost upon
11797 reconfiguration or reboot. This ensures that the system remains exactly
11800 @deftp {Data Type} user-account
11801 Objects of this type represent user accounts. The following members may
11806 The name of the user account.
11810 This is the name (a string) or identifier (a number) of the user group
11811 this account belongs to.
11813 @item @code{supplementary-groups} (default: @code{'()})
11814 Optionally, this can be defined as a list of group names that this
11815 account belongs to.
11817 @item @code{uid} (default: @code{#f})
11818 This is the user ID for this account (a number), or @code{#f}. In the
11819 latter case, a number is automatically chosen by the system when the
11820 account is created.
11822 @item @code{comment} (default: @code{""})
11823 A comment about the account, such as the account owner's full name.
11825 @item @code{home-directory}
11826 This is the name of the home directory for the account.
11828 @item @code{create-home-directory?} (default: @code{#t})
11829 Indicates whether the home directory of this account should be created
11830 if it does not exist yet.
11832 @item @code{shell} (default: Bash)
11833 This is a G-expression denoting the file name of a program to be used as
11834 the shell (@pxref{G-Expressions}).
11836 @item @code{system?} (default: @code{#f})
11837 This Boolean value indicates whether the account is a ``system''
11838 account. System accounts are sometimes treated specially; for instance,
11839 graphical login managers do not list them.
11841 @anchor{user-account-password}
11842 @cindex password, for user accounts
11843 @item @code{password} (default: @code{#f})
11844 You would normally leave this field to @code{#f}, initialize user
11845 passwords as @code{root} with the @command{passwd} command, and then let
11846 users change it with @command{passwd}. Passwords set with
11847 @command{passwd} are of course preserved across reboot and
11850 If you @emph{do} want to set an initial password for an account, then
11851 this field must contain the encrypted password, as a string. You can use the
11852 @code{crypt} procedure for this purpose:
11859 ;; Specify a SHA-512-hashed initial password.
11860 (password (crypt "InitialPassword!" "$6$abc")))
11864 The hash of this initial password will be available in a file in
11865 @file{/gnu/store}, readable by all the users, so this method must be used with
11869 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11870 more information on password encryption, and @ref{Encryption,,, guile, GNU
11871 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11877 User group declarations are even simpler:
11880 (user-group (name "students"))
11883 @deftp {Data Type} user-group
11884 This type is for, well, user groups. There are just a few fields:
11888 The name of the group.
11890 @item @code{id} (default: @code{#f})
11891 The group identifier (a number). If @code{#f}, a new number is
11892 automatically allocated when the group is created.
11894 @item @code{system?} (default: @code{#f})
11895 This Boolean value indicates whether the group is a ``system'' group.
11896 System groups have low numerical IDs.
11898 @item @code{password} (default: @code{#f})
11899 What, user groups can have a password? Well, apparently yes. Unless
11900 @code{#f}, this field specifies the password of the group.
11905 For convenience, a variable lists all the basic user groups one may
11908 @defvr {Scheme Variable} %base-groups
11909 This is the list of basic user groups that users and/or packages expect
11910 to be present on the system. This includes groups such as ``root'',
11911 ``wheel'', and ``users'', as well as groups used to control access to
11912 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11915 @defvr {Scheme Variable} %base-user-accounts
11916 This is the list of basic system accounts that programs may expect to
11917 find on a GNU/Linux system, such as the ``nobody'' account.
11919 Note that the ``root'' account is not included here. It is a
11920 special-case and is automatically added whether or not it is specified.
11923 @node Keyboard Layout
11924 @section Keyboard Layout
11926 @cindex keyboard layout
11928 To specify what each key of your keyboard does, you need to tell the operating
11929 system what @dfn{keyboard layout} you want to use. The default, when nothing
11930 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11931 However, German speakers will usually prefer the German QWERTZ layout, French
11932 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11933 or bépo, and they might even want to further customize the effect of some of
11934 the keys. This section explains how to get that done.
11936 @cindex keyboard layout, definition
11937 There are three components that will want to know about your keyboard layout:
11941 The @emph{bootloader} may want to know what keyboard layout you want to use
11942 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11943 you want, for instance, to make sure that you can type the passphrase of your
11944 encrypted root partition using the right layout.
11947 The @emph{operating system kernel}, Linux, will need that so that the console
11948 is properly configured (@pxref{operating-system Reference,
11949 @code{keyboard-layout}}).
11952 The @emph{graphical display server}, usually Xorg, also has its own idea of
11953 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11956 Guix allows you to configure all three separately but, fortunately, it allows
11957 you to share the same keyboard layout for all three components.
11959 @cindex XKB, keyboard layouts
11960 Keyboard layouts are represented by records created by the
11961 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11962 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11963 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11964 optional variant name, an optional keyboard model name, and a possibly empty
11965 list of additional options. In most cases the layout name is all you care
11966 about. Here are a few example:
11969 ;; The German QWERTZ layout. Here we assume a standard
11970 ;; "pc105" keyboard model.
11971 (keyboard-layout "de")
11973 ;; The bépo variant of the French layout.
11974 (keyboard-layout "fr" "bepo")
11976 ;; The Catalan layout.
11977 (keyboard-layout "es" "cat")
11979 ;; Arabic layout with "Alt-Shift" to switch to US layout.
11980 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
11982 ;; The Latin American Spanish layout. In addition, the
11983 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11984 ;; and the "Menu" key is used as a "Compose" key to enter
11985 ;; accented letters.
11986 (keyboard-layout "latam"
11987 #:options '("ctrl:nocaps" "compose:menu"))
11989 ;; The Russian layout for a ThinkPad keyboard.
11990 (keyboard-layout "ru" #:model "thinkpad")
11992 ;; The "US international" layout, which is the US layout plus
11993 ;; dead keys to enter accented characters. This is for an
11994 ;; Apple MacBook keyboard.
11995 (keyboard-layout "us" "intl" #:model "macbook78")
11998 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11999 for a complete list of supported layouts, variants, and models.
12001 @cindex keyboard layout, configuration
12002 Let's say you want your system to use the Turkish keyboard layout throughout
12003 your system---bootloader, console, and Xorg. Here's what your system
12004 configuration would look like:
12006 @findex set-xorg-configuration
12008 ;; Using the Turkish layout for the bootloader, the console,
12013 (keyboard-layout (keyboard-layout "tr")) ;for the console
12014 (bootloader (bootloader-configuration
12015 (bootloader grub-efi-bootloader)
12016 (target "/boot/efi")
12017 (keyboard-layout keyboard-layout))) ;for GRUB
12018 (services (cons (set-xorg-configuration
12019 (xorg-configuration ;for Xorg
12020 (keyboard-layout keyboard-layout)))
12021 %desktop-services)))
12024 In the example above, for GRUB and for Xorg, we just refer to the
12025 @code{keyboard-layout} field defined above, but we could just as well refer to
12026 a different layout. The @code{set-xorg-configuration} procedure communicates
12027 the desired Xorg configuration to the graphical log-in manager, by default
12030 We've discussed how to specify the @emph{default} keyboard layout of your
12031 system when it starts, but you can also adjust it at run time:
12035 If you're using GNOME, its settings panel has a ``Region & Language'' entry
12036 where you can select one or more keyboard layouts.
12039 Under Xorg, the @command{setxkbmap} command (from the same-named package)
12040 allows you to change the current layout. For example, this is how you would
12041 change the layout to US Dvorak:
12044 setxkbmap us dvorak
12048 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
12049 console. However, note that @code{loadkeys} does @emph{not} use the XKB
12050 keyboard layout categorization described above. The command below loads the
12051 French bépo layout:
12062 A @dfn{locale} defines cultural conventions for a particular language
12063 and region of the world (@pxref{Locales,,, libc, The GNU C Library
12064 Reference Manual}). Each locale has a name that typically has the form
12065 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
12066 @code{fr_LU.utf8} designates the locale for the French language, with
12067 cultural conventions from Luxembourg, and using the UTF-8 encoding.
12069 @cindex locale definition
12070 Usually, you will want to specify the default locale for the machine
12071 using the @code{locale} field of the @code{operating-system} declaration
12072 (@pxref{operating-system Reference, @code{locale}}).
12074 The selected locale is automatically added to the @dfn{locale
12075 definitions} known to the system if needed, with its codeset inferred
12076 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
12077 @code{UTF-8} codeset. Additional locale definitions can be specified in
12078 the @code{locale-definitions} slot of @code{operating-system}---this is
12079 useful, for instance, if the codeset could not be inferred from the
12080 locale name. The default set of locale definitions includes some widely
12081 used locales, but not all the available locales, in order to save space.
12083 For instance, to add the North Frisian locale for Germany, the value of
12087 (cons (locale-definition
12088 (name "fy_DE.utf8") (source "fy_DE"))
12089 %default-locale-definitions)
12092 Likewise, to save space, one might want @code{locale-definitions} to
12093 list only the locales that are actually used, as in:
12096 (list (locale-definition
12097 (name "ja_JP.eucjp") (source "ja_JP")
12098 (charset "EUC-JP")))
12102 The compiled locale definitions are available at
12103 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
12104 version, which is the default location where the GNU@tie{}libc provided
12105 by Guix looks for locale data. This can be overridden using the
12106 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
12107 @code{LOCPATH} and locale packages}).
12109 The @code{locale-definition} form is provided by the @code{(gnu system
12110 locale)} module. Details are given below.
12112 @deftp {Data Type} locale-definition
12113 This is the data type of a locale definition.
12118 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
12119 Reference Manual}, for more information on locale names.
12121 @item @code{source}
12122 The name of the source for that locale. This is typically the
12123 @code{@var{language}_@var{territory}} part of the locale name.
12125 @item @code{charset} (default: @code{"UTF-8"})
12126 The ``character set'' or ``code set'' for that locale,
12127 @uref{https://www.iana.org/assignments/character-sets, as defined by
12133 @defvr {Scheme Variable} %default-locale-definitions
12134 A list of commonly used UTF-8 locales, used as the default
12135 value of the @code{locale-definitions} field of @code{operating-system}
12138 @cindex locale name
12139 @cindex normalized codeset in locale names
12140 These locale definitions use the @dfn{normalized codeset} for the part
12141 that follows the dot in the name (@pxref{Using gettextized software,
12142 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
12143 instance it has @code{uk_UA.utf8} but @emph{not}, say,
12144 @code{uk_UA.UTF-8}.
12147 @subsection Locale Data Compatibility Considerations
12149 @cindex incompatibility, of locale data
12150 @code{operating-system} declarations provide a @code{locale-libcs} field
12151 to specify the GNU@tie{}libc packages that are used to compile locale
12152 declarations (@pxref{operating-system Reference}). ``Why would I
12153 care?'', you may ask. Well, it turns out that the binary format of
12154 locale data is occasionally incompatible from one libc version to
12157 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
12158 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
12159 For instance, a program linked against libc version 2.21 is unable to
12160 read locale data produced with libc 2.22; worse, that program
12161 @emph{aborts} instead of simply ignoring the incompatible locale
12162 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
12163 the incompatible locale data, which is already an improvement.}.
12164 Similarly, a program linked against libc 2.22 can read most, but not
12165 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
12166 data is incompatible); thus calls to @code{setlocale} may fail, but
12167 programs will not abort.
12169 The ``problem'' with Guix is that users have a lot of freedom: They can
12170 choose whether and when to upgrade software in their profiles, and might
12171 be using a libc version different from the one the system administrator
12172 used to build the system-wide locale data.
12174 Fortunately, unprivileged users can also install their own locale data
12175 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
12176 @code{GUIX_LOCPATH} and locale packages}).
12178 Still, it is best if the system-wide locale data at
12179 @file{/run/current-system/locale} is built for all the libc versions
12180 actually in use on the system, so that all the programs can access
12181 it---this is especially crucial on a multi-user system. To do that, the
12182 administrator can specify several libc packages in the
12183 @code{locale-libcs} field of @code{operating-system}:
12186 (use-package-modules base)
12190 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
12193 This example would lead to a system containing locale definitions for
12194 both libc 2.21 and the current version of libc in
12195 @file{/run/current-system/locale}.
12201 @cindex system services
12202 An important part of preparing an @code{operating-system} declaration is
12203 listing @dfn{system services} and their configuration (@pxref{Using the
12204 Configuration System}). System services are typically daemons launched
12205 when the system boots, or other actions needed at that time---e.g.,
12206 configuring network access.
12208 Guix has a broad definition of ``service'' (@pxref{Service
12209 Composition}), but many services are managed by the GNU@tie{}Shepherd
12210 (@pxref{Shepherd Services}). On a running system, the @command{herd}
12211 command allows you to list the available services, show their status,
12212 start and stop them, or do other specific operations (@pxref{Jump
12213 Start,,, shepherd, The GNU Shepherd Manual}). For example:
12219 The above command, run as @code{root}, lists the currently defined
12220 services. The @command{herd doc} command shows a synopsis of the given
12221 service and its associated actions:
12225 Run libc's name service cache daemon (nscd).
12227 # herd doc nscd action invalidate
12228 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
12231 The @command{start}, @command{stop}, and @command{restart} sub-commands
12232 have the effect you would expect. For instance, the commands below stop
12233 the nscd service and restart the Xorg display server:
12237 Service nscd has been stopped.
12238 # herd restart xorg-server
12239 Service xorg-server has been stopped.
12240 Service xorg-server has been started.
12243 The following sections document the available services, starting with
12244 the core services, that may be used in an @code{operating-system}
12248 * Base Services:: Essential system services.
12249 * Scheduled Job Execution:: The mcron service.
12250 * Log Rotation:: The rottlog service.
12251 * Networking Services:: Network setup, SSH daemon, etc.
12252 * X Window:: Graphical display.
12253 * Printing Services:: Local and remote printer support.
12254 * Desktop Services:: D-Bus and desktop services.
12255 * Sound Services:: ALSA and Pulseaudio services.
12256 * Database Services:: SQL databases, key-value stores, etc.
12257 * Mail Services:: IMAP, POP3, SMTP, and all that.
12258 * Messaging Services:: Messaging services.
12259 * Telephony Services:: Telephony services.
12260 * Monitoring Services:: Monitoring services.
12261 * Kerberos Services:: Kerberos services.
12262 * LDAP Services:: LDAP services.
12263 * Web Services:: Web servers.
12264 * Certificate Services:: TLS certificates via Let's Encrypt.
12265 * DNS Services:: DNS daemons.
12266 * VPN Services:: VPN daemons.
12267 * Network File System:: NFS related services.
12268 * Continuous Integration:: The Cuirass service.
12269 * Power Management Services:: Extending battery life.
12270 * Audio Services:: The MPD.
12271 * Virtualization Services:: Virtualization services.
12272 * Version Control Services:: Providing remote access to Git repositories.
12273 * Game Services:: Game servers.
12274 * PAM Mount Service:: Service to mount volumes when logging in.
12275 * Guix Services:: Services relating specifically to Guix.
12276 * Linux Services:: Services tied to the Linux kernel.
12277 * Miscellaneous Services:: Other services.
12280 @node Base Services
12281 @subsection Base Services
12283 The @code{(gnu services base)} module provides definitions for the basic
12284 services that one expects from the system. The services exported by
12285 this module are listed below.
12287 @defvr {Scheme Variable} %base-services
12288 This variable contains a list of basic services (@pxref{Service Types
12289 and Services}, for more information on service objects) one would
12290 expect from the system: a login service (mingetty) on each tty, syslogd,
12291 the libc name service cache daemon (nscd), the udev device manager, and
12294 This is the default value of the @code{services} field of
12295 @code{operating-system} declarations. Usually, when customizing a
12296 system, you will want to append services to @code{%base-services}, like
12300 (append (list (service avahi-service-type)
12301 (service openssh-service-type))
12306 @defvr {Scheme Variable} special-files-service-type
12307 This is the service that sets up ``special files'' such as
12308 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
12310 The value associated with @code{special-files-service-type} services
12311 must be a list of tuples where the first element is the ``special file''
12312 and the second element is its target. By default it is:
12314 @cindex @file{/bin/sh}
12315 @cindex @file{sh}, in @file{/bin}
12317 `(("/bin/sh" ,(file-append bash "/bin/sh")))
12320 @cindex @file{/usr/bin/env}
12321 @cindex @file{env}, in @file{/usr/bin}
12322 If you want to add, say, @code{/usr/bin/env} to your system, you can
12326 `(("/bin/sh" ,(file-append bash "/bin/sh"))
12327 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
12330 Since this is part of @code{%base-services}, you can use
12331 @code{modify-services} to customize the set of special files
12332 (@pxref{Service Reference, @code{modify-services}}). But the simple way
12333 to add a special file is @i{via} the @code{extra-special-file} procedure
12337 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
12338 Use @var{target} as the ``special file'' @var{file}.
12340 For example, adding the following lines to the @code{services} field of
12341 your operating system declaration leads to a @file{/usr/bin/env}
12345 (extra-special-file "/usr/bin/env"
12346 (file-append coreutils "/bin/env"))
12350 @deffn {Scheme Procedure} host-name-service @var{name}
12351 Return a service that sets the host name to @var{name}.
12354 @defvr {Scheme Variable} console-font-service-type
12355 Install the given fonts on the specified ttys (fonts are per
12356 virtual console on the kernel Linux). The value of this service is a list of
12357 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
12358 package or any valid argument to @command{setfont}, as in this example:
12361 `(("tty1" . "LatGrkCyr-8x16")
12362 ("tty2" . ,(file-append
12364 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
12365 ("tty3" . ,(file-append
12367 "/share/consolefonts/ter-132n"))) ; for HDPI
12371 @deffn {Scheme Procedure} login-service @var{config}
12372 Return a service to run login according to @var{config}, a
12373 @code{<login-configuration>} object, which specifies the message of the day,
12374 among other things.
12377 @deftp {Data Type} login-configuration
12378 This is the data type representing the configuration of login.
12383 @cindex message of the day
12384 A file-like object containing the ``message of the day''.
12386 @item @code{allow-empty-passwords?} (default: @code{#t})
12387 Allow empty passwords by default so that first-time users can log in when
12388 the 'root' account has just been created.
12393 @deffn {Scheme Procedure} mingetty-service @var{config}
12394 Return a service to run mingetty according to @var{config}, a
12395 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12399 @deftp {Data Type} mingetty-configuration
12400 This is the data type representing the configuration of Mingetty, which
12401 provides the default implementation of virtual console log-in.
12406 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12408 @item @code{auto-login} (default: @code{#f})
12409 When true, this field must be a string denoting the user name under
12410 which the system automatically logs in. When it is @code{#f}, a
12411 user name and password must be entered to log in.
12413 @item @code{login-program} (default: @code{#f})
12414 This must be either @code{#f}, in which case the default log-in program
12415 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12416 the name of the log-in program.
12418 @item @code{login-pause?} (default: @code{#f})
12419 When set to @code{#t} in conjunction with @var{auto-login}, the user
12420 will have to press a key before the log-in shell is launched.
12422 @item @code{mingetty} (default: @var{mingetty})
12423 The Mingetty package to use.
12428 @deffn {Scheme Procedure} agetty-service @var{config}
12429 Return a service to run agetty according to @var{config}, an
12430 @code{<agetty-configuration>} object, which specifies the tty to run,
12431 among other things.
12434 @deftp {Data Type} agetty-configuration
12435 This is the data type representing the configuration of agetty, which
12436 implements virtual and serial console log-in. See the @code{agetty(8)}
12437 man page for more information.
12442 The name of the console this agetty runs on, as a string---e.g.,
12443 @code{"ttyS0"}. This argument is optional, it will default to
12444 a reasonable default serial port used by the kernel Linux.
12446 For this, if there is a value for an option @code{agetty.tty} in the kernel
12447 command line, agetty will extract the device name of the serial port
12448 from it and use that.
12450 If not and if there is a value for an option @code{console} with a tty in
12451 the Linux command line, agetty will extract the device name of the
12452 serial port from it and use that.
12454 In both cases, agetty will leave the other serial device settings
12455 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12458 @item @code{baud-rate} (default: @code{#f})
12459 A string containing a comma-separated list of one or more baud rates, in
12462 @item @code{term} (default: @code{#f})
12463 A string containing the value used for the @code{TERM} environment
12466 @item @code{eight-bits?} (default: @code{#f})
12467 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12470 @item @code{auto-login} (default: @code{#f})
12471 When passed a login name, as a string, the specified user will be logged
12472 in automatically without prompting for their login name or password.
12474 @item @code{no-reset?} (default: @code{#f})
12475 When @code{#t}, don't reset terminal cflags (control modes).
12477 @item @code{host} (default: @code{#f})
12478 This accepts a string containing the ``login_host'', which will be written
12479 into the @file{/var/run/utmpx} file.
12481 @item @code{remote?} (default: @code{#f})
12482 When set to @code{#t} in conjunction with @var{host}, this will add an
12483 @code{-r} fakehost option to the command line of the login program
12484 specified in @var{login-program}.
12486 @item @code{flow-control?} (default: @code{#f})
12487 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12489 @item @code{no-issue?} (default: @code{#f})
12490 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12491 not be displayed before presenting the login prompt.
12493 @item @code{init-string} (default: @code{#f})
12494 This accepts a string that will be sent to the tty or modem before
12495 sending anything else. It can be used to initialize a modem.
12497 @item @code{no-clear?} (default: @code{#f})
12498 When set to @code{#t}, agetty will not clear the screen before showing
12501 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12502 This must be either a gexp denoting the name of a log-in program, or
12503 unset, in which case the default value is the @command{login} from the
12506 @item @code{local-line} (default: @code{#f})
12507 Control the CLOCAL line flag. This accepts one of three symbols as
12508 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12509 the default value chosen by agetty is @code{'auto}.
12511 @item @code{extract-baud?} (default: @code{#f})
12512 When set to @code{#t}, instruct agetty to try to extract the baud rate
12513 from the status messages produced by certain types of modems.
12515 @item @code{skip-login?} (default: @code{#f})
12516 When set to @code{#t}, do not prompt the user for a login name. This
12517 can be used with @var{login-program} field to use non-standard login
12520 @item @code{no-newline?} (default: @code{#f})
12521 When set to @code{#t}, do not print a newline before printing the
12522 @file{/etc/issue} file.
12524 @c Is this dangerous only when used with login-program, or always?
12525 @item @code{login-options} (default: @code{#f})
12526 This option accepts a string containing options that are passed to the
12527 login program. When used with the @var{login-program}, be aware that a
12528 malicious user could try to enter a login name containing embedded
12529 options that could be parsed by the login program.
12531 @item @code{login-pause} (default: @code{#f})
12532 When set to @code{#t}, wait for any key before showing the login prompt.
12533 This can be used in conjunction with @var{auto-login} to save memory by
12534 lazily spawning shells.
12536 @item @code{chroot} (default: @code{#f})
12537 Change root to the specified directory. This option accepts a directory
12540 @item @code{hangup?} (default: @code{#f})
12541 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12542 specified terminal.
12544 @item @code{keep-baud?} (default: @code{#f})
12545 When set to @code{#t}, try to keep the existing baud rate. The baud
12546 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12549 @item @code{timeout} (default: @code{#f})
12550 When set to an integer value, terminate if no user name could be read
12551 within @var{timeout} seconds.
12553 @item @code{detect-case?} (default: @code{#f})
12554 When set to @code{#t}, turn on support for detecting an uppercase-only
12555 terminal. This setting will detect a login name containing only
12556 uppercase letters as indicating an uppercase-only terminal and turn on
12557 some upper-to-lower case conversions. Note that this will not support
12558 Unicode characters.
12560 @item @code{wait-cr?} (default: @code{#f})
12561 When set to @code{#t}, wait for the user or modem to send a
12562 carriage-return or linefeed character before displaying
12563 @file{/etc/issue} or login prompt. This is typically used with the
12564 @var{init-string} option.
12566 @item @code{no-hints?} (default: @code{#f})
12567 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12570 @item @code{no-hostname?} (default: @code{#f})
12571 By default, the hostname is printed. When this option is set to
12572 @code{#t}, no hostname will be shown at all.
12574 @item @code{long-hostname?} (default: @code{#f})
12575 By default, the hostname is only printed until the first dot. When this
12576 option is set to @code{#t}, the fully qualified hostname by
12577 @code{gethostname} or @code{getaddrinfo} is shown.
12579 @item @code{erase-characters} (default: @code{#f})
12580 This option accepts a string of additional characters that should be
12581 interpreted as backspace when the user types their login name.
12583 @item @code{kill-characters} (default: @code{#f})
12584 This option accepts a string that should be interpreted to mean ``ignore
12585 all previous characters'' (also called a ``kill'' character) when the user
12586 types their login name.
12588 @item @code{chdir} (default: @code{#f})
12589 This option accepts, as a string, a directory path that will be changed
12592 @item @code{delay} (default: @code{#f})
12593 This options accepts, as an integer, the number of seconds to sleep
12594 before opening the tty and displaying the login prompt.
12596 @item @code{nice} (default: @code{#f})
12597 This option accepts, as an integer, the nice value with which to run the
12598 @command{login} program.
12600 @item @code{extra-options} (default: @code{'()})
12601 This option provides an ``escape hatch'' for the user to provide arbitrary
12602 command-line arguments to @command{agetty} as a list of strings.
12607 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12608 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12609 according to @var{config}, a @code{<kmscon-configuration>} object, which
12610 specifies the tty to run, among other things.
12613 @deftp {Data Type} kmscon-configuration
12614 This is the data type representing the configuration of Kmscon, which
12615 implements virtual console log-in.
12619 @item @code{virtual-terminal}
12620 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12622 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12623 A gexp denoting the name of the log-in program. The default log-in program is
12624 @command{login} from the Shadow tool suite.
12626 @item @code{login-arguments} (default: @code{'("-p")})
12627 A list of arguments to pass to @command{login}.
12629 @item @code{auto-login} (default: @code{#f})
12630 When passed a login name, as a string, the specified user will be logged
12631 in automatically without prompting for their login name or password.
12633 @item @code{hardware-acceleration?} (default: #f)
12634 Whether to use hardware acceleration.
12636 @item @code{kmscon} (default: @var{kmscon})
12637 The Kmscon package to use.
12642 @cindex name service cache daemon
12644 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12645 [#:name-services '()]
12646 Return a service that runs the libc name service cache daemon (nscd) with the
12647 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12648 Service Switch}, for an example.
12650 For convenience, the Shepherd service for nscd provides the following actions:
12654 @cindex cache invalidation, nscd
12655 @cindex nscd, cache invalidation
12656 This invalidate the given cache. For instance, running:
12659 herd invalidate nscd hosts
12663 invalidates the host name lookup cache of nscd.
12666 Running @command{herd statistics nscd} displays information about nscd usage
12672 @defvr {Scheme Variable} %nscd-default-configuration
12673 This is the default @code{<nscd-configuration>} value (see below) used
12674 by @code{nscd-service}. It uses the caches defined by
12675 @code{%nscd-default-caches}; see below.
12678 @deftp {Data Type} nscd-configuration
12679 This is the data type representing the name service cache daemon (nscd)
12684 @item @code{name-services} (default: @code{'()})
12685 List of packages denoting @dfn{name services} that must be visible to
12686 the nscd---e.g., @code{(list @var{nss-mdns})}.
12688 @item @code{glibc} (default: @var{glibc})
12689 Package object denoting the GNU C Library providing the @command{nscd}
12692 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12693 Name of the nscd log file. This is where debugging output goes when
12694 @code{debug-level} is strictly positive.
12696 @item @code{debug-level} (default: @code{0})
12697 Integer denoting the debugging levels. Higher numbers mean that more
12698 debugging output is logged.
12700 @item @code{caches} (default: @code{%nscd-default-caches})
12701 List of @code{<nscd-cache>} objects denoting things to be cached; see
12707 @deftp {Data Type} nscd-cache
12708 Data type representing a cache database of nscd and its parameters.
12712 @item @code{database}
12713 This is a symbol representing the name of the database to be cached.
12714 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12715 @code{services}, which designate the corresponding NSS database
12716 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12718 @item @code{positive-time-to-live}
12719 @itemx @code{negative-time-to-live} (default: @code{20})
12720 A number representing the number of seconds during which a positive or
12721 negative lookup result remains in cache.
12723 @item @code{check-files?} (default: @code{#t})
12724 Whether to check for updates of the files corresponding to
12727 For instance, when @var{database} is @code{hosts}, setting this flag
12728 instructs nscd to check for updates in @file{/etc/hosts} and to take
12731 @item @code{persistent?} (default: @code{#t})
12732 Whether the cache should be stored persistently on disk.
12734 @item @code{shared?} (default: @code{#t})
12735 Whether the cache should be shared among users.
12737 @item @code{max-database-size} (default: 32@tie{}MiB)
12738 Maximum size in bytes of the database cache.
12740 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12741 @c settings, so leave them out.
12746 @defvr {Scheme Variable} %nscd-default-caches
12747 List of @code{<nscd-cache>} objects used by default by
12748 @code{nscd-configuration} (see above).
12750 It enables persistent and aggressive caching of service and host name
12751 lookups. The latter provides better host name lookup performance,
12752 resilience in the face of unreliable name servers, and also better
12753 privacy---often the result of host name lookups is in local cache, so
12754 external name servers do not even need to be queried.
12757 @anchor{syslog-configuration-type}
12760 @deftp {Data Type} syslog-configuration
12761 This data type represents the configuration of the syslog daemon.
12764 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12765 The syslog daemon to use.
12767 @item @code{config-file} (default: @code{%default-syslog.conf})
12768 The syslog configuration file to use.
12773 @anchor{syslog-service}
12775 @deffn {Scheme Procedure} syslog-service @var{config}
12776 Return a service that runs a syslog daemon according to @var{config}.
12778 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12779 information on the configuration file syntax.
12782 @defvr {Scheme Variable} guix-service-type
12783 This is the type of the service that runs the build daemon,
12784 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12785 @code{guix-configuration} record as described below.
12788 @anchor{guix-configuration-type}
12789 @deftp {Data Type} guix-configuration
12790 This data type represents the configuration of the Guix build daemon.
12791 @xref{Invoking guix-daemon}, for more information.
12794 @item @code{guix} (default: @var{guix})
12795 The Guix package to use.
12797 @item @code{build-group} (default: @code{"guixbuild"})
12798 Name of the group for build user accounts.
12800 @item @code{build-accounts} (default: @code{10})
12801 Number of build user accounts to create.
12803 @item @code{authorize-key?} (default: @code{#t})
12804 @cindex substitutes, authorization thereof
12805 Whether to authorize the substitute keys listed in
12806 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12807 (@pxref{Substitutes}).
12809 @vindex %default-authorized-guix-keys
12810 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12811 The list of authorized key files for archive imports, as a list of
12812 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12813 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12815 @item @code{use-substitutes?} (default: @code{#t})
12816 Whether to use substitutes.
12818 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12819 The list of URLs where to look for substitutes by default.
12821 @item @code{max-silent-time} (default: @code{0})
12822 @itemx @code{timeout} (default: @code{0})
12823 The number of seconds of silence and the number of seconds of activity,
12824 respectively, after which a build process times out. A value of zero
12825 disables the timeout.
12827 @item @code{log-compression} (default: @code{'bzip2})
12828 The type of compression used for build logs---one of @code{gzip},
12829 @code{bzip2}, or @code{none}.
12831 @item @code{extra-options} (default: @code{'()})
12832 List of extra command-line options for @command{guix-daemon}.
12834 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12835 File where @command{guix-daemon}'s standard output and standard error
12838 @cindex HTTP proxy, for @code{guix-daemon}
12839 @cindex proxy, for @code{guix-daemon} HTTP access
12840 @item @code{http-proxy} (default: @code{#f})
12841 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
12842 derivations and substitutes.
12844 It is also possible to change the daemon's proxy at run time through the
12845 @code{set-http-proxy} action, which restarts it:
12848 herd set-http-proxy guix-daemon http://localhost:8118
12851 To clear the proxy settings, run:
12854 herd set-http-proxy guix-daemon
12857 @item @code{tmpdir} (default: @code{#f})
12858 A directory path where the @command{guix-daemon} will perform builds.
12863 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12864 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12865 udev rules can be provided as a list of files through the @var{rules}
12866 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
12867 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
12868 creation of such rule files.
12870 The @command{herd rules udev} command, as root, returns the name of the
12871 directory containing all the active udev rules.
12874 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12875 Return a udev-rule file named @var{file-name} containing the rules
12876 defined by the @var{contents} literal.
12878 In the following example, a rule for a USB device is defined to be
12879 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12880 upon detecting a USB device with a given product identifier.
12883 (define %example-udev-rule
12885 "90-usb-thing.rules"
12886 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12887 "ATTR@{product@}==\"Example\", "
12888 "RUN+=\"/path/to/script\"")))
12892 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
12893 [#:groups @var{groups}]
12894 Return a service that extends @code{udev-service-type } with @var{rules}
12895 and @code{account-service-type} with @var{groups} as system groups.
12896 This works by creating a singleton service type
12897 @code{@var{name}-udev-rules}, of which the returned service is an
12900 Here we show how it can be used to extend @code{udev-service-type} with the
12901 previously defined rule @code{%example-udev-rule}.
12907 (cons (udev-rules-service 'usb-thing %example-udev-rule)
12908 %desktop-services)))
12912 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12913 Return a udev file named @var{file-name} containing the rules defined
12914 within @var{file}, a file-like object.
12916 The following example showcases how we can use an existing rule file.
12919 (use-modules (guix download) ;for url-fetch
12920 (guix packages) ;for origin
12923 (define %android-udev-rules
12925 "51-android-udev.rules"
12926 (let ((version "20170910"))
12929 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12930 "android-udev-rules/" version "/51-android.rules"))
12932 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12936 Additionally, Guix package definitions can be included in @var{rules} in
12937 order to extend the udev rules with the definitions found under their
12938 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12939 @var{file->udev-rule} example, we could have used the
12940 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12941 packages android)} module.
12943 The following example shows how to use the @var{android-udev-rules}
12944 package so that the Android tool @command{adb} can detect devices
12945 without root privileges. It also details how to create the
12946 @code{adbusers} group, which is required for the proper functioning of
12947 the rules defined within the @code{android-udev-rules} package. To
12948 create such a group, we must define it both as part of the
12949 @code{supplementary-groups} of our @code{user-account} declaration, as
12950 well as in the @var{groups} of the @code{udev-rules-service} procedure.
12953 (use-modules (gnu packages android) ;for android-udev-rules
12954 (gnu system shadow) ;for user-group
12959 (users (cons (user-account
12961 (supplementary-groups
12962 '("adbusers" ;for adb
12963 "wheel" "netdev" "audio" "video")))))
12966 (cons (udev-rules-service 'android android-udev-rules
12967 #:groups '("adbusers"))
12968 %desktop-services)))
12971 @defvr {Scheme Variable} urandom-seed-service-type
12972 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
12973 when rebooting. It also tries to seed @file{/dev/urandom} from
12974 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12978 @defvr {Scheme Variable} %random-seed-file
12979 This is the name of the file where some random bytes are saved by
12980 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12981 It defaults to @file{/var/lib/random-seed}.
12986 @defvr {Scheme Variable} gpm-service-type
12987 This is the type of the service that runs GPM, the @dfn{general-purpose
12988 mouse daemon}, which provides mouse support to the Linux console. GPM
12989 allows users to use the mouse in the console, notably to select, copy,
12992 The value for services of this type must be a @code{gpm-configuration}
12993 (see below). This service is not part of @code{%base-services}.
12996 @deftp {Data Type} gpm-configuration
12997 Data type representing the configuration of GPM.
13000 @item @code{options} (default: @code{%default-gpm-options})
13001 Command-line options passed to @command{gpm}. The default set of
13002 options instruct @command{gpm} to listen to mouse events on
13003 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13006 @item @code{gpm} (default: @code{gpm})
13007 The GPM package to use.
13012 @anchor{guix-publish-service-type}
13013 @deffn {Scheme Variable} guix-publish-service-type
13014 This is the service type for @command{guix publish} (@pxref{Invoking
13015 guix publish}). Its value must be a @code{guix-publish-configuration}
13016 object, as described below.
13018 This assumes that @file{/etc/guix} already contains a signing key pair as
13019 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13020 archive}). If that is not the case, the service will fail to start.
13023 @deftp {Data Type} guix-publish-configuration
13024 Data type representing the configuration of the @code{guix publish}
13028 @item @code{guix} (default: @code{guix})
13029 The Guix package to use.
13031 @item @code{port} (default: @code{80})
13032 The TCP port to listen for connections.
13034 @item @code{host} (default: @code{"localhost"})
13035 The host (and thus, network interface) to listen to. Use
13036 @code{"0.0.0.0"} to listen on all the network interfaces.
13038 @item @code{compression} (default: @code{'(("gzip" 3))})
13039 This is a list of compression method/level tuple used when compressing
13040 substitutes. For example, to compress all substitutes with @emph{both} lzip
13041 at level 7 and gzip at level 9, write:
13044 '(("lzip" 7) ("gzip" 9))
13047 Level 9 achieves the best compression ratio at the expense of increased CPU
13048 usage, whereas level 1 achieves fast compression.
13050 An empty list disables compression altogether.
13052 @item @code{nar-path} (default: @code{"nar"})
13053 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
13054 publish, @code{--nar-path}}, for details.
13056 @item @code{cache} (default: @code{#f})
13057 When it is @code{#f}, disable caching and instead generate archives on
13058 demand. Otherwise, this should be the name of a directory---e.g.,
13059 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
13060 archives and meta-data ready to be sent. @xref{Invoking guix publish,
13061 @option{--cache}}, for more information on the tradeoffs involved.
13063 @item @code{workers} (default: @code{#f})
13064 When it is an integer, this is the number of worker threads used for
13065 caching; when @code{#f}, the number of processors is used.
13066 @xref{Invoking guix publish, @option{--workers}}, for more information.
13068 @item @code{ttl} (default: @code{#f})
13069 When it is an integer, this denotes the @dfn{time-to-live} in seconds
13070 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
13071 for more information.
13075 @anchor{rngd-service}
13076 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
13077 [#:device "/dev/hwrng"]
13078 Return a service that runs the @command{rngd} program from @var{rng-tools}
13079 to add @var{device} to the kernel's entropy pool. The service will fail if
13080 @var{device} does not exist.
13083 @anchor{pam-limits-service}
13084 @cindex session limits
13089 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
13091 Return a service that installs a configuration file for the
13092 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
13093 @code{pam_limits} module}. The procedure optionally takes a list of
13094 @code{pam-limits-entry} values, which can be used to specify
13095 @code{ulimit} limits and nice priority limits to user sessions.
13097 The following limits definition sets two hard and soft limits for all
13098 login sessions of users in the @code{realtime} group:
13101 (pam-limits-service
13103 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
13104 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
13107 The first entry increases the maximum realtime priority for
13108 non-privileged processes; the second entry lifts any restriction of the
13109 maximum address space that can be locked in memory. These settings are
13110 commonly used for real-time audio systems.
13113 @node Scheduled Job Execution
13114 @subsection Scheduled Job Execution
13118 @cindex scheduling jobs
13119 The @code{(gnu services mcron)} module provides an interface to
13120 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
13121 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
13122 Unix @command{cron} daemon; the main difference is that it is
13123 implemented in Guile Scheme, which provides a lot of flexibility when
13124 specifying the scheduling of jobs and their actions.
13126 The example below defines an operating system that runs the
13127 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
13128 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
13129 well as the @command{mkid} command on behalf of an unprivileged user
13130 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
13131 gexps to introduce job definitions that are passed to mcron
13132 (@pxref{G-Expressions}).
13135 (use-modules (guix) (gnu) (gnu services mcron))
13136 (use-package-modules base idutils)
13138 (define updatedb-job
13139 ;; Run 'updatedb' at 3AM every day. Here we write the
13140 ;; job's action as a Scheme procedure.
13141 #~(job '(next-hour '(3))
13143 (execl (string-append #$findutils "/bin/updatedb")
13145 "--prunepaths=/tmp /var/tmp /gnu/store"))))
13147 (define garbage-collector-job
13148 ;; Collect garbage 5 minutes after midnight every day.
13149 ;; The job's action is a shell command.
13150 #~(job "5 0 * * *" ;Vixie cron syntax
13153 (define idutils-job
13154 ;; Update the index database as user "charlie" at 12:15PM
13155 ;; and 19:15PM. This runs from the user's home directory.
13156 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
13157 (string-append #$idutils "/bin/mkid src")
13162 (services (cons (service mcron-service-type
13163 (mcron-configuration
13164 (jobs (list garbage-collector-job
13170 For more complex jobs defined in Scheme where you need control over the top
13171 level, for instance to introduce a @code{use-modules} form, you can move your
13172 code to a separate program using the @code{program-file} procedure of the
13173 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
13177 (define %battery-alert-job
13178 ;; Beep when the battery percentage falls below %MIN-LEVEL.
13180 '(next-minute (range 0 60 1))
13182 "battery-alert.scm"
13183 (with-imported-modules (source-module-closure
13184 '((guix build utils)))
13186 (define %min-level 20)
13187 (use-modules (guix build utils)
13190 (ice-9 textual-ports)
13192 (setenv "LC_ALL" "C") ;ensure English output
13193 (and-let* ((input-pipe (open-pipe*
13195 #$(file-append acpi "/bin/acpi")))
13196 (output (get-string-all input-pipe))
13197 (m (string-match "Discharging, ([0-9]+)%" output))
13198 (level (string->number (match:substring m 1)))
13199 ((< level %min-level)))
13200 (format #t "warning: Battery level is low (~a%)~%" level)
13201 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
13204 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
13205 for more information on mcron job specifications. Below is the
13206 reference of the mcron service.
13208 On a running system, you can use the @code{schedule} action of the service to
13209 visualize the mcron jobs that will be executed next:
13212 # herd schedule mcron
13216 The example above lists the next five tasks that will be executed, but you can
13217 also specify the number of tasks to display:
13220 # herd schedule mcron 10
13223 @defvr {Scheme Variable} mcron-service-type
13224 This is the type of the @code{mcron} service, whose value is an
13225 @code{mcron-configuration} object.
13227 This service type can be the target of a service extension that provides
13228 it additional job specifications (@pxref{Service Composition}). In
13229 other words, it is possible to define services that provide additional
13233 @deftp {Data Type} mcron-configuration
13234 Data type representing the configuration of mcron.
13237 @item @code{mcron} (default: @var{mcron})
13238 The mcron package to use.
13241 This is a list of gexps (@pxref{G-Expressions}), where each gexp
13242 corresponds to an mcron job specification (@pxref{Syntax, mcron job
13243 specifications,, mcron, GNU@tie{}mcron}).
13249 @subsection Log Rotation
13252 @cindex log rotation
13254 Log files such as those found in @file{/var/log} tend to grow endlessly,
13255 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
13256 their contents in separate files, possibly compressed. The @code{(gnu
13257 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
13258 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
13260 This service is part of @code{%base-services}, and thus enabled by
13261 default, with the default settings, for commonly encountered log files.
13262 The example below shows how to extend it with an additional
13263 @dfn{rotation}, should you need to do that (usually, services that
13264 produce log files already take care of that):
13267 (use-modules (guix) (gnu))
13268 (use-service-modules admin)
13270 (define my-log-files
13271 ;; Log files that I want to rotate.
13272 '("/var/log/something.log" "/var/log/another.log"))
13276 (services (cons (simple-service 'rotate-my-stuff
13277 rottlog-service-type
13278 (list (log-rotation
13280 (files my-log-files))))
13284 @defvr {Scheme Variable} rottlog-service-type
13285 This is the type of the Rottlog service, whose value is a
13286 @code{rottlog-configuration} object.
13288 Other services can extend this one with new @code{log-rotation} objects
13289 (see below), thereby augmenting the set of files to be rotated.
13291 This service type can define mcron jobs (@pxref{Scheduled Job
13292 Execution}) to run the rottlog service.
13295 @deftp {Data Type} rottlog-configuration
13296 Data type representing the configuration of rottlog.
13299 @item @code{rottlog} (default: @code{rottlog})
13300 The Rottlog package to use.
13302 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
13303 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
13304 rottlog, GNU Rot[t]log Manual}).
13306 @item @code{rotations} (default: @code{%default-rotations})
13307 A list of @code{log-rotation} objects as defined below.
13310 This is a list of gexps where each gexp corresponds to an mcron job
13311 specification (@pxref{Scheduled Job Execution}).
13315 @deftp {Data Type} log-rotation
13316 Data type representing the rotation of a group of log files.
13318 Taking an example from the Rottlog manual (@pxref{Period Related File
13319 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
13325 (files '("/var/log/apache/*"))
13326 (options '("storedir apache-archives"
13332 The list of fields is as follows:
13335 @item @code{frequency} (default: @code{'weekly})
13336 The log rotation frequency, a symbol.
13339 The list of files or file glob patterns to rotate.
13341 @item @code{options} (default: @code{'()})
13342 The list of rottlog options for this rotation (@pxref{Configuration
13343 parameters,,, rottlog, GNU Rot[t]lg Manual}).
13345 @item @code{post-rotate} (default: @code{#f})
13346 Either @code{#f} or a gexp to execute once the rotation has completed.
13350 @defvr {Scheme Variable} %default-rotations
13351 Specifies weekly rotation of @code{%rotated-files} and of
13352 @file{/var/log/guix-daemon.log}.
13355 @defvr {Scheme Variable} %rotated-files
13356 The list of syslog-controlled files to be rotated. By default it is:
13357 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
13358 "/var/log/maillog")}.
13361 @node Networking Services
13362 @subsection Networking Services
13364 The @code{(gnu services networking)} module provides services to configure
13365 the network interface.
13367 @cindex DHCP, networking service
13368 @defvr {Scheme Variable} dhcp-client-service-type
13369 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
13370 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
13371 is the DHCP client package to use, @code{isc-dhcp} by default.
13374 @deffn {Scheme Procedure} dhcpd-service-type
13375 This type defines a service that runs a DHCP daemon. To create a
13376 service of this type, you must supply a @code{<dhcpd-configuration>}.
13380 (service dhcpd-service-type
13381 (dhcpd-configuration
13382 (config-file (local-file "my-dhcpd.conf"))
13383 (interfaces '("enp0s25"))))
13387 @deftp {Data Type} dhcpd-configuration
13389 @item @code{package} (default: @code{isc-dhcp})
13390 The package that provides the DHCP daemon. This package is expected to
13391 provide the daemon at @file{sbin/dhcpd} relative to its output
13392 directory. The default package is the
13393 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13394 @item @code{config-file} (default: @code{#f})
13395 The configuration file to use. This is required. It will be passed to
13396 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13397 object (@pxref{G-Expressions, file-like objects}). See @code{man
13398 dhcpd.conf} for details on the configuration file syntax.
13399 @item @code{version} (default: @code{"4"})
13400 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13401 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13402 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13404 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13405 The run directory to use. At service activation time, this directory
13406 will be created if it does not exist.
13407 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13408 The PID file to use. This corresponds to the @code{-pf} option of
13409 @code{dhcpd}. See @code{man dhcpd} for details.
13410 @item @code{interfaces} (default: @code{'()})
13411 The names of the network interfaces on which dhcpd should listen for
13412 broadcasts. If this list is not empty, then its elements (which must be
13413 strings) will be appended to the @code{dhcpd} invocation when starting
13414 the daemon. It may not be necessary to explicitly specify any
13415 interfaces here; see @code{man dhcpd} for details.
13419 @defvr {Scheme Variable} static-networking-service-type
13420 This is the type for statically-configured network interfaces.
13421 @c TODO Document <static-networking> data structures.
13424 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13425 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13426 [#:requirement @code{'(udev)}]
13427 Return a service that starts @var{interface} with address @var{ip}. If
13428 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13429 it must be a string specifying the default network gateway. @var{requirement}
13430 can be used to declare a dependency on another service before configuring the
13433 This procedure can be called several times, one for each network
13434 interface of interest. Behind the scenes what it does is extend
13435 @code{static-networking-service-type} with additional network interfaces
13441 (static-networking-service "eno1" "192.168.1.82"
13442 #:gateway "192.168.1.2"
13443 #:name-servers '("192.168.1.2"))
13450 @cindex network management
13451 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13452 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13453 management daemon that aims to simplify wired and wireless networking.
13455 This service adds the @var{wicd} package to the global profile, providing
13456 several commands to interact with the daemon and configure networking:
13457 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13458 and @command{wicd-curses} user interfaces.
13461 @cindex ModemManager
13463 @defvr {Scheme Variable} modem-manager-service-type
13464 This is the service type for the
13465 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13466 service. The value for this service type is a
13467 @code{modem-manager-configuration} record.
13469 This service is part of @code{%desktop-services} (@pxref{Desktop
13473 @deftp {Data Type} modem-manager-configuration
13474 Data type representing the configuration of ModemManager.
13477 @item @code{modem-manager} (default: @code{modem-manager})
13478 The ModemManager package to use.
13483 @cindex USB_ModeSwitch
13484 @cindex Modeswitching
13486 @defvr {Scheme Variable} usb-modeswitch-service-type
13487 This is the service type for the
13488 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13489 value for this service type is a @code{usb-modeswitch-configuration} record.
13491 When plugged in, some USB modems (and other USB devices) initially present
13492 themselves as a read-only storage medium and not as a modem. They need to be
13493 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13494 installs udev rules to automatically modeswitch these devices when they are
13497 This service is part of @code{%desktop-services} (@pxref{Desktop
13501 @deftp {Data Type} usb-modeswitch-configuration
13502 Data type representing the configuration of USB_ModeSwitch.
13505 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13506 The USB_ModeSwitch package providing the binaries for modeswitching.
13508 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13509 The package providing the device data and udev rules file used by
13512 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13513 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13514 config file shipped with USB_ModeSwitch is used which disables logging to
13515 @file{/var/log} among other default settings. If set to @code{#f}, no config
13521 @cindex NetworkManager
13523 @defvr {Scheme Variable} network-manager-service-type
13524 This is the service type for the
13525 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13526 service. The value for this service type is a
13527 @code{network-manager-configuration} record.
13529 This service is part of @code{%desktop-services} (@pxref{Desktop
13533 @deftp {Data Type} network-manager-configuration
13534 Data type representing the configuration of NetworkManager.
13537 @item @code{network-manager} (default: @code{network-manager})
13538 The NetworkManager package to use.
13540 @item @code{dns} (default: @code{"default"})
13541 Processing mode for DNS, which affects how NetworkManager uses the
13542 @code{resolv.conf} configuration file.
13546 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13547 provided by currently active connections.
13550 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13551 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13552 then update @code{resolv.conf} to point to the local nameserver.
13554 With this setting, you can share your network connection. For example when
13555 you want to share your network connection to another laptop @i{via} an
13556 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13557 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13558 and reestablish the connection (or reboot).
13560 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13561 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13562 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13563 browser on your host system, or connect to the VM @i{via} SSH
13564 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13565 host-to-guest connection, run this command once:
13568 nmcli connection add type tun \
13569 connection.interface-name tap0 \
13570 tun.mode tap tun.owner $(id -u) \
13571 ipv4.method shared \
13572 ipv4.addresses 172.28.112.1/24
13575 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13576 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13577 @command{qemu-system-...}.
13580 NetworkManager will not modify @code{resolv.conf}.
13583 @item @code{vpn-plugins} (default: @code{'()})
13584 This is the list of available plugins for virtual private networks
13585 (VPNs). An example of this is the @code{network-manager-openvpn}
13586 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13592 @deffn {Scheme Variable} connman-service-type
13593 This is the service type to run @url{https://01.org/connman,Connman},
13594 a network connection manager.
13596 Its value must be an
13597 @code{connman-configuration} record as in this example:
13600 (service connman-service-type
13601 (connman-configuration
13602 (disable-vpn? #t)))
13605 See below for details about @code{connman-configuration}.
13608 @deftp {Data Type} connman-configuration
13609 Data Type representing the configuration of connman.
13612 @item @code{connman} (default: @var{connman})
13613 The connman package to use.
13615 @item @code{disable-vpn?} (default: @code{#f})
13616 When true, disable connman's vpn plugin.
13620 @cindex WPA Supplicant
13621 @defvr {Scheme Variable} wpa-supplicant-service-type
13622 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13623 supplicant}, an authentication daemon required to authenticate against
13624 encrypted WiFi or ethernet networks.
13627 @deftp {Data Type} wpa-supplicant-configuration
13628 Data type representing the configuration of WPA Supplicant.
13630 It takes the following parameters:
13633 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13634 The WPA Supplicant package to use.
13636 @item @code{dbus?} (default: @code{#t})
13637 Whether to listen for requests on D-Bus.
13639 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13640 Where to store the PID file.
13642 @item @code{interface} (default: @code{#f})
13643 If this is set, it must specify the name of a network interface that
13644 WPA supplicant will control.
13646 @item @code{config-file} (default: @code{#f})
13647 Optional configuration file to use.
13649 @item @code{extra-options} (default: @code{'()})
13650 List of additional command-line arguments to pass to the daemon.
13654 @cindex hostapd service, for Wi-Fi access points
13655 @cindex Wi-Fi access points, hostapd service
13656 @defvr {Scheme Variable} hostapd-service-type
13657 This is the service type to run the @uref{https://w1.fi/hostapd/,
13658 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
13659 authentication servers. Its associated value must be a
13660 @code{hostapd-configuration} as shown below:
13663 ;; Use wlan1 to run the access point for "My Network".
13664 (service hostapd-service-type
13665 (hostapd-configuration
13666 (interface "wlan1")
13667 (ssid "My Network")
13672 @deftp {Data Type} hostapd-configuration
13673 This data type represents the configuration of the hostapd service, with
13674 the following fields:
13677 @item @code{package} (default: @code{hostapd})
13678 The hostapd package to use.
13680 @item @code{interface} (default: @code{"wlan0"})
13681 The network interface to run the WiFi access point.
13684 The SSID (@dfn{service set identifier}), a string that identifies this
13687 @item @code{broadcast-ssid?} (default: @code{#t})
13688 Whether to broadcast this SSID.
13690 @item @code{channel} (default: @code{1})
13691 The WiFi channel to use.
13693 @item @code{driver} (default: @code{"nl80211"})
13694 The driver interface type. @code{"nl80211"} is used with all Linux
13695 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
13696 RADIUS server that does # not control any wireless/wired driver.
13698 @item @code{extra-settings} (default: @code{""})
13699 Extra settings to append as-is to the hostapd configuration file. See
13700 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
13701 configuration file reference.
13705 @defvr {Scheme Variable} simulated-wifi-service-type
13706 This is the type of a service to simulate WiFi networking, which can be
13707 useful in virtual machines for testing purposes. The service loads the
13709 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
13710 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
13711 network that can be seen on @code{wlan0}, by default.
13713 The service's value is a @code{hostapd-configuration} record.
13717 @defvr {Scheme Variable} iptables-service-type
13718 This is the service type to set up an iptables configuration. iptables is a
13719 packet filtering framework supported by the Linux kernel. This service
13720 supports configuring iptables for both IPv4 and IPv6. A simple example
13721 configuration rejecting all incoming connections except those to the ssh port
13725 (service iptables-service-type
13726 (iptables-configuration
13727 (ipv4-rules (plain-file "iptables.rules" "*filter
13731 -A INPUT -p tcp --dport 22 -j ACCEPT
13732 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13735 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13739 -A INPUT -p tcp --dport 22 -j ACCEPT
13740 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13746 @deftp {Data Type} iptables-configuration
13747 The data type representing the configuration of iptables.
13750 @item @code{iptables} (default: @code{iptables})
13751 The iptables package that provides @code{iptables-restore} and
13752 @code{ip6tables-restore}.
13753 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13754 The iptables rules to use. It will be passed to @code{iptables-restore}.
13755 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13757 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13758 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13759 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13765 @defvr {Scheme Variable} nftables-service-type
13766 This is the service type to set up a nftables configuration. nftables is a
13767 netfilter project that aims to replace the existing iptables, ip6tables,
13768 arptables and ebtables framework. It provides a new packet filtering
13769 framework, a new user-space utility @command{nft}, and a compatibility layer
13770 for iptables. This service comes with a default ruleset
13771 @code{%default-nftables-ruleset} that rejecting all incomming connections
13772 except those to the ssh port 22. To use it, simply write:
13775 (service nftables-service-type)
13779 @deftp {Data Type} nftables-configuration
13780 The data type representing the configuration of nftables.
13783 @item @code{package} (default: @code{nftables})
13784 The nftables package that provides @command{nft}.
13785 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13786 The nftables ruleset to use. This may be any ``file-like'' object
13787 (@pxref{G-Expressions, file-like objects}).
13791 @cindex NTP (Network Time Protocol), service
13792 @cindex ntpd, service for the Network Time Protocol daemon
13793 @cindex real time clock
13794 @defvr {Scheme Variable} ntp-service-type
13795 This is the type of the service running the @uref{https://www.ntp.org,
13796 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13797 system clock synchronized with that of the specified NTP servers.
13799 The value of this service is an @code{ntpd-configuration} object, as described
13803 @deftp {Data Type} ntp-configuration
13804 This is the data type for the NTP service configuration.
13807 @item @code{servers} (default: @code{%ntp-servers})
13808 This is the list of servers (@code{<ntp-server>} records) with which
13809 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13812 @item @code{allow-large-adjustment?} (default: @code{#t})
13813 This determines whether @command{ntpd} is allowed to make an initial
13814 adjustment of more than 1,000 seconds.
13816 @item @code{ntp} (default: @code{ntp})
13817 The NTP package to use.
13821 @defvr {Scheme Variable} %ntp-servers
13822 List of host names used as the default NTP servers. These are servers of the
13823 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13826 @deftp {Data Type} ntp-server
13827 The data type representing the configuration of a NTP server.
13830 @item @code{type} (default: @code{'server})
13831 The type of the NTP server, given as a symbol. One of @code{'pool},
13832 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13834 @item @code{address}
13835 The address of the server, as a string.
13837 @item @code{options}
13838 NTPD options to use with that specific server, given as a list of option names
13839 and/or of option names and values tuples. The following example define a server
13840 to use with the options @option{iburst} and @option{prefer}, as well as
13841 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13846 (address "some.ntp.server.org")
13847 (options `(iburst (version 3) (maxpoll 16) prefer))))
13853 @deffn {Scheme Procedure} openntpd-service-type
13854 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13855 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13856 clock synchronized with that of the given servers.
13860 openntpd-service-type
13861 (openntpd-configuration
13862 (listen-on '("127.0.0.1" "::1"))
13863 (sensor '("udcf0 correction 70000"))
13864 (constraint-from '("www.gnu.org"))
13865 (constraints-from '("https://www.google.com/"))
13866 (allow-large-adjustment? #t)))
13871 @defvr {Scheme Variable} %openntpd-servers
13872 This variable is a list of the server addresses defined in
13873 @code{%ntp-servers}.
13876 @deftp {Data Type} openntpd-configuration
13878 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13879 The openntpd executable to use.
13880 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13881 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13882 @item @code{query-from} (default: @code{'()})
13883 A list of local IP address the ntpd daemon should use for outgoing queries.
13884 @item @code{sensor} (default: @code{'()})
13885 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13886 will listen to each sensor that actually exists and ignore non-existent ones.
13887 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13889 @item @code{server} (default: @code{'()})
13890 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13891 @item @code{servers} (default: @code{%openntp-servers})
13892 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13893 @item @code{constraint-from} (default: @code{'()})
13894 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13895 This time information is not used for precision but acts as an authenticated
13896 constraint, thereby reducing the impact of unauthenticated NTP
13897 man-in-the-middle attacks.
13898 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13900 @item @code{constraints-from} (default: @code{'()})
13901 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13902 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13903 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13904 @item @code{allow-large-adjustment?} (default: @code{#f})
13905 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13911 @deffn {Scheme variable} inetd-service-type
13912 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13913 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13914 connections on internet sockets, and lazily starts the specified server
13915 program when a connection is made on one of these sockets.
13917 The value of this service is an @code{inetd-configuration} object. The
13918 following example configures the @command{inetd} daemon to provide the
13919 built-in @command{echo} service, as well as an smtp service which
13920 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13921 gateway @code{hostname}:
13926 (inetd-configuration
13930 (socket-type 'stream)
13937 (socket-type 'stream)
13941 (program (file-append openssh "/bin/ssh"))
13943 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13944 "-W" "smtp-server:25" "user@@hostname")))))))
13947 See below for more details about @code{inetd-configuration}.
13950 @deftp {Data Type} inetd-configuration
13951 Data type representing the configuration of @command{inetd}.
13954 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13955 The @command{inetd} executable to use.
13957 @item @code{entries} (default: @code{'()})
13958 A list of @command{inetd} service entries. Each entry should be created
13959 by the @code{inetd-entry} constructor.
13963 @deftp {Data Type} inetd-entry
13964 Data type representing an entry in the @command{inetd} configuration.
13965 Each entry corresponds to a socket where @command{inetd} will listen for
13969 @item @code{node} (default: @code{#f})
13970 Optional string, a comma-separated list of local addresses
13971 @command{inetd} should use when listening for this service.
13972 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13973 description of all options.
13975 A string, the name must correspond to an entry in @code{/etc/services}.
13976 @item @code{socket-type}
13977 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13979 @item @code{protocol}
13980 A string, must correspond to an entry in @code{/etc/protocols}.
13981 @item @code{wait?} (default: @code{#t})
13982 Whether @command{inetd} should wait for the server to exit before
13983 listening to new service requests.
13985 A string containing the user (and, optionally, group) name of the user
13986 as whom the server should run. The group name can be specified in a
13987 suffix, separated by a colon or period, i.e.@: @code{"user"},
13988 @code{"user:group"} or @code{"user.group"}.
13989 @item @code{program} (default: @code{"internal"})
13990 The server program which will serve the requests, or @code{"internal"}
13991 if @command{inetd} should use a built-in service.
13992 @item @code{arguments} (default: @code{'()})
13993 A list strings or file-like objects, which are the server program's
13994 arguments, starting with the zeroth argument, i.e.@: the name of the
13995 program itself. For @command{inetd}'s internal services, this entry
13996 must be @code{'()} or @code{'("internal")}.
13999 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14000 detailed discussion of each configuration field.
14004 @defvr {Scheme Variable} tor-service-type
14005 This is the type for a service that runs the @uref{https://torproject.org,
14006 Tor} anonymous networking daemon. The service is configured using a
14007 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14008 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14012 @deftp {Data Type} tor-configuration
14014 @item @code{tor} (default: @code{tor})
14015 The package that provides the Tor daemon. This package is expected to provide
14016 the daemon at @file{bin/tor} relative to its output directory. The default
14017 package is the @uref{https://www.torproject.org, Tor Project's}
14020 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14021 The configuration file to use. It will be appended to a default configuration
14022 file, and the final configuration file will be passed to @code{tor} via its
14023 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14024 file-like objects}). See @code{man tor} for details on the configuration file
14027 @item @code{hidden-services} (default: @code{'()})
14028 The list of @code{<hidden-service>} records to use. For any hidden service
14029 you include in this list, appropriate configuration to enable the hidden
14030 service will be automatically added to the default configuration file. You
14031 may conveniently create @code{<hidden-service>} records using the
14032 @code{tor-hidden-service} procedure described below.
14034 @item @code{socks-socket-type} (default: @code{'tcp})
14035 The default socket type that Tor should use for its SOCKS socket. This must
14036 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
14037 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
14038 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
14039 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
14042 If you want to customize the SOCKS socket in more detail, leave
14043 @code{socks-socket-type} at its default value of @code{'tcp} and use
14044 @code{config-file} to override the default by providing your own
14045 @code{SocksPort} option.
14049 @cindex hidden service
14050 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
14051 Define a new Tor @dfn{hidden service} called @var{name} and implementing
14052 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
14055 '((22 "127.0.0.1:22")
14056 (80 "127.0.0.1:8080"))
14059 In this example, port 22 of the hidden service is mapped to local port 22, and
14060 port 80 is mapped to local port 8080.
14062 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
14063 the @file{hostname} file contains the @code{.onion} host name for the hidden
14066 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
14067 project's documentation} for more information.
14070 The @code{(gnu services rsync)} module provides the following services:
14072 You might want an rsync daemon if you have files that you want available
14073 so anyone (or just yourself) can download existing files or upload new
14076 @deffn {Scheme Variable} rsync-service-type
14077 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
14078 The value for this service type is a
14079 @command{rsync-configuration} record as in this example:
14082 (service rsync-service-type)
14085 See below for details about @code{rsync-configuration}.
14088 @deftp {Data Type} rsync-configuration
14089 Data type representing the configuration for @code{rsync-service}.
14092 @item @code{package} (default: @var{rsync})
14093 @code{rsync} package to use.
14095 @item @code{port-number} (default: @code{873})
14096 TCP port on which @command{rsync} listens for incoming connections. If port
14097 is less than @code{1024} @command{rsync} needs to be started as the
14098 @code{root} user and group.
14100 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
14101 Name of the file where @command{rsync} writes its PID.
14103 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
14104 Name of the file where @command{rsync} writes its lock file.
14106 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
14107 Name of the file where @command{rsync} writes its log file.
14109 @item @code{use-chroot?} (default: @var{#t})
14110 Whether to use chroot for @command{rsync} shared directory.
14112 @item @code{share-path} (default: @file{/srv/rsync})
14113 Location of the @command{rsync} shared directory.
14115 @item @code{share-comment} (default: @code{"Rsync share"})
14116 Comment of the @command{rsync} shared directory.
14118 @item @code{read-only?} (default: @var{#f})
14119 Read-write permissions to shared directory.
14121 @item @code{timeout} (default: @code{300})
14122 I/O timeout in seconds.
14124 @item @code{user} (default: @var{"root"})
14125 Owner of the @code{rsync} process.
14127 @item @code{group} (default: @var{"root"})
14128 Group of the @code{rsync} process.
14130 @item @code{uid} (default: @var{"rsyncd"})
14131 User name or user ID that file transfers to and from that module should take
14132 place as when the daemon was run as @code{root}.
14134 @item @code{gid} (default: @var{"rsyncd"})
14135 Group name or group ID that will be used when accessing the module.
14140 Furthermore, @code{(gnu services ssh)} provides the following services.
14144 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
14145 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
14146 [#:allow-empty-passwords? #f] [#:root-login? #f] @
14147 [#:syslog-output? #t] [#:x11-forwarding? #t] @
14148 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
14149 [#:public-key-authentication? #t] [#:initialize? #t]
14150 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
14151 @var{host-key} must designate a file containing the host key, and readable
14154 When @var{daemonic?} is true, @command{lshd} will detach from the
14155 controlling terminal and log its output to syslogd, unless one sets
14156 @var{syslog-output?} to false. Obviously, it also makes lsh-service
14157 depend on existence of syslogd service. When @var{pid-file?} is true,
14158 @command{lshd} writes its PID to the file called @var{pid-file}.
14160 When @var{initialize?} is true, automatically create the seed and host key
14161 upon service activation if they do not exist yet. This may take long and
14162 require interaction.
14164 When @var{initialize?} is false, it is up to the user to initialize the
14165 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
14166 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
14167 basics,,, lsh, LSH Manual}).
14169 When @var{interfaces} is empty, lshd listens for connections on all the
14170 network interfaces; otherwise, @var{interfaces} must be a list of host names
14173 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
14174 passwords, and @var{root-login?} specifies whether to accept log-ins as
14177 The other options should be self-descriptive.
14182 @deffn {Scheme Variable} openssh-service-type
14183 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
14184 shell daemon, @command{sshd}. Its value must be an
14185 @code{openssh-configuration} record as in this example:
14188 (service openssh-service-type
14189 (openssh-configuration
14190 (x11-forwarding? #t)
14191 (permit-root-login 'without-password)
14193 `(("alice" ,(local-file "alice.pub"))
14194 ("bob" ,(local-file "bob.pub"))))))
14197 See below for details about @code{openssh-configuration}.
14199 This service can be extended with extra authorized keys, as in this
14203 (service-extension openssh-service-type
14204 (const `(("charlie"
14205 ,(local-file "charlie.pub")))))
14209 @deftp {Data Type} openssh-configuration
14210 This is the configuration record for OpenSSH's @command{sshd}.
14213 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
14214 Name of the file where @command{sshd} writes its PID.
14216 @item @code{port-number} (default: @code{22})
14217 TCP port on which @command{sshd} listens for incoming connections.
14219 @item @code{permit-root-login} (default: @code{#f})
14220 This field determines whether and when to allow logins as root. If
14221 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
14222 If it's the symbol @code{'without-password}, then root logins are
14223 permitted but not with password-based authentication.
14225 @item @code{allow-empty-passwords?} (default: @code{#f})
14226 When true, users with empty passwords may log in. When false, they may
14229 @item @code{password-authentication?} (default: @code{#t})
14230 When true, users may log in with their password. When false, they have
14231 other authentication methods.
14233 @item @code{public-key-authentication?} (default: @code{#t})
14234 When true, users may log in using public key authentication. When
14235 false, users have to use other authentication method.
14237 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
14238 This is used only by protocol version 2.
14240 @item @code{x11-forwarding?} (default: @code{#f})
14241 When true, forwarding of X11 graphical client connections is
14242 enabled---in other words, @command{ssh} options @option{-X} and
14243 @option{-Y} will work.
14245 @item @code{allow-agent-forwarding?} (default: @code{#t})
14246 Whether to allow agent forwarding.
14248 @item @code{allow-tcp-forwarding?} (default: @code{#t})
14249 Whether to allow TCP forwarding.
14251 @item @code{gateway-ports?} (default: @code{#f})
14252 Whether to allow gateway ports.
14254 @item @code{challenge-response-authentication?} (default: @code{#f})
14255 Specifies whether challenge response authentication is allowed (e.g.@: via
14258 @item @code{use-pam?} (default: @code{#t})
14259 Enables the Pluggable Authentication Module interface. If set to
14260 @code{#t}, this will enable PAM authentication using
14261 @code{challenge-response-authentication?} and
14262 @code{password-authentication?}, in addition to PAM account and session
14263 module processing for all authentication types.
14265 Because PAM challenge response authentication usually serves an
14266 equivalent role to password authentication, you should disable either
14267 @code{challenge-response-authentication?} or
14268 @code{password-authentication?}.
14270 @item @code{print-last-log?} (default: @code{#t})
14271 Specifies whether @command{sshd} should print the date and time of the
14272 last user login when a user logs in interactively.
14274 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
14275 Configures external subsystems (e.g.@: file transfer daemon).
14277 This is a list of two-element lists, each of which containing the
14278 subsystem name and a command (with optional arguments) to execute upon
14281 The command @command{internal-sftp} implements an in-process SFTP
14282 server. Alternately, one can specify the @command{sftp-server} command:
14284 (service openssh-service-type
14285 (openssh-configuration
14287 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
14290 @item @code{accepted-environment} (default: @code{'()})
14291 List of strings describing which environment variables may be exported.
14293 Each string gets on its own line. See the @code{AcceptEnv} option in
14294 @code{man sshd_config}.
14296 This example allows ssh-clients to export the @code{COLORTERM} variable.
14297 It is set by terminal emulators, which support colors. You can use it in
14298 your shell's resource file to enable colors for the prompt and commands
14299 if this variable is set.
14302 (service openssh-service-type
14303 (openssh-configuration
14304 (accepted-environment '("COLORTERM"))))
14307 @item @code{authorized-keys} (default: @code{'()})
14308 @cindex authorized keys, SSH
14309 @cindex SSH authorized keys
14310 This is the list of authorized keys. Each element of the list is a user
14311 name followed by one or more file-like objects that represent SSH public
14315 (openssh-configuration
14317 `(("rekado" ,(local-file "rekado.pub"))
14318 ("chris" ,(local-file "chris.pub"))
14319 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
14323 registers the specified public keys for user accounts @code{rekado},
14324 @code{chris}, and @code{root}.
14326 Additional authorized keys can be specified @i{via}
14327 @code{service-extension}.
14329 Note that this does @emph{not} interfere with the use of
14330 @file{~/.ssh/authorized_keys}.
14332 @item @code{log-level} (default: @code{'info})
14333 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
14334 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
14335 page for @file{sshd_config} for the full list of level names.
14337 @item @code{extra-content} (default: @code{""})
14338 This field can be used to append arbitrary text to the configuration file. It
14339 is especially useful for elaborate configurations that cannot be expressed
14340 otherwise. This configuration, for example, would generally disable root
14341 logins, but permit them from one specific IP address:
14344 (openssh-configuration
14346 Match Address 192.168.0.1
14347 PermitRootLogin yes"))
14353 @deffn {Scheme Procedure} dropbear-service [@var{config}]
14354 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
14355 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
14358 For example, to specify a Dropbear service listening on port 1234, add
14359 this call to the operating system's @code{services} field:
14362 (dropbear-service (dropbear-configuration
14363 (port-number 1234)))
14367 @deftp {Data Type} dropbear-configuration
14368 This data type represents the configuration of a Dropbear SSH daemon.
14371 @item @code{dropbear} (default: @var{dropbear})
14372 The Dropbear package to use.
14374 @item @code{port-number} (default: 22)
14375 The TCP port where the daemon waits for incoming connections.
14377 @item @code{syslog-output?} (default: @code{#t})
14378 Whether to enable syslog output.
14380 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
14381 File name of the daemon's PID file.
14383 @item @code{root-login?} (default: @code{#f})
14384 Whether to allow @code{root} logins.
14386 @item @code{allow-empty-passwords?} (default: @code{#f})
14387 Whether to allow empty passwords.
14389 @item @code{password-authentication?} (default: @code{#t})
14390 Whether to enable password-based authentication.
14395 @deffn {Scheme Variable} autossh-service-type
14396 This is the type for the @uref{https://www.harding.motd.ca/autossh,
14397 AutoSSH} program that runs a copy of @code{ssh} and monitors it,
14398 restarting it as necessary should it die or stop passing traffic.
14399 AutoSSH can be run manually from the commandline by passing arguments to
14400 the binary @code{autossh} from the package @code{autossh}, but it can
14401 also be run as a guix service. This latter usecase is documented here.
14403 AutoSSH can be used to forward local traffic to a remote machine using an SSH tunnel,
14404 and it respects the @file{~/.ssh/config} of the user it is run as.
14406 For example, to specify a service running autossh as the user @code{pino}
14407 and forwarding all local connections to port @code{8081} to @code{remote:8081}
14408 using an SSH tunnel, add this call to the operating system's @code{services} field:
14411 (service autossh-service-type
14412 (autossh-configuration
14414 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
14418 @deftp {Data Type} autossh-configuration
14419 This data type represents the configuration of an AutoSSH service.
14423 @item @code{user} (default @code{"autossh"})
14424 The user as which the AutoSSH service is to be run.
14425 This assumes that the specified user exists.
14427 @item @code{poll} (default @code{600})
14428 Specifies the connection poll time in seconds.
14430 @item @code{first-poll} (default @code{#f})
14431 Specifies how long autossh waits before the first connection test in seconds.
14432 After this first test, polling is resumed at the pace defined in @code{poll}.
14433 When set to @code{#f}, the first poll is not treated specially and
14434 will also use the connection poll specified in @code{poll}
14436 @item @code{gate-time} (default @code{30})
14437 Specifies (in seconds) how long an SSH connection must be active
14438 before it is considered successful.
14440 @item @code{log-level} (default @code{1})
14441 The log level, corresponding to the levels used by syslog
14442 (so @code{0} is the most silent while @code{7} is the chattiest.)
14444 @item @code{max-start} (default @code{#f})
14445 The maximum number of times SSH may be (re)started before AutoSSH exits.
14446 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
14448 @item @code{message} (default @code{""})
14449 The message to append to the echo message sent when testing connections.
14451 @item @code{port} (default @code{"0"})
14452 The ports used for monitoring the connection. When set to @code{"0"},
14453 monitoring is disabled. When set to @code{"n"} where @code{n} is a positive integer,
14454 ports @code{n} and @code{n+1} are used for monitoring the connection, such that
14455 port @code{n} is the base monitoring port and @code{n+1} is the echo port.
14456 When set to @code{"n:m"} where @code{n} and @code{m} are positive integers,
14457 the ports @code{n} and @code{n+1} are used for monitoring the connection, such
14458 that port @code{n} is the base monitoring port and @code{m} is the echo port.
14460 @item @code{ssh-options} (default @code{'()})
14461 The list of commandline arguments to pass to ssh when it is run.
14462 Options @code{-f} and @code{-M ....} are reserved for AutoSSH
14463 and may cause undefined behaviour.
14468 @defvr {Scheme Variable} %facebook-host-aliases
14469 This variable contains a string for use in @file{/etc/hosts}
14470 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
14471 line contains a entry that maps a known server name of the Facebook
14472 on-line service---e.g., @code{www.facebook.com}---to the local
14473 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
14475 This variable is typically used in the @code{hosts-file} field of an
14476 @code{operating-system} declaration (@pxref{operating-system Reference,
14477 @file{/etc/hosts}}):
14480 (use-modules (gnu) (guix))
14483 (host-name "mymachine")
14486 ;; Create a /etc/hosts file with aliases for "localhost"
14487 ;; and "mymachine", as well as for Facebook servers.
14488 (plain-file "hosts"
14489 (string-append (local-host-aliases host-name)
14490 %facebook-host-aliases))))
14493 This mechanism can prevent programs running locally, such as Web
14494 browsers, from accessing Facebook.
14497 The @code{(gnu services avahi)} provides the following definition.
14499 @defvr {Scheme Variable} avahi-service-type
14500 This is the service that runs @command{avahi-daemon}, a system-wide
14501 mDNS/DNS-SD responder that allows for service discovery and
14502 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
14503 Its value must be a @code{zero-configuration} record---see below.
14505 This service extends the name service cache daemon (nscd) so that it can
14506 resolve @code{.local} host names using
14507 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
14508 Service Switch}, for information on host name resolution.
14510 Additionally, add the @var{avahi} package to the system profile so that
14511 commands such as @command{avahi-browse} are directly usable.
14514 @deftp {Data Type} avahi-configuration
14515 Data type representation the configuration for Avahi.
14519 @item @code{host-name} (default: @code{#f})
14520 If different from @code{#f}, use that as the host name to
14521 publish for this machine; otherwise, use the machine's actual host name.
14523 @item @code{publish?} (default: @code{#t})
14524 When true, allow host names and services to be published (broadcast) over the
14527 @item @code{publish-workstation?} (default: @code{#t})
14528 When true, @command{avahi-daemon} publishes the machine's host name and IP
14529 address via mDNS on the local network. To view the host names published on
14530 your local network, you can run:
14533 avahi-browse _workstation._tcp
14536 @item @code{wide-area?} (default: @code{#f})
14537 When true, DNS-SD over unicast DNS is enabled.
14539 @item @code{ipv4?} (default: @code{#t})
14540 @itemx @code{ipv6?} (default: @code{#t})
14541 These fields determine whether to use IPv4/IPv6 sockets.
14543 @item @code{domains-to-browse} (default: @code{'()})
14544 This is a list of domains to browse.
14548 @deffn {Scheme Variable} openvswitch-service-type
14549 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14550 service, whose value should be an @code{openvswitch-configuration}
14554 @deftp {Data Type} openvswitch-configuration
14555 Data type representing the configuration of Open vSwitch, a multilayer
14556 virtual switch which is designed to enable massive network automation
14557 through programmatic extension.
14560 @item @code{package} (default: @var{openvswitch})
14561 Package object of the Open vSwitch.
14566 @defvr {Scheme Variable} pagekite-service-type
14567 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14568 a tunneling solution for making localhost servers publicly visible, even from
14569 behind restrictive firewalls or NAT without forwarded ports. The value for
14570 this service type is a @code{pagekite-configuration} record.
14572 Here's an example exposing the local HTTP and SSH daemons:
14575 (service pagekite-service-type
14576 (pagekite-configuration
14577 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14578 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14579 (extra-file "/etc/pagekite.rc")))
14583 @deftp {Data Type} pagekite-configuration
14584 Data type representing the configuration of PageKite.
14587 @item @code{package} (default: @var{pagekite})
14588 Package object of PageKite.
14590 @item @code{kitename} (default: @code{#f})
14591 PageKite name for authenticating to the frontend server.
14593 @item @code{kitesecret} (default: @code{#f})
14594 Shared secret for authenticating to the frontend server. You should probably
14595 put this inside @code{extra-file} instead.
14597 @item @code{frontend} (default: @code{#f})
14598 Connect to the named PageKite frontend server instead of the
14599 @uref{https://pagekite.net,,pagekite.net} service.
14601 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14602 List of service kites to use. Exposes HTTP on port 80 by default. The format
14603 is @code{proto:kitename:host:port:secret}.
14605 @item @code{extra-file} (default: @code{#f})
14606 Extra configuration file to read, which you are expected to create manually.
14607 Use this to add additional options and manage shared secrets out-of-band.
14613 @subsection X Window
14616 @cindex X Window System
14617 @cindex login manager
14618 Support for the X Window graphical display system---specifically
14619 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14620 there is no @code{xorg-service} procedure. Instead, the X server is
14621 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14624 @cindex GNOME, login manager
14625 GDM of course allows users to log in into window managers and desktop
14626 environments other than GNOME; for those using GNOME, GDM is required for
14627 features such as automatic screen locking.
14629 @cindex window manager
14630 To use X11, you must install at least one @dfn{window manager}---for
14631 example the @code{windowmaker} or @code{openbox} packages---preferably
14632 by adding it to the @code{packages} field of your operating system
14633 definition (@pxref{operating-system Reference, system-wide packages}).
14635 @defvr {Scheme Variable} gdm-service-type
14636 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14637 Desktop Manager} (GDM), a program that manages graphical display servers and
14638 handles graphical user logins. Its value must be a @code{gdm-configuration}
14641 @cindex session types (X11)
14642 @cindex X11 session types
14643 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14644 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14645 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14646 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14647 set of packages automatically makes them available at the log-in screen.
14649 In addition, @file{~/.xsession} files are honored. When available,
14650 @file{~/.xsession} must be an executable that starts a window manager
14651 and/or other X clients.
14654 @deftp {Data Type} gdm-configuration
14656 @item @code{auto-login?} (default: @code{#f})
14657 @itemx @code{default-user} (default: @code{#f})
14658 When @code{auto-login?} is false, GDM presents a log-in screen.
14660 When @code{auto-login?} is true, GDM logs in directly as
14661 @code{default-user}.
14663 @item @code{debug?} (default: @code{#f})
14664 When true, GDM writes debug messages to its log.
14666 @item @code{gnome-shell-assets} (default: ...)
14667 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14669 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14670 Configuration of the Xorg graphical server.
14672 @item @code{xsession} (default: @code{(xinitrc)})
14673 Script to run before starting a X session.
14675 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14676 File name of the @code{dbus-daemon} executable.
14678 @item @code{gdm} (default: @code{gdm})
14679 The GDM package to use.
14683 @defvr {Scheme Variable} slim-service-type
14684 This is the type for the SLiM graphical login manager for X11.
14686 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14687 allows users to choose a session from the log-in screen using @kbd{F1}. It
14688 also honors @file{~/.xsession} files.
14690 Unlike GDM, SLiM does not spawn the user session on a different VT after
14691 logging in, which means that you can only start one graphical session. If you
14692 want to be able to run multiple graphical sessions at the same time you have
14693 to add multiple SLiM services to your system services. The following example
14694 shows how to replace the default GDM service with two SLiM services on tty7
14698 (use-modules (gnu services)
14699 (gnu services desktop)
14700 (gnu services xorg)
14701 (srfi srfi-1)) ;for 'remove'
14705 (services (cons* (service slim-service-type (slim-configuration
14708 (service slim-service-type (slim-configuration
14711 (remove (lambda (service)
14712 (eq? (service-kind service) gdm-service-type))
14713 %desktop-services))))
14718 @deftp {Data Type} slim-configuration
14719 Data type representing the configuration of @code{slim-service-type}.
14722 @item @code{allow-empty-passwords?} (default: @code{#t})
14723 Whether to allow logins with empty passwords.
14725 @item @code{auto-login?} (default: @code{#f})
14726 @itemx @code{default-user} (default: @code{""})
14727 When @code{auto-login?} is false, SLiM presents a log-in screen.
14729 When @code{auto-login?} is true, SLiM logs in directly as
14730 @code{default-user}.
14732 @item @code{theme} (default: @code{%default-slim-theme})
14733 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14734 The graphical theme to use and its name.
14736 @item @code{auto-login-session} (default: @code{#f})
14737 If true, this must be the name of the executable to start as the default
14738 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14740 If false, a session described by one of the available @file{.desktop}
14741 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14745 You must install at least one window manager in the system profile or in
14746 your user profile. Failing to do that, if @code{auto-login-session} is
14747 false, you will be unable to log in.
14750 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14751 Configuration of the Xorg graphical server.
14753 @item @code{display} (default @code{":0"})
14754 The display on which to start the Xorg graphical server.
14756 @item @code{vt} (default @code{"vt7"})
14757 The VT on which to start the Xorg graphical server.
14759 @item @code{xauth} (default: @code{xauth})
14760 The XAuth package to use.
14762 @item @code{shepherd} (default: @code{shepherd})
14763 The Shepherd package used when invoking @command{halt} and
14766 @item @code{sessreg} (default: @code{sessreg})
14767 The sessreg package used in order to register the session.
14769 @item @code{slim} (default: @code{slim})
14770 The SLiM package to use.
14774 @defvr {Scheme Variable} %default-theme
14775 @defvrx {Scheme Variable} %default-theme-name
14776 The default SLiM theme and its name.
14780 @deftp {Data Type} sddm-configuration
14781 This is the data type representing the SDDM service configuration.
14784 @item @code{display-server} (default: "x11")
14785 Select display server to use for the greeter. Valid values are
14786 @samp{"x11"} or @samp{"wayland"}.
14788 @item @code{numlock} (default: "on")
14789 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
14791 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14792 Command to run when halting.
14794 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14795 Command to run when rebooting.
14797 @item @code{theme} (default "maldives")
14798 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
14799 @samp{"maldives"} or @samp{"maya"}.
14801 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14802 Directory to look for themes.
14804 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14805 Directory to look for faces.
14807 @item @code{default-path} (default "/run/current-system/profile/bin")
14808 Default PATH to use.
14810 @item @code{minimum-uid} (default: 1000)
14811 Minimum UID displayed in SDDM and allowed for log-in.
14813 @item @code{maximum-uid} (default: 2000)
14814 Maximum UID to display in SDDM.
14816 @item @code{remember-last-user?} (default #t)
14817 Remember last user.
14819 @item @code{remember-last-session?} (default #t)
14820 Remember last session.
14822 @item @code{hide-users} (default "")
14823 Usernames to hide from SDDM greeter.
14825 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14826 Users with shells listed will be hidden from the SDDM greeter.
14828 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14829 Script to run before starting a wayland session.
14831 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14832 Directory to look for desktop files starting wayland sessions.
14834 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14835 Configuration of the Xorg graphical server.
14837 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14840 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14843 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14844 Script to run after starting xorg-server.
14846 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14847 Script to run before stopping xorg-server.
14849 @item @code{xsession-command} (default: @code{xinitrc})
14850 Script to run before starting a X session.
14852 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14853 Directory to look for desktop files starting X sessions.
14855 @item @code{minimum-vt} (default: 7)
14858 @item @code{auto-login-user} (default "")
14859 User to use for auto-login.
14861 @item @code{auto-login-session} (default "")
14862 Desktop file to use for auto-login.
14864 @item @code{relogin?} (default #f)
14865 Relogin after logout.
14870 @cindex login manager
14872 @defvr {Scheme Variable} sddm-service-type
14873 This is the type of the service to run the
14874 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
14875 must be a @code{sddm-configuration} record (see below).
14877 Here's an example use:
14880 (service sddm-service-type
14881 (sddm-configuration
14882 (auto-login-user "alice")
14883 (auto-login-session "xfce.desktop")))
14887 @deftp {Data Type} sddm-configuration
14888 This data type represents the configuration of the SDDM login manager.
14889 The available fields are:
14892 @item @code{sddm} (default: @code{sddm})
14893 The SDDM package to use.
14895 @item @code{display-server} (default: @code{"x11"})
14896 This must be either @code{"x11"} or @code{"wayland"}.
14898 @c FIXME: Add more fields.
14900 @item @code{auto-login-user} (default: @code{""})
14901 If non-empty, this is the user account under which to log in
14904 @item @code{auto-login-session} (default: @code{""})
14905 If non-empty, this is the @file{.desktop} file name to use as the
14906 auto-login session.
14910 @cindex Xorg, configuration
14911 @deftp {Data Type} xorg-configuration
14912 This data type represents the configuration of the Xorg graphical display
14913 server. Note that there is not Xorg service; instead, the X server is started
14914 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14915 of these display managers aggregates an @code{xorg-configuration} record.
14918 @item @code{modules} (default: @code{%default-xorg-modules})
14919 This is a list of @dfn{module packages} loaded by the Xorg
14920 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14922 @item @code{fonts} (default: @code{%default-xorg-fonts})
14923 This is a list of font directories to add to the server's @dfn{font path}.
14925 @item @code{drivers} (default: @code{'()})
14926 This must be either the empty list, in which case Xorg chooses a graphics
14927 driver automatically, or a list of driver names that will be tried in this
14928 order---e.g., @code{("modesetting" "vesa")}.
14930 @item @code{resolutions} (default: @code{'()})
14931 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14932 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14935 @cindex keyboard layout, for Xorg
14936 @cindex keymap, for Xorg
14937 @item @code{keyboard-layout} (default: @code{#f})
14938 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14939 English (``qwerty'') for a 105-key PC keyboard.
14941 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14942 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14943 information on how to specify the keyboard layout.
14945 @item @code{extra-config} (default: @code{'()})
14946 This is a list of strings or objects appended to the configuration file. It
14947 is used to pass extra text to be added verbatim to the configuration file.
14949 @item @code{server} (default: @code{xorg-server})
14950 This is the package providing the Xorg server.
14952 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14953 This is the list of command-line arguments to pass to the X server. The
14954 default is @code{-nolisten tcp}.
14958 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14959 [@var{login-manager-service-type}]
14960 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14961 @var{config}, an @code{<xorg-configuration>} record.
14963 Since the Xorg configuration is embedded in the log-in manager's
14964 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14965 shorthand to set the Xorg configuration.
14968 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14969 Return a @code{startx} script in which the modules, fonts, etc. specified
14970 in @var{config}, are available. The result should be used in place of
14973 Usually the X server is started by a login manager.
14977 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14978 Add @var{package}, a package for a screen locker or screen saver whose
14979 command is @var{program}, to the set of setuid programs and add a PAM entry
14980 for it. For example:
14983 (screen-locker-service xlockmore "xlock")
14986 makes the good ol' XlockMore usable.
14990 @node Printing Services
14991 @subsection Printing Services
14993 @cindex printer support with CUPS
14994 The @code{(gnu services cups)} module provides a Guix service definition
14995 for the CUPS printing service. To add printer support to a Guix
14996 system, add a @code{cups-service} to the operating system definition:
14998 @deffn {Scheme Variable} cups-service-type
14999 The service type for the CUPS print server. Its value should be a valid
15000 CUPS configuration (see below). To use the default settings, simply
15003 (service cups-service-type)
15007 The CUPS configuration controls the basic things about your CUPS
15008 installation: what interfaces it listens on, what to do if a print job
15009 fails, how much logging to do, and so on. To actually add a printer,
15010 you have to visit the @url{http://localhost:631} URL, or use a tool such
15011 as GNOME's printer configuration services. By default, configuring a
15012 CUPS service will generate a self-signed certificate if needed, for
15013 secure connections to the print server.
15015 Suppose you want to enable the Web interface of CUPS and also add
15016 support for Epson printers @i{via} the @code{escpr} package and for HP
15017 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
15018 like this (you need to use the @code{(gnu packages cups)} module):
15021 (service cups-service-type
15022 (cups-configuration
15023 (web-interface? #t)
15025 (list cups-filters escpr hplip-minimal))))
15028 Note: If you wish to use the Qt5 based GUI which comes with the hplip
15029 package then it is suggested that you install the @code{hplip} package,
15030 either in your OS configuration file or as your user.
15032 The available configuration parameters follow. Each parameter
15033 definition is preceded by its type; for example, @samp{string-list foo}
15034 indicates that the @code{foo} parameter should be specified as a list of
15035 strings. There is also a way to specify the configuration as a string,
15036 if you have an old @code{cupsd.conf} file that you want to port over
15037 from some other system; see the end for more details.
15039 @c The following documentation was initially generated by
15040 @c (generate-documentation) in (gnu services cups). Manually maintained
15041 @c documentation is better, so we shouldn't hesitate to edit below as
15042 @c needed. However if the change you want to make to this documentation
15043 @c can be done in an automated way, it's probably easier to change
15044 @c (generate-documentation) than to make it below and have to deal with
15045 @c the churn as CUPS updates.
15048 Available @code{cups-configuration} fields are:
15050 @deftypevr {@code{cups-configuration} parameter} package cups
15054 @deftypevr {@code{cups-configuration} parameter} package-list extensions
15055 Drivers and other extensions to the CUPS package.
15058 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
15059 Configuration of where to write logs, what directories to use for print
15060 spools, and related privileged configuration parameters.
15062 Available @code{files-configuration} fields are:
15064 @deftypevr {@code{files-configuration} parameter} log-location access-log
15065 Defines the access log filename. Specifying a blank filename disables
15066 access log generation. The value @code{stderr} causes log entries to be
15067 sent to the standard error file when the scheduler is running in the
15068 foreground, or to the system log daemon when run in the background. The
15069 value @code{syslog} causes log entries to be sent to the system log
15070 daemon. The server name may be included in filenames using the string
15071 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
15073 Defaults to @samp{"/var/log/cups/access_log"}.
15076 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
15077 Where CUPS should cache data.
15079 Defaults to @samp{"/var/cache/cups"}.
15082 @deftypevr {@code{files-configuration} parameter} string config-file-perm
15083 Specifies the permissions for all configuration files that the scheduler
15086 Note that the permissions for the printers.conf file are currently
15087 masked to only allow access from the scheduler user (typically root).
15088 This is done because printer device URIs sometimes contain sensitive
15089 authentication information that should not be generally known on the
15090 system. There is no way to disable this security feature.
15092 Defaults to @samp{"0640"}.
15095 @deftypevr {@code{files-configuration} parameter} log-location error-log
15096 Defines the error log filename. Specifying a blank filename disables
15097 error log generation. The value @code{stderr} causes log entries to be
15098 sent to the standard error file when the scheduler is running in the
15099 foreground, or to the system log daemon when run in the background. The
15100 value @code{syslog} causes log entries to be sent to the system log
15101 daemon. The server name may be included in filenames using the string
15102 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
15104 Defaults to @samp{"/var/log/cups/error_log"}.
15107 @deftypevr {@code{files-configuration} parameter} string fatal-errors
15108 Specifies which errors are fatal, causing the scheduler to exit. The
15113 No errors are fatal.
15116 All of the errors below are fatal.
15119 Browsing initialization errors are fatal, for example failed connections
15120 to the DNS-SD daemon.
15123 Configuration file syntax errors are fatal.
15126 Listen or Port errors are fatal, except for IPv6 failures on the
15127 loopback or @code{any} addresses.
15130 Log file creation or write errors are fatal.
15133 Bad startup file permissions are fatal, for example shared TLS
15134 certificate and key files with world-read permissions.
15137 Defaults to @samp{"all -browse"}.
15140 @deftypevr {@code{files-configuration} parameter} boolean file-device?
15141 Specifies whether the file pseudo-device can be used for new printer
15142 queues. The URI @uref{file:///dev/null} is always allowed.
15144 Defaults to @samp{#f}.
15147 @deftypevr {@code{files-configuration} parameter} string group
15148 Specifies the group name or ID that will be used when executing external
15151 Defaults to @samp{"lp"}.
15154 @deftypevr {@code{files-configuration} parameter} string log-file-perm
15155 Specifies the permissions for all log files that the scheduler writes.
15157 Defaults to @samp{"0644"}.
15160 @deftypevr {@code{files-configuration} parameter} log-location page-log
15161 Defines the page log filename. Specifying a blank filename disables
15162 page log generation. The value @code{stderr} causes log entries to be
15163 sent to the standard error file when the scheduler is running in the
15164 foreground, or to the system log daemon when run in the background. The
15165 value @code{syslog} causes log entries to be sent to the system log
15166 daemon. The server name may be included in filenames using the string
15167 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
15169 Defaults to @samp{"/var/log/cups/page_log"}.
15172 @deftypevr {@code{files-configuration} parameter} string remote-root
15173 Specifies the username that is associated with unauthenticated accesses
15174 by clients claiming to be the root user. The default is @code{remroot}.
15176 Defaults to @samp{"remroot"}.
15179 @deftypevr {@code{files-configuration} parameter} file-name request-root
15180 Specifies the directory that contains print jobs and other HTTP request
15183 Defaults to @samp{"/var/spool/cups"}.
15186 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
15187 Specifies the level of security sandboxing that is applied to print
15188 filters, backends, and other child processes of the scheduler; either
15189 @code{relaxed} or @code{strict}. This directive is currently only
15190 used/supported on macOS.
15192 Defaults to @samp{strict}.
15195 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
15196 Specifies the location of TLS certificates and private keys. CUPS will
15197 look for public and private keys in this directory: a @code{.crt} files
15198 for PEM-encoded certificates and corresponding @code{.key} files for
15199 PEM-encoded private keys.
15201 Defaults to @samp{"/etc/cups/ssl"}.
15204 @deftypevr {@code{files-configuration} parameter} file-name server-root
15205 Specifies the directory containing the server configuration files.
15207 Defaults to @samp{"/etc/cups"}.
15210 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
15211 Specifies whether the scheduler calls fsync(2) after writing
15212 configuration or state files.
15214 Defaults to @samp{#f}.
15217 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
15218 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
15221 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
15222 Specifies the directory where temporary files are stored.
15224 Defaults to @samp{"/var/spool/cups/tmp"}.
15227 @deftypevr {@code{files-configuration} parameter} string user
15228 Specifies the user name or ID that is used when running external
15231 Defaults to @samp{"lp"}.
15234 @deftypevr {@code{files-configuration} parameter} string set-env
15235 Set the specified environment variable to be passed to child processes.
15237 Defaults to @samp{"variable value"}.
15241 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
15242 Specifies the logging level for the AccessLog file. The @code{config}
15243 level logs when printers and classes are added, deleted, or modified and
15244 when configuration files are accessed or updated. The @code{actions}
15245 level logs when print jobs are submitted, held, released, modified, or
15246 canceled, and any of the conditions for @code{config}. The @code{all}
15247 level logs all requests.
15249 Defaults to @samp{actions}.
15252 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
15253 Specifies whether to purge job history data automatically when it is no
15254 longer required for quotas.
15256 Defaults to @samp{#f}.
15259 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
15260 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
15261 For example, @samp{"_cups" "_print"} will tell network clients that both
15262 CUPS sharing and IPP Everywhere are supported.
15264 Defaults to @samp{"_cups"}.
15267 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
15268 Specifies which protocols to use for local printer sharing.
15270 Defaults to @samp{dnssd}.
15273 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
15274 Specifies whether the CUPS web interface is advertised.
15276 Defaults to @samp{#f}.
15279 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
15280 Specifies whether shared printers are advertised.
15282 Defaults to @samp{#f}.
15285 @deftypevr {@code{cups-configuration} parameter} string classification
15286 Specifies the security classification of the server. Any valid banner
15287 name can be used, including @samp{"classified"}, @samp{"confidential"},
15288 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
15289 banner can be omitted to disable secure printing functions.
15291 Defaults to @samp{""}.
15294 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
15295 Specifies whether users may override the classification (cover page) of
15296 individual print jobs using the @code{job-sheets} option.
15298 Defaults to @samp{#f}.
15301 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
15302 Specifies the default type of authentication to use.
15304 Defaults to @samp{Basic}.
15307 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
15308 Specifies whether encryption will be used for authenticated requests.
15310 Defaults to @samp{Required}.
15313 @deftypevr {@code{cups-configuration} parameter} string default-language
15314 Specifies the default language to use for text and web content.
15316 Defaults to @samp{"en"}.
15319 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
15320 Specifies the default paper size for new print queues. @samp{"Auto"}
15321 uses a locale-specific default, while @samp{"None"} specifies there is
15322 no default paper size. Specific size names are typically
15323 @samp{"Letter"} or @samp{"A4"}.
15325 Defaults to @samp{"Auto"}.
15328 @deftypevr {@code{cups-configuration} parameter} string default-policy
15329 Specifies the default access policy to use.
15331 Defaults to @samp{"default"}.
15334 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
15335 Specifies whether local printers are shared by default.
15337 Defaults to @samp{#t}.
15340 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
15341 Specifies the delay for updating of configuration and state files, in
15342 seconds. A value of 0 causes the update to happen as soon as possible,
15343 typically within a few milliseconds.
15345 Defaults to @samp{30}.
15348 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
15349 Specifies what to do when an error occurs. Possible values are
15350 @code{abort-job}, which will discard the failed print job;
15351 @code{retry-job}, which will retry the job at a later time;
15352 @code{retry-current-job}, which retries the failed job immediately; and
15353 @code{stop-printer}, which stops the printer.
15355 Defaults to @samp{stop-printer}.
15358 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
15359 Specifies the maximum cost of filters that are run concurrently, which
15360 can be used to minimize disk, memory, and CPU resource problems. A
15361 limit of 0 disables filter limiting. An average print to a
15362 non-PostScript printer needs a filter limit of about 200. A PostScript
15363 printer needs about half that (100). Setting the limit below these
15364 thresholds will effectively limit the scheduler to printing a single job
15367 Defaults to @samp{0}.
15370 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
15371 Specifies the scheduling priority of filters that are run to print a
15372 job. The nice value ranges from 0, the highest priority, to 19, the
15375 Defaults to @samp{0}.
15378 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
15379 Specifies whether to do reverse lookups on connecting clients. The
15380 @code{double} setting causes @code{cupsd} to verify that the hostname
15381 resolved from the address matches one of the addresses returned for that
15382 hostname. Double lookups also prevent clients with unregistered
15383 addresses from connecting to your server. Only set this option to
15384 @code{#t} or @code{double} if absolutely required.
15386 Defaults to @samp{#f}.
15389 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
15390 Specifies the number of seconds to wait before killing the filters and
15391 backend associated with a canceled or held job.
15393 Defaults to @samp{30}.
15396 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
15397 Specifies the interval between retries of jobs in seconds. This is
15398 typically used for fax queues but can also be used with normal print
15399 queues whose error policy is @code{retry-job} or
15400 @code{retry-current-job}.
15402 Defaults to @samp{30}.
15405 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
15406 Specifies the number of retries that are done for jobs. This is
15407 typically used for fax queues but can also be used with normal print
15408 queues whose error policy is @code{retry-job} or
15409 @code{retry-current-job}.
15411 Defaults to @samp{5}.
15414 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
15415 Specifies whether to support HTTP keep-alive connections.
15417 Defaults to @samp{#t}.
15420 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
15421 Specifies how long an idle client connection remains open, in seconds.
15423 Defaults to @samp{30}.
15426 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
15427 Specifies the maximum size of print files, IPP requests, and HTML form
15428 data. A limit of 0 disables the limit check.
15430 Defaults to @samp{0}.
15433 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
15434 Listens on the specified interfaces for connections. Valid values are
15435 of the form @var{address}:@var{port}, where @var{address} is either an
15436 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
15437 indicate all addresses. Values can also be file names of local UNIX
15438 domain sockets. The Listen directive is similar to the Port directive
15439 but allows you to restrict access to specific interfaces or networks.
15442 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
15443 Specifies the number of pending connections that will be allowed. This
15444 normally only affects very busy servers that have reached the MaxClients
15445 limit, but can also be triggered by large numbers of simultaneous
15446 connections. When the limit is reached, the operating system will
15447 refuse additional connections until the scheduler can accept the pending
15450 Defaults to @samp{128}.
15453 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
15454 Specifies a set of additional access controls.
15456 Available @code{location-access-controls} fields are:
15458 @deftypevr {@code{location-access-controls} parameter} file-name path
15459 Specifies the URI path to which the access control applies.
15462 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
15463 Access controls for all access to this path, in the same format as the
15464 @code{access-controls} of @code{operation-access-control}.
15466 Defaults to @samp{()}.
15469 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
15470 Access controls for method-specific access to this path.
15472 Defaults to @samp{()}.
15474 Available @code{method-access-controls} fields are:
15476 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
15477 If @code{#t}, apply access controls to all methods except the listed
15478 methods. Otherwise apply to only the listed methods.
15480 Defaults to @samp{#f}.
15483 @deftypevr {@code{method-access-controls} parameter} method-list methods
15484 Methods to which this access control applies.
15486 Defaults to @samp{()}.
15489 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
15490 Access control directives, as a list of strings. Each string should be
15491 one directive, such as @samp{"Order allow,deny"}.
15493 Defaults to @samp{()}.
15498 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
15499 Specifies the number of debugging messages that are retained for logging
15500 if an error occurs in a print job. Debug messages are logged regardless
15501 of the LogLevel setting.
15503 Defaults to @samp{100}.
15506 @deftypevr {@code{cups-configuration} parameter} log-level log-level
15507 Specifies the level of logging for the ErrorLog file. The value
15508 @code{none} stops all logging while @code{debug2} logs everything.
15510 Defaults to @samp{info}.
15513 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
15514 Specifies the format of the date and time in the log files. The value
15515 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
15517 Defaults to @samp{standard}.
15520 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15521 Specifies the maximum number of simultaneous clients that are allowed by
15524 Defaults to @samp{100}.
15527 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15528 Specifies the maximum number of simultaneous clients that are allowed
15529 from a single address.
15531 Defaults to @samp{100}.
15534 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15535 Specifies the maximum number of copies that a user can print of each
15538 Defaults to @samp{9999}.
15541 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15542 Specifies the maximum time a job may remain in the @code{indefinite}
15543 hold state before it is canceled. A value of 0 disables cancellation of
15546 Defaults to @samp{0}.
15549 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15550 Specifies the maximum number of simultaneous jobs that are allowed. Set
15551 to 0 to allow an unlimited number of jobs.
15553 Defaults to @samp{500}.
15556 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15557 Specifies the maximum number of simultaneous jobs that are allowed per
15558 printer. A value of 0 allows up to MaxJobs jobs per printer.
15560 Defaults to @samp{0}.
15563 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15564 Specifies the maximum number of simultaneous jobs that are allowed per
15565 user. A value of 0 allows up to MaxJobs jobs per user.
15567 Defaults to @samp{0}.
15570 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15571 Specifies the maximum time a job may take to print before it is
15572 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
15574 Defaults to @samp{10800}.
15577 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15578 Specifies the maximum size of the log files before they are rotated, in
15579 bytes. The value 0 disables log rotation.
15581 Defaults to @samp{1048576}.
15584 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15585 Specifies the maximum amount of time to allow between files in a
15586 multiple file print job, in seconds.
15588 Defaults to @samp{300}.
15591 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15592 Specifies the format of PageLog lines. Sequences beginning with percent
15593 (@samp{%}) characters are replaced with the corresponding information,
15594 while all other characters are copied literally. The following percent
15595 sequences are recognized:
15599 insert a single percent character
15602 insert the value of the specified IPP attribute
15605 insert the number of copies for the current page
15608 insert the current page number
15611 insert the current date and time in common log format
15617 insert the printer name
15620 insert the username
15623 A value of the empty string disables page logging. The string @code{%p
15624 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15625 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15628 Defaults to @samp{""}.
15631 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15632 Passes the specified environment variable(s) to child processes; a list
15635 Defaults to @samp{()}.
15638 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15639 Specifies named access control policies.
15641 Available @code{policy-configuration} fields are:
15643 @deftypevr {@code{policy-configuration} parameter} string name
15644 Name of the policy.
15647 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15648 Specifies an access list for a job's private values. @code{@@ACL} maps
15649 to the printer's requesting-user-name-allowed or
15650 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15651 owner. @code{@@SYSTEM} maps to the groups listed for the
15652 @code{system-group} field of the @code{files-config} configuration,
15653 which is reified into the @code{cups-files.conf(5)} file. Other
15654 possible elements of the access list include specific user names, and
15655 @code{@@@var{group}} to indicate members of a specific group. The
15656 access list may also be simply @code{all} or @code{default}.
15658 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15661 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15662 Specifies the list of job values to make private, or @code{all},
15663 @code{default}, or @code{none}.
15665 Defaults to @samp{"job-name job-originating-host-name
15666 job-originating-user-name phone"}.
15669 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15670 Specifies an access list for a subscription's private values.
15671 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15672 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15673 owner. @code{@@SYSTEM} maps to the groups listed for the
15674 @code{system-group} field of the @code{files-config} configuration,
15675 which is reified into the @code{cups-files.conf(5)} file. Other
15676 possible elements of the access list include specific user names, and
15677 @code{@@@var{group}} to indicate members of a specific group. The
15678 access list may also be simply @code{all} or @code{default}.
15680 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15683 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15684 Specifies the list of job values to make private, or @code{all},
15685 @code{default}, or @code{none}.
15687 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15688 notify-subscriber-user-name notify-user-data"}.
15691 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15692 Access control by IPP operation.
15694 Defaults to @samp{()}.
15698 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15699 Specifies whether job files (documents) are preserved after a job is
15700 printed. If a numeric value is specified, job files are preserved for
15701 the indicated number of seconds after printing. Otherwise a boolean
15702 value applies indefinitely.
15704 Defaults to @samp{86400}.
15707 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15708 Specifies whether the job history is preserved after a job is printed.
15709 If a numeric value is specified, the job history is preserved for the
15710 indicated number of seconds after printing. If @code{#t}, the job
15711 history is preserved until the MaxJobs limit is reached.
15713 Defaults to @samp{#t}.
15716 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15717 Specifies the amount of time to wait for job completion before
15718 restarting the scheduler.
15720 Defaults to @samp{30}.
15723 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15724 Specifies the maximum amount of memory to use when converting documents
15725 into bitmaps for a printer.
15727 Defaults to @samp{"128m"}.
15730 @deftypevr {@code{cups-configuration} parameter} string server-admin
15731 Specifies the email address of the server administrator.
15733 Defaults to @samp{"root@@localhost.localdomain"}.
15736 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15737 The ServerAlias directive is used for HTTP Host header validation when
15738 clients connect to the scheduler from external interfaces. Using the
15739 special name @code{*} can expose your system to known browser-based DNS
15740 rebinding attacks, even when accessing sites through a firewall. If the
15741 auto-discovery of alternate names does not work, we recommend listing
15742 each alternate name with a ServerAlias directive instead of using
15745 Defaults to @samp{*}.
15748 @deftypevr {@code{cups-configuration} parameter} string server-name
15749 Specifies the fully-qualified host name of the server.
15751 Defaults to @samp{"localhost"}.
15754 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15755 Specifies what information is included in the Server header of HTTP
15756 responses. @code{None} disables the Server header. @code{ProductOnly}
15757 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15758 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15759 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15760 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15761 2.0.0 (@var{uname}) IPP/2.0}.
15763 Defaults to @samp{Minimal}.
15766 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15767 Listens on the specified interfaces for encrypted connections. Valid
15768 values are of the form @var{address}:@var{port}, where @var{address} is
15769 either an IPv6 address enclosed in brackets, an IPv4 address, or
15770 @code{*} to indicate all addresses.
15772 Defaults to @samp{()}.
15775 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15776 Sets encryption options. By default, CUPS only supports encryption
15777 using TLS v1.0 or higher using known secure cipher suites. Security is
15778 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15779 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15780 suites, which are required for some older clients. The @code{AllowSSL3} option
15781 enables SSL v3.0, which is required for some older clients that do not support
15782 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15783 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15784 protocol version to TLS v1.1.
15786 Defaults to @samp{()}.
15789 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15790 Specifies whether the scheduler requires clients to strictly adhere to
15791 the IPP specifications.
15793 Defaults to @samp{#f}.
15796 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15797 Specifies the HTTP request timeout, in seconds.
15799 Defaults to @samp{300}.
15803 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15804 Specifies whether the web interface is enabled.
15806 Defaults to @samp{#f}.
15809 At this point you're probably thinking ``oh dear, Guix manual, I like
15810 you but you can stop already with the configuration options''. Indeed.
15811 However, one more point: it could be that you have an existing
15812 @code{cupsd.conf} that you want to use. In that case, you can pass an
15813 @code{opaque-cups-configuration} as the configuration of a
15814 @code{cups-service-type}.
15816 Available @code{opaque-cups-configuration} fields are:
15818 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15822 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15823 The contents of the @code{cupsd.conf}, as a string.
15826 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15827 The contents of the @code{cups-files.conf} file, as a string.
15830 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15831 strings of the same name, you could instantiate a CUPS service like
15835 (service cups-service-type
15836 (opaque-cups-configuration
15837 (cupsd.conf cupsd.conf)
15838 (cups-files.conf cups-files.conf)))
15842 @node Desktop Services
15843 @subsection Desktop Services
15845 The @code{(gnu services desktop)} module provides services that are
15846 usually useful in the context of a ``desktop'' setup---that is, on a
15847 machine running a graphical display server, possibly with graphical user
15848 interfaces, etc. It also defines services that provide specific desktop
15849 environments like GNOME, Xfce or MATE.
15851 To simplify things, the module defines a variable containing the set of
15852 services that users typically expect on a machine with a graphical
15853 environment and networking:
15855 @defvr {Scheme Variable} %desktop-services
15856 This is a list of services that builds upon @code{%base-services} and
15857 adds or adjusts services for a typical ``desktop'' setup.
15859 In particular, it adds a graphical login manager (@pxref{X Window,
15860 @code{gdm-service-type}}), screen lockers, a network management tool
15861 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15862 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15863 energy and color management services, the @code{elogind} login and seat
15864 manager, the Polkit privilege service, the GeoClue location service, the
15865 AccountsService daemon that allows authorized users change system passwords,
15866 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15867 name service switch service configured to be able to use @code{nss-mdns}
15868 (@pxref{Name Service Switch, mDNS}).
15871 The @code{%desktop-services} variable can be used as the @code{services}
15872 field of an @code{operating-system} declaration (@pxref{operating-system
15873 Reference, @code{services}}).
15875 Additionally, the @code{gnome-desktop-service-type},
15876 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15877 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15878 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15879 services like the backlight adjustment helpers and the power management
15880 utilities are added to the system, extending @code{polkit} and @code{dbus}
15881 appropriately, allowing GNOME to operate with elevated privileges on a
15882 limited number of special-purpose system interfaces. Additionally,
15883 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15884 metapackage to the system profile. Likewise, adding the Xfce service
15885 not only adds the @code{xfce} metapackage to the system profile, but it
15886 also gives the Thunar file manager the ability to open a ``root-mode''
15887 file management window, if the user authenticates using the
15888 administrator's password via the standard polkit graphical interface.
15889 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15890 appropriately, allowing MATE to operate with elevated privileges on a
15891 limited number of special-purpose system interfaces. Additionally,
15892 adding a service of type @code{mate-desktop-service-type} adds the MATE
15893 metapackage to the system profile. ``Adding Enlightenment'' means that
15894 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15895 are set as setuid, allowing Enlightenment's screen locker and other
15896 functionality to work as expected.
15898 The desktop environments in Guix use the Xorg display server by
15899 default. If you'd like to use the newer display server protocol
15900 called Wayland, you need to use the @code{sddm-service} instead of
15901 GDM as the graphical login manager. You should then
15902 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15903 also try starting GNOME on Wayland manually from a TTY with the
15904 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15905 gnome-session``. Currently only GNOME has support for Wayland.
15907 @defvr {Scheme Variable} gnome-desktop-service-type
15908 This is the type of the service that adds the @uref{https://www.gnome.org,
15909 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15910 object (see below.)
15912 This service adds the @code{gnome} package to the system profile, and extends
15913 polkit with the actions from @code{gnome-settings-daemon}.
15916 @deftp {Data Type} gnome-desktop-configuration
15917 Configuration record for the GNOME desktop environment.
15920 @item @code{gnome} (default: @code{gnome})
15921 The GNOME package to use.
15925 @defvr {Scheme Variable} xfce-desktop-service-type
15926 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15927 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15930 This service adds the @code{xfce} package to the system profile, and
15931 extends polkit with the ability for @code{thunar} to manipulate the file
15932 system as root from within a user session, after the user has authenticated
15933 with the administrator's password.
15936 @deftp {Data Type} xfce-desktop-configuration
15937 Configuration record for the Xfce desktop environment.
15940 @item @code{xfce} (default: @code{xfce})
15941 The Xfce package to use.
15945 @deffn {Scheme Variable} mate-desktop-service-type
15946 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15947 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15948 object (see below.)
15950 This service adds the @code{mate} package to the system
15951 profile, and extends polkit with the actions from
15952 @code{mate-settings-daemon}.
15955 @deftp {Data Type} mate-desktop-configuration
15956 Configuration record for the MATE desktop environment.
15959 @item @code{mate} (default: @code{mate})
15960 The MATE package to use.
15964 @deffn {Scheme Variable} enlightenment-desktop-service-type
15965 Return a service that adds the @code{enlightenment} package to the system
15966 profile, and extends dbus with actions from @code{efl}.
15969 @deftp {Data Type} enlightenment-desktop-service-configuration
15971 @item @code{enlightenment} (default: @code{enlightenment})
15972 The enlightenment package to use.
15976 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15977 the default @code{%desktop-services} variable doesn't include any of
15978 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15979 @code{%desktop-services} in the @code{services} field of your
15980 @code{operating-system}:
15983 (use-modules (gnu))
15984 (use-service-modules desktop)
15987 ;; cons* adds items to the list given as its last argument.
15988 (services (cons* (service gnome-desktop-service-type)
15989 (service xfce-desktop-service)
15990 %desktop-services))
15994 These desktop environments will then be available as options in the
15995 graphical login window.
15997 The actual service definitions included in @code{%desktop-services} and
15998 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15999 are described below.
16001 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
16002 Return a service that runs the ``system bus'', using @var{dbus}, with
16003 support for @var{services}.
16005 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
16006 facility. Its system bus is used to allow system services to communicate
16007 and to be notified of system-wide events.
16009 @var{services} must be a list of packages that provide an
16010 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
16011 and policy files. For example, to allow avahi-daemon to use the system bus,
16012 @var{services} must be equal to @code{(list avahi)}.
16015 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
16016 Return a service that runs the @code{elogind} login and
16017 seat management daemon. @uref{https://github.com/elogind/elogind,
16018 Elogind} exposes a D-Bus interface that can be used to know which users
16019 are logged in, know what kind of sessions they have open, suspend the
16020 system, inhibit system suspend, reboot the system, and other tasks.
16022 Elogind handles most system-level power events for a computer, for
16023 example suspending the system when a lid is closed, or shutting it down
16024 when the power button is pressed.
16026 The @var{config} keyword argument specifies the configuration for
16027 elogind, and should be the result of an @code{(elogind-configuration
16028 (@var{parameter} @var{value})...)} invocation. Available parameters and
16029 their default values are:
16032 @item kill-user-processes?
16034 @item kill-only-users
16036 @item kill-exclude-users
16038 @item inhibit-delay-max-seconds
16040 @item handle-power-key
16042 @item handle-suspend-key
16044 @item handle-hibernate-key
16046 @item handle-lid-switch
16048 @item handle-lid-switch-docked
16050 @item power-key-ignore-inhibited?
16052 @item suspend-key-ignore-inhibited?
16054 @item hibernate-key-ignore-inhibited?
16056 @item lid-switch-ignore-inhibited?
16058 @item holdoff-timeout-seconds
16062 @item idle-action-seconds
16064 @item runtime-directory-size-percent
16066 @item runtime-directory-size
16070 @item suspend-state
16071 @code{("mem" "standby" "freeze")}
16074 @item hibernate-state
16076 @item hibernate-mode
16077 @code{("platform" "shutdown")}
16078 @item hybrid-sleep-state
16080 @item hybrid-sleep-mode
16081 @code{("suspend" "platform" "shutdown")}
16085 @deffn {Scheme Procedure} accountsservice-service @
16086 [#:accountsservice @var{accountsservice}]
16087 Return a service that runs AccountsService, a system service that can
16088 list available accounts, change their passwords, and so on.
16089 AccountsService integrates with PolicyKit to enable unprivileged users
16090 to acquire the capability to modify their system configuration.
16091 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
16092 accountsservice web site} for more information.
16094 The @var{accountsservice} keyword argument is the @code{accountsservice}
16095 package to expose as a service.
16098 @deffn {Scheme Procedure} polkit-service @
16099 [#:polkit @var{polkit}]
16100 Return a service that runs the
16101 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
16102 management service}, which allows system administrators to grant access to
16103 privileged operations in a structured way. By querying the Polkit service, a
16104 privileged system component can know when it should grant additional
16105 capabilities to ordinary users. For example, an ordinary user can be granted
16106 the capability to suspend the system if the user is logged in locally.
16109 @defvr {Scheme Variable} polkit-wheel-service
16110 Service that adds the @code{wheel} group as admins to the Polkit
16111 service. This makes it so that users in the @code{wheel} group are queried
16112 for their own passwords when performing administrative actions instead of
16113 @code{root}'s, similar to the behaviour used by @code{sudo}.
16116 @defvr {Scheme Variable} upower-service-type
16117 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
16118 system-wide monitor for power consumption and battery levels, with the given
16119 configuration settings.
16121 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
16122 notably used by GNOME.
16125 @deftp {Data Type} upower-configuration
16126 Data type representation the configuration for UPower.
16130 @item @code{upower} (default: @var{upower})
16131 Package to use for @code{upower}.
16133 @item @code{watts-up-pro?} (default: @code{#f})
16134 Enable the Watts Up Pro device.
16136 @item @code{poll-batteries?} (default: @code{#t})
16137 Enable polling the kernel for battery level changes.
16139 @item @code{ignore-lid?} (default: @code{#f})
16140 Ignore the lid state, this can be useful if it's incorrect on a device.
16142 @item @code{use-percentage-for-policy?} (default: @code{#f})
16143 Whether battery percentage based policy should be used. The default is to use
16144 the time left, change to @code{#t} to use the percentage.
16146 @item @code{percentage-low} (default: @code{10})
16147 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16148 at which the battery is considered low.
16150 @item @code{percentage-critical} (default: @code{3})
16151 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16152 at which the battery is considered critical.
16154 @item @code{percentage-action} (default: @code{2})
16155 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
16156 at which action will be taken.
16158 @item @code{time-low} (default: @code{1200})
16159 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16160 seconds at which the battery is considered low.
16162 @item @code{time-critical} (default: @code{300})
16163 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16164 seconds at which the battery is considered critical.
16166 @item @code{time-action} (default: @code{120})
16167 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
16168 seconds at which action will be taken.
16170 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
16171 The action taken when @code{percentage-action} or @code{time-action} is
16172 reached (depending on the configuration of @code{use-percentage-for-policy?}).
16174 Possible values are:
16184 @code{'hybrid-sleep}.
16190 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
16191 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
16192 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
16193 notifications and ways to mount/unmount disks. Programs that talk to UDisks
16194 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
16197 @deffn {Scheme Variable} colord-service-type
16198 This is the type of the service that runs @command{colord}, a system
16199 service with a D-Bus
16200 interface to manage the color profiles of input and output devices such as
16201 screens and scanners. It is notably used by the GNOME Color Manager graphical
16202 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
16203 site} for more information.
16206 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
16207 Return a configuration allowing an application to access GeoClue
16208 location data. @var{name} is the Desktop ID of the application, without
16209 the @code{.desktop} part. If @var{allowed?} is true, the application
16210 will have access to location information by default. The boolean
16211 @var{system?} value indicates whether an application is a system component
16212 or not. Finally @var{users} is a list of UIDs of all users for which
16213 this application is allowed location info access. An empty users list
16214 means that all users are allowed.
16217 @cindex scanner access
16218 @deffn {Scheme Procedure} sane-service-type
16219 This service provides access to scanners @i{via}
16220 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
16224 @defvr {Scheme Variable} %standard-geoclue-applications
16225 The standard list of well-known GeoClue application configurations,
16226 granting authority to the GNOME date-and-time utility to ask for the
16227 current location in order to set the time zone, and allowing the
16228 IceCat and Epiphany web browsers to request location information.
16229 IceCat and Epiphany both query the user before allowing a web page to
16230 know the user's location.
16233 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
16234 [#:whitelist '()] @
16235 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
16236 [#:submit-data? #f]
16237 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
16238 [#:submission-nick "geoclue"] @
16239 [#:applications %standard-geoclue-applications]
16240 Return a service that runs the GeoClue location service. This service
16241 provides a D-Bus interface to allow applications to request access to a
16242 user's physical location, and optionally to add information to online
16243 location databases. See
16244 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
16245 web site} for more information.
16248 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
16249 [@w{#:auto-enable? #f}]
16250 Return a service that runs the @command{bluetoothd} daemon, which
16251 manages all the Bluetooth devices and provides a number of D-Bus
16252 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
16253 powered automatically at boot, which can be useful when using a
16254 bluetooth keyboard or mouse.
16256 Users need to be in the @code{lp} group to access the D-Bus service.
16259 @defvr {Scheme Variable} gnome-keyring-service-type
16260 This is the type of the service that adds the
16261 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
16262 value is a @code{gnome-keyring-configuration} object (see below.)
16264 This service adds the @code{gnome-keyring} package to the system profile
16265 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
16266 a user's login keyring when they log in or setting its password with passwd.
16269 @deftp {Data Type} gnome-keyring-configuration
16270 Configuration record for the GNOME Keyring service.
16273 @item @code{keyring} (default: @code{gnome-keyring})
16274 The GNOME keyring package to use.
16276 @item @code{pam-services}
16277 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
16278 services to extend, where @var{service} is the name of an existing
16279 service to extend and @var{kind} is one of @code{login} or
16282 If @code{login} is given, it adds an optional
16283 @code{pam_gnome_keyring.so} to the auth block without arguments and to
16284 the session block with @code{auto_start}. If @code{passwd} is given, it
16285 adds an optional @code{pam_gnome_keyring.so} to the password block
16288 By default, this field contains ``gdm-password'' with the value @code{login}
16289 and ``passwd'' is with the value @code{passwd}.
16294 @node Sound Services
16295 @subsection Sound Services
16297 @cindex sound support
16299 @cindex PulseAudio, sound support
16301 The @code{(gnu services sound)} module provides a service to configure the
16302 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
16303 preferred ALSA output driver.
16305 @deffn {Scheme Variable} alsa-service-type
16306 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
16307 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
16308 configuration file. The value for this type is a @command{alsa-configuration}
16309 record as in this example:
16312 (service alsa-service-type)
16315 See below for details about @code{alsa-configuration}.
16318 @deftp {Data Type} alsa-configuration
16319 Data type representing the configuration for @code{alsa-service}.
16322 @item @code{alsa-plugins} (default: @var{alsa-plugins})
16323 @code{alsa-plugins} package to use.
16325 @item @code{pulseaudio?} (default: @var{#t})
16326 Whether ALSA applications should transparently be made to use the
16327 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
16329 Using PulseAudio allows you to run several sound-producing applications
16330 at the same time and to individual control them @i{via}
16331 @command{pavucontrol}, among other things.
16333 @item @code{extra-options} (default: @var{""})
16334 String to append to the @file{/etc/asound.conf} file.
16339 Individual users who want to override the system configuration of ALSA can do
16340 it with the @file{~/.asoundrc} file:
16343 # In guix, we have to specify the absolute path for plugins.
16345 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
16348 # Routing ALSA to jack:
16349 # <http://jackaudio.org/faq/routing_alsa.html>.
16353 0 system:playback_1
16354 1 system:playback_2
16371 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
16374 @deffn {Scheme Variable} pulseaudio-service-type
16375 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
16376 sound server. It exists to allow system overrides of the default settings
16377 via @code{pulseaudio-configuration}, see below.
16380 This service overrides per-user configuration files. If you want
16381 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
16382 have to unset the environment variables @code{PULSE_CONFIG} and
16383 @code{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
16387 This service on its own does not ensure, that the @code{pulseaudio} package
16388 exists on your machine. It merely adds configuration files for it, as
16389 detailed below. In the (admittedly unlikely) case, that you find yourself
16390 without a @code{pulseaudio} package, consider enabling it through the
16391 @code{alsa-service-type} above.
16395 @deftp {Data Type} pulseaudio-configuration
16396 Data type representing the configuration for @code{pulseaudio-service}.
16399 @item @var{client-conf} (default: @code{'()})
16400 List of settings to set in @file{client.conf}.
16401 Accepts a list of strings or a symbol-value pairs. A string will be
16402 inserted as-is with a newline added. A pair will be formatted as
16403 ``key = value'', again with a newline added.
16405 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
16406 List of settings to set in @file{daemon.conf}, formatted just like
16409 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
16410 Script file to use as as @file{default.pa}.
16412 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
16413 Script file to use as as @file{system.pa}.
16417 @deffn {Scheme Variable} ladspa-service-type
16418 This service sets the @var{LADSPA_PATH} variable, so that programs, which
16419 respect it, e.g. PulseAudio, can load LADSPA plugins.
16421 The following example will setup the service to enable modules from the
16422 @code{swh-plugins} package:
16425 (service ladspa-service-type
16426 (ladspa-configuration (plugins (list swh-plugins))))
16429 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
16434 @node Database Services
16435 @subsection Database Services
16439 The @code{(gnu services databases)} module provides the following services.
16441 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
16442 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
16443 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
16444 Return a service that runs @var{postgresql}, the PostgreSQL database
16447 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
16448 creates a database cluster with @var{locale} as the default
16449 locale, stored in @var{data-directory}. It then listens on @var{port}.
16451 @cindex postgresql extension-packages
16452 Additional extensions are loaded from packages listed in
16453 @var{extension-packages}. Extensions are available at runtime. For instance,
16454 to create a geographic database using the @code{postgis} extension, a user can
16455 configure the postgresql-service as in this example:
16459 (use-package-modules databases geo)
16463 ;; postgresql is required to run `psql' but postgis is not required for
16464 ;; proper operation.
16465 (packages (cons* postgresql %base-packages))
16468 (postgresql-service #:extension-packages (list postgis))
16472 Then the extension becomes visible and you can initialise an empty geographic
16473 database in this way:
16477 > create database postgistest;
16478 > \connect postgistest;
16479 > create extension postgis;
16480 > create extension postgis_topology;
16483 There is no need to add this field for contrib extensions such as hstore or
16484 dblink as they are already loadable by postgresql. This field is only
16485 required to add extensions provided by other packages.
16488 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
16489 Return a service that runs @command{mysqld}, the MySQL or MariaDB
16492 The optional @var{config} argument specifies the configuration for
16493 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
16496 @deftp {Data Type} mysql-configuration
16497 Data type representing the configuration of @var{mysql-service}.
16500 @item @code{mysql} (default: @var{mariadb})
16501 Package object of the MySQL database server, can be either @var{mariadb}
16504 For MySQL, a temporary root password will be displayed at activation time.
16505 For MariaDB, the root password is empty.
16507 @item @code{port} (default: @code{3306})
16508 TCP port on which the database server listens for incoming connections.
16512 @defvr {Scheme Variable} memcached-service-type
16513 This is the service type for the @uref{https://memcached.org/,
16514 Memcached} service, which provides a distributed in memory cache. The
16515 value for the service type is a @code{memcached-configuration} object.
16519 (service memcached-service-type)
16522 @deftp {Data Type} memcached-configuration
16523 Data type representing the configuration of memcached.
16526 @item @code{memcached} (default: @code{memcached})
16527 The Memcached package to use.
16529 @item @code{interfaces} (default: @code{'("0.0.0.0")})
16530 Network interfaces on which to listen.
16532 @item @code{tcp-port} (default: @code{11211})
16533 Port on which to accept connections on,
16535 @item @code{udp-port} (default: @code{11211})
16536 Port on which to accept UDP connections on, a value of 0 will disable
16537 listening on a UDP socket.
16539 @item @code{additional-options} (default: @code{'()})
16540 Additional command line options to pass to @code{memcached}.
16544 @defvr {Scheme Variable} mongodb-service-type
16545 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
16546 The value for the service type is a @code{mongodb-configuration} object.
16550 (service mongodb-service-type)
16553 @deftp {Data Type} mongodb-configuration
16554 Data type representing the configuration of mongodb.
16557 @item @code{mongodb} (default: @code{mongodb})
16558 The MongoDB package to use.
16560 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
16561 The configuration file for MongoDB.
16563 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
16564 This value is used to create the directory, so that it exists and is
16565 owned by the mongodb user. It should match the data-directory which
16566 MongoDB is configured to use through the configuration file.
16570 @defvr {Scheme Variable} redis-service-type
16571 This is the service type for the @uref{https://redis.io/, Redis}
16572 key/value store, whose value is a @code{redis-configuration} object.
16575 @deftp {Data Type} redis-configuration
16576 Data type representing the configuration of redis.
16579 @item @code{redis} (default: @code{redis})
16580 The Redis package to use.
16582 @item @code{bind} (default: @code{"127.0.0.1"})
16583 Network interface on which to listen.
16585 @item @code{port} (default: @code{6379})
16586 Port on which to accept connections on, a value of 0 will disable
16587 listening on a TCP socket.
16589 @item @code{working-directory} (default: @code{"/var/lib/redis"})
16590 Directory in which to store the database and related files.
16594 @node Mail Services
16595 @subsection Mail Services
16599 The @code{(gnu services mail)} module provides Guix service definitions
16600 for email services: IMAP, POP3, and LMTP servers, as well as mail
16601 transport agents (MTAs). Lots of acronyms! These services are detailed
16602 in the subsections below.
16604 @subsubheading Dovecot Service
16606 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
16607 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
16610 By default, Dovecot does not need much configuration; the default
16611 configuration object created by @code{(dovecot-configuration)} will
16612 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
16613 certificate will be generated for TLS-protected connections, though
16614 Dovecot will also listen on cleartext ports by default. There are a
16615 number of options, though, which mail administrators might need to change,
16616 and as is the case with other services, Guix allows the system
16617 administrator to specify these parameters via a uniform Scheme interface.
16619 For example, to specify that mail is located at @code{maildir~/.mail},
16620 one would instantiate the Dovecot service like this:
16623 (dovecot-service #:config
16624 (dovecot-configuration
16625 (mail-location "maildir:~/.mail")))
16628 The available configuration parameters follow. Each parameter
16629 definition is preceded by its type; for example, @samp{string-list foo}
16630 indicates that the @code{foo} parameter should be specified as a list of
16631 strings. There is also a way to specify the configuration as a string,
16632 if you have an old @code{dovecot.conf} file that you want to port over
16633 from some other system; see the end for more details.
16635 @c The following documentation was initially generated by
16636 @c (generate-documentation) in (gnu services mail). Manually maintained
16637 @c documentation is better, so we shouldn't hesitate to edit below as
16638 @c needed. However if the change you want to make to this documentation
16639 @c can be done in an automated way, it's probably easier to change
16640 @c (generate-documentation) than to make it below and have to deal with
16641 @c the churn as dovecot updates.
16643 Available @code{dovecot-configuration} fields are:
16645 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16646 The dovecot package.
16649 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16650 A list of IPs or hosts where to listen for connections. @samp{*}
16651 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16652 interfaces. If you want to specify non-default ports or anything more
16653 complex, customize the address and port fields of the
16654 @samp{inet-listener} of the specific services you are interested in.
16657 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16658 List of protocols we want to serve. Available protocols include
16659 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16661 Available @code{protocol-configuration} fields are:
16663 @deftypevr {@code{protocol-configuration} parameter} string name
16664 The name of the protocol.
16667 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16668 UNIX socket path to the master authentication server to find users.
16669 This is used by imap (for shared users) and lda.
16670 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16673 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16674 Space separated list of plugins to load.
16677 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16678 Maximum number of IMAP connections allowed for a user from each IP
16679 address. NOTE: The username is compared case-sensitively.
16680 Defaults to @samp{10}.
16685 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16686 List of services to enable. Available services include @samp{imap},
16687 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16690 Available @code{service-configuration} fields are:
16692 @deftypevr {@code{service-configuration} parameter} string kind
16693 The service kind. Valid values include @code{director},
16694 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16695 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16696 @code{tcpwrap}, @code{quota-warning}, or anything else.
16699 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16700 Listeners for the service. A listener is either a
16701 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16702 an @code{inet-listener-configuration}.
16703 Defaults to @samp{()}.
16705 Available @code{unix-listener-configuration} fields are:
16707 @deftypevr {@code{unix-listener-configuration} parameter} string path
16708 Path to the file, relative to @code{base-dir} field. This is also used as
16712 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16713 The access mode for the socket.
16714 Defaults to @samp{"0600"}.
16717 @deftypevr {@code{unix-listener-configuration} parameter} string user
16718 The user to own the socket.
16719 Defaults to @samp{""}.
16722 @deftypevr {@code{unix-listener-configuration} parameter} string group
16723 The group to own the socket.
16724 Defaults to @samp{""}.
16728 Available @code{fifo-listener-configuration} fields are:
16730 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16731 Path to the file, relative to @code{base-dir} field. This is also used as
16735 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16736 The access mode for the socket.
16737 Defaults to @samp{"0600"}.
16740 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16741 The user to own the socket.
16742 Defaults to @samp{""}.
16745 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16746 The group to own the socket.
16747 Defaults to @samp{""}.
16751 Available @code{inet-listener-configuration} fields are:
16753 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16754 The protocol to listen for.
16757 @deftypevr {@code{inet-listener-configuration} parameter} string address
16758 The address on which to listen, or empty for all addresses.
16759 Defaults to @samp{""}.
16762 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16763 The port on which to listen.
16766 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16767 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16769 Defaults to @samp{#t}.
16774 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16775 Maximum number of simultaneous client connections per process. Once
16776 this number of connections is received, the next incoming connection
16777 will prompt Dovecot to spawn another process. If set to 0,
16778 @code{default-client-limit} is used instead.
16780 Defaults to @samp{0}.
16784 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16785 Number of connections to handle before starting a new process.
16786 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16787 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16788 Defaults to @samp{1}.
16792 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16793 Maximum number of processes that can exist for this service. If set to
16794 0, @code{default-process-limit} is used instead.
16796 Defaults to @samp{0}.
16800 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16801 Number of processes to always keep waiting for more connections.
16802 Defaults to @samp{0}.
16805 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16806 If you set @samp{service-count 0}, you probably need to grow
16808 Defaults to @samp{256000000}.
16813 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16814 Dict configuration, as created by the @code{dict-configuration}
16817 Available @code{dict-configuration} fields are:
16819 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16820 A list of key-value pairs that this dict should hold.
16821 Defaults to @samp{()}.
16826 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16827 A list of passdb configurations, each one created by the
16828 @code{passdb-configuration} constructor.
16830 Available @code{passdb-configuration} fields are:
16832 @deftypevr {@code{passdb-configuration} parameter} string driver
16833 The driver that the passdb should use. Valid values include
16834 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16836 Defaults to @samp{"pam"}.
16839 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16840 Space separated list of arguments to the passdb driver.
16841 Defaults to @samp{""}.
16846 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16847 List of userdb configurations, each one created by the
16848 @code{userdb-configuration} constructor.
16850 Available @code{userdb-configuration} fields are:
16852 @deftypevr {@code{userdb-configuration} parameter} string driver
16853 The driver that the userdb should use. Valid values include
16854 @samp{passwd} and @samp{static}.
16855 Defaults to @samp{"passwd"}.
16858 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16859 Space separated list of arguments to the userdb driver.
16860 Defaults to @samp{""}.
16863 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16864 Override fields from passwd.
16865 Defaults to @samp{()}.
16870 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16871 Plug-in configuration, created by the @code{plugin-configuration}
16875 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16876 List of namespaces. Each item in the list is created by the
16877 @code{namespace-configuration} constructor.
16879 Available @code{namespace-configuration} fields are:
16881 @deftypevr {@code{namespace-configuration} parameter} string name
16882 Name for this namespace.
16885 @deftypevr {@code{namespace-configuration} parameter} string type
16886 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16887 Defaults to @samp{"private"}.
16890 @deftypevr {@code{namespace-configuration} parameter} string separator
16891 Hierarchy separator to use. You should use the same separator for
16892 all namespaces or some clients get confused. @samp{/} is usually a good
16893 one. The default however depends on the underlying mail storage
16895 Defaults to @samp{""}.
16898 @deftypevr {@code{namespace-configuration} parameter} string prefix
16899 Prefix required to access this namespace. This needs to be
16900 different for all namespaces. For example @samp{Public/}.
16901 Defaults to @samp{""}.
16904 @deftypevr {@code{namespace-configuration} parameter} string location
16905 Physical location of the mailbox. This is in the same format as
16906 mail_location, which is also the default for it.
16907 Defaults to @samp{""}.
16910 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16911 There can be only one INBOX, and this setting defines which
16913 Defaults to @samp{#f}.
16916 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16917 If namespace is hidden, it's not advertised to clients via NAMESPACE
16918 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16919 useful when converting from another server with different namespaces
16920 which you want to deprecate but still keep working. For example you can
16921 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16923 Defaults to @samp{#f}.
16926 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16927 Show the mailboxes under this namespace with the LIST command. This
16928 makes the namespace visible for clients that do not support the NAMESPACE
16929 extension. The special @code{children} value lists child mailboxes, but
16930 hides the namespace prefix.
16931 Defaults to @samp{#t}.
16934 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16935 Namespace handles its own subscriptions. If set to @code{#f}, the
16936 parent namespace handles them. The empty prefix should always have this
16938 Defaults to @samp{#t}.
16941 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16942 List of predefined mailboxes in this namespace.
16943 Defaults to @samp{()}.
16945 Available @code{mailbox-configuration} fields are:
16947 @deftypevr {@code{mailbox-configuration} parameter} string name
16948 Name for this mailbox.
16951 @deftypevr {@code{mailbox-configuration} parameter} string auto
16952 @samp{create} will automatically create this mailbox.
16953 @samp{subscribe} will both create and subscribe to the mailbox.
16954 Defaults to @samp{"no"}.
16957 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16958 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16959 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16960 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16961 Defaults to @samp{()}.
16968 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16969 Base directory where to store runtime data.
16970 Defaults to @samp{"/var/run/dovecot/"}.
16973 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16974 Greeting message for clients.
16975 Defaults to @samp{"Dovecot ready."}.
16978 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16979 List of trusted network ranges. Connections from these IPs are
16980 allowed to override their IP addresses and ports (for logging and for
16981 authentication checks). @samp{disable-plaintext-auth} is also ignored
16982 for these networks. Typically you would specify your IMAP proxy servers
16984 Defaults to @samp{()}.
16987 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16988 List of login access check sockets (e.g.@: tcpwrap).
16989 Defaults to @samp{()}.
16992 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16993 Show more verbose process titles (in ps). Currently shows user name
16994 and IP address. Useful for seeing who is actually using the IMAP
16995 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16997 Defaults to @samp{#f}.
17000 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
17001 Should all processes be killed when Dovecot master process shuts down.
17002 Setting this to @code{#f} means that Dovecot can be upgraded without
17003 forcing existing client connections to close (although that could also
17004 be a problem if the upgrade is e.g.@: due to a security fix).
17005 Defaults to @samp{#t}.
17008 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
17009 If non-zero, run mail commands via this many connections to doveadm
17010 server, instead of running them directly in the same process.
17011 Defaults to @samp{0}.
17014 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
17015 UNIX socket or host:port used for connecting to doveadm server.
17016 Defaults to @samp{"doveadm-server"}.
17019 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
17020 List of environment variables that are preserved on Dovecot startup
17021 and passed down to all of its child processes. You can also give
17022 key=value pairs to always set specific settings.
17025 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
17026 Disable LOGIN command and all other plaintext authentications unless
17027 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
17028 matches the local IP (i.e.@: you're connecting from the same computer),
17029 the connection is considered secure and plaintext authentication is
17030 allowed. See also ssl=required setting.
17031 Defaults to @samp{#t}.
17034 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
17035 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
17036 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
17037 for caching to be used.
17038 Defaults to @samp{0}.
17041 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
17042 Time to live for cached data. After TTL expires the cached record
17043 is no longer used, *except* if the main database lookup returns internal
17044 failure. We also try to handle password changes automatically: If
17045 user's previous authentication was successful, but this one wasn't, the
17046 cache isn't used. For now this works only with plaintext
17048 Defaults to @samp{"1 hour"}.
17051 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
17052 TTL for negative hits (user not found, password mismatch).
17053 0 disables caching them completely.
17054 Defaults to @samp{"1 hour"}.
17057 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
17058 List of realms for SASL authentication mechanisms that need them.
17059 You can leave it empty if you don't want to support multiple realms.
17060 Many clients simply use the first one listed here, so keep the default
17062 Defaults to @samp{()}.
17065 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
17066 Default realm/domain to use if none was specified. This is used for
17067 both SASL realms and appending @@domain to username in plaintext
17069 Defaults to @samp{""}.
17072 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
17073 List of allowed characters in username. If the user-given username
17074 contains a character not listed in here, the login automatically fails.
17075 This is just an extra check to make sure user can't exploit any
17076 potential quote escaping vulnerabilities with SQL/LDAP databases. If
17077 you want to allow all characters, set this value to empty.
17078 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
17081 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
17082 Username character translations before it's looked up from
17083 databases. The value contains series of from -> to characters. For
17084 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
17085 translated to @samp{@@}.
17086 Defaults to @samp{""}.
17089 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
17090 Username formatting before it's looked up from databases. You can
17091 use the standard variables here, e.g.@: %Lu would lowercase the username,
17092 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
17093 change the @samp{@@} into @samp{-AT-}. This translation is done after
17094 @samp{auth-username-translation} changes.
17095 Defaults to @samp{"%Lu"}.
17098 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
17099 If you want to allow master users to log in by specifying the master
17100 username within the normal username string (i.e.@: not using SASL
17101 mechanism's support for it), you can specify the separator character
17102 here. The format is then <username><separator><master username>.
17103 UW-IMAP uses @samp{*} as the separator, so that could be a good
17105 Defaults to @samp{""}.
17108 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
17109 Username to use for users logging in with ANONYMOUS SASL
17111 Defaults to @samp{"anonymous"}.
17114 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
17115 Maximum number of dovecot-auth worker processes. They're used to
17116 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
17117 They're automatically created and destroyed as needed.
17118 Defaults to @samp{30}.
17121 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
17122 Host name to use in GSSAPI principal names. The default is to use
17123 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
17124 allow all keytab entries.
17125 Defaults to @samp{""}.
17128 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
17129 Kerberos keytab to use for the GSSAPI mechanism. Will use the
17130 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
17131 need to change the auth service to run as root to be able to read this
17133 Defaults to @samp{""}.
17136 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
17137 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
17138 and @samp{ntlm-auth} helper.
17139 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
17140 Defaults to @samp{#f}.
17143 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
17144 Path for Samba's @samp{ntlm-auth} helper binary.
17145 Defaults to @samp{"/usr/bin/ntlm_auth"}.
17148 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
17149 Time to delay before replying to failed authentications.
17150 Defaults to @samp{"2 secs"}.
17153 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
17154 Require a valid SSL client certificate or the authentication
17156 Defaults to @samp{#f}.
17159 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
17160 Take the username from client's SSL certificate, using
17161 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
17163 Defaults to @samp{#f}.
17166 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
17167 List of wanted authentication mechanisms. Supported mechanisms are:
17168 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
17169 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
17170 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
17171 @samp{disable-plaintext-auth} setting.
17174 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
17175 List of IPs or hostnames to all director servers, including ourself.
17176 Ports can be specified as ip:port. The default port is the same as what
17177 director service's @samp{inet-listener} is using.
17178 Defaults to @samp{()}.
17181 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
17182 List of IPs or hostnames to all backend mail servers. Ranges are
17183 allowed too, like 10.0.0.10-10.0.0.30.
17184 Defaults to @samp{()}.
17187 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
17188 How long to redirect users to a specific server after it no longer
17189 has any connections.
17190 Defaults to @samp{"15 min"}.
17193 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
17194 How the username is translated before being hashed. Useful values
17195 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
17196 are shared within domain.
17197 Defaults to @samp{"%Lu"}.
17200 @deftypevr {@code{dovecot-configuration} parameter} string log-path
17201 Log file to use for error messages. @samp{syslog} logs to syslog,
17202 @samp{/dev/stderr} logs to stderr.
17203 Defaults to @samp{"syslog"}.
17206 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
17207 Log file to use for informational messages. Defaults to
17209 Defaults to @samp{""}.
17212 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
17213 Log file to use for debug messages. Defaults to
17214 @samp{info-log-path}.
17215 Defaults to @samp{""}.
17218 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
17219 Syslog facility to use if you're logging to syslog. Usually if you
17220 don't want to use @samp{mail}, you'll use local0..local7. Also other
17221 standard facilities are supported.
17222 Defaults to @samp{"mail"}.
17225 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
17226 Log unsuccessful authentication attempts and the reasons why they
17228 Defaults to @samp{#f}.
17231 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
17232 In case of password mismatches, log the attempted password. Valid
17233 values are no, plain and sha1. sha1 can be useful for detecting brute
17234 force password attempts vs. user simply trying the same password over
17235 and over again. You can also truncate the value to n chars by appending
17236 ":n" (e.g.@: sha1:6).
17237 Defaults to @samp{"no"}.
17240 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
17241 Even more verbose logging for debugging purposes. Shows for example
17243 Defaults to @samp{#f}.
17246 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
17247 In case of password mismatches, log the passwords and used scheme so
17248 the problem can be debugged. Enabling this also enables
17250 Defaults to @samp{#f}.
17253 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
17254 Enable mail process debugging. This can help you figure out why
17255 Dovecot isn't finding your mails.
17256 Defaults to @samp{#f}.
17259 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
17260 Show protocol level SSL errors.
17261 Defaults to @samp{#f}.
17264 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
17265 Prefix for each line written to log file. % codes are in
17266 strftime(3) format.
17267 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
17270 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
17271 List of elements we want to log. The elements which have a
17272 non-empty variable value are joined together to form a comma-separated
17276 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
17277 Login log format. %s contains @samp{login-log-format-elements}
17278 string, %$ contains the data we want to log.
17279 Defaults to @samp{"%$: %s"}.
17282 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
17283 Log prefix for mail processes. See doc/wiki/Variables.txt for list
17284 of possible variables you can use.
17285 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
17288 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
17289 Format to use for logging mail deliveries. You can use variables:
17292 Delivery status message (e.g.@: @samp{saved to INBOX})
17304 Defaults to @samp{"msgid=%m: %$"}.
17307 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
17308 Location for users' mailboxes. The default is empty, which means
17309 that Dovecot tries to find the mailboxes automatically. This won't work
17310 if the user doesn't yet have any mail, so you should explicitly tell
17311 Dovecot the full location.
17313 If you're using mbox, giving a path to the INBOX
17314 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
17315 where the other mailboxes are kept. This is called the @emph{root mail
17316 directory}, and it must be the first path given in the
17317 @samp{mail-location} setting.
17319 There are a few special variables you can use, e.g.:
17325 user part in user@@domain, same as %u if there's no domain
17327 domain part in user@@domain, empty if there's no domain
17332 See doc/wiki/Variables.txt for full list. Some examples:
17334 @item maildir:~/Maildir
17335 @item mbox:~/mail:INBOX=/var/mail/%u
17336 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
17338 Defaults to @samp{""}.
17341 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
17342 System user and group used to access mails. If you use multiple,
17343 userdb can override these by returning uid or gid fields. You can use
17344 either numbers or names. <doc/wiki/UserIds.txt>.
17345 Defaults to @samp{""}.
17348 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
17350 Defaults to @samp{""}.
17353 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
17354 Group to enable temporarily for privileged operations. Currently
17355 this is used only with INBOX when either its initial creation or
17356 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
17358 Defaults to @samp{""}.
17361 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
17362 Grant access to these supplementary groups for mail processes.
17363 Typically these are used to set up access to shared mailboxes. Note
17364 that it may be dangerous to set these if users can create symlinks
17365 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
17366 could allow a user to delete others' mailboxes, or @code{ln -s
17367 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
17371 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
17372 Allow full file system access to clients. There's no access checks
17373 other than what the operating system does for the active UID/GID. It
17374 works with both maildir and mboxes, allowing you to prefix mailboxes
17375 names with e.g.@: @file{/path/} or @file{~user/}.
17376 Defaults to @samp{#f}.
17379 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
17380 Don't use @code{mmap()} at all. This is required if you store indexes to
17381 shared file systems (NFS or clustered file system).
17382 Defaults to @samp{#f}.
17385 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
17386 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
17387 supports @samp{O_EXCL} since version 3, so this should be safe to use
17388 nowadays by default.
17389 Defaults to @samp{#t}.
17392 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
17393 When to use fsync() or fdatasync() calls:
17396 Whenever necessary to avoid losing important data
17398 Useful with e.g.@: NFS when @code{write()}s are delayed
17400 Never use it (best performance, but crashes can lose data).
17402 Defaults to @samp{"optimized"}.
17405 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
17406 Mail storage exists in NFS. Set this to yes to make Dovecot flush
17407 NFS caches whenever needed. If you're using only a single mail server
17409 Defaults to @samp{#f}.
17412 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
17413 Mail index files also exist in NFS. Setting this to yes requires
17414 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
17415 Defaults to @samp{#f}.
17418 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
17419 Locking method for index files. Alternatives are fcntl, flock and
17420 dotlock. Dotlocking uses some tricks which may create more disk I/O
17421 than other locking methods. NFS users: flock doesn't work, remember to
17422 change @samp{mmap-disable}.
17423 Defaults to @samp{"fcntl"}.
17426 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
17427 Directory in which LDA/LMTP temporarily stores incoming mails >128
17429 Defaults to @samp{"/tmp"}.
17432 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
17433 Valid UID range for users. This is mostly to make sure that users can't
17434 log in as daemons or other system users. Note that denying root logins is
17435 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
17437 Defaults to @samp{500}.
17440 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
17442 Defaults to @samp{0}.
17445 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
17446 Valid GID range for users. Users having non-valid GID as primary group ID
17447 aren't allowed to log in. If user belongs to supplementary groups with
17448 non-valid GIDs, those groups are not set.
17449 Defaults to @samp{1}.
17452 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
17454 Defaults to @samp{0}.
17457 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
17458 Maximum allowed length for mail keyword name. It's only forced when
17459 trying to create new keywords.
17460 Defaults to @samp{50}.
17463 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
17464 List of directories under which chrooting is allowed for mail
17465 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
17466 too). This setting doesn't affect @samp{login-chroot}
17467 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
17468 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
17469 which local users can modify, that may lead to root exploit. Usually
17470 this should be done only if you don't allow shell access for users.
17471 <doc/wiki/Chrooting.txt>.
17472 Defaults to @samp{()}.
17475 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
17476 Default chroot directory for mail processes. This can be overridden
17477 for specific users in user database by giving @samp{/./} in user's home
17478 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
17479 there is no real need to do chrooting, Dovecot doesn't allow users to
17480 access files outside their mail directory anyway. If your home
17481 directories are prefixed with the chroot directory, append @samp{/.} to
17482 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
17483 Defaults to @samp{""}.
17486 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
17487 UNIX socket path to master authentication server to find users.
17488 This is used by imap (for shared users) and lda.
17489 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17492 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
17493 Directory where to look up mail plugins.
17494 Defaults to @samp{"/usr/lib/dovecot"}.
17497 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
17498 List of plugins to load for all services. Plugins specific to IMAP,
17499 LDA, etc.@: are added to this list in their own .conf files.
17500 Defaults to @samp{()}.
17503 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
17504 The minimum number of mails in a mailbox before updates are done to
17505 cache file. This allows optimizing Dovecot's behavior to do less disk
17506 writes at the cost of more disk reads.
17507 Defaults to @samp{0}.
17510 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
17511 When IDLE command is running, mailbox is checked once in a while to
17512 see if there are any new mails or other changes. This setting defines
17513 the minimum time to wait between those checks. Dovecot can also use
17514 dnotify, inotify and kqueue to find out immediately when changes
17516 Defaults to @samp{"30 secs"}.
17519 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
17520 Save mails with CR+LF instead of plain LF. This makes sending those
17521 mails take less CPU, especially with sendfile() syscall with Linux and
17522 FreeBSD. But it also creates a bit more disk I/O which may just make it
17523 slower. Also note that if other software reads the mboxes/maildirs,
17524 they may handle the extra CRs wrong and cause problems.
17525 Defaults to @samp{#f}.
17528 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
17529 By default LIST command returns all entries in maildir beginning
17530 with a dot. Enabling this option makes Dovecot return only entries
17531 which are directories. This is done by stat()ing each entry, so it
17532 causes more disk I/O.
17533 (For systems setting struct @samp{dirent->d_type} this check is free
17534 and it's done always regardless of this setting).
17535 Defaults to @samp{#f}.
17538 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
17539 When copying a message, do it with hard links whenever possible.
17540 This makes the performance much better, and it's unlikely to have any
17542 Defaults to @samp{#t}.
17545 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
17546 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
17547 directory only when its mtime changes unexpectedly or when we can't find
17548 the mail otherwise.
17549 Defaults to @samp{#f}.
17552 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
17553 Which locking methods to use for locking mbox. There are four
17558 Create <mailbox>.lock file. This is the oldest and most NFS-safe
17559 solution. If you want to use /var/mail/ like directory, the users will
17560 need write access to that directory.
17562 Same as dotlock, but if it fails because of permissions or because there
17563 isn't enough disk space, just skip it.
17565 Use this if possible. Works with NFS too if lockd is used.
17567 May not exist in all systems. Doesn't work with NFS.
17569 May not exist in all systems. Doesn't work with NFS.
17572 You can use multiple locking methods; if you do the order they're declared
17573 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
17574 locking methods as well. Some operating systems don't allow using some of
17575 them simultaneously.
17578 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
17582 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
17583 Maximum time to wait for lock (all of them) before aborting.
17584 Defaults to @samp{"5 mins"}.
17587 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
17588 If dotlock exists but the mailbox isn't modified in any way,
17589 override the lock file after this much time.
17590 Defaults to @samp{"2 mins"}.
17593 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
17594 When mbox changes unexpectedly we have to fully read it to find out
17595 what changed. If the mbox is large this can take a long time. Since
17596 the change is usually just a newly appended mail, it'd be faster to
17597 simply read the new mails. If this setting is enabled, Dovecot does
17598 this but still safely fallbacks to re-reading the whole mbox file
17599 whenever something in mbox isn't how it's expected to be. The only real
17600 downside to this setting is that if some other MUA changes message
17601 flags, Dovecot doesn't notice it immediately. Note that a full sync is
17602 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
17603 Defaults to @samp{#t}.
17606 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
17607 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
17608 EXAMINE, EXPUNGE or CHECK commands. If this is set,
17609 @samp{mbox-dirty-syncs} is ignored.
17610 Defaults to @samp{#f}.
17613 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
17614 Delay writing mbox headers until doing a full write sync (EXPUNGE
17615 and CHECK commands and when closing the mailbox). This is especially
17616 useful for POP3 where clients often delete all mails. The downside is
17617 that our changes aren't immediately visible to other MUAs.
17618 Defaults to @samp{#t}.
17621 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
17622 If mbox size is smaller than this (e.g.@: 100k), don't write index
17623 files. If an index file already exists it's still read, just not
17625 Defaults to @samp{0}.
17628 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17629 Maximum dbox file size until it's rotated.
17630 Defaults to @samp{10000000}.
17633 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17634 Maximum dbox file age until it's rotated. Typically in days. Day
17635 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17637 Defaults to @samp{"1d"}.
17640 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17641 When creating new mdbox files, immediately preallocate their size to
17642 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17643 with some file systems (ext4, xfs).
17644 Defaults to @samp{#f}.
17647 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17648 sdbox and mdbox support saving mail attachments to external files,
17649 which also allows single instance storage for them. Other backends
17650 don't support this for now.
17652 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17654 Directory root where to store mail attachments. Disabled, if empty.
17655 Defaults to @samp{""}.
17658 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17659 Attachments smaller than this aren't saved externally. It's also
17660 possible to write a plugin to disable saving specific attachments
17662 Defaults to @samp{128000}.
17665 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17666 File system backend to use for saving attachments:
17669 No SiS done by Dovecot (but this might help FS's own deduplication)
17671 SiS with immediate byte-by-byte comparison during saving
17672 @item sis-queue posix
17673 SiS with delayed comparison and deduplication.
17675 Defaults to @samp{"sis posix"}.
17678 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17679 Hash format to use in attachment filenames. You can add any text and
17680 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17681 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17682 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17683 Defaults to @samp{"%@{sha1@}"}.
17686 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17688 Defaults to @samp{100}.
17691 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17693 Defaults to @samp{1000}.
17696 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17697 Default VSZ (virtual memory size) limit for service processes.
17698 This is mainly intended to catch and kill processes that leak memory
17699 before they eat up everything.
17700 Defaults to @samp{256000000}.
17703 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17704 Login user is internally used by login processes. This is the most
17705 untrusted user in Dovecot system. It shouldn't have access to anything
17707 Defaults to @samp{"dovenull"}.
17710 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17711 Internal user is used by unprivileged processes. It should be
17712 separate from login user, so that login processes can't disturb other
17714 Defaults to @samp{"dovecot"}.
17717 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17718 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17719 Defaults to @samp{"required"}.
17722 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17723 PEM encoded X.509 SSL/TLS certificate (public key).
17724 Defaults to @samp{"</etc/dovecot/default.pem"}.
17727 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17728 PEM encoded SSL/TLS private key. The key is opened before
17729 dropping root privileges, so keep the key file unreadable by anyone but
17731 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17734 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17735 If key file is password protected, give the password here.
17736 Alternatively give it when starting dovecot with -p parameter. Since
17737 this file is often world-readable, you may want to place this setting
17738 instead to a different.
17739 Defaults to @samp{""}.
17742 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17743 PEM encoded trusted certificate authority. Set this only if you
17744 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17745 contain the CA certificate(s) followed by the matching
17746 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17747 Defaults to @samp{""}.
17750 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17751 Require that CRL check succeeds for client certificates.
17752 Defaults to @samp{#t}.
17755 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17756 Request client to send a certificate. If you also want to require
17757 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17758 Defaults to @samp{#f}.
17761 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17762 Which field from certificate to use for username. commonName and
17763 x500UniqueIdentifier are the usual choices. You'll also need to set
17764 @samp{auth-ssl-username-from-cert? #t}.
17765 Defaults to @samp{"commonName"}.
17768 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17769 Minimum SSL protocol version to accept.
17770 Defaults to @samp{"TLSv1"}.
17773 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17774 SSL ciphers to use.
17775 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17778 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17779 SSL crypto device to use, for valid values run "openssl engine".
17780 Defaults to @samp{""}.
17783 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17784 Address to use when sending rejection mails.
17785 %d expands to recipient domain.
17786 Defaults to @samp{"postmaster@@%d"}.
17789 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17790 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17791 and in LMTP replies. Default is the system's real hostname@@domain.
17792 Defaults to @samp{""}.
17795 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17796 If user is over quota, return with temporary failure instead of
17798 Defaults to @samp{#f}.
17801 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17802 Binary to use for sending mails.
17803 Defaults to @samp{"/usr/sbin/sendmail"}.
17806 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17807 If non-empty, send mails via this SMTP host[:port] instead of
17809 Defaults to @samp{""}.
17812 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17813 Subject: header to use for rejection mails. You can use the same
17814 variables as for @samp{rejection-reason} below.
17815 Defaults to @samp{"Rejected: %s"}.
17818 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17819 Human readable error message for rejection mails. You can use
17832 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17835 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17836 Delimiter character between local-part and detail in email
17838 Defaults to @samp{"+"}.
17841 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17842 Header where the original recipient address (SMTP's RCPT TO:
17843 address) is taken from if not available elsewhere. With dovecot-lda -a
17844 parameter overrides this. A commonly used header for this is
17846 Defaults to @samp{""}.
17849 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17850 Should saving a mail to a nonexistent mailbox automatically create
17852 Defaults to @samp{#f}.
17855 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17856 Should automatically created mailboxes be also automatically
17858 Defaults to @samp{#f}.
17861 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17862 Maximum IMAP command line length. Some clients generate very long
17863 command lines with huge mailboxes, so you may need to raise this if you
17864 get "Too long argument" or "IMAP command line too large" errors
17866 Defaults to @samp{64000}.
17869 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17870 IMAP logout format string:
17873 total number of bytes read from client
17875 total number of bytes sent to client.
17877 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17878 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@}"}.
17881 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17882 Override the IMAP CAPABILITY response. If the value begins with '+',
17883 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17884 Defaults to @samp{""}.
17887 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17888 How long to wait between "OK Still here" notifications when client
17890 Defaults to @samp{"2 mins"}.
17893 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17894 ID field names and values to send to clients. Using * as the value
17895 makes Dovecot use the default value. The following fields have default
17896 values currently: name, version, os, os-version, support-url,
17898 Defaults to @samp{""}.
17901 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17902 ID fields sent by client to log. * means everything.
17903 Defaults to @samp{""}.
17906 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17907 Workarounds for various client bugs:
17910 @item delay-newmail
17911 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17912 CHECK commands. Some clients ignore them otherwise, for example OSX
17913 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17914 may show user "Message no longer in server" errors. Note that OE6
17915 still breaks even with this workaround if synchronization is set to
17918 @item tb-extra-mailbox-sep
17919 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17920 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17921 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17923 @item tb-lsub-flags
17924 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17925 This makes Thunderbird realize they aren't selectable and show them
17926 greyed out, instead of only later giving "not selectable" popup error.
17928 Defaults to @samp{()}.
17931 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17932 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17933 Defaults to @samp{""}.
17937 Whew! Lots of configuration options. The nice thing about it though is
17938 that Guix has a complete interface to Dovecot's configuration
17939 language. This allows not only a nice way to declare configurations,
17940 but also offers reflective capabilities as well: users can write code to
17941 inspect and transform configurations from within Scheme.
17943 However, it could be that you just want to get a @code{dovecot.conf} up
17944 and running. In that case, you can pass an
17945 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17946 @code{dovecot-service}. As its name indicates, an opaque configuration
17947 does not have easy reflective capabilities.
17949 Available @code{opaque-dovecot-configuration} fields are:
17951 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17952 The dovecot package.
17955 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17956 The contents of the @code{dovecot.conf}, as a string.
17959 For example, if your @code{dovecot.conf} is just the empty string, you
17960 could instantiate a dovecot service like this:
17963 (dovecot-service #:config
17964 (opaque-dovecot-configuration
17968 @subsubheading OpenSMTPD Service
17970 @deffn {Scheme Variable} opensmtpd-service-type
17971 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17972 service, whose value should be an @code{opensmtpd-configuration} object
17973 as in this example:
17976 (service opensmtpd-service-type
17977 (opensmtpd-configuration
17978 (config-file (local-file "./my-smtpd.conf"))))
17982 @deftp {Data Type} opensmtpd-configuration
17983 Data type representing the configuration of opensmtpd.
17986 @item @code{package} (default: @var{opensmtpd})
17987 Package object of the OpenSMTPD SMTP server.
17989 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17990 File-like object of the OpenSMTPD configuration file to use. By default
17991 it listens on the loopback network interface, and allows for mail from
17992 users and daemons on the local machine, as well as permitting email to
17993 remote servers. Run @command{man smtpd.conf} for more information.
17998 @subsubheading Exim Service
18000 @cindex mail transfer agent (MTA)
18001 @cindex MTA (mail transfer agent)
18004 @deffn {Scheme Variable} exim-service-type
18005 This is the type of the @uref{https://exim.org, Exim} mail transfer
18006 agent (MTA), whose value should be an @code{exim-configuration} object
18007 as in this example:
18010 (service exim-service-type
18011 (exim-configuration
18012 (config-file (local-file "./my-exim.conf"))))
18016 In order to use an @code{exim-service-type} service you must also have a
18017 @code{mail-aliases-service-type} service present in your
18018 @code{operating-system} (even if it has no aliases).
18020 @deftp {Data Type} exim-configuration
18021 Data type representing the configuration of exim.
18024 @item @code{package} (default: @var{exim})
18025 Package object of the Exim server.
18027 @item @code{config-file} (default: @code{#f})
18028 File-like object of the Exim configuration file to use. If its value is
18029 @code{#f} then use the default configuration file from the package
18030 provided in @code{package}. The resulting configuration file is loaded
18031 after setting the @code{exim_user} and @code{exim_group} configuration
18037 @subsubheading Getmail service
18042 @deffn {Scheme Variable} getmail-service-type
18043 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
18044 mail retriever, whose value should be an @code{getmail-configuration}.
18047 Available @code{getmail-configuration} fields are:
18049 @deftypevr {@code{getmail-configuration} parameter} symbol name
18050 A symbol to identify the getmail service.
18052 Defaults to @samp{"unset"}.
18056 @deftypevr {@code{getmail-configuration} parameter} package package
18057 The getmail package to use.
18061 @deftypevr {@code{getmail-configuration} parameter} string user
18062 The user to run getmail as.
18064 Defaults to @samp{"getmail"}.
18068 @deftypevr {@code{getmail-configuration} parameter} string group
18069 The group to run getmail as.
18071 Defaults to @samp{"getmail"}.
18075 @deftypevr {@code{getmail-configuration} parameter} string directory
18076 The getmail directory to use.
18078 Defaults to @samp{"/var/lib/getmail/default"}.
18082 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
18083 The getmail configuration file to use.
18085 Available @code{getmail-configuration-file} fields are:
18087 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
18088 What mail account to retrieve mail from, and how to access that account.
18090 Available @code{getmail-retriever-configuration} fields are:
18092 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
18093 The type of mail retriever to use. Valid values include @samp{passwd}
18096 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
18100 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
18101 Username to login to the mail server with.
18103 Defaults to @samp{unset}.
18107 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
18108 Username to login to the mail server with.
18110 Defaults to @samp{unset}.
18114 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
18115 Port number to connect to.
18117 Defaults to @samp{#f}.
18121 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
18122 Override fields from passwd.
18124 Defaults to @samp{""}.
18128 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
18129 Override fields from passwd.
18131 Defaults to @samp{()}.
18135 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
18136 PEM-formatted key file to use for the TLS negotiation.
18138 Defaults to @samp{""}.
18142 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
18143 PEM-formatted certificate file to use for the TLS negotiation.
18145 Defaults to @samp{""}.
18149 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
18150 CA certificates to use.
18152 Defaults to @samp{""}.
18156 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
18157 Extra retriever parameters.
18159 Defaults to @samp{()}.
18165 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
18166 What to do with retrieved messages.
18168 Available @code{getmail-destination-configuration} fields are:
18170 @deftypevr {@code{getmail-destination-configuration} parameter} string type
18171 The type of mail destination. Valid values include @samp{Maildir},
18172 @samp{Mboxrd} and @samp{MDA_external}.
18174 Defaults to @samp{unset}.
18178 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
18179 The path option for the mail destination. The behaviour depends on the
18182 Defaults to @samp{""}.
18186 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
18187 Extra destination parameters
18189 Defaults to @samp{()}.
18195 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
18198 Available @code{getmail-options-configuration} fields are:
18200 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
18201 If set to @samp{0}, getmail will only print warnings and errors. A
18202 value of @samp{1} means that messages will be printed about retrieving
18203 and deleting messages. If set to @samp{2}, getmail will print messages
18204 about each of it's actions.
18206 Defaults to @samp{1}.
18210 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
18211 If true, getmail will retrieve all available messages. Otherwise it
18212 will only retrieve messages it hasn't seen previously.
18214 Defaults to @samp{#t}.
18218 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
18219 If set to true, messages will be deleted from the server after
18220 retrieving and successfully delivering them. Otherwise, messages will
18221 be left on the server.
18223 Defaults to @samp{#f}.
18227 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
18228 Getmail will delete messages this number of days after seeing them, if
18229 they have been delivered. This means messages will be left on the
18230 server this number of days after delivering them. A value of @samp{0}
18231 disabled this feature.
18233 Defaults to @samp{0}.
18237 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
18238 Delete messages larger than this of bytes after retrieving them, even if
18239 the delete and delete-after options are disabled. A value of @samp{0}
18240 disables this feature.
18242 Defaults to @samp{0}.
18246 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
18247 Retrieve messages totalling up to this number of bytes before closing
18248 the session with the server. A value of @samp{0} disables this feature.
18250 Defaults to @samp{0}.
18254 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
18255 Don't retrieve messages larger than this number of bytes. A value of
18256 @samp{0} disables this feature.
18258 Defaults to @samp{0}.
18262 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
18263 If true, getmail will add a Delivered-To header to messages.
18265 Defaults to @samp{#t}.
18269 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
18270 If set, getmail adds a Received header to the messages.
18272 Defaults to @samp{#t}.
18276 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
18277 Getmail will record a log of its actions to the named file. A value of
18278 @samp{""} disables this feature.
18280 Defaults to @samp{""}.
18284 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
18285 If true, getmail will record a log of its actions using the system
18288 Defaults to @samp{#f}.
18292 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
18293 If true, getmail will log information about messages not retrieved and
18294 the reason for not retrieving them, as well as starting and ending
18297 Defaults to @samp{#f}.
18301 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
18302 Extra options to include.
18304 Defaults to @samp{()}.
18312 @deftypevr {@code{getmail-configuration} parameter} list idle
18313 A list of mailboxes that getmail should wait on the server for new mail
18314 notifications. This depends on the server supporting the IDLE
18317 Defaults to @samp{()}.
18321 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
18322 Environment variables to set for getmail.
18324 Defaults to @samp{()}.
18328 @subsubheading Mail Aliases Service
18330 @cindex email aliases
18331 @cindex aliases, for email addresses
18333 @deffn {Scheme Variable} mail-aliases-service-type
18334 This is the type of the service which provides @code{/etc/aliases},
18335 specifying how to deliver mail to users on this system.
18338 (service mail-aliases-service-type
18339 '(("postmaster" "bob")
18340 ("bob" "bob@@example.com" "bob@@example2.com")))
18344 The configuration for a @code{mail-aliases-service-type} service is an
18345 association list denoting how to deliver mail that comes to this
18346 system. Each entry is of the form @code{(alias addresses ...)}, with
18347 @code{alias} specifying the local alias and @code{addresses} specifying
18348 where to deliver this user's mail.
18350 The aliases aren't required to exist as users on the local system. In
18351 the above example, there doesn't need to be a @code{postmaster} entry in
18352 the @code{operating-system}'s @code{user-accounts} in order to deliver
18353 the @code{postmaster} mail to @code{bob} (which subsequently would
18354 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
18356 @subsubheading GNU Mailutils IMAP4 Daemon
18357 @cindex GNU Mailutils IMAP4 Daemon
18359 @deffn {Scheme Variable} imap4d-service-type
18360 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
18361 mailutils, GNU Mailutils Manual}), whose value should be an
18362 @code{imap4d-configuration} object as in this example:
18365 (service imap4d-service-type
18366 (imap4d-configuration
18367 (config-file (local-file "imap4d.conf"))))
18371 @deftp {Data Type} imap4d-configuration
18372 Data type representing the configuration of @command{imap4d}.
18375 @item @code{package} (default: @code{mailutils})
18376 The package that provides @command{imap4d}.
18378 @item @code{config-file} (default: @code{%default-imap4d-config-file})
18379 File-like object of the configuration file to use, by default it will listen
18380 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
18381 Mailutils Manual}, for details.
18386 @node Messaging Services
18387 @subsection Messaging Services
18392 The @code{(gnu services messaging)} module provides Guix service
18393 definitions for messaging services: currently only Prosody is supported.
18395 @subsubheading Prosody Service
18397 @deffn {Scheme Variable} prosody-service-type
18398 This is the type for the @uref{https://prosody.im, Prosody XMPP
18399 communication server}. Its value must be a @code{prosody-configuration}
18400 record as in this example:
18403 (service prosody-service-type
18404 (prosody-configuration
18405 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
18408 (int-component-configuration
18409 (hostname "conference.example.net")
18411 (mod-muc (mod-muc-configuration)))))
18414 (virtualhost-configuration
18415 (domain "example.net"))))))
18418 See below for details about @code{prosody-configuration}.
18422 By default, Prosody does not need much configuration. Only one
18423 @code{virtualhosts} field is needed: it specifies the domain you wish
18426 You can perform various sanity checks on the generated configuration
18427 with the @code{prosodyctl check} command.
18429 Prosodyctl will also help you to import certificates from the
18430 @code{letsencrypt} directory so that the @code{prosody} user can access
18431 them. See @url{https://prosody.im/doc/letsencrypt}.
18434 prosodyctl --root cert import /etc/letsencrypt/live
18437 The available configuration parameters follow. Each parameter
18438 definition is preceded by its type; for example, @samp{string-list foo}
18439 indicates that the @code{foo} parameter should be specified as a list of
18440 strings. Types starting with @code{maybe-} denote parameters that won't
18441 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
18443 There is also a way to specify the configuration as a string, if you
18444 have an old @code{prosody.cfg.lua} file that you want to port over from
18445 some other system; see the end for more details.
18447 The @code{file-object} type designates either a file-like object
18448 (@pxref{G-Expressions, file-like objects}) or a file name.
18450 @c The following documentation was initially generated by
18451 @c (generate-documentation) in (gnu services messaging). Manually maintained
18452 @c documentation is better, so we shouldn't hesitate to edit below as
18453 @c needed. However if the change you want to make to this documentation
18454 @c can be done in an automated way, it's probably easier to change
18455 @c (generate-documentation) than to make it below and have to deal with
18456 @c the churn as Prosody updates.
18458 Available @code{prosody-configuration} fields are:
18460 @deftypevr {@code{prosody-configuration} parameter} package prosody
18461 The Prosody package.
18464 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
18465 Location of the Prosody data storage directory. See
18466 @url{https://prosody.im/doc/configure}.
18467 Defaults to @samp{"/var/lib/prosody"}.
18470 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
18471 Additional plugin directories. They are searched in all the specified
18472 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
18473 Defaults to @samp{()}.
18476 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
18477 Every virtual host and component needs a certificate so that clients and
18478 servers can securely verify its identity. Prosody will automatically load
18479 certificates/keys from the directory specified here.
18480 Defaults to @samp{"/etc/prosody/certs"}.
18483 @deftypevr {@code{prosody-configuration} parameter} string-list admins
18484 This is a list of accounts that are admins for the server. Note that you
18485 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
18486 @url{https://prosody.im/doc/creating_accounts}.
18487 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
18488 Defaults to @samp{()}.
18491 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
18492 Enable use of libevent for better performance under high load. See
18493 @url{https://prosody.im/doc/libevent}.
18494 Defaults to @samp{#f}.
18497 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
18498 This is the list of modules Prosody will load on startup. It looks for
18499 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
18500 Documentation on modules can be found at:
18501 @url{https://prosody.im/doc/modules}.
18502 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
18505 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
18506 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
18507 should you want to disable them then add them to this list.
18508 Defaults to @samp{()}.
18511 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
18512 Path to a text file where the shared groups are defined. If this path is
18513 empty then @samp{mod_groups} does nothing. See
18514 @url{https://prosody.im/doc/modules/mod_groups}.
18515 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
18518 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
18519 Disable account creation by default, for security. See
18520 @url{https://prosody.im/doc/creating_accounts}.
18521 Defaults to @samp{#f}.
18524 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
18525 These are the SSL/TLS-related settings. Most of them are disabled so to
18526 use Prosody's defaults. If you do not completely understand these options, do
18527 not add them to your config, it is easy to lower the security of your server
18528 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
18530 Available @code{ssl-configuration} fields are:
18532 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
18533 This determines what handshake to use.
18536 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
18537 Path to your private key file.
18540 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
18541 Path to your certificate file.
18544 @deftypevr {@code{ssl-configuration} parameter} file-object capath
18545 Path to directory containing root certificates that you wish Prosody to
18546 trust when verifying the certificates of remote servers.
18547 Defaults to @samp{"/etc/ssl/certs"}.
18550 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
18551 Path to a file containing root certificates that you wish Prosody to trust.
18552 Similar to @code{capath} but with all certificates concatenated together.
18555 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
18556 A list of verification options (these mostly map to OpenSSL's
18557 @code{set_verify()} flags).
18560 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
18561 A list of general options relating to SSL/TLS. These map to OpenSSL's
18562 @code{set_options()}. For a full list of options available in LuaSec, see the
18566 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
18567 How long a chain of certificate authorities to check when looking for a
18568 trusted root certificate.
18571 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
18572 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
18573 clients, and in what order.
18576 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
18577 A path to a file containing parameters for Diffie-Hellman key exchange. You
18578 can create such a file with:
18579 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
18582 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
18583 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
18584 @samp{"secp384r1"}.
18587 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
18588 A list of ``extra'' verification options.
18591 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
18592 Password for encrypted private keys.
18597 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
18598 Whether to force all client-to-server connections to be encrypted or not.
18599 See @url{https://prosody.im/doc/modules/mod_tls}.
18600 Defaults to @samp{#f}.
18603 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
18604 Set of mechanisms that will never be offered. See
18605 @url{https://prosody.im/doc/modules/mod_saslauth}.
18606 Defaults to @samp{("DIGEST-MD5")}.
18609 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
18610 Whether to force all server-to-server connections to be encrypted or not.
18611 See @url{https://prosody.im/doc/modules/mod_tls}.
18612 Defaults to @samp{#f}.
18615 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
18616 Whether to require encryption and certificate authentication. This
18617 provides ideal security, but requires servers you communicate with to support
18618 encryption AND present valid, trusted certificates. See
18619 @url{https://prosody.im/doc/s2s#security}.
18620 Defaults to @samp{#f}.
18623 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
18624 Many servers don't support encryption or have invalid or self-signed
18625 certificates. You can list domains here that will not be required to
18626 authenticate using certificates. They will be authenticated using DNS. See
18627 @url{https://prosody.im/doc/s2s#security}.
18628 Defaults to @samp{()}.
18631 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18632 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18633 valid certificates for some domains by specifying a list here. See
18634 @url{https://prosody.im/doc/s2s#security}.
18635 Defaults to @samp{()}.
18638 @deftypevr {@code{prosody-configuration} parameter} string authentication
18639 Select the authentication backend to use. The default provider stores
18640 passwords in plaintext and uses Prosody's configured data storage to store the
18641 authentication data. If you do not trust your server please see
18642 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18643 about using the hashed backend. See also
18644 @url{https://prosody.im/doc/authentication}
18645 Defaults to @samp{"internal_plain"}.
18648 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18649 Set logging options. Advanced logging configuration is not yet supported
18650 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18651 Defaults to @samp{"*syslog"}.
18654 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18655 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18656 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18659 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18660 Maximum allowed size of the HTTP body (in bytes).
18663 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18664 Some modules expose their own URL in various ways. This URL is built
18665 from the protocol, host and port used. If Prosody sits behind a proxy, the
18666 public URL will be @code{http-external-url} instead. See
18667 @url{https://prosody.im/doc/http#external_url}.
18670 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18671 A host in Prosody is a domain on which user accounts can be created. For
18672 example if you want your users to have addresses like
18673 @samp{"john.smith@@example.com"} then you need to add a host
18674 @samp{"example.com"}. All options in this list will apply only to this host.
18676 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
18677 the actual physical host that Prosody is installed on. A single Prosody
18678 instance can serve many domains, each one defined as a VirtualHost entry in
18679 Prosody's configuration. Conversely a server that hosts a single domain would
18680 have just one VirtualHost entry.
18682 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18684 Available @code{virtualhost-configuration} fields are:
18686 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:
18687 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18688 Domain you wish Prosody to serve.
18693 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18694 Components are extra services on a server which are available to clients,
18695 usually on a subdomain of the main server (such as
18696 @samp{"mycomponent.example.com"}). Example components might be chatroom
18697 servers, user directories, or gateways to other protocols.
18699 Internal components are implemented with Prosody-specific plugins. To add an
18700 internal component, you simply fill the hostname field, and the plugin you wish
18701 to use for the component.
18703 See @url{https://prosody.im/doc/components}.
18704 Defaults to @samp{()}.
18706 Available @code{int-component-configuration} fields are:
18708 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:
18709 @deftypevr {@code{int-component-configuration} parameter} string hostname
18710 Hostname of the component.
18713 @deftypevr {@code{int-component-configuration} parameter} string plugin
18714 Plugin you wish to use for the component.
18717 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18718 Multi-user chat (MUC) is Prosody's module for allowing you to create
18719 hosted chatrooms/conferences for XMPP users.
18721 General information on setting up and using multi-user chatrooms can be found
18722 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
18723 which you should read if you are new to XMPP chatrooms.
18725 See also @url{https://prosody.im/doc/modules/mod_muc}.
18727 Available @code{mod-muc-configuration} fields are:
18729 @deftypevr {@code{mod-muc-configuration} parameter} string name
18730 The name to return in service discovery responses.
18731 Defaults to @samp{"Prosody Chatrooms"}.
18734 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18735 If @samp{#t}, this will only allow admins to create new chatrooms.
18736 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18737 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18738 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18739 restricts to service administrators only.
18740 Defaults to @samp{#f}.
18743 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18744 Maximum number of history messages that will be sent to the member that has
18745 just joined the room.
18746 Defaults to @samp{20}.
18753 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18754 External components use XEP-0114, which most standalone components
18755 support. To add an external component, you simply fill the hostname field. See
18756 @url{https://prosody.im/doc/components}.
18757 Defaults to @samp{()}.
18759 Available @code{ext-component-configuration} fields are:
18761 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:
18762 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18763 Password which the component will use to log in.
18766 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18767 Hostname of the component.
18772 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18773 Port(s) Prosody listens on for component connections.
18774 Defaults to @samp{(5347)}.
18777 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18778 Interface Prosody listens on for component connections.
18779 Defaults to @samp{"127.0.0.1"}.
18782 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18783 Raw content that will be added to the configuration file.
18786 It could be that you just want to get a @code{prosody.cfg.lua}
18787 up and running. In that case, you can pass an
18788 @code{opaque-prosody-configuration} record as the value of
18789 @code{prosody-service-type}. As its name indicates, an opaque configuration
18790 does not have easy reflective capabilities.
18791 Available @code{opaque-prosody-configuration} fields are:
18793 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18794 The prosody package.
18797 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18798 The contents of the @code{prosody.cfg.lua} to use.
18801 For example, if your @code{prosody.cfg.lua} is just the empty
18802 string, you could instantiate a prosody service like this:
18805 (service prosody-service-type
18806 (opaque-prosody-configuration
18807 (prosody.cfg.lua "")))
18810 @c end of Prosody auto-generated documentation
18812 @subsubheading BitlBee Service
18814 @cindex IRC (Internet Relay Chat)
18815 @cindex IRC gateway
18816 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18817 interface to a variety of messaging protocols such as XMPP.
18819 @defvr {Scheme Variable} bitlbee-service-type
18820 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18821 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18824 To have BitlBee listen on port 6667 on localhost, add this line to your
18828 (service bitlbee-service-type)
18832 @deftp {Data Type} bitlbee-configuration
18833 This is the configuration for BitlBee, with the following fields:
18836 @item @code{interface} (default: @code{"127.0.0.1"})
18837 @itemx @code{port} (default: @code{6667})
18838 Listen on the network interface corresponding to the IP address
18839 specified in @var{interface}, on @var{port}.
18841 When @var{interface} is @code{127.0.0.1}, only local clients can
18842 connect; when it is @code{0.0.0.0}, connections can come from any
18843 networking interface.
18845 @item @code{bitlbee} (default: @code{bitlbee})
18846 The BitlBee package to use.
18848 @item @code{plugins} (default: @code{'()})
18849 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18851 @item @code{extra-settings} (default: @code{""})
18852 Configuration snippet added as-is to the BitlBee configuration file.
18856 @subsubheading Quassel Service
18858 @cindex IRC (Internet Relay Chat)
18859 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18860 meaning that one or more clients can attach to and detach from the
18863 @defvr {Scheme Variable} quassel-service-type
18864 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18865 IRC backend daemon. Its value is a @code{quassel-configuration}
18869 @deftp {Data Type} quassel-configuration
18870 This is the configuration for Quassel, with the following fields:
18873 @item @code{quassel} (default: @code{quassel})
18874 The Quassel package to use.
18876 @item @code{interface} (default: @code{"::,0.0.0.0"})
18877 @item @code{port} (default: @code{4242})
18878 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18879 interfaces specified in the comma delimited @var{interface}, on
18882 @item @code{loglevel} (default: @code{"Info"})
18883 The level of logging desired. Accepted values are Debug, Info, Warning
18888 @node Telephony Services
18889 @subsection Telephony Services
18891 @cindex Murmur (VoIP server)
18892 @cindex VoIP server
18893 This section describes how to set up and run a Murmur server. Murmur is
18894 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18897 @deftp {Data Type} murmur-configuration
18898 The service type for the Murmur server. An example configuration can
18902 (service murmur-service-type
18903 (murmur-configuration
18905 "Welcome to this Mumble server running on Guix!")
18906 (cert-required? #t) ;disallow text password logins
18907 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18908 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18911 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18912 password with the command that is printed during the activation phase.
18914 It is recommended to register a normal Mumble user account
18915 and grant it admin or moderator rights.
18916 You can use the @code{mumble} client to
18917 login as new normal user, register yourself, and log out.
18918 For the next step login with the name @code{SuperUser} use
18919 the @code{SuperUser} password that you set previously,
18920 and grant your newly registered mumble user administrator or moderator
18921 rights and create some channels.
18923 Available @code{murmur-configuration} fields are:
18926 @item @code{package} (default: @code{mumble})
18927 Package that contains @code{bin/murmurd}.
18929 @item @code{user} (default: @code{"murmur"})
18930 User who will run the Murmur server.
18932 @item @code{group} (default: @code{"murmur"})
18933 Group of the user who will run the murmur server.
18935 @item @code{port} (default: @code{64738})
18936 Port on which the server will listen.
18938 @item @code{welcome-text} (default: @code{""})
18939 Welcome text sent to clients when they connect.
18941 @item @code{server-password} (default: @code{""})
18942 Password the clients have to enter in order to connect.
18944 @item @code{max-users} (default: @code{100})
18945 Maximum of users that can be connected to the server at once.
18947 @item @code{max-user-bandwidth} (default: @code{#f})
18948 Maximum voice traffic a user can send per second.
18950 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18951 File name of the sqlite database.
18952 The service's user will become the owner of the directory.
18954 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18955 File name of the log file.
18956 The service's user will become the owner of the directory.
18958 @item @code{autoban-attempts} (default: @code{10})
18959 Maximum number of logins a user can make in @code{autoban-timeframe}
18960 without getting auto banned for @code{autoban-time}.
18962 @item @code{autoban-timeframe} (default: @code{120})
18963 Timeframe for autoban in seconds.
18965 @item @code{autoban-time} (default: @code{300})
18966 Amount of time in seconds for which a client gets banned
18967 when violating the autoban limits.
18969 @item @code{opus-threshold} (default: @code{100})
18970 Percentage of clients that need to support opus
18971 before switching over to opus audio codec.
18973 @item @code{channel-nesting-limit} (default: @code{10})
18974 How deep channels can be nested at maximum.
18976 @item @code{channelname-regex} (default: @code{#f})
18977 A string in form of a Qt regular expression that channel names must conform to.
18979 @item @code{username-regex} (default: @code{#f})
18980 A string in form of a Qt regular expression that user names must conform to.
18982 @item @code{text-message-length} (default: @code{5000})
18983 Maximum size in bytes that a user can send in one text chat message.
18985 @item @code{image-message-length} (default: @code{(* 128 1024)})
18986 Maximum size in bytes that a user can send in one image message.
18988 @item @code{cert-required?} (default: @code{#f})
18989 If it is set to @code{#t} clients that use weak password authentication
18990 will not be accepted. Users must have completed the certificate wizard to join.
18992 @item @code{remember-channel?} (default: @code{#f})
18993 Should murmur remember the last channel each user was in when they disconnected
18994 and put them into the remembered channel when they rejoin.
18996 @item @code{allow-html?} (default: @code{#f})
18997 Should html be allowed in text messages, user comments, and channel descriptions.
18999 @item @code{allow-ping?} (default: @code{#f})
19000 Setting to true exposes the current user count, the maximum user count, and
19001 the server's maximum bandwidth per client to unauthenticated users. In the
19002 Mumble client, this information is shown in the Connect dialog.
19004 Disabling this setting will prevent public listing of the server.
19006 @item @code{bonjour?} (default: @code{#f})
19007 Should the server advertise itself in the local network through the bonjour protocol.
19009 @item @code{send-version?} (default: @code{#f})
19010 Should the murmur server version be exposed in ping requests.
19012 @item @code{log-days} (default: @code{31})
19013 Murmur also stores logs in the database, which are accessible via RPC.
19014 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
19015 or -1 to disable logging to the database.
19017 @item @code{obfuscate-ips?} (default: @code{#t})
19018 Should logged ips be obfuscated to protect the privacy of users.
19020 @item @code{ssl-cert} (default: @code{#f})
19021 File name of the SSL/TLS certificate used for encrypted connections.
19024 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
19026 @item @code{ssl-key} (default: @code{#f})
19027 Filepath to the ssl private key used for encrypted connections.
19029 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
19032 @item @code{ssl-dh-params} (default: @code{#f})
19033 File name of a PEM-encoded file with Diffie-Hellman parameters
19034 for the SSL/TLS encryption. Alternatively you set it to
19035 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
19036 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
19038 @item @code{ssl-ciphers} (default: @code{#f})
19039 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
19042 This option is specified using
19043 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
19044 OpenSSL cipher list notation}.
19046 It is recommended that you try your cipher string using 'openssl ciphers <string>'
19047 before setting it here, to get a feel for which cipher suites you will get.
19048 After setting this option, it is recommend that you inspect your Murmur log
19049 to ensure that Murmur is using the cipher suites that you expected it to.
19051 Note: Changing this option may impact the backwards compatibility of your
19052 Murmur server, and can remove the ability for older Mumble clients to be able
19055 @item @code{public-registration} (default: @code{#f})
19056 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
19058 You can optionally register your server in the public server list that the
19059 @code{mumble} client shows on startup.
19060 You cannot register your server if you have set a @code{server-password},
19061 or set @code{allow-ping} to @code{#f}.
19063 It might take a few hours until it shows up in the public list.
19065 @item @code{file} (default: @code{#f})
19066 Optional alternative override for this configuration.
19070 @deftp {Data Type} murmur-public-registration-configuration
19071 Configuration for public registration of a murmur service.
19075 This is a display name for your server. Not to be confused with the hostname.
19077 @item @code{password}
19078 A password to identify your registration.
19079 Subsequent updates will need the same password. Don't lose your password.
19082 This should be a @code{http://} or @code{https://} link to your web
19085 @item @code{hostname} (default: @code{#f})
19086 By default your server will be listed by its IP address.
19087 If it is set your server will be linked by this host name instead.
19093 @node Monitoring Services
19094 @subsection Monitoring Services
19096 @subsubheading Tailon Service
19098 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
19099 viewing and searching log files.
19101 The following example will configure the service with default values.
19102 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
19105 (service tailon-service-type)
19108 The following example customises more of the Tailon configuration,
19109 adding @command{sed} to the list of allowed commands.
19112 (service tailon-service-type
19113 (tailon-configuration
19115 (tailon-configuration-file
19116 (allowed-commands '("tail" "grep" "awk" "sed"))))))
19120 @deftp {Data Type} tailon-configuration
19121 Data type representing the configuration of Tailon.
19122 This type has the following parameters:
19125 @item @code{config-file} (default: @code{(tailon-configuration-file)})
19126 The configuration file to use for Tailon. This can be set to a
19127 @dfn{tailon-configuration-file} record value, or any gexp
19128 (@pxref{G-Expressions}).
19130 For example, to instead use a local file, the @code{local-file} function
19134 (service tailon-service-type
19135 (tailon-configuration
19136 (config-file (local-file "./my-tailon.conf"))))
19139 @item @code{package} (default: @code{tailon})
19140 The tailon package to use.
19145 @deftp {Data Type} tailon-configuration-file
19146 Data type representing the configuration options for Tailon.
19147 This type has the following parameters:
19150 @item @code{files} (default: @code{(list "/var/log")})
19151 List of files to display. The list can include strings for a single file
19152 or directory, or a list, where the first item is the name of a
19153 subsection, and the remaining items are the files or directories in that
19156 @item @code{bind} (default: @code{"localhost:8080"})
19157 Address and port to which Tailon should bind on.
19159 @item @code{relative-root} (default: @code{#f})
19160 URL path to use for Tailon, set to @code{#f} to not use a path.
19162 @item @code{allow-transfers?} (default: @code{#t})
19163 Allow downloading the log files in the web interface.
19165 @item @code{follow-names?} (default: @code{#t})
19166 Allow tailing of not-yet existent files.
19168 @item @code{tail-lines} (default: @code{200})
19169 Number of lines to read initially from each file.
19171 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
19172 Commands to allow running. By default, @code{sed} is disabled.
19174 @item @code{debug?} (default: @code{#f})
19175 Set @code{debug?} to @code{#t} to show debug messages.
19177 @item @code{wrap-lines} (default: @code{#t})
19178 Initial line wrapping state in the web interface. Set to @code{#t} to
19179 initially wrap lines (the default), or to @code{#f} to initially not
19182 @item @code{http-auth} (default: @code{#f})
19183 HTTP authentication type to use. Set to @code{#f} to disable
19184 authentication (the default). Supported values are @code{"digest"} or
19187 @item @code{users} (default: @code{#f})
19188 If HTTP authentication is enabled (see @code{http-auth}), access will be
19189 restricted to the credentials provided here. To configure users, use a
19190 list of pairs, where the first element of the pair is the username, and
19191 the 2nd element of the pair is the password.
19194 (tailon-configuration-file
19195 (http-auth "basic")
19196 (users '(("user1" . "password1")
19197 ("user2" . "password2"))))
19204 @subsubheading Darkstat Service
19206 Darkstat is a packet sniffer that captures network traffic, calculates
19207 statistics about usage, and serves reports over HTTP.
19209 @defvar {Scheme Variable} darkstat-service-type
19210 This is the service type for the
19211 @uref{https://unix4lyfe.org/darkstat/, darkstat}
19212 service, its value must be a @code{darkstat-configuration} record as in
19216 (service darkstat-service-type
19217 (darkstat-configuration
19218 (interface "eno1")))
19222 @deftp {Data Type} darkstat-configuration
19223 Data type representing the configuration of @command{darkstat}.
19226 @item @code{package} (default: @code{darkstat})
19227 The darkstat package to use.
19229 @item @code{interface}
19230 Capture traffic on the specified network interface.
19232 @item @code{port} (default: @code{"667"})
19233 Bind the web interface to the specified port.
19235 @item @code{bind-address} (default: @code{"127.0.0.1"})
19236 Bind the web interface to the specified address.
19238 @item @code{base} (default: @code{"/"})
19239 Specify the path of the base URL. This can be useful if
19240 @command{darkstat} is accessed via a reverse proxy.
19245 @subsubheading Prometheus Node Exporter Service
19247 @cindex prometheus-node-exporter
19248 The Prometheus ``node exporter'' makes hardware and operating system statistics
19249 provided by the Linux kernel available for the Prometheus monitoring system.
19250 This service should be deployed on all physical nodes and virtual machines,
19251 where monitoring these statistics is desirable.
19253 @defvar {Scheme variable} prometheus-node-exporter-service-type
19254 This is the service type for the
19255 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
19256 service, its value must be a @code{prometheus-node-exporter-configuration}
19257 record as in this example:
19260 (service prometheus-node-exporter-service-type
19261 (prometheus-node-exporter-configuration
19262 (web-listen-address ":9100")))
19266 @deftp {Data Type} prometheus-node-exporter-configuration
19267 Data type representing the configuration of @command{node_exporter}.
19270 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
19271 The prometheus-node-exporter package to use.
19273 @item @code{web-listen-address} (default: @code{":9100"})
19274 Bind the web interface to the specified address.
19279 @subsubheading Zabbix server
19280 @cindex zabbix zabbix-server
19281 Zabbix provides monitoring metrics, among others network utilization, CPU load
19282 and disk space consumption:
19285 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
19286 @item Auto-discovery of servers and network devices and interfaces.
19287 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
19288 @item Distributed monitoring with centralized web administration.
19289 @item Native high performance agents.
19290 @item SLA, and ITIL KPI metrics on reporting.
19291 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
19292 @item Remote command execution through Zabbix proxies.
19295 @c %start of fragment
19297 Available @code{zabbix-server-configuration} fields are:
19299 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
19300 The zabbix-server package.
19304 @deftypevr {@code{zabbix-server-configuration} parameter} string user
19305 User who will run the Zabbix server.
19307 Defaults to @samp{"zabbix"}.
19311 @deftypevr {@code{zabbix-server-configuration} parameter} group group
19312 Group who will run the Zabbix server.
19314 Defaults to @samp{"zabbix"}.
19318 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
19319 Database host name.
19321 Defaults to @samp{"127.0.0.1"}.
19325 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
19328 Defaults to @samp{"zabbix"}.
19332 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
19335 Defaults to @samp{"zabbix"}.
19339 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
19340 Database password. Please, use @code{include-files} with
19341 @code{DBPassword=SECRET} inside a specified file instead.
19343 Defaults to @samp{""}.
19347 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
19350 Defaults to @samp{5432}.
19354 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
19355 Specifies where log messages are written to:
19359 @code{system} - syslog.
19362 @code{file} - file specified with @code{log-file} parameter.
19365 @code{console} - standard output.
19369 Defaults to @samp{""}.
19373 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
19374 Log file name for @code{log-type} @code{file} parameter.
19376 Defaults to @samp{"/var/log/zabbix/server.log"}.
19380 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
19383 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
19387 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
19388 The location of certificate authority (CA) files for SSL server
19389 certificate verification.
19391 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
19395 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
19396 Location of SSL client certificates.
19398 Defaults to @samp{"/etc/ssl/certs"}.
19402 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
19403 Extra options will be appended to Zabbix server configuration file.
19405 Defaults to @samp{""}.
19409 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
19410 You may include individual files or all files in a directory in the
19411 configuration file.
19413 Defaults to @samp{()}.
19417 @c %end of fragment
19419 @subsubheading Zabbix agent
19420 @cindex zabbix zabbix-agent
19422 Zabbix agent gathers information for Zabbix server.
19424 @c %start of fragment
19426 Available @code{zabbix-agent-configuration} fields are:
19428 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
19429 The zabbix-agent package.
19433 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
19434 User who will run the Zabbix agent.
19436 Defaults to @samp{"zabbix"}.
19440 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
19441 Group who will run the Zabbix agent.
19443 Defaults to @samp{"zabbix"}.
19447 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
19448 Unique, case sensitive hostname which is required for active checks and
19449 must match hostname as configured on the server.
19451 Defaults to @samp{"Zabbix server"}.
19455 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
19456 Specifies where log messages are written to:
19460 @code{system} - syslog.
19463 @code{file} - file specified with @code{log-file} parameter.
19466 @code{console} - standard output.
19470 Defaults to @samp{""}.
19474 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
19475 Log file name for @code{log-type} @code{file} parameter.
19477 Defaults to @samp{"/var/log/zabbix/agent.log"}.
19481 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
19484 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
19488 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
19489 List of IP addresses, optionally in CIDR notation, or hostnames of
19490 Zabbix servers and Zabbix proxies. Incoming connections will be
19491 accepted only from the hosts listed here.
19493 Defaults to @samp{("127.0.0.1")}.
19497 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
19498 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
19499 proxies for active checks. If port is not specified, default port is
19500 used. If this parameter is not specified, active checks are disabled.
19502 Defaults to @samp{("127.0.0.1")}.
19506 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
19507 Extra options will be appended to Zabbix server configuration file.
19509 Defaults to @samp{""}.
19513 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
19514 You may include individual files or all files in a directory in the
19515 configuration file.
19517 Defaults to @samp{()}.
19521 @c %end of fragment
19523 @subsubheading Zabbix front-end
19524 @cindex zabbix zabbix-front-end
19526 This service provides a WEB interface to Zabbix server.
19528 @c %start of fragment
19530 Available @code{zabbix-front-end-configuration} fields are:
19532 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
19533 NGINX configuration.
19537 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
19538 Database host name.
19540 Defaults to @samp{"localhost"}.
19544 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
19547 Defaults to @samp{5432}.
19551 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
19554 Defaults to @samp{"zabbix"}.
19558 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
19561 Defaults to @samp{"zabbix"}.
19565 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
19566 Database password. Please, use @code{db-secret-file} instead.
19568 Defaults to @samp{""}.
19572 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
19573 Secret file which will be appended to @file{zabbix.conf.php} file. This
19574 file contains credentials for use by Zabbix front-end. You are expected
19575 to create it manually.
19577 Defaults to @samp{""}.
19581 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
19582 Zabbix server hostname.
19584 Defaults to @samp{"localhost"}.
19588 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
19589 Zabbix server port.
19591 Defaults to @samp{10051}.
19596 @c %end of fragment
19598 @node Kerberos Services
19599 @subsection Kerberos Services
19602 The @code{(gnu services kerberos)} module provides services relating to
19603 the authentication protocol @dfn{Kerberos}.
19605 @subsubheading Krb5 Service
19607 Programs using a Kerberos client library normally
19608 expect a configuration file in @file{/etc/krb5.conf}.
19609 This service generates such a file from a definition provided in the
19610 operating system declaration.
19611 It does not cause any daemon to be started.
19613 No ``keytab'' files are provided by this service---you must explicitly create them.
19614 This service is known to work with the MIT client library, @code{mit-krb5}.
19615 Other implementations have not been tested.
19617 @defvr {Scheme Variable} krb5-service-type
19618 A service type for Kerberos 5 clients.
19622 Here is an example of its use:
19624 (service krb5-service-type
19625 (krb5-configuration
19626 (default-realm "EXAMPLE.COM")
19627 (allow-weak-crypto? #t)
19630 (name "EXAMPLE.COM")
19631 (admin-server "groucho.example.com")
19632 (kdc "karl.example.com"))
19635 (admin-server "kerb-admin.argrx.edu")
19636 (kdc "keys.argrx.edu"))))))
19640 This example provides a Kerberos@tie{}5 client configuration which:
19642 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19643 of which have distinct administration servers and key distribution centers;
19644 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19645 specified by clients;
19646 @item Accepts services which only support encryption types known to be weak.
19649 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19650 Only the most commonly used ones are described here.
19651 For a full list, and more detailed explanation of each, see the MIT
19652 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19656 @deftp {Data Type} krb5-realm
19657 @cindex realm, kerberos
19660 This field is a string identifying the name of the realm.
19661 A common convention is to use the fully qualified DNS name of your organization,
19662 converted to upper case.
19664 @item @code{admin-server}
19665 This field is a string identifying the host where the administration server is
19669 This field is a string identifying the key distribution center
19674 @deftp {Data Type} krb5-configuration
19677 @item @code{allow-weak-crypto?} (default: @code{#f})
19678 If this flag is @code{#t} then services which only offer encryption algorithms
19679 known to be weak will be accepted.
19681 @item @code{default-realm} (default: @code{#f})
19682 This field should be a string identifying the default Kerberos
19683 realm for the client.
19684 You should set this field to the name of your Kerberos realm.
19685 If this value is @code{#f}
19686 then a realm must be specified with every Kerberos principal when invoking programs
19687 such as @command{kinit}.
19689 @item @code{realms}
19690 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19692 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19698 @subsubheading PAM krb5 Service
19701 The @code{pam-krb5} service allows for login authentication and password
19702 management via Kerberos.
19703 You will need this service if you want PAM enabled applications to authenticate
19704 users using Kerberos.
19706 @defvr {Scheme Variable} pam-krb5-service-type
19707 A service type for the Kerberos 5 PAM module.
19710 @deftp {Data Type} pam-krb5-configuration
19711 Data type representing the configuration of the Kerberos 5 PAM module.
19712 This type has the following parameters:
19714 @item @code{pam-krb5} (default: @code{pam-krb5})
19715 The pam-krb5 package to use.
19717 @item @code{minimum-uid} (default: @code{1000})
19718 The smallest user ID for which Kerberos authentications should be attempted.
19719 Local accounts with lower values will silently fail to authenticate.
19724 @node LDAP Services
19725 @subsection LDAP Services
19727 @cindex nslcd, LDAP service
19729 The @code{(gnu services authentication)} module provides the
19730 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19731 server. In addition to configuring the service itself, you may want to add
19732 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19733 Switch} for detailed information.
19735 Here is a simple operating system declaration with a default configuration of
19736 the @code{nslcd-service-type} and a Name Service Switch configuration that
19737 consults the @code{ldap} name service last:
19740 (use-service-modules authentication)
19741 (use-modules (gnu system nss))
19747 (service nslcd-service-type)
19748 (service dhcp-client-service-type)
19750 (name-service-switch
19751 (let ((services (list (name-service (name "db"))
19752 (name-service (name "files"))
19753 (name-service (name "ldap")))))
19754 (name-service-switch
19755 (inherit %mdns-host-lookup-nss)
19756 (password services)
19759 (netgroup services)
19760 (gshadow services)))))
19763 @c %start of generated documentation for nslcd-configuration
19765 Available @code{nslcd-configuration} fields are:
19767 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19768 The @code{nss-pam-ldapd} package to use.
19772 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19773 The number of threads to start that can handle requests and perform LDAP
19774 queries. Each thread opens a separate connection to the LDAP server.
19775 The default is to start 5 threads.
19777 Defaults to @samp{disabled}.
19781 @deftypevr {@code{nslcd-configuration} parameter} string uid
19782 This specifies the user id with which the daemon should be run.
19784 Defaults to @samp{"nslcd"}.
19788 @deftypevr {@code{nslcd-configuration} parameter} string gid
19789 This specifies the group id with which the daemon should be run.
19791 Defaults to @samp{"nslcd"}.
19795 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19796 This option controls the way logging is done via a list containing
19797 SCHEME and LEVEL. The SCHEME argument may either be the symbols
19798 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
19799 argument is optional and specifies the log level. The log level may be
19800 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
19801 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
19802 specified log level or higher are logged.
19804 Defaults to @samp{("/var/log/nslcd" info)}.
19808 @deftypevr {@code{nslcd-configuration} parameter} list uri
19809 The list of LDAP server URIs. Normally, only the first server will be
19810 used with the following servers as fall-back.
19812 Defaults to @samp{("ldap://localhost:389/")}.
19816 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19817 The version of the LDAP protocol to use. The default is to use the
19818 maximum version supported by the LDAP library.
19820 Defaults to @samp{disabled}.
19824 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19825 Specifies the distinguished name with which to bind to the directory
19826 server for lookups. The default is to bind anonymously.
19828 Defaults to @samp{disabled}.
19832 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19833 Specifies the credentials with which to bind. This option is only
19834 applicable when used with binddn.
19836 Defaults to @samp{disabled}.
19840 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19841 Specifies the distinguished name to use when the root user tries to
19842 modify a user's password using the PAM module.
19844 Defaults to @samp{disabled}.
19848 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19849 Specifies the credentials with which to bind if the root user tries to
19850 change a user's password. This option is only applicable when used with
19853 Defaults to @samp{disabled}.
19857 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19858 Specifies the SASL mechanism to be used when performing SASL
19861 Defaults to @samp{disabled}.
19865 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19866 Specifies the SASL realm to be used when performing SASL authentication.
19868 Defaults to @samp{disabled}.
19872 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19873 Specifies the authentication identity to be used when performing SASL
19876 Defaults to @samp{disabled}.
19880 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19881 Specifies the authorization identity to be used when performing SASL
19884 Defaults to @samp{disabled}.
19888 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19889 Determines whether the LDAP server host name should be canonicalised. If
19890 this is enabled the LDAP library will do a reverse host name lookup. By
19891 default, it is left up to the LDAP library whether this check is
19894 Defaults to @samp{disabled}.
19898 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19899 Set the name for the GSS-API Kerberos credentials cache.
19901 Defaults to @samp{disabled}.
19905 @deftypevr {@code{nslcd-configuration} parameter} string base
19906 The directory search base.
19908 Defaults to @samp{"dc=example,dc=com"}.
19912 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19913 Specifies the search scope (subtree, onelevel, base or children). The
19914 default scope is subtree; base scope is almost never useful for name
19915 service lookups; children scope is not supported on all servers.
19917 Defaults to @samp{(subtree)}.
19921 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19922 Specifies the policy for dereferencing aliases. The default policy is
19923 to never dereference aliases.
19925 Defaults to @samp{disabled}.
19929 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19930 Specifies whether automatic referral chasing should be enabled. The
19931 default behaviour is to chase referrals.
19933 Defaults to @samp{disabled}.
19937 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19938 This option allows for custom attributes to be looked up instead of the
19939 default RFC 2307 attributes. It is a list of maps, each consisting of
19940 the name of a map, the RFC 2307 attribute to match and the query
19941 expression for the attribute as it is available in the directory.
19943 Defaults to @samp{()}.
19947 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19948 A list of filters consisting of the name of a map to which the filter
19949 applies and an LDAP search filter expression.
19951 Defaults to @samp{()}.
19955 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19956 Specifies the time limit in seconds to use when connecting to the
19957 directory server. The default value is 10 seconds.
19959 Defaults to @samp{disabled}.
19963 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19964 Specifies the time limit (in seconds) to wait for a response from the
19965 LDAP server. A value of zero, which is the default, is to wait
19966 indefinitely for searches to be completed.
19968 Defaults to @samp{disabled}.
19972 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19973 Specifies the period if inactivity (in seconds) after which the con‐
19974 nection to the LDAP server will be closed. The default is not to time
19977 Defaults to @samp{disabled}.
19981 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19982 Specifies the number of seconds to sleep when connecting to all LDAP
19983 servers fails. By default one second is waited between the first
19984 failure and the first retry.
19986 Defaults to @samp{disabled}.
19990 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19991 Specifies the time after which the LDAP server is considered to be
19992 permanently unavailable. Once this time is reached retries will be done
19993 only once per this time period. The default value is 10 seconds.
19995 Defaults to @samp{disabled}.
19999 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
20000 Specifies whether to use SSL/TLS or not (the default is not to). If
20001 'start-tls is specified then StartTLS is used rather than raw LDAP over
20004 Defaults to @samp{disabled}.
20008 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
20009 Specifies what checks to perform on a server-supplied certificate. The
20010 meaning of the values is described in the ldap.conf(5) manual page.
20012 Defaults to @samp{disabled}.
20016 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
20017 Specifies the directory containing X.509 certificates for peer authen‐
20018 tication. This parameter is ignored when using GnuTLS.
20020 Defaults to @samp{disabled}.
20024 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
20025 Specifies the path to the X.509 certificate for peer authentication.
20027 Defaults to @samp{disabled}.
20031 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
20032 Specifies the path to an entropy source. This parameter is ignored when
20035 Defaults to @samp{disabled}.
20039 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
20040 Specifies the ciphers to use for TLS as a string.
20042 Defaults to @samp{disabled}.
20046 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
20047 Specifies the path to the file containing the local certificate for
20048 client TLS authentication.
20050 Defaults to @samp{disabled}.
20054 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
20055 Specifies the path to the file containing the private key for client TLS
20058 Defaults to @samp{disabled}.
20062 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
20063 Set this to a number greater than 0 to request paged results from the
20064 LDAP server in accordance with RFC2696. The default (0) is to not
20065 request paged results.
20067 Defaults to @samp{disabled}.
20071 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
20072 This option prevents group membership lookups through LDAP for the
20073 specified users. Alternatively, the value 'all-local may be used. With
20074 that value nslcd builds a full list of non-LDAP users on startup.
20076 Defaults to @samp{disabled}.
20080 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
20081 This option ensures that LDAP users with a numeric user id lower than
20082 the specified value are ignored.
20084 Defaults to @samp{disabled}.
20088 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
20089 This option specifies an offset that is added to all LDAP numeric user
20090 ids. This can be used to avoid user id collisions with local users.
20092 Defaults to @samp{disabled}.
20096 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
20097 This option specifies an offset that is added to all LDAP numeric group
20098 ids. This can be used to avoid user id collisions with local groups.
20100 Defaults to @samp{disabled}.
20104 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
20105 If this option is set, the member attribute of a group may point to
20106 another group. Members of nested groups are also returned in the higher
20107 level group and parent groups are returned when finding groups for a
20108 specific user. The default is not to perform extra searches for nested
20111 Defaults to @samp{disabled}.
20115 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
20116 If this option is set, the group member list is not retrieved when
20117 looking up groups. Lookups for finding which groups a user belongs to
20118 will remain functional so the user will likely still get the correct
20119 groups assigned on login.
20121 Defaults to @samp{disabled}.
20125 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
20126 If this option is set, functions which cause all user/group entries to
20127 be loaded from the directory will not succeed in doing so. This can
20128 dramatically reduce LDAP server load in situations where there are a
20129 great number of users and/or groups. This option is not recommended for
20130 most configurations.
20132 Defaults to @samp{disabled}.
20136 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
20137 This option can be used to specify how user and group names are verified
20138 within the system. This pattern is used to check all user and group
20139 names that are requested and returned from LDAP.
20141 Defaults to @samp{disabled}.
20145 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
20146 This specifies whether or not to perform searches using case-insensitive
20147 matching. Enabling this could open up the system to authorization
20148 bypass vulnerabilities and introduce nscd cache poisoning
20149 vulnerabilities which allow denial of service.
20151 Defaults to @samp{disabled}.
20155 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
20156 This option specifies whether password policy controls are requested and
20157 handled from the LDAP server when performing user authentication.
20159 Defaults to @samp{disabled}.
20163 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
20164 By default nslcd performs an LDAP search with the user's credentials
20165 after BIND (authentication) to ensure that the BIND operation was
20166 successful. The default search is a simple check to see if the user's
20167 DN exists. A search filter can be specified that will be used instead.
20168 It should return at least one entry.
20170 Defaults to @samp{disabled}.
20174 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
20175 This option allows flexible fine tuning of the authorisation check that
20176 should be performed. The search filter specified is executed and if any
20177 entries match, access is granted, otherwise access is denied.
20179 Defaults to @samp{disabled}.
20183 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
20184 If this option is set password modification using pam_ldap will be
20185 denied and the specified message will be presented to the user instead.
20186 The message can be used to direct the user to an alternative means of
20187 changing their password.
20189 Defaults to @samp{disabled}.
20193 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
20194 List of pam service names for which LDAP authentication should suffice.
20196 Defaults to @samp{()}.
20200 @c %end of generated documentation for nslcd-configuration
20204 @subsection Web Services
20209 The @code{(gnu services web)} module provides the Apache HTTP Server,
20210 the nginx web server, and also a fastcgi wrapper daemon.
20212 @subsubheading Apache HTTP Server
20214 @deffn {Scheme Variable} httpd-service-type
20215 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
20216 (@dfn{httpd}). The value for this service type is a
20217 @code{httpd-configuration} record.
20219 A simple example configuration is given below.
20222 (service httpd-service-type
20223 (httpd-configuration
20226 (server-name "www.example.com")
20227 (document-root "/srv/http/www.example.com")))))
20230 Other services can also extend the @code{httpd-service-type} to add to
20234 (simple-service 'www.example.com-server httpd-service-type
20238 (list (string-join '("ServerName www.example.com"
20239 "DocumentRoot /srv/http/www.example.com")
20244 The details for the @code{httpd-configuration}, @code{httpd-module},
20245 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
20248 @deffn {Data Type} httpd-configuration
20249 This data type represents the configuration for the httpd service.
20252 @item @code{package} (default: @code{httpd})
20253 The httpd package to use.
20255 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20256 The pid file used by the shepherd-service.
20258 @item @code{config} (default: @code{(httpd-config-file)})
20259 The configuration file to use with the httpd service. The default value
20260 is a @code{httpd-config-file} record, but this can also be a different
20261 G-expression that generates a file, for example a @code{plain-file}. A
20262 file outside of the store can also be specified through a string.
20267 @deffn {Data Type} httpd-module
20268 This data type represents a module for the httpd service.
20272 The name of the module.
20275 The file for the module. This can be relative to the httpd package being
20276 used, the absolute location of a file, or a G-expression for a file
20277 within the store, for example @code{(file-append mod-wsgi
20278 "/modules/mod_wsgi.so")}.
20283 @defvr {Scheme Variable} %default-httpd-modules
20284 A default list of @code{httpd-module} objects.
20287 @deffn {Data Type} httpd-config-file
20288 This data type represents a configuration file for the httpd service.
20291 @item @code{modules} (default: @code{%default-httpd-modules})
20292 The modules to load. Additional modules can be added here, or loaded by
20293 additional configuration.
20295 For example, in order to handle requests for PHP files, you can use Apache’s
20296 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
20299 (service httpd-service-type
20300 (httpd-configuration
20305 (name "proxy_module")
20306 (file "modules/mod_proxy.so"))
20308 (name "proxy_fcgi_module")
20309 (file "modules/mod_proxy_fcgi.so"))
20310 %default-httpd-modules))
20311 (extra-config (list "\
20312 <FilesMatch \\.php$>
20313 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
20314 </FilesMatch>"))))))
20315 (service php-fpm-service-type
20316 (php-fpm-configuration
20317 (socket "/var/run/php-fpm.sock")
20318 (socket-group "httpd")))
20321 @item @code{server-root} (default: @code{httpd})
20322 The @code{ServerRoot} in the configuration file, defaults to the httpd
20323 package. Directives including @code{Include} and @code{LoadModule} are
20324 taken as relative to the server root.
20326 @item @code{server-name} (default: @code{#f})
20327 The @code{ServerName} in the configuration file, used to specify the
20328 request scheme, hostname and port that the server uses to identify
20331 This doesn't need to be set in the server config, and can be specified
20332 in virtual hosts. The default is @code{#f} to not specify a
20335 @item @code{document-root} (default: @code{"/srv/http"})
20336 The @code{DocumentRoot} from which files will be served.
20338 @item @code{listen} (default: @code{'("80")})
20339 The list of values for the @code{Listen} directives in the config
20340 file. The value should be a list of strings, when each string can
20341 specify the port number to listen on, and optionally the IP address and
20344 @item @code{pid-file} (default: @code{"/var/run/httpd"})
20345 The @code{PidFile} to use. This should match the @code{pid-file} set in
20346 the @code{httpd-configuration} so that the Shepherd service is
20347 configured correctly.
20349 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
20350 The @code{ErrorLog} to which the server will log errors.
20352 @item @code{user} (default: @code{"httpd"})
20353 The @code{User} which the server will answer requests as.
20355 @item @code{group} (default: @code{"httpd"})
20356 The @code{Group} which the server will answer requests as.
20358 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
20359 A flat list of strings and G-expressions which will be added to the end
20360 of the configuration file.
20362 Any values which the service is extended with will be appended to this
20368 @deffn {Data Type} httpd-virtualhost
20369 This data type represents a virtualhost configuration block for the httpd service.
20371 These should be added to the extra-config for the httpd-service.
20374 (simple-service 'www.example.com-server httpd-service-type
20378 (list (string-join '("ServerName www.example.com"
20379 "DocumentRoot /srv/http/www.example.com")
20384 @item @code{addresses-and-ports}
20385 The addresses and ports for the @code{VirtualHost} directive.
20387 @item @code{contents}
20388 The contents of the @code{VirtualHost} directive, this should be a list
20389 of strings and G-expressions.
20394 @subsubheading NGINX
20396 @deffn {Scheme Variable} nginx-service-type
20397 Service type for the @uref{https://nginx.org/,NGinx} web server. The
20398 value for this service type is a @code{<nginx-configuration>} record.
20400 A simple example configuration is given below.
20403 (service nginx-service-type
20404 (nginx-configuration
20406 (list (nginx-server-configuration
20407 (server-name '("www.example.com"))
20408 (root "/srv/http/www.example.com"))))))
20411 In addition to adding server blocks to the service configuration
20412 directly, this service can be extended by other services to add server
20413 blocks, as in this example:
20416 (simple-service 'my-extra-server nginx-service-type
20417 (list (nginx-server-configuration
20418 (root "/srv/http/extra-website")
20419 (try-files (list "$uri" "$uri/index.html")))))
20423 At startup, @command{nginx} has not yet read its configuration file, so
20424 it uses a default file to log error messages. If it fails to load its
20425 configuration file, that is where error messages are logged. After the
20426 configuration file is loaded, the default error log file changes as per
20427 configuration. In our case, startup error messages can be found in
20428 @file{/var/run/nginx/logs/error.log}, and after configuration in
20429 @file{/var/log/nginx/error.log}. The second location can be changed
20430 with the @var{log-directory} configuration option.
20432 @deffn {Data Type} nginx-configuration
20433 This data type represents the configuration for NGinx. Some
20434 configuration can be done through this and the other provided record
20435 types, or alternatively, a config file can be provided.
20438 @item @code{nginx} (default: @code{nginx})
20439 The nginx package to use.
20441 @item @code{log-directory} (default: @code{"/var/log/nginx"})
20442 The directory to which NGinx will write log files.
20444 @item @code{run-directory} (default: @code{"/var/run/nginx"})
20445 The directory in which NGinx will create a pid file, and write temporary
20448 @item @code{server-blocks} (default: @code{'()})
20449 A list of @dfn{server blocks} to create in the generated configuration
20450 file, the elements should be of type
20451 @code{<nginx-server-configuration>}.
20453 The following example would setup NGinx to serve @code{www.example.com}
20454 from the @code{/srv/http/www.example.com} directory, without using
20457 (service nginx-service-type
20458 (nginx-configuration
20460 (list (nginx-server-configuration
20461 (server-name '("www.example.com"))
20462 (root "/srv/http/www.example.com"))))))
20465 @item @code{upstream-blocks} (default: @code{'()})
20466 A list of @dfn{upstream blocks} to create in the generated configuration
20467 file, the elements should be of type
20468 @code{<nginx-upstream-configuration>}.
20470 Configuring upstreams through the @code{upstream-blocks} can be useful
20471 when combined with @code{locations} in the
20472 @code{<nginx-server-configuration>} records. The following example
20473 creates a server configuration with one location configuration, that
20474 will proxy requests to a upstream configuration, which will handle
20475 requests with two servers.
20480 (nginx-configuration
20482 (list (nginx-server-configuration
20483 (server-name '("www.example.com"))
20484 (root "/srv/http/www.example.com")
20487 (nginx-location-configuration
20489 (body '("proxy_pass http://server-proxy;"))))))))
20491 (list (nginx-upstream-configuration
20492 (name "server-proxy")
20493 (servers (list "server1.example.com"
20494 "server2.example.com")))))))
20497 @item @code{file} (default: @code{#f})
20498 If a configuration @var{file} is provided, this will be used, rather than
20499 generating a configuration file from the provided @code{log-directory},
20500 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
20501 proper operation, these arguments should match what is in @var{file} to ensure
20502 that the directories are created when the service is activated.
20504 This can be useful if you have an existing configuration file, or it's
20505 not possible to do what is required through the other parts of the
20506 nginx-configuration record.
20508 @item @code{server-names-hash-bucket-size} (default: @code{#f})
20509 Bucket size for the server names hash tables, defaults to @code{#f} to
20510 use the size of the processors cache line.
20512 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
20513 Maximum bucket size for the server names hash tables.
20515 @item @code{modules} (default: @code{'()})
20516 List of nginx dynamic modules to load. This should be a list of file
20517 names of loadable modules, as in this example:
20522 (file-append nginx-accept-language-module "\
20523 /etc/nginx/modules/ngx_http_accept_language_module.so")))
20526 @item @code{global-directives} (default: @code{'((events . ()))})
20527 Association list of global directives for the top level of the nginx
20528 configuration. Values may themselves be association lists.
20532 `((worker_processes . 16)
20534 (events . ((worker_connections . 1024)))))
20537 @item @code{extra-content} (default: @code{""})
20538 Extra content for the @code{http} block. Should be string or a string
20539 valued G-expression.
20544 @deftp {Data Type} nginx-server-configuration
20545 Data type representing the configuration of an nginx server block.
20546 This type has the following parameters:
20549 @item @code{listen} (default: @code{'("80" "443 ssl")})
20550 Each @code{listen} directive sets the address and port for IP, or the
20551 path for a UNIX-domain socket on which the server will accept requests.
20552 Both address and port, or only address or only port can be specified.
20553 An address may also be a hostname, for example:
20556 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
20559 @item @code{server-name} (default: @code{(list 'default)})
20560 A list of server names this server represents. @code{'default} represents the
20561 default server for connections matching no other server.
20563 @item @code{root} (default: @code{"/srv/http"})
20564 Root of the website nginx will serve.
20566 @item @code{locations} (default: @code{'()})
20567 A list of @dfn{nginx-location-configuration} or
20568 @dfn{nginx-named-location-configuration} records to use within this
20571 @item @code{index} (default: @code{(list "index.html")})
20572 Index files to look for when clients ask for a directory. If it cannot be found,
20573 Nginx will send the list of files in the directory.
20575 @item @code{try-files} (default: @code{'()})
20576 A list of files whose existence is checked in the specified order.
20577 @code{nginx} will use the first file it finds to process the request.
20579 @item @code{ssl-certificate} (default: @code{#f})
20580 Where to find the certificate for secure connections. Set it to @code{#f} if
20581 you don't have a certificate or you don't want to use HTTPS.
20583 @item @code{ssl-certificate-key} (default: @code{#f})
20584 Where to find the private key for secure connections. Set it to @code{#f} if
20585 you don't have a key or you don't want to use HTTPS.
20587 @item @code{server-tokens?} (default: @code{#f})
20588 Whether the server should add its configuration to response.
20590 @item @code{raw-content} (default: @code{'()})
20591 A list of raw lines added to the server block.
20596 @deftp {Data Type} nginx-upstream-configuration
20597 Data type representing the configuration of an nginx @code{upstream}
20598 block. This type has the following parameters:
20602 Name for this group of servers.
20604 @item @code{servers}
20605 Specify the addresses of the servers in the group. The address can be
20606 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
20607 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
20608 prefix @samp{unix:}. For addresses using an IP address or domain name,
20609 the default port is 80, and a different port can be specified
20615 @deftp {Data Type} nginx-location-configuration
20616 Data type representing the configuration of an nginx @code{location}
20617 block. This type has the following parameters:
20621 URI which this location block matches.
20623 @anchor{nginx-location-configuration body}
20625 Body of the location block, specified as a list of strings. This can contain
20627 configuration directives. For example, to pass requests to a upstream
20628 server group defined using an @code{nginx-upstream-configuration} block,
20629 the following directive would be specified in the body @samp{(list "proxy_pass
20630 http://upstream-name;")}.
20635 @deftp {Data Type} nginx-named-location-configuration
20636 Data type representing the configuration of an nginx named location
20637 block. Named location blocks are used for request redirection, and not
20638 used for regular request processing. This type has the following
20643 Name to identify this location block.
20646 @xref{nginx-location-configuration body}, as the body for named location
20647 blocks can be used in a similar way to the
20648 @code{nginx-location-configuration body}. One restriction is that the
20649 body of a named location block cannot contain location blocks.
20654 @subsubheading Varnish Cache
20656 Varnish is a fast cache server that sits in between web applications
20657 and end users. It proxies requests from clients and caches the
20658 accessed URLs such that multiple requests for the same resource only
20659 creates one request to the back-end.
20661 @defvr {Scheme Variable} varnish-service-type
20662 Service type for the Varnish daemon.
20665 @deftp {Data Type} varnish-configuration
20666 Data type representing the @code{varnish} service configuration.
20667 This type has the following parameters:
20670 @item @code{package} (default: @code{varnish})
20671 The Varnish package to use.
20673 @item @code{name} (default: @code{"default"})
20674 A name for this Varnish instance. Varnish will create a directory in
20675 @file{/var/varnish/} with this name and keep temporary files there. If
20676 the name starts with a forward slash, it is interpreted as an absolute
20679 Pass the @code{-n} argument to other Varnish programs to connect to the
20680 named instance, e.g.@: @command{varnishncsa -n default}.
20682 @item @code{backend} (default: @code{"localhost:8080"})
20683 The backend to use. This option has no effect if @code{vcl} is set.
20685 @item @code{vcl} (default: #f)
20686 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20687 is @code{#f}, Varnish will proxy @code{backend} using the default
20688 configuration. Otherwise this must be a file-like object with valid
20691 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20692 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
20693 can do something along these lines:
20696 (define %gnu-mirror
20697 (plain-file "gnu.vcl"
20699 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20703 (services (cons (service varnish-service-type
20704 (varnish-configuration
20706 (vcl %gnu-mirror)))
20710 The configuration of an already running Varnish instance can be inspected
20711 and changed using the @command{varnishadm} program.
20713 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20714 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20715 comprehensive documentation on Varnish and its configuration language.
20717 @item @code{listen} (default: @code{'("localhost:80")})
20718 List of addresses Varnish will listen on.
20720 @item @code{storage} (default: @code{'("malloc,128m")})
20721 List of storage backends that will be available in VCL.
20723 @item @code{parameters} (default: @code{'()})
20724 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20726 @item @code{extra-options} (default: @code{'()})
20727 Additional arguments to pass to the @command{varnishd} process.
20732 @subsubheading Patchwork
20734 Patchwork is a patch tracking system. It can collect patches sent to a
20735 mailing list, and display them in a web interface.
20737 @defvr {Scheme Variable} patchwork-service-type
20738 Service type for Patchwork.
20741 The following example is an example of a minimal service for Patchwork, for
20742 the @code{patchwork.example.com} domain.
20745 (service patchwork-service-type
20746 (patchwork-configuration
20747 (domain "patchwork.example.com")
20749 (patchwork-settings-module
20750 (allowed-hosts (list domain))
20751 (default-from-email "patchwork@@patchwork.example.com")))
20752 (getmail-retriever-config
20753 (getmail-retriever-configuration
20754 (type "SimpleIMAPSSLRetriever")
20755 (server "imap.example.com")
20757 (username "patchwork")
20759 (list (file-append coreutils "/bin/cat")
20760 "/etc/getmail-patchwork-imap-password"))
20762 '((mailboxes . ("Patches"))))))))
20766 There are three records for configuring the Patchwork service. The
20767 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20768 within the HTTPD service.
20770 The @code{settings-module} field within the @code{<patchwork-configuration>}
20771 record can be populated with the @code{<patchwork-settings-module>} record,
20772 which describes a settings module that is generated within the Guix store.
20774 For the @code{database-configuration} field within the
20775 @code{<patchwork-settings-module>}, the
20776 @code{<patchwork-database-configuration>} must be used.
20778 @deftp {Data Type} patchwork-configuration
20779 Data type representing the Patchwork service configuration. This type has the
20780 following parameters:
20783 @item @code{patchwork} (default: @code{patchwork})
20784 The Patchwork package to use.
20786 @item @code{domain}
20787 The domain to use for Patchwork, this is used in the HTTPD service virtual
20790 @item @code{settings-module}
20791 The settings module to use for Patchwork. As a Django application, Patchwork
20792 is configured with a Python module containing the settings. This can either be
20793 an instance of the @code{<patchwork-settings-module>} record, any other record
20794 that represents the settings in the store, or a directory outside of the
20797 @item @code{static-path} (default: @code{"/static/"})
20798 The path under which the HTTPD service should serve the static files.
20800 @item @code{getmail-retriever-config}
20801 The getmail-retriever-configuration record value to use with
20802 Patchwork. Getmail will be configured with this value, the messages will be
20803 delivered to Patchwork.
20808 @deftp {Data Type} patchwork-settings-module
20809 Data type representing a settings module for Patchwork. Some of these
20810 settings relate directly to Patchwork, but others relate to Django, the web
20811 framework used by Patchwork, or the Django Rest Framework library. This type
20812 has the following parameters:
20815 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20816 The database connection settings used for Patchwork. See the
20817 @code{<patchwork-database-configuration>} record type for more information.
20819 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20820 Patchwork, as a Django web application uses a secret key for cryptographically
20821 signing values. This file should contain a unique unpredictable value.
20823 If this file does not exist, it will be created and populated with a random
20824 value by the patchwork-setup shepherd service.
20826 This setting relates to Django.
20828 @item @code{allowed-hosts}
20829 A list of valid hosts for this Patchwork service. This should at least include
20830 the domain specified in the @code{<patchwork-configuration>} record.
20832 This is a Django setting.
20834 @item @code{default-from-email}
20835 The email address from which Patchwork should send email by default.
20837 This is a Patchwork setting.
20839 @item @code{static-url} (default: @code{#f})
20840 The URL to use when serving static assets. It can be part of a URL, or a full
20841 URL, but must end in a @code{/}.
20843 If the default value is used, the @code{static-path} value from the
20844 @code{<patchwork-configuration>} record will be used.
20846 This is a Django setting.
20848 @item @code{admins} (default: @code{'()})
20849 Email addresses to send the details of errors that occur. Each value should
20850 be a list containing two elements, the name and then the email address.
20852 This is a Django setting.
20854 @item @code{debug?} (default: @code{#f})
20855 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20856 messages will be shown.
20858 This is a Django setting.
20860 @item @code{enable-rest-api?} (default: @code{#t})
20861 Whether to enable the Patchwork REST API.
20863 This is a Patchwork setting.
20865 @item @code{enable-xmlrpc?} (default: @code{#t})
20866 Whether to enable the XML RPC API.
20868 This is a Patchwork setting.
20870 @item @code{force-https-links?} (default: @code{#t})
20871 Whether to use HTTPS links on Patchwork pages.
20873 This is a Patchwork setting.
20875 @item @code{extra-settings} (default: @code{""})
20876 Extra code to place at the end of the Patchwork settings module.
20881 @deftp {Data Type} patchwork-database-configuration
20882 Data type representing the database configuration for Patchwork.
20885 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20886 The database engine to use.
20888 @item @code{name} (default: @code{"patchwork"})
20889 The name of the database to use.
20891 @item @code{user} (default: @code{"httpd"})
20892 The user to connect to the database as.
20894 @item @code{password} (default: @code{""})
20895 The password to use when connecting to the database.
20897 @item @code{host} (default: @code{""})
20898 The host to make the database connection to.
20900 @item @code{port} (default: @code{""})
20901 The port on which to connect to the database.
20906 @subsubheading Mumi
20908 @cindex Mumi, Debbugs Web interface
20909 @cindex Debbugs, Mumi Web interface
20910 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
20911 Web interface to the Debbugs bug tracker, by default for
20912 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
20913 but it also fetches and indexes mail retrieved from Debbugs.
20915 @defvr {Scheme Variable} mumi-service-type
20916 This is the service type for Mumi.
20919 @deftp {Data Type} mumi-configuration
20920 Data type representing the Mumi service configuration. This type has the
20924 @item @code{mumi} (default: @code{mumi})
20925 The Mumi package to use.
20927 @item @code{mailer?} (default: @code{#true})
20928 Whether to enable or disable the mailer component.
20930 @item @code{mumi-configuration-sender}
20931 The email address used as the sender for comments.
20933 @item @code{mumi-configuration-smtp}
20934 A URI to configure the SMTP settings for Mailutils. This could be
20935 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
20936 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
20937 mailutils, GNU@tie{}Mailutils}.
20943 @subsubheading FastCGI
20946 FastCGI is an interface between the front-end and the back-end of a web
20947 service. It is a somewhat legacy facility; new web services should
20948 generally just talk HTTP between the front-end and the back-end.
20949 However there are a number of back-end services such as PHP or the
20950 optimized HTTP Git repository access that use FastCGI, so we have
20951 support for it in Guix.
20953 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20954 dispatch some subset of its requests to the fastcgi backend, which
20955 listens on a local TCP or UNIX socket. There is an intermediary
20956 @code{fcgiwrap} program that sits between the actual backend process and
20957 the web server. The front-end indicates which backend program to run,
20958 passing that information to the @code{fcgiwrap} process.
20960 @defvr {Scheme Variable} fcgiwrap-service-type
20961 A service type for the @code{fcgiwrap} FastCGI proxy.
20964 @deftp {Data Type} fcgiwrap-configuration
20965 Data type representing the configuration of the @code{fcgiwrap} service.
20966 This type has the following parameters:
20968 @item @code{package} (default: @code{fcgiwrap})
20969 The fcgiwrap package to use.
20971 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20972 The socket on which the @code{fcgiwrap} process should listen, as a
20973 string. Valid @var{socket} values include
20974 @code{unix:@var{/path/to/unix/socket}},
20975 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20976 @code{tcp6:[@var{ipv6_addr}]:port}.
20978 @item @code{user} (default: @code{fcgiwrap})
20979 @itemx @code{group} (default: @code{fcgiwrap})
20980 The user and group names, as strings, under which to run the
20981 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20982 the user asks for the specific user or group names @code{fcgiwrap} that
20983 the corresponding user and/or group is present on the system.
20985 It is possible to configure a FastCGI-backed web service to pass HTTP
20986 authentication information from the front-end to the back-end, and to
20987 allow @code{fcgiwrap} to run the back-end process as a corresponding
20988 local user. To enable this capability on the back-end, run
20989 @code{fcgiwrap} as the @code{root} user and group. Note that this
20990 capability also has to be configured on the front-end as well.
20995 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20996 with some additional features useful for sites of any size.
20998 These features include:
21000 @item Adaptive process spawning
21001 @item Basic statistics (similar to Apache's mod_status)
21002 @item Advanced process management with graceful stop/start
21003 @item Ability to start workers with different uid/gid/chroot/environment
21004 and different php.ini (replaces safe_mode)
21005 @item Stdout & stderr logging
21006 @item Emergency restart in case of accidental opcode cache destruction
21007 @item Accelerated upload support
21008 @item Support for a "slowlog"
21009 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
21010 a special function to finish request & flush all data while continuing to do
21011 something time-consuming (video converting, stats processing, etc.)
21013 ...@: and much more.
21015 @defvr {Scheme Variable} php-fpm-service-type
21016 A Service type for @code{php-fpm}.
21019 @deftp {Data Type} php-fpm-configuration
21020 Data Type for php-fpm service configuration.
21022 @item @code{php} (default: @code{php})
21023 The php package to use.
21024 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
21025 The address on which to accept FastCGI requests. Valid syntaxes are:
21027 @item @code{"ip.add.re.ss:port"}
21028 Listen on a TCP socket to a specific address on a specific port.
21029 @item @code{"port"}
21030 Listen on a TCP socket to all addresses on a specific port.
21031 @item @code{"/path/to/unix/socket"}
21032 Listen on a unix socket.
21035 @item @code{user} (default: @code{php-fpm})
21036 User who will own the php worker processes.
21037 @item @code{group} (default: @code{php-fpm})
21038 Group of the worker processes.
21039 @item @code{socket-user} (default: @code{php-fpm})
21040 User who can speak to the php-fpm socket.
21041 @item @code{socket-group} (default: @code{nginx})
21042 Group that can speak to the php-fpm socket.
21043 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
21044 The process id of the php-fpm process is written to this file
21045 once the service has started.
21046 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
21047 Log for the php-fpm master process.
21048 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
21049 Detailed settings for the php-fpm process manager.
21052 @item @code{<php-fpm-dynamic-process-manager-configuration>}
21053 @item @code{<php-fpm-static-process-manager-configuration>}
21054 @item @code{<php-fpm-on-demand-process-manager-configuration>}
21056 @item @code{display-errors} (default @code{#f})
21057 Determines whether php errors and warning should be sent to clients
21058 and displayed in their browsers.
21059 This is useful for local php development, but a security risk for public sites,
21060 as error messages can reveal passwords and personal data.
21061 @item @code{timezone} (default @code{#f})
21062 Specifies @code{php_admin_value[date.timezone]} parameter.
21063 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
21064 This file will log the @code{stderr} outputs of php worker processes.
21065 Can be set to @code{#f} to disable logging.
21066 @item @code{file} (default @code{#f})
21067 An optional override of the whole configuration.
21068 You can use the @code{mixed-text-file} function or an absolute filepath for it.
21072 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
21073 Data Type for the @code{dynamic} php-fpm process manager. With the
21074 @code{dynamic} process manager, spare worker processes are kept around
21075 based on it's configured limits.
21077 @item @code{max-children} (default: @code{5})
21078 Maximum of worker processes.
21079 @item @code{start-servers} (default: @code{2})
21080 How many worker processes should be started on start-up.
21081 @item @code{min-spare-servers} (default: @code{1})
21082 How many spare worker processes should be kept around at minimum.
21083 @item @code{max-spare-servers} (default: @code{3})
21084 How many spare worker processes should be kept around at maximum.
21088 @deftp {Data type} php-fpm-static-process-manager-configuration
21089 Data Type for the @code{static} php-fpm process manager. With the
21090 @code{static} process manager, an unchanging number of worker processes
21093 @item @code{max-children} (default: @code{5})
21094 Maximum of worker processes.
21098 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
21099 Data Type for the @code{on-demand} php-fpm process manager. With the
21100 @code{on-demand} process manager, worker processes are only created as
21103 @item @code{max-children} (default: @code{5})
21104 Maximum of worker processes.
21105 @item @code{process-idle-timeout} (default: @code{10})
21106 The time in seconds after which a process with no requests is killed.
21111 @deffn {Scheme Procedure} nginx-php-location @
21112 [#:nginx-package nginx] @
21113 [socket (string-append "/var/run/php" @
21114 (version-major (package-version php)) @
21116 A helper function to quickly add php to an @code{nginx-server-configuration}.
21119 A simple services setup for nginx with php can look like this:
21121 (services (cons* (service dhcp-client-service-type)
21122 (service php-fpm-service-type)
21123 (service nginx-service-type
21124 (nginx-server-configuration
21125 (server-name '("example.com"))
21126 (root "/srv/http/")
21128 (list (nginx-php-location)))
21130 (ssl-certificate #f)
21131 (ssl-certificate-key #f)))
21135 @cindex cat-avatar-generator
21136 The cat avatar generator is a simple service to demonstrate the use of php-fpm
21137 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
21138 the hash of a user's email address.
21140 @deffn {Scheme Procedure} cat-avatar-generator-service @
21141 [#:cache-dir "/var/cache/cat-avatar-generator"] @
21142 [#:package cat-avatar-generator] @
21143 [#:configuration (nginx-server-configuration)]
21144 Returns an nginx-server-configuration that inherits @code{configuration}. It
21145 extends the nginx configuration to add a server block that serves @code{package},
21146 a version of cat-avatar-generator. During execution, cat-avatar-generator will
21147 be able to use @code{cache-dir} as its cache directory.
21150 A simple setup for cat-avatar-generator can look like this:
21152 (services (cons* (cat-avatar-generator-service
21154 (nginx-server-configuration
21155 (server-name '("example.com"))))
21160 @subsubheading Hpcguix-web
21162 @cindex hpcguix-web
21163 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
21164 program is a customizable web interface to browse Guix packages,
21165 initially designed for users of high-performance computing (HPC)
21168 @defvr {Scheme Variable} hpcguix-web-service-type
21169 The service type for @code{hpcguix-web}.
21172 @deftp {Data Type} hpcguix-web-configuration
21173 Data type for the hpcguix-web service configuration.
21177 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
21178 configuration. The main items available in this spec are:
21181 @item @code{title-prefix} (default: @code{"hpcguix | "})
21182 The page title prefix.
21184 @item @code{guix-command} (default: @code{"guix"})
21185 The @command{guix} command.
21187 @item @code{package-filter-proc} (default: @code{(const #t)})
21188 A procedure specifying how to filter packages that are displayed.
21190 @item @code{package-page-extension-proc} (default: @code{(const '())})
21191 Extension package for @code{hpcguix-web}.
21193 @item @code{menu} (default: @code{'()})
21194 Additional entry in page @code{menu}.
21196 @item @code{channels} (default: @code{%default-channels})
21197 List of channels from which the package list is built (@pxref{Channels}).
21199 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
21200 The expiration time, in seconds, after which the package list is rebuilt from
21201 the latest instances of the given channels.
21204 See the hpcguix-web repository for a
21205 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
21208 @item @code{package} (default: @code{hpcguix-web})
21209 The hpcguix-web package to use.
21213 A typical hpcguix-web service declaration looks like this:
21216 (service hpcguix-web-service-type
21217 (hpcguix-web-configuration
21219 #~(define site-config
21220 (hpcweb-configuration
21221 (title-prefix "Guix-HPC - ")
21222 (menu '(("/about" "ABOUT"))))))))
21226 The hpcguix-web service periodically updates the package list it publishes by
21227 pulling channels from Git. To that end, it needs to access X.509 certificates
21228 so that it can authenticate Git servers when communicating over HTTPS, and it
21229 assumes that @file{/etc/ssl/certs} contains those certificates.
21231 Thus, make sure to add @code{nss-certs} or another certificate package to the
21232 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
21233 more information on X.509 certificates.
21236 @node Certificate Services
21237 @subsection Certificate Services
21240 @cindex HTTP, HTTPS
21241 @cindex Let's Encrypt
21242 @cindex TLS certificates
21243 The @code{(gnu services certbot)} module provides a service to
21244 automatically obtain a valid TLS certificate from the Let's Encrypt
21245 certificate authority. These certificates can then be used to serve
21246 content securely over HTTPS or other TLS-based protocols, with the
21247 knowledge that the client will be able to verify the server's
21250 @url{https://letsencrypt.org/, Let's Encrypt} provides the
21251 @code{certbot} tool to automate the certification process. This tool
21252 first securely generates a key on the server. It then makes a request
21253 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
21254 checks that the request originates from the host in question by using a
21255 challenge-response protocol, requiring the server to provide its
21256 response over HTTP. If that protocol completes successfully, the CA
21257 signs the key, resulting in a certificate. That certificate is valid
21258 for a limited period of time, and therefore to continue to provide TLS
21259 services, the server needs to periodically ask the CA to renew its
21262 The certbot service automates this process: the initial key
21263 generation, the initial certification request to the Let's Encrypt
21264 service, the web server challenge/response integration, writing the
21265 certificate to disk, the automated periodic renewals, and the deployment
21266 tasks associated with the renewal (e.g.@: reloading services, copying keys
21267 with different permissions).
21269 Certbot is run twice a day, at a random minute within the hour. It
21270 won't do anything until your certificates are due for renewal or
21271 revoked, but running it regularly would give your service a chance of
21272 staying online in case a Let's Encrypt-initiated revocation happened for
21275 By using this service, you agree to the ACME Subscriber Agreement, which
21276 can be found there:
21277 @url{https://acme-v01.api.letsencrypt.org/directory}.
21279 @defvr {Scheme Variable} certbot-service-type
21280 A service type for the @code{certbot} Let's Encrypt client. Its value
21281 must be a @code{certbot-configuration} record as in this example:
21284 (define %nginx-deploy-hook
21286 "nginx-deploy-hook"
21287 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
21288 (kill pid SIGHUP))))
21290 (service certbot-service-type
21291 (certbot-configuration
21292 (email "foo@@example.net")
21295 (certificate-configuration
21296 (domains '("example.net" "www.example.net"))
21297 (deploy-hook %nginx-deploy-hook))
21298 (certificate-configuration
21299 (domains '("bar.example.net")))))))
21302 See below for details about @code{certbot-configuration}.
21305 @deftp {Data Type} certbot-configuration
21306 Data type representing the configuration of the @code{certbot} service.
21307 This type has the following parameters:
21310 @item @code{package} (default: @code{certbot})
21311 The certbot package to use.
21313 @item @code{webroot} (default: @code{/var/www})
21314 The directory from which to serve the Let's Encrypt challenge/response
21317 @item @code{certificates} (default: @code{()})
21318 A list of @code{certificates-configuration}s for which to generate
21319 certificates and request signatures. Each certificate has a @code{name}
21320 and several @code{domains}.
21323 Mandatory email used for registration, recovery contact, and important
21324 account notifications.
21326 @item @code{server} (default: @code{#f})
21327 Optional URL of ACME server. Setting this overrides certbot's default,
21328 which is the Let's Encrypt server.
21330 @item @code{rsa-key-size} (default: @code{2048})
21331 Size of the RSA key.
21333 @item @code{default-location} (default: @i{see below})
21334 The default @code{nginx-location-configuration}. Because @code{certbot}
21335 needs to be able to serve challenges and responses, it needs to be able
21336 to run a web server. It does so by extending the @code{nginx} web
21337 service with an @code{nginx-server-configuration} listening on the
21338 @var{domains} on port 80, and which has a
21339 @code{nginx-location-configuration} for the @code{/.well-known/} URI
21340 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
21341 these nginx configuration data types.
21343 Requests to other URL paths will be matched by the
21344 @code{default-location}, which if present is added to all
21345 @code{nginx-server-configuration}s.
21347 By default, the @code{default-location} will issue a redirect from
21348 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
21349 you to define what to serve on your site via @code{https}.
21351 Pass @code{#f} to not issue a default location.
21355 @deftp {Data Type} certificate-configuration
21356 Data type representing the configuration of a certificate.
21357 This type has the following parameters:
21360 @item @code{name} (default: @i{see below})
21361 This name is used by Certbot for housekeeping and in file paths; it
21362 doesn't affect the content of the certificate itself. To see
21363 certificate names, run @code{certbot certificates}.
21365 Its default is the first provided domain.
21367 @item @code{domains} (default: @code{()})
21368 The first domain provided will be the subject CN of the certificate, and
21369 all domains will be Subject Alternative Names on the certificate.
21371 @item @code{challenge} (default: @code{#f})
21372 The challenge type that has to be run by certbot. If @code{#f} is specified,
21373 default to the HTTP challenge. If a value is specified, defaults to the
21374 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
21375 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
21376 and gives Let's Encrypt permission to log the public IP address of the
21377 requesting machine.
21379 @item @code{authentication-hook} (default: @code{#f})
21380 Command to be run in a shell once for each certificate challenge to be
21381 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
21382 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
21383 contains the validation string and @code{$CERTBOT_TOKEN} contains the
21384 file name of the resource requested when performing an HTTP-01 challenge.
21386 @item @code{cleanup-hook} (default: @code{#f})
21387 Command to be run in a shell once for each certificate challenge that
21388 have been answered by the @code{auth-hook}. For this command, the shell
21389 variables available in the @code{auth-hook} script are still available, and
21390 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
21391 of the @code{auth-hook} script.
21393 @item @code{deploy-hook} (default: @code{#f})
21394 Command to be run in a shell once for each successfully issued
21395 certificate. For this command, the shell variable
21396 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
21397 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
21398 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
21399 contain a space-delimited list of renewed certificate domains (for
21400 example, @samp{"example.com www.example.com"}.
21405 For each @code{certificate-configuration}, the certificate is saved to
21406 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
21407 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
21409 @subsection DNS Services
21410 @cindex DNS (domain name system)
21411 @cindex domain name system (DNS)
21413 The @code{(gnu services dns)} module provides services related to the
21414 @dfn{domain name system} (DNS). It provides a server service for hosting
21415 an @emph{authoritative} DNS server for multiple zones, slave or master.
21416 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
21417 caching and forwarding DNS server for the LAN, which uses
21418 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
21420 @subsubheading Knot Service
21422 An example configuration of an authoritative server for two zones, one master
21426 (define-zone-entries example.org.zone
21427 ;; Name TTL Class Type Data
21428 ("@@" "" "IN" "A" "127.0.0.1")
21429 ("@@" "" "IN" "NS" "ns")
21430 ("ns" "" "IN" "A" "127.0.0.1"))
21432 (define master-zone
21433 (knot-zone-configuration
21434 (domain "example.org")
21436 (origin "example.org")
21437 (entries example.org.zone)))))
21440 (knot-zone-configuration
21441 (domain "plop.org")
21442 (dnssec-policy "default")
21443 (master (list "plop-master"))))
21445 (define plop-master
21446 (knot-remote-configuration
21448 (address (list "208.76.58.171"))))
21452 (services (cons* (service knot-service-type
21453 (knot-configuration
21454 (remotes (list plop-master))
21455 (zones (list master-zone slave-zone))))
21460 @deffn {Scheme Variable} knot-service-type
21461 This is the type for the Knot DNS server.
21463 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
21464 zones, that is to say domain names you would buy from a registrar. This server
21465 is not a resolver, meaning that it can only resolve names for which it is
21466 authoritative. This server can be configured to serve zones as a master server
21467 or a slave server as a per-zone basis. Slave zones will get their data from
21468 masters, and will serve it as an authoritative server. From the point of view
21469 of a resolver, there is no difference between master and slave.
21471 The following data types are used to configure the Knot DNS server:
21474 @deftp {Data Type} knot-key-configuration
21475 Data type representing a key.
21476 This type has the following parameters:
21479 @item @code{id} (default: @code{""})
21480 An identifier for other configuration fields to refer to this key. IDs must
21481 be unique and must not be empty.
21483 @item @code{algorithm} (default: @code{#f})
21484 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
21485 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
21486 and @code{'hmac-sha512}.
21488 @item @code{secret} (default: @code{""})
21489 The secret key itself.
21494 @deftp {Data Type} knot-acl-configuration
21495 Data type representing an Access Control List (ACL) configuration.
21496 This type has the following parameters:
21499 @item @code{id} (default: @code{""})
21500 An identifier for ether configuration fields to refer to this key. IDs must be
21501 unique and must not be empty.
21503 @item @code{address} (default: @code{'()})
21504 An ordered list of IP addresses, network subnets, or network ranges represented
21505 with strings. The query must match one of them. Empty value means that
21506 address match is not required.
21508 @item @code{key} (default: @code{'()})
21509 An ordered list of references to keys represented with strings. The string
21510 must match a key ID defined in a @code{knot-key-configuration}. No key means
21511 that a key is not require to match that ACL.
21513 @item @code{action} (default: @code{'()})
21514 An ordered list of actions that are permitted or forbidden by this ACL. Possible
21515 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
21516 and @code{'update}.
21518 @item @code{deny?} (default: @code{#f})
21519 When true, the ACL defines restrictions. Listed actions are forbidden. When
21520 false, listed actions are allowed.
21525 @deftp {Data Type} zone-entry
21526 Data type representing a record entry in a zone file.
21527 This type has the following parameters:
21530 @item @code{name} (default: @code{"@@"})
21531 The name of the record. @code{"@@"} refers to the origin of the zone. Names
21532 are relative to the origin of the zone. For example, in the @code{example.org}
21533 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
21534 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
21535 refers to @code{ns.example.org}.
21537 @item @code{ttl} (default: @code{""})
21538 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
21540 @item @code{class} (default: @code{"IN"})
21541 The class of the record. Knot currently supports only @code{"IN"} and
21542 partially @code{"CH"}.
21544 @item @code{type} (default: @code{"A"})
21545 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
21546 address), NS (Name Server) and MX (Mail eXchange). Many other types are
21549 @item @code{data} (default: @code{""})
21550 The data contained in the record. For instance an IP address associated with
21551 an A record, or a domain name associated with an NS record. Remember that
21552 domain names are relative to the origin unless they end with a dot.
21557 @deftp {Data Type} zone-file
21558 Data type representing the content of a zone file.
21559 This type has the following parameters:
21562 @item @code{entries} (default: @code{'()})
21563 The list of entries. The SOA record is taken care of, so you don't need to
21564 put it in the list of entries. This list should probably contain an entry
21565 for your primary authoritative DNS server. Other than using a list of entries
21566 directly, you can use @code{define-zone-entries} to define a object containing
21567 the list of entries more easily, that you can later pass to the @code{entries}
21568 field of the @code{zone-file}.
21570 @item @code{origin} (default: @code{""})
21571 The name of your zone. This parameter cannot be empty.
21573 @item @code{ns} (default: @code{"ns"})
21574 The domain of your primary authoritative DNS server. The name is relative to
21575 the origin, unless it ends with a dot. It is mandatory that this primary
21576 DNS server corresponds to an NS record in the zone and that it is associated
21577 to an IP address in the list of entries.
21579 @item @code{mail} (default: @code{"hostmaster"})
21580 An email address people can contact you at, as the owner of the zone. This
21581 is translated as @code{<mail>@@<origin>}.
21583 @item @code{serial} (default: @code{1})
21584 The serial number of the zone. As this is used to keep track of changes by
21585 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
21586 Always increment it when you make a change in your zone.
21588 @item @code{refresh} (default: @code{(* 2 24 3600)})
21589 The frequency at which slaves will do a zone transfer. This value is a number
21590 of seconds. It can be computed by multiplications or with
21591 @code{(string->duration)}.
21593 @item @code{retry} (default: @code{(* 15 60)})
21594 The period after which a slave will retry to contact its master when it fails
21595 to do so a first time.
21597 @item @code{expiry} (default: @code{(* 14 24 3600)})
21598 Default TTL of records. Existing records are considered correct for at most
21599 this amount of time. After this period, resolvers will invalidate their cache
21600 and check again that it still exists.
21602 @item @code{nx} (default: @code{3600})
21603 Default TTL of inexistant records. This delay is usually short because you want
21604 your new domains to reach everyone quickly.
21609 @deftp {Data Type} knot-remote-configuration
21610 Data type representing a remote configuration.
21611 This type has the following parameters:
21614 @item @code{id} (default: @code{""})
21615 An identifier for other configuration fields to refer to this remote. IDs must
21616 be unique and must not be empty.
21618 @item @code{address} (default: @code{'()})
21619 An ordered list of destination IP addresses. Addresses are tried in sequence.
21620 An optional port can be given with the @@ separator. For instance:
21621 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
21623 @item @code{via} (default: @code{'()})
21624 An ordered list of source IP addresses. An empty list will have Knot choose
21625 an appropriate source IP. An optional port can be given with the @@ separator.
21626 The default is to choose at random.
21628 @item @code{key} (default: @code{#f})
21629 A reference to a key, that is a string containing the identifier of a key
21630 defined in a @code{knot-key-configuration} field.
21635 @deftp {Data Type} knot-keystore-configuration
21636 Data type representing a keystore to hold dnssec keys.
21637 This type has the following parameters:
21640 @item @code{id} (default: @code{""})
21641 The id of the keystore. It must not be empty.
21643 @item @code{backend} (default: @code{'pem})
21644 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
21646 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
21647 The configuration string of the backend. An example for the PKCS#11 is:
21648 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
21649 For the pem backend, the string represents a path in the file system.
21654 @deftp {Data Type} knot-policy-configuration
21655 Data type representing a dnssec policy. Knot DNS is able to automatically
21656 sign your zones. It can either generate and manage your keys automatically or
21657 use keys that you generate.
21659 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
21660 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
21661 zone. In order to be trusted, the KSK needs to be present in the parent zone
21662 (usually a top-level domain). If your registrar supports dnssec, you will
21663 have to send them your KSK's hash so they can add a DS record in their zone.
21664 This is not automated and need to be done each time you change your KSK.
21666 The policy also defines the lifetime of keys. Usually, ZSK can be changed
21667 easily and use weaker cryptographic functions (they use lower parameters) in
21668 order to sign records quickly, so they are changed often. The KSK however
21669 requires manual interaction with the registrar, so they are changed less often
21670 and use stronger parameters because they sign only one record.
21672 This type has the following parameters:
21675 @item @code{id} (default: @code{""})
21676 The id of the policy. It must not be empty.
21678 @item @code{keystore} (default: @code{"default"})
21679 A reference to a keystore, that is a string containing the identifier of a
21680 keystore defined in a @code{knot-keystore-configuration} field. The
21681 @code{"default"} identifier means the default keystore (a kasp database that
21682 was setup by this service).
21684 @item @code{manual?} (default: @code{#f})
21685 Whether the key management is manual or automatic.
21687 @item @code{single-type-signing?} (default: @code{#f})
21688 When @code{#t}, use the Single-Type Signing Scheme.
21690 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21691 An algorithm of signing keys and issued signatures.
21693 @item @code{ksk-size} (default: @code{256})
21694 The length of the KSK. Note that this value is correct for the default
21695 algorithm, but would be unsecure for other algorithms.
21697 @item @code{zsk-size} (default: @code{256})
21698 The length of the ZSK. Note that this value is correct for the default
21699 algorithm, but would be unsecure for other algorithms.
21701 @item @code{dnskey-ttl} (default: @code{'default})
21702 The TTL value for DNSKEY records added into zone apex. The special
21703 @code{'default} value means same as the zone SOA TTL.
21705 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21706 The period between ZSK publication and the next rollover initiation.
21708 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21709 An extra delay added for each key rollover step. This value should be high
21710 enough to cover propagation of data from the master server to all slaves.
21712 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21713 A validity period of newly issued signatures.
21715 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21716 A period how long before a signature expiration the signature will be refreshed.
21718 @item @code{nsec3?} (default: @code{#f})
21719 When @code{#t}, NSEC3 will be used instead of NSEC.
21721 @item @code{nsec3-iterations} (default: @code{5})
21722 The number of additional times the hashing is performed.
21724 @item @code{nsec3-salt-length} (default: @code{8})
21725 The length of a salt field in octets, which is appended to the original owner
21726 name before hashing.
21728 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21729 The validity period of newly issued salt field.
21734 @deftp {Data Type} knot-zone-configuration
21735 Data type representing a zone served by Knot.
21736 This type has the following parameters:
21739 @item @code{domain} (default: @code{""})
21740 The domain served by this configuration. It must not be empty.
21742 @item @code{file} (default: @code{""})
21743 The file where this zone is saved. This parameter is ignored by master zones.
21744 Empty means default location that depends on the domain name.
21746 @item @code{zone} (default: @code{(zone-file)})
21747 The content of the zone file. This parameter is ignored by slave zones. It
21748 must contain a zone-file record.
21750 @item @code{master} (default: @code{'()})
21751 A list of master remotes. When empty, this zone is a master. When set, this
21752 zone is a slave. This is a list of remotes identifiers.
21754 @item @code{ddns-master} (default: @code{#f})
21755 The main master. When empty, it defaults to the first master in the list of
21758 @item @code{notify} (default: @code{'()})
21759 A list of slave remote identifiers.
21761 @item @code{acl} (default: @code{'()})
21762 A list of acl identifiers.
21764 @item @code{semantic-checks?} (default: @code{#f})
21765 When set, this adds more semantic checks to the zone.
21767 @item @code{disable-any?} (default: @code{#f})
21768 When set, this forbids queries of the ANY type.
21770 @item @code{zonefile-sync} (default: @code{0})
21771 The delay between a modification in memory and on disk. 0 means immediate
21774 @item @code{zonefile-load} (default: @code{#f})
21775 The way the zone file contents are applied during zone load. Possible values
21779 @item @code{#f} for using the default value from Knot,
21780 @item @code{'none} for not using the zone file at all,
21781 @item @code{'difference} for computing the difference between already available
21782 contents and zone contents and applying it to the current zone contents,
21783 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21784 ignoring the SOA serial in the zone file, while the server takes care of it
21786 @item @code{'whole} for loading zone contents from the zone file.
21789 @item @code{journal-content} (default: @code{#f})
21790 The way the journal is used to store zone and its changes. Possible values
21791 are @code{'none} to not use it at all, @code{'changes} to store changes and
21792 @code{'all} to store contents. @code{#f} does not set this option, so the
21793 default value from Knot is used.
21795 @item @code{max-journal-usage} (default: @code{#f})
21796 The maximum size for the journal on disk. @code{#f} does not set this option,
21797 so the default value from Knot is used.
21799 @item @code{max-journal-depth} (default: @code{#f})
21800 The maximum size of the history. @code{#f} does not set this option, so the
21801 default value from Knot is used.
21803 @item @code{max-zone-size} (default: @code{#f})
21804 The maximum size of the zone file. This limit is enforced for incoming
21805 transfer and updates. @code{#f} does not set this option, so the default
21806 value from Knot is used.
21808 @item @code{dnssec-policy} (default: @code{#f})
21809 A reference to a @code{knot-policy-configuration} record, or the special
21810 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21813 @item @code{serial-policy} (default: @code{'increment})
21814 A policy between @code{'increment} and @code{'unixtime}.
21819 @deftp {Data Type} knot-configuration
21820 Data type representing the Knot configuration.
21821 This type has the following parameters:
21824 @item @code{knot} (default: @code{knot})
21827 @item @code{run-directory} (default: @code{"/var/run/knot"})
21828 The run directory. This directory will be used for pid file and sockets.
21830 @item @code{includes} (default: @code{'()})
21831 A list of strings or file-like objects denoting other files that must be
21832 included at the top of the configuration file.
21834 @cindex secrets, Knot service
21835 This can be used to manage secrets out-of-band. For example, secret
21836 keys may be stored in an out-of-band file not managed by Guix, and
21837 thus not visible in @file{/gnu/store}---e.g., you could store secret
21838 key configuration in @file{/etc/knot/secrets.conf} and add this file
21839 to the @code{includes} list.
21841 One can generate a secret tsig key (for nsupdate and zone transfers with the
21842 keymgr command from the knot package. Note that the package is not automatically
21843 installed by the service. The following example shows how to generate a new
21847 keymgr -t mysecret > /etc/knot/secrets.conf
21848 chmod 600 /etc/knot/secrets.conf
21851 Also note that the generated key will be named @var{mysecret}, so it is the
21852 name that needs to be used in the @var{key} field of the
21853 @code{knot-acl-configuration} record and in other places that need to refer
21856 It can also be used to add configuration not supported by this interface.
21858 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21859 An ip address on which to listen.
21861 @item @code{listen-v6} (default: @code{"::"})
21862 An ip address on which to listen.
21864 @item @code{listen-port} (default: @code{53})
21865 A port on which to listen.
21867 @item @code{keys} (default: @code{'()})
21868 The list of knot-key-configuration used by this configuration.
21870 @item @code{acls} (default: @code{'()})
21871 The list of knot-acl-configuration used by this configuration.
21873 @item @code{remotes} (default: @code{'()})
21874 The list of knot-remote-configuration used by this configuration.
21876 @item @code{zones} (default: @code{'()})
21877 The list of knot-zone-configuration used by this configuration.
21882 @subsubheading Knot Resolver Service
21884 @deffn {Scheme Variable} knot-resolver-service-type
21885 This this the type of the knot resolver service, whose value should be
21886 an @code{knot-resolver-configuration} object as in this example:
21889 (service knot-resolver-service-type
21890 (knot-resolver-configuration
21891 (kresd-config-file (plain-file "kresd.conf" "
21892 net.listen('192.168.0.1', 5353)
21893 user('knot-resolver', 'knot-resolver')
21894 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21895 cache.size = 100 * MB
21899 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21902 @deftp {Data Type} knot-resolver-configuration
21903 Data type representing the configuration of knot-resolver.
21906 @item @code{package} (default: @var{knot-resolver})
21907 Package object of the knot DNS resolver.
21909 @item @code{kresd-config-file} (default: %kresd.conf)
21910 File-like object of the kresd configuration file to use, by default it
21911 will listen on @code{127.0.0.1} and @code{::1}.
21913 @item @code{garbage-collection-interval} (default: 1000)
21914 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21920 @subsubheading Dnsmasq Service
21922 @deffn {Scheme Variable} dnsmasq-service-type
21923 This is the type of the dnsmasq service, whose value should be an
21924 @code{dnsmasq-configuration} object as in this example:
21927 (service dnsmasq-service-type
21928 (dnsmasq-configuration
21930 (servers '("192.168.1.1"))))
21934 @deftp {Data Type} dnsmasq-configuration
21935 Data type representing the configuration of dnsmasq.
21938 @item @code{package} (default: @var{dnsmasq})
21939 Package object of the dnsmasq server.
21941 @item @code{no-hosts?} (default: @code{#f})
21942 When true, don't read the hostnames in /etc/hosts.
21944 @item @code{port} (default: @code{53})
21945 The port to listen on. Setting this to zero completely disables DNS
21946 responses, leaving only DHCP and/or TFTP functions.
21948 @item @code{local-service?} (default: @code{#t})
21949 Accept DNS queries only from hosts whose address is on a local subnet,
21950 ie a subnet for which an interface exists on the server.
21952 @item @code{listen-addresses} (default: @code{'()})
21953 Listen on the given IP addresses.
21955 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21956 The file to read the IP address of the upstream nameservers from.
21958 @item @code{no-resolv?} (default: @code{#f})
21959 When true, don't read @var{resolv-file}.
21961 @item @code{servers} (default: @code{'()})
21962 Specify IP address of upstream servers directly.
21964 @item @code{addresses} (default: @code{'()})
21965 For each entry, specify an IP address to return for any host in the
21966 given domains. Queries in the domains are never forwarded and always
21967 replied to with the specified IP address.
21969 This is useful for redirecting hosts locally, for example:
21972 (service dnsmasq-service-type
21973 (dnsmasq-configuration
21975 '(; Redirect to a local web-server.
21976 "/example.org/127.0.0.1"
21977 ; Redirect subdomain to a specific IP.
21978 "/subdomain.example.org/192.168.1.42"))))
21981 Note that rules in @file{/etc/hosts} take precedence over this.
21983 @item @code{cache-size} (default: @code{150})
21984 Set the size of dnsmasq's cache. Setting the cache size to zero
21987 @item @code{negative-cache?} (default: @code{#t})
21988 When false, disable negative caching.
21993 @subsubheading ddclient Service
21996 The ddclient service described below runs the ddclient daemon, which takes
21997 care of automatically updating DNS entries for service providers such as
21998 @uref{https://dyn.com/dns/, Dyn}.
22000 The following example show instantiates the service with its default
22004 (service ddclient-service-type)
22007 Note that ddclient needs to access credentials that are stored in a
22008 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
22009 @code{secret-file} below.) You are expected to create this file manually, in
22010 an ``out-of-band'' fashion (you @emph{could} make this file part of the
22011 service configuration, for instance by using @code{plain-file}, but it will be
22012 world-readable @i{via} @file{/gnu/store}.) See the examples in the
22013 @file{share/ddclient} directory of the @code{ddclient} package.
22015 @c %start of fragment
22017 Available @code{ddclient-configuration} fields are:
22019 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
22020 The ddclient package.
22024 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
22025 The period after which ddclient will retry to check IP and domain name.
22027 Defaults to @samp{300}.
22031 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
22032 Use syslog for the output.
22034 Defaults to @samp{#t}.
22038 @deftypevr {@code{ddclient-configuration} parameter} string mail
22041 Defaults to @samp{"root"}.
22045 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
22046 Mail failed update to user.
22048 Defaults to @samp{"root"}.
22052 @deftypevr {@code{ddclient-configuration} parameter} string pid
22053 The ddclient PID file.
22055 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
22059 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
22060 Enable SSL support.
22062 Defaults to @samp{#t}.
22066 @deftypevr {@code{ddclient-configuration} parameter} string user
22067 Specifies the user name or ID that is used when running ddclient
22070 Defaults to @samp{"ddclient"}.
22074 @deftypevr {@code{ddclient-configuration} parameter} string group
22075 Group of the user who will run the ddclient program.
22077 Defaults to @samp{"ddclient"}.
22081 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
22082 Secret file which will be appended to @file{ddclient.conf} file. This
22083 file contains credentials for use by ddclient. You are expected to
22084 create it manually.
22086 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
22090 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
22091 Extra options will be appended to @file{ddclient.conf} file.
22093 Defaults to @samp{()}.
22098 @c %end of fragment
22102 @subsection VPN Services
22103 @cindex VPN (virtual private network)
22104 @cindex virtual private network (VPN)
22106 The @code{(gnu services vpn)} module provides services related to
22107 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
22108 your machine to connect to a VPN, and a @emph{server} service for your machine
22109 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
22111 @deffn {Scheme Procedure} openvpn-client-service @
22112 [#:config (openvpn-client-configuration)]
22114 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
22117 @deffn {Scheme Procedure} openvpn-server-service @
22118 [#:config (openvpn-server-configuration)]
22120 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
22122 Both can be run simultaneously.
22125 @c %automatically generated documentation
22127 Available @code{openvpn-client-configuration} fields are:
22129 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
22130 The OpenVPN package.
22134 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
22135 The OpenVPN pid file.
22137 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22141 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
22142 The protocol (UDP or TCP) used to open a channel between clients and
22145 Defaults to @samp{udp}.
22149 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
22150 The device type used to represent the VPN connection.
22152 Defaults to @samp{tun}.
22156 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
22157 The certificate authority to check connections against.
22159 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22163 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
22164 The certificate of the machine the daemon is running on. It should be
22165 signed by the authority given in @code{ca}.
22167 Defaults to @samp{"/etc/openvpn/client.crt"}.
22171 @deftypevr {@code{openvpn-client-configuration} parameter} string key
22172 The key of the machine the daemon is running on. It must be the key whose
22173 certificate is @code{cert}.
22175 Defaults to @samp{"/etc/openvpn/client.key"}.
22179 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
22180 Whether to use the lzo compression algorithm.
22182 Defaults to @samp{#t}.
22186 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
22187 Don't re-read key files across SIGUSR1 or --ping-restart.
22189 Defaults to @samp{#t}.
22193 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
22194 Don't close and reopen TUN/TAP device or run up/down scripts across
22195 SIGUSR1 or --ping-restart restarts.
22197 Defaults to @samp{#t}.
22201 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
22202 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22203 poll/epoll/select prior to the write operation.
22205 Defaults to @samp{#f}.
22208 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
22211 Defaults to @samp{3}.
22215 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
22216 Add an additional layer of HMAC authentication on top of the TLS control
22217 channel to protect against DoS attacks.
22219 Defaults to @samp{#f}.
22223 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
22224 Authenticate with server using username/password. The option is a file
22225 containing username/password on 2 lines. Do not use a file-like object as it
22226 would be added to the store and readable by any user.
22228 Defaults to @samp{'disabled}.
22231 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
22232 Whether to check the server certificate has server usage extension.
22234 Defaults to @samp{#t}.
22238 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
22239 Bind to a specific local port number.
22241 Defaults to @samp{#f}.
22245 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
22246 Retry resolving server address.
22248 Defaults to @samp{#t}.
22252 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
22253 A list of remote servers to connect to.
22255 Defaults to @samp{()}.
22257 Available @code{openvpn-remote-configuration} fields are:
22259 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
22262 Defaults to @samp{"my-server"}.
22266 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
22267 Port number the server listens to.
22269 Defaults to @samp{1194}.
22274 @c %end of automatic openvpn-client documentation
22276 @c %automatically generated documentation
22278 Available @code{openvpn-server-configuration} fields are:
22280 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
22281 The OpenVPN package.
22285 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
22286 The OpenVPN pid file.
22288 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
22292 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
22293 The protocol (UDP or TCP) used to open a channel between clients and
22296 Defaults to @samp{udp}.
22300 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
22301 The device type used to represent the VPN connection.
22303 Defaults to @samp{tun}.
22307 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
22308 The certificate authority to check connections against.
22310 Defaults to @samp{"/etc/openvpn/ca.crt"}.
22314 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
22315 The certificate of the machine the daemon is running on. It should be
22316 signed by the authority given in @code{ca}.
22318 Defaults to @samp{"/etc/openvpn/client.crt"}.
22322 @deftypevr {@code{openvpn-server-configuration} parameter} string key
22323 The key of the machine the daemon is running on. It must be the key whose
22324 certificate is @code{cert}.
22326 Defaults to @samp{"/etc/openvpn/client.key"}.
22330 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
22331 Whether to use the lzo compression algorithm.
22333 Defaults to @samp{#t}.
22337 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
22338 Don't re-read key files across SIGUSR1 or --ping-restart.
22340 Defaults to @samp{#t}.
22344 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
22345 Don't close and reopen TUN/TAP device or run up/down scripts across
22346 SIGUSR1 or --ping-restart restarts.
22348 Defaults to @samp{#t}.
22352 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
22353 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
22354 poll/epoll/select prior to the write operation.
22356 Defaults to @samp{#f}.
22359 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
22362 Defaults to @samp{3}.
22366 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
22367 Add an additional layer of HMAC authentication on top of the TLS control
22368 channel to protect against DoS attacks.
22370 Defaults to @samp{#f}.
22374 @deftypevr {@code{openvpn-server-configuration} parameter} number port
22375 Specifies the port number on which the server listens.
22377 Defaults to @samp{1194}.
22381 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
22382 An ip and mask specifying the subnet inside the virtual network.
22384 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
22388 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
22389 A CIDR notation specifying the IPv6 subnet inside the virtual network.
22391 Defaults to @samp{#f}.
22395 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
22396 The Diffie-Hellman parameters file.
22398 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
22402 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
22403 The file that records client IPs.
22405 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
22409 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
22410 When true, the server will act as a gateway for its clients.
22412 Defaults to @samp{#f}.
22416 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
22417 When true, clients are allowed to talk to each other inside the VPN.
22419 Defaults to @samp{#f}.
22423 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
22424 Causes ping-like messages to be sent back and forth over the link so
22425 that each side knows when the other side has gone down. @code{keepalive}
22426 requires a pair. The first element is the period of the ping sending,
22427 and the second element is the timeout before considering the other side
22432 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
22433 The maximum number of clients.
22435 Defaults to @samp{100}.
22439 @deftypevr {@code{openvpn-server-configuration} parameter} string status
22440 The status file. This file shows a small report on current connection.
22441 It is truncated and rewritten every minute.
22443 Defaults to @samp{"/var/run/openvpn/status"}.
22447 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
22448 The list of configuration for some clients.
22450 Defaults to @samp{()}.
22452 Available @code{openvpn-ccd-configuration} fields are:
22454 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
22457 Defaults to @samp{"client"}.
22461 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
22464 Defaults to @samp{#f}.
22468 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
22471 Defaults to @samp{#f}.
22478 @c %end of automatic openvpn-server documentation
22481 @node Network File System
22482 @subsection Network File System
22485 The @code{(gnu services nfs)} module provides the following services,
22486 which are most commonly used in relation to mounting or exporting
22487 directory trees as @dfn{network file systems} (NFS).
22489 While it is possible to use the individual components that together make
22490 up a Network File System service, we recommended to configure an NFS
22491 server with the @code{nfs-service-type}.
22493 @subsubheading NFS Service
22494 @cindex NFS, server
22496 The NFS service takes care of setting up all NFS component services,
22497 kernel configuration file systems, and installs configuration files in
22498 the locations that NFS expects.
22500 @defvr {Scheme Variable} nfs-service-type
22501 A service type for a complete NFS server.
22504 @deftp {Data Type} nfs-configuration
22505 This data type represents the configuration of the NFS service and all
22508 It has the following parameters:
22510 @item @code{nfs-utils} (default: @code{nfs-utils})
22511 The nfs-utils package to use.
22513 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
22514 If a list of string values is provided, the @command{rpc.nfsd} daemon
22515 will be limited to supporting the given versions of the NFS protocol.
22517 @item @code{exports} (default: @code{'()})
22518 This is a list of directories the NFS server should export. Each entry
22519 is a list consisting of two elements: a directory name and a string
22520 containing all options. This is an example in which the directory
22521 @file{/export} is served to all NFS clients as a read-only share:
22527 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
22530 @item @code{rpcmountd-port} (default: @code{#f})
22531 The network port that the @command{rpc.mountd} daemon should use.
22533 @item @code{rpcstatd-port} (default: @code{#f})
22534 The network port that the @command{rpc.statd} daemon should use.
22536 @item @code{rpcbind} (default: @code{rpcbind})
22537 The rpcbind package to use.
22539 @item @code{idmap-domain} (default: @code{"localdomain"})
22540 The local NFSv4 domain name.
22542 @item @code{nfsd-port} (default: @code{2049})
22543 The network port that the @command{nfsd} daemon should use.
22545 @item @code{nfsd-threads} (default: @code{8})
22546 The number of threads used by the @command{nfsd} daemon.
22548 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22549 The directory where the pipefs file system is mounted.
22551 @item @code{debug} (default: @code{'()"})
22552 A list of subsystems for which debugging output should be enabled. This
22553 is a list of symbols. Any of these symbols are valid: @code{nfsd},
22554 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
22558 If you don't need a complete NFS service or prefer to build it yourself
22559 you can use the individual component services that are documented below.
22561 @subsubheading RPC Bind Service
22564 The RPC Bind service provides a facility to map program numbers into
22565 universal addresses.
22566 Many NFS related services use this facility. Hence it is automatically
22567 started when a dependent service starts.
22569 @defvr {Scheme Variable} rpcbind-service-type
22570 A service type for the RPC portmapper daemon.
22574 @deftp {Data Type} rpcbind-configuration
22575 Data type representing the configuration of the RPC Bind Service.
22576 This type has the following parameters:
22578 @item @code{rpcbind} (default: @code{rpcbind})
22579 The rpcbind package to use.
22581 @item @code{warm-start?} (default: @code{#t})
22582 If this parameter is @code{#t}, then the daemon will read a
22583 state file on startup thus reloading state information saved by a previous
22589 @subsubheading Pipefs Pseudo File System
22593 The pipefs file system is used to transfer NFS related data
22594 between the kernel and user space programs.
22596 @defvr {Scheme Variable} pipefs-service-type
22597 A service type for the pipefs pseudo file system.
22600 @deftp {Data Type} pipefs-configuration
22601 Data type representing the configuration of the pipefs pseudo file system service.
22602 This type has the following parameters:
22604 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22605 The directory to which the file system is to be attached.
22610 @subsubheading GSS Daemon Service
22613 @cindex global security system
22615 The @dfn{global security system} (GSS) daemon provides strong security for RPC
22617 Before exchanging RPC requests an RPC client must establish a security
22618 context. Typically this is done using the Kerberos command @command{kinit}
22619 or automatically at login time using PAM services (@pxref{Kerberos Services}).
22621 @defvr {Scheme Variable} gss-service-type
22622 A service type for the Global Security System (GSS) daemon.
22625 @deftp {Data Type} gss-configuration
22626 Data type representing the configuration of the GSS daemon service.
22627 This type has the following parameters:
22629 @item @code{nfs-utils} (default: @code{nfs-utils})
22630 The package in which the @command{rpc.gssd} command is to be found.
22632 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22633 The directory where the pipefs file system is mounted.
22639 @subsubheading IDMAP Daemon Service
22641 @cindex name mapper
22643 The idmap daemon service provides mapping between user IDs and user names.
22644 Typically it is required in order to access file systems mounted via NFSv4.
22646 @defvr {Scheme Variable} idmap-service-type
22647 A service type for the Identity Mapper (IDMAP) daemon.
22650 @deftp {Data Type} idmap-configuration
22651 Data type representing the configuration of the IDMAP daemon service.
22652 This type has the following parameters:
22654 @item @code{nfs-utils} (default: @code{nfs-utils})
22655 The package in which the @command{rpc.idmapd} command is to be found.
22657 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
22658 The directory where the pipefs file system is mounted.
22660 @item @code{domain} (default: @code{#f})
22661 The local NFSv4 domain name.
22662 This must be a string or @code{#f}.
22663 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
22665 @item @code{verbosity} (default: @code{0})
22666 The verbosity level of the daemon.
22671 @node Continuous Integration
22672 @subsection Continuous Integration
22674 @cindex continuous integration
22675 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
22676 continuous integration tool for Guix. It can be used both for development and
22677 for providing substitutes to others (@pxref{Substitutes}).
22679 The @code{(gnu services cuirass)} module provides the following service.
22681 @defvr {Scheme Procedure} cuirass-service-type
22682 The type of the Cuirass service. Its value must be a
22683 @code{cuirass-configuration} object, as described below.
22686 To add build jobs, you have to set the @code{specifications} field of the
22687 configuration. Here is an example of a service that polls the Guix repository
22688 and builds the packages from a manifest. Some of the packages are defined in
22689 the @code{"custom-packages"} input, which is the equivalent of
22690 @code{GUIX_PACKAGE_PATH}.
22693 (define %cuirass-specs
22695 '((#:name . "my-manifest")
22696 (#:load-path-inputs . ("guix"))
22697 (#:package-path-inputs . ("custom-packages"))
22698 (#:proc-input . "guix")
22699 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
22700 (#:proc . cuirass-jobs)
22701 (#:proc-args . ((subset . "manifests")
22702 (systems . ("x86_64-linux"))
22703 (manifests . (("config" . "guix/manifest.scm")))))
22704 (#:inputs . (((#:name . "guix")
22705 (#:url . "git://git.savannah.gnu.org/guix.git")
22706 (#:load-path . ".")
22707 (#:branch . "master")
22708 (#:no-compile? . #t))
22709 ((#:name . "config")
22710 (#:url . "https://git.example.org/config.git")
22711 (#:load-path . ".")
22712 (#:branch . "master")
22713 (#:no-compile? . #t))
22714 ((#:name . "custom-packages")
22715 (#:url . "https://git.example.org/custom-packages.git")
22716 (#:load-path . ".")
22717 (#:branch . "master")
22718 (#:no-compile? . #t)))))))
22720 (service cuirass-service-type
22721 (cuirass-configuration
22722 (specifications %cuirass-specs)))
22725 While information related to build jobs is located directly in the
22726 specifications, global settings for the @command{cuirass} process are
22727 accessible in other @code{cuirass-configuration} fields.
22729 @deftp {Data Type} cuirass-configuration
22730 Data type representing the configuration of Cuirass.
22733 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
22734 Location of the log file.
22736 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
22737 Location of the log file used by the web interface.
22739 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
22740 Location of the repository cache.
22742 @item @code{user} (default: @code{"cuirass"})
22743 Owner of the @code{cuirass} process.
22745 @item @code{group} (default: @code{"cuirass"})
22746 Owner's group of the @code{cuirass} process.
22748 @item @code{interval} (default: @code{60})
22749 Number of seconds between the poll of the repositories followed by the
22752 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
22753 Location of sqlite database which contains the build results and previously
22754 added specifications.
22756 @item @code{ttl} (default: @code{(* 30 24 3600)})
22757 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
22758 are registered for build results. This means that build results are protected
22759 from garbage collection for at least @var{ttl} seconds.
22761 @item @code{port} (default: @code{8081})
22762 Port number used by the HTTP server.
22764 @item @code{host} (default: @code{"localhost"})
22765 Listen on the network interface for @var{host}. The default is to
22766 accept connections from localhost.
22768 @item @code{specifications} (default: @code{#~'()})
22769 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
22770 where a specification is an association list
22771 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
22772 keys are keywords (@code{#:keyword-example}) as shown in the example
22775 @item @code{use-substitutes?} (default: @code{#f})
22776 This allows using substitutes to avoid building every dependencies of a job
22779 @item @code{one-shot?} (default: @code{#f})
22780 Only evaluate specifications and build derivations once.
22782 @item @code{fallback?} (default: @code{#f})
22783 When substituting a pre-built binary fails, fall back to building
22786 @item @code{extra-options} (default: @code{'()})
22787 Extra options to pass when running the Cuirass processes.
22789 @item @code{cuirass} (default: @code{cuirass})
22790 The Cuirass package to use.
22794 @node Power Management Services
22795 @subsection Power Management Services
22798 @cindex power management with TLP
22799 @subsubheading TLP daemon
22801 The @code{(gnu services pm)} module provides a Guix service definition
22802 for the Linux power management tool TLP.
22804 TLP enables various powersaving modes in userspace and kernel.
22805 Contrary to @code{upower-service}, it is not a passive,
22806 monitoring tool, as it will apply custom settings each time a new power
22807 source is detected. More information can be found at
22808 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22810 @deffn {Scheme Variable} tlp-service-type
22811 The service type for the TLP tool. Its value should be a valid
22812 TLP configuration (see below). To use the default settings, simply
22815 (service tlp-service-type)
22819 By default TLP does not need much configuration but most TLP parameters
22820 can be tweaked using @code{tlp-configuration}.
22822 Each parameter definition is preceded by its type; for example,
22823 @samp{boolean foo} indicates that the @code{foo} parameter
22824 should be specified as a boolean. Types starting with
22825 @code{maybe-} denote parameters that won't show up in TLP config file
22826 when their value is @code{'disabled}.
22828 @c The following documentation was initially generated by
22829 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22830 @c documentation is better, so we shouldn't hesitate to edit below as
22831 @c needed. However if the change you want to make to this documentation
22832 @c can be done in an automated way, it's probably easier to change
22833 @c (generate-documentation) than to make it below and have to deal with
22834 @c the churn as TLP updates.
22836 Available @code{tlp-configuration} fields are:
22838 @deftypevr {@code{tlp-configuration} parameter} package tlp
22843 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22844 Set to true if you wish to enable TLP.
22846 Defaults to @samp{#t}.
22850 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22851 Default mode when no power supply can be detected. Alternatives are AC
22854 Defaults to @samp{"AC"}.
22858 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22859 Number of seconds Linux kernel has to wait after the disk goes idle,
22860 before syncing on AC.
22862 Defaults to @samp{0}.
22866 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22867 Same as @code{disk-idle-ac} but on BAT mode.
22869 Defaults to @samp{2}.
22873 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22874 Dirty pages flushing periodicity, expressed in seconds.
22876 Defaults to @samp{15}.
22880 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22881 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22883 Defaults to @samp{60}.
22887 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22888 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22889 alternatives are powersave and performance. With acpi-cpufreq driver,
22890 alternatives are ondemand, powersave, performance and conservative.
22892 Defaults to @samp{disabled}.
22896 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22897 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22899 Defaults to @samp{disabled}.
22903 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22904 Set the min available frequency for the scaling governor on AC.
22906 Defaults to @samp{disabled}.
22910 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22911 Set the max available frequency for the scaling governor on AC.
22913 Defaults to @samp{disabled}.
22917 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22918 Set the min available frequency for the scaling governor on BAT.
22920 Defaults to @samp{disabled}.
22924 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22925 Set the max available frequency for the scaling governor on BAT.
22927 Defaults to @samp{disabled}.
22931 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22932 Limit the min P-state to control the power dissipation of the CPU, in AC
22933 mode. Values are stated as a percentage of the available performance.
22935 Defaults to @samp{disabled}.
22939 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22940 Limit the max P-state to control the power dissipation of the CPU, in AC
22941 mode. Values are stated as a percentage of the available performance.
22943 Defaults to @samp{disabled}.
22947 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22948 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22950 Defaults to @samp{disabled}.
22954 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22955 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22957 Defaults to @samp{disabled}.
22961 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22962 Enable CPU turbo boost feature on AC mode.
22964 Defaults to @samp{disabled}.
22968 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22969 Same as @code{cpu-boost-on-ac?} on BAT mode.
22971 Defaults to @samp{disabled}.
22975 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22976 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22977 used under light load conditions.
22979 Defaults to @samp{#f}.
22983 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22984 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22986 Defaults to @samp{#t}.
22990 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22991 Enable Linux kernel NMI watchdog.
22993 Defaults to @samp{#f}.
22997 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22998 For Linux kernels with PHC patch applied, change CPU voltages. An
22999 example value would be @samp{"F:V F:V F:V F:V"}.
23001 Defaults to @samp{disabled}.
23005 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
23006 Set CPU performance versus energy saving policy on AC. Alternatives are
23007 performance, normal, powersave.
23009 Defaults to @samp{"performance"}.
23013 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
23014 Same as @code{energy-perf-policy-ac} but on BAT mode.
23016 Defaults to @samp{"powersave"}.
23020 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
23025 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
23026 Hard disk advanced power management level.
23030 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
23031 Same as @code{disk-apm-bat} but on BAT mode.
23035 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
23036 Hard disk spin down timeout. One value has to be specified for each
23037 declared hard disk.
23039 Defaults to @samp{disabled}.
23043 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
23044 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
23046 Defaults to @samp{disabled}.
23050 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
23051 Select IO scheduler for disk devices. One value has to be specified for
23052 each declared hard disk. Example alternatives are cfq, deadline and
23055 Defaults to @samp{disabled}.
23059 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
23060 SATA aggressive link power management (ALPM) level. Alternatives are
23061 min_power, medium_power, max_performance.
23063 Defaults to @samp{"max_performance"}.
23067 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
23068 Same as @code{sata-linkpwr-ac} but on BAT mode.
23070 Defaults to @samp{"min_power"}.
23074 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
23075 Exclude specified SATA host devices for link power management.
23077 Defaults to @samp{disabled}.
23081 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
23082 Enable Runtime Power Management for AHCI controller and disks on AC
23085 Defaults to @samp{disabled}.
23089 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
23090 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
23092 Defaults to @samp{disabled}.
23096 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
23097 Seconds of inactivity before disk is suspended.
23099 Defaults to @samp{15}.
23103 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
23104 PCI Express Active State Power Management level. Alternatives are
23105 default, performance, powersave.
23107 Defaults to @samp{"performance"}.
23111 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
23112 Same as @code{pcie-aspm-ac} but on BAT mode.
23114 Defaults to @samp{"powersave"}.
23118 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
23119 Radeon graphics clock speed level. Alternatives are low, mid, high,
23122 Defaults to @samp{"high"}.
23126 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
23127 Same as @code{radeon-power-ac} but on BAT mode.
23129 Defaults to @samp{"low"}.
23133 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
23134 Radeon dynamic power management method (DPM). Alternatives are battery,
23137 Defaults to @samp{"performance"}.
23141 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
23142 Same as @code{radeon-dpm-state-ac} but on BAT mode.
23144 Defaults to @samp{"battery"}.
23148 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
23149 Radeon DPM performance level. Alternatives are auto, low, high.
23151 Defaults to @samp{"auto"}.
23155 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
23156 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
23158 Defaults to @samp{"auto"}.
23162 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
23163 Wifi power saving mode.
23165 Defaults to @samp{#f}.
23169 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
23170 Same as @code{wifi-power-ac?} but on BAT mode.
23172 Defaults to @samp{#t}.
23176 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
23177 Disable wake on LAN.
23179 Defaults to @samp{#t}.
23183 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
23184 Timeout duration in seconds before activating audio power saving on
23185 Intel HDA and AC97 devices. A value of 0 disables power saving.
23187 Defaults to @samp{0}.
23191 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
23192 Same as @code{sound-powersave-ac} but on BAT mode.
23194 Defaults to @samp{1}.
23198 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
23199 Disable controller in powersaving mode on Intel HDA devices.
23201 Defaults to @samp{#t}.
23205 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
23206 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
23207 powered on again by releasing (and reinserting) the eject lever or by
23208 pressing the disc eject button on newer models.
23210 Defaults to @samp{#f}.
23214 @deftypevr {@code{tlp-configuration} parameter} string bay-device
23215 Name of the optical drive device to power off.
23217 Defaults to @samp{"sr0"}.
23221 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
23222 Runtime Power Management for PCI(e) bus devices. Alternatives are on
23225 Defaults to @samp{"on"}.
23229 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
23230 Same as @code{runtime-pm-ac} but on BAT mode.
23232 Defaults to @samp{"auto"}.
23236 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
23237 Runtime Power Management for all PCI(e) bus devices, except blacklisted
23240 Defaults to @samp{#t}.
23244 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
23245 Exclude specified PCI(e) device addresses from Runtime Power Management.
23247 Defaults to @samp{disabled}.
23251 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
23252 Exclude PCI(e) devices assigned to the specified drivers from Runtime
23257 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
23258 Enable USB autosuspend feature.
23260 Defaults to @samp{#t}.
23264 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
23265 Exclude specified devices from USB autosuspend.
23267 Defaults to @samp{disabled}.
23271 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
23272 Exclude WWAN devices from USB autosuspend.
23274 Defaults to @samp{#t}.
23278 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
23279 Include specified devices into USB autosuspend, even if they are already
23280 excluded by the driver or via @code{usb-blacklist-wwan?}.
23282 Defaults to @samp{disabled}.
23286 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
23287 Enable USB autosuspend before shutdown.
23289 Defaults to @samp{disabled}.
23293 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
23294 Restore radio device state (bluetooth, wifi, wwan) from previous
23295 shutdown on system startup.
23297 Defaults to @samp{#f}.
23302 @cindex CPU frequency scaling with thermald
23303 @subsubheading Thermald daemon
23305 The @code{(gnu services pm)} module provides an interface to
23306 thermald, a CPU frequency scaling service which helps prevent overheating.
23308 @defvr {Scheme Variable} thermald-service-type
23309 This is the service type for
23310 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
23311 Thermal Daemon, which is responsible for controlling the thermal state
23312 of processors and preventing overheating.
23315 @deftp {Data Type} thermald-configuration
23316 Data type representing the configuration of @code{thermald-service-type}.
23319 @item @code{ignore-cpuid-check?} (default: @code{#f})
23320 Ignore cpuid check for supported CPU models.
23322 @item @code{thermald} (default: @var{thermald})
23323 Package object of thermald.
23328 @node Audio Services
23329 @subsection Audio Services
23331 The @code{(gnu services audio)} module provides a service to start MPD
23332 (the Music Player Daemon).
23335 @subsubheading Music Player Daemon
23337 The Music Player Daemon (MPD) is a service that can play music while
23338 being controlled from the local machine or over the network by a variety
23341 The following example shows how one might run @code{mpd} as user
23342 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
23345 (service mpd-service-type
23351 @defvr {Scheme Variable} mpd-service-type
23352 The service type for @command{mpd}
23355 @deftp {Data Type} mpd-configuration
23356 Data type representing the configuration of @command{mpd}.
23359 @item @code{user} (default: @code{"mpd"})
23360 The user to run mpd as.
23362 @item @code{music-dir} (default: @code{"~/Music"})
23363 The directory to scan for music files.
23365 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
23366 The directory to store playlists.
23368 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
23369 The location of the music database.
23371 @item @code{state-file} (default: @code{"~/.mpd/state"})
23372 The location of the file that stores current MPD's state.
23374 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
23375 The location of the sticker database.
23377 @item @code{port} (default: @code{"6600"})
23378 The port to run mpd on.
23380 @item @code{address} (default: @code{"any"})
23381 The address that mpd will bind to. To use a Unix domain socket,
23382 an absolute path can be specified here.
23384 @item @code{outputs} (default: @code{"(list (mpd-output))"})
23385 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
23390 @deftp {Data Type} mpd-output
23391 Data type representing an @command{mpd} audio output.
23394 @item @code{name} (default: @code{"MPD"})
23395 The name of the audio output.
23397 @item @code{type} (default: @code{"pulse"})
23398 The type of audio output.
23400 @item @code{enabled?} (default: @code{#t})
23401 Specifies whether this audio output is enabled when MPD is started. By
23402 default, all audio outputs are enabled. This is just the default
23403 setting when there is no state file; with a state file, the previous
23406 @item @code{tags?} (default: @code{#t})
23407 If set to @code{#f}, then MPD will not send tags to this output. This
23408 is only useful for output plugins that can receive tags, for example the
23409 @code{httpd} output plugin.
23411 @item @code{always-on?} (default: @code{#f})
23412 If set to @code{#t}, then MPD attempts to keep this audio output always
23413 open. This may be useful for streaming servers, when you don’t want to
23414 disconnect all listeners even when playback is accidentally stopped.
23416 @item @code{mixer-type}
23417 This field accepts a symbol that specifies which mixer should be used
23418 for this audio output: the @code{hardware} mixer, the @code{software}
23419 mixer, the @code{null} mixer (allows setting the volume, but with no
23420 effect; this can be used as a trick to implement an external mixer
23421 External Mixer) or no mixer (@code{none}).
23423 @item @code{extra-options} (default: @code{'()"})
23424 An association list of option symbols to string values to be appended to
23425 the audio output configuration.
23430 The following example shows a configuration of @code{mpd} that provides
23431 an HTTP audio streaming output.
23434 (service mpd-service-type
23442 `((encoder . "vorbis")
23443 (port . "8080"))))))))
23447 @node Virtualization Services
23448 @subsection Virtualization services
23450 The @code{(gnu services virtualization)} module provides services for
23451 the libvirt and virtlog daemons, as well as other virtualization-related
23454 @subsubheading Libvirt daemon
23455 @code{libvirtd} is the server side daemon component of the libvirt
23456 virtualization management system. This daemon runs on host servers
23457 and performs required management tasks for virtualized guests.
23459 @deffn {Scheme Variable} libvirt-service-type
23460 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
23461 Its value must be a @code{libvirt-configuration}.
23464 (service libvirt-service-type
23465 (libvirt-configuration
23466 (unix-sock-group "libvirt")
23467 (tls-port "16555")))
23471 @c Auto-generated with (generate-libvirt-documentation)
23472 Available @code{libvirt-configuration} fields are:
23474 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
23479 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
23480 Flag listening for secure TLS connections on the public TCP/IP port.
23481 must set @code{listen} for this to have any effect.
23483 It is necessary to setup a CA and issue server certificates before using
23486 Defaults to @samp{#t}.
23490 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
23491 Listen for unencrypted TCP connections on the public TCP/IP port. must
23492 set @code{listen} for this to have any effect.
23494 Using the TCP socket requires SASL authentication by default. Only SASL
23495 mechanisms which support data encryption are allowed. This is
23496 DIGEST_MD5 and GSSAPI (Kerberos5)
23498 Defaults to @samp{#f}.
23502 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
23503 Port for accepting secure TLS connections This can be a port number, or
23506 Defaults to @samp{"16514"}.
23510 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
23511 Port for accepting insecure TCP connections This can be a port number,
23514 Defaults to @samp{"16509"}.
23518 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
23519 IP address or hostname used for client connections.
23521 Defaults to @samp{"0.0.0.0"}.
23525 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
23526 Flag toggling mDNS advertisement of the libvirt service.
23528 Alternatively can disable for all services on a host by stopping the
23531 Defaults to @samp{#f}.
23535 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
23536 Default mDNS advertisement name. This must be unique on the immediate
23539 Defaults to @samp{"Virtualization Host <hostname>"}.
23543 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
23544 UNIX domain socket group ownership. This can be used to allow a
23545 'trusted' set of users access to management capabilities without
23548 Defaults to @samp{"root"}.
23552 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
23553 UNIX socket permissions for the R/O socket. This is used for monitoring
23556 Defaults to @samp{"0777"}.
23560 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
23561 UNIX socket permissions for the R/W socket. Default allows only root.
23562 If PolicyKit is enabled on the socket, the default will change to allow
23563 everyone (eg, 0777)
23565 Defaults to @samp{"0770"}.
23569 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
23570 UNIX socket permissions for the admin socket. Default allows only owner
23571 (root), do not change it unless you are sure to whom you are exposing
23574 Defaults to @samp{"0777"}.
23578 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
23579 The directory in which sockets will be found/created.
23581 Defaults to @samp{"/var/run/libvirt"}.
23585 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
23586 Authentication scheme for UNIX read-only sockets. By default socket
23587 permissions allow anyone to connect
23589 Defaults to @samp{"polkit"}.
23593 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
23594 Authentication scheme for UNIX read-write sockets. By default socket
23595 permissions only allow root. If PolicyKit support was compiled into
23596 libvirt, the default will be to use 'polkit' auth.
23598 Defaults to @samp{"polkit"}.
23602 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
23603 Authentication scheme for TCP sockets. If you don't enable SASL, then
23604 all TCP traffic is cleartext. Don't do this outside of a dev/test
23607 Defaults to @samp{"sasl"}.
23611 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
23612 Authentication scheme for TLS sockets. TLS sockets already have
23613 encryption provided by the TLS layer, and limited authentication is done
23616 It is possible to make use of any SASL authentication mechanism as well,
23617 by using 'sasl' for this option
23619 Defaults to @samp{"none"}.
23623 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
23624 API access control scheme.
23626 By default an authenticated user is allowed access to all APIs. Access
23627 drivers can place restrictions on this.
23629 Defaults to @samp{()}.
23633 @deftypevr {@code{libvirt-configuration} parameter} string key-file
23634 Server key file path. If set to an empty string, then no private key is
23637 Defaults to @samp{""}.
23641 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
23642 Server key file path. If set to an empty string, then no certificate is
23645 Defaults to @samp{""}.
23649 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
23650 Server key file path. If set to an empty string, then no CA certificate
23653 Defaults to @samp{""}.
23657 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
23658 Certificate revocation list path. If set to an empty string, then no
23661 Defaults to @samp{""}.
23665 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
23666 Disable verification of our own server certificates.
23668 When libvirtd starts it performs some sanity checks against its own
23671 Defaults to @samp{#f}.
23675 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
23676 Disable verification of client certificates.
23678 Client certificate verification is the primary authentication mechanism.
23679 Any client which does not present a certificate signed by the CA will be
23682 Defaults to @samp{#f}.
23686 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
23687 Whitelist of allowed x509 Distinguished Name.
23689 Defaults to @samp{()}.
23693 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
23694 Whitelist of allowed SASL usernames. The format for username depends on
23695 the SASL authentication mechanism.
23697 Defaults to @samp{()}.
23701 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
23702 Override the compile time default TLS priority string. The default is
23703 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
23704 is desired for libvirt to deviate from the global default settings.
23706 Defaults to @samp{"NORMAL"}.
23710 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
23711 Maximum number of concurrent client connections to allow over all
23714 Defaults to @samp{5000}.
23718 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
23719 Maximum length of queue of connections waiting to be accepted by the
23720 daemon. Note, that some protocols supporting retransmission may obey
23721 this so that a later reattempt at connection succeeds.
23723 Defaults to @samp{1000}.
23727 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
23728 Maximum length of queue of accepted but not yet authenticated clients.
23729 Set this to zero to turn this feature off
23731 Defaults to @samp{20}.
23735 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
23736 Number of workers to start up initially.
23738 Defaults to @samp{5}.
23742 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
23743 Maximum number of worker threads.
23745 If the number of active clients exceeds @code{min-workers}, then more
23746 threads are spawned, up to max_workers limit. Typically you'd want
23747 max_workers to equal maximum number of clients allowed.
23749 Defaults to @samp{20}.
23753 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
23754 Number of priority workers. If all workers from above pool are stuck,
23755 some calls marked as high priority (notably domainDestroy) can be
23756 executed in this pool.
23758 Defaults to @samp{5}.
23762 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
23763 Total global limit on concurrent RPC calls.
23765 Defaults to @samp{20}.
23769 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
23770 Limit on concurrent requests from a single client connection. To avoid
23771 one client monopolizing the server this should be a small fraction of
23772 the global max_requests and max_workers parameter.
23774 Defaults to @samp{5}.
23778 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
23779 Same as @code{min-workers} but for the admin interface.
23781 Defaults to @samp{1}.
23785 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
23786 Same as @code{max-workers} but for the admin interface.
23788 Defaults to @samp{5}.
23792 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
23793 Same as @code{max-clients} but for the admin interface.
23795 Defaults to @samp{5}.
23799 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
23800 Same as @code{max-queued-clients} but for the admin interface.
23802 Defaults to @samp{5}.
23806 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23807 Same as @code{max-client-requests} but for the admin interface.
23809 Defaults to @samp{5}.
23813 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23814 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23816 Defaults to @samp{3}.
23820 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23823 A filter allows to select a different logging level for a given category
23824 of logs The format for a filter is one of:
23835 where @code{name} is a string which is matched against the category
23836 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23837 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
23838 name in the filter can be a substring of the full category name, in
23839 order to match multiple similar categories), the optional @samp{"+"}
23840 prefix tells libvirt to log stack trace for each message matching name,
23841 and @code{x} is the minimal level where matching messages should be
23859 Multiple filters can be defined in a single filters statement, they just
23860 need to be separated by spaces.
23862 Defaults to @samp{"3:remote 4:event"}.
23866 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23869 An output is one of the places to save logging information. The format
23870 for an output can be:
23874 output goes to stderr
23876 @item x:syslog:name
23877 use syslog for the output and use the given name as the ident
23879 @item x:file:file_path
23880 output to a file, with the given filepath
23883 output to journald logging system
23887 In all case the x prefix is the minimal level, acting as a filter
23904 Multiple outputs can be defined, they just need to be separated by
23907 Defaults to @samp{"3:stderr"}.
23911 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23912 Allows usage of the auditing subsystem to be altered
23916 0: disable all auditing
23919 1: enable auditing, only if enabled on host
23922 2: enable auditing, and exit if disabled on host.
23926 Defaults to @samp{1}.
23930 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23931 Send audit messages via libvirt logging infrastructure.
23933 Defaults to @samp{#f}.
23937 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23938 Host UUID. UUID must not have all digits be the same.
23940 Defaults to @samp{""}.
23944 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23945 Source to read host UUID.
23949 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23952 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23956 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23959 Defaults to @samp{"smbios"}.
23963 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23964 A keepalive message is sent to a client after @code{keepalive_interval}
23965 seconds of inactivity to check if the client is still responding. If
23966 set to -1, libvirtd will never send keepalive requests; however clients
23967 can still send them and the daemon will send responses.
23969 Defaults to @samp{5}.
23973 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23974 Maximum number of keepalive messages that are allowed to be sent to the
23975 client without getting any response before the connection is considered
23978 In other words, the connection is automatically closed approximately
23979 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23980 the last message received from the client. When @code{keepalive-count}
23981 is set to 0, connections will be automatically closed after
23982 @code{keepalive-interval} seconds of inactivity without sending any
23983 keepalive messages.
23985 Defaults to @samp{5}.
23989 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23990 Same as above but for admin interface.
23992 Defaults to @samp{5}.
23996 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23997 Same as above but for admin interface.
23999 Defaults to @samp{5}.
24003 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
24004 Timeout for Open vSwitch calls.
24006 The @code{ovs-vsctl} utility is used for the configuration and its
24007 timeout option is set by default to 5 seconds to avoid potential
24008 infinite waits blocking libvirt.
24010 Defaults to @samp{5}.
24014 @c %end of autogenerated docs
24016 @subsubheading Virtlog daemon
24017 The virtlogd service is a server side daemon component of libvirt that is
24018 used to manage logs from virtual machine consoles.
24020 This daemon is not used directly by libvirt client applications, rather it
24021 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
24022 standalone daemon, the main @code{libvirtd} daemon can be restarted without
24023 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
24024 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
24026 @deffn {Scheme Variable} virtlog-service-type
24027 This is the type of the virtlog daemon.
24028 Its value must be a @code{virtlog-configuration}.
24031 (service virtlog-service-type
24032 (virtlog-configuration
24033 (max-clients 1000)))
24037 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
24038 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24040 Defaults to @samp{3}.
24044 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
24047 A filter allows to select a different logging level for a given category
24048 of logs The format for a filter is one of:
24059 where @code{name} is a string which is matched against the category
24060 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
24061 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
24062 be a substring of the full category name, in order to match multiple
24063 similar categories), the optional "+" prefix tells libvirt to log stack
24064 trace for each message matching name, and @code{x} is the minimal level
24065 where matching messages should be logged:
24082 Multiple filters can be defined in a single filters statement, they just
24083 need to be separated by spaces.
24085 Defaults to @samp{"3:remote 4:event"}.
24089 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
24092 An output is one of the places to save logging information The format
24093 for an output can be:
24097 output goes to stderr
24099 @item x:syslog:name
24100 use syslog for the output and use the given name as the ident
24102 @item x:file:file_path
24103 output to a file, with the given filepath
24106 output to journald logging system
24110 In all case the x prefix is the minimal level, acting as a filter
24127 Multiple outputs can be defined, they just need to be separated by
24130 Defaults to @samp{"3:stderr"}.
24134 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
24135 Maximum number of concurrent client connections to allow over all
24138 Defaults to @samp{1024}.
24142 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
24143 Maximum file size before rolling over.
24145 Defaults to @samp{2MB}
24149 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
24150 Maximum number of backup files to keep.
24152 Defaults to @samp{3}
24156 @subsubheading Transparent Emulation with QEMU
24159 @cindex @code{binfmt_misc}
24160 @code{qemu-binfmt-service-type} provides support for transparent
24161 emulation of program binaries built for different architectures---e.g.,
24162 it allows you to transparently execute an ARMv7 program on an x86_64
24163 machine. It achieves this by combining the @uref{https://www.qemu.org,
24164 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
24166 @defvr {Scheme Variable} qemu-binfmt-service-type
24167 This is the type of the QEMU/binfmt service for transparent emulation.
24168 Its value must be a @code{qemu-binfmt-configuration} object, which
24169 specifies the QEMU package to use as well as the architecture we want to
24173 (service qemu-binfmt-service-type
24174 (qemu-binfmt-configuration
24175 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
24178 In this example, we enable transparent emulation for the ARM and aarch64
24179 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
24180 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
24181 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
24184 @deftp {Data Type} qemu-binfmt-configuration
24185 This is the configuration for the @code{qemu-binfmt} service.
24188 @item @code{platforms} (default: @code{'()})
24189 The list of emulated QEMU platforms. Each item must be a @dfn{platform
24190 object} as returned by @code{lookup-qemu-platforms} (see below).
24192 @item @code{guix-support?} (default: @code{#f})
24193 When it is true, QEMU and all its dependencies are added to the build
24194 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
24195 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
24196 handlers to be used within the build environment, which in turn means
24197 that you can transparently build programs for another architecture.
24199 For example, let's suppose you're on an x86_64 machine and you have this
24203 (service qemu-binfmt-service-type
24204 (qemu-binfmt-configuration
24205 (platforms (lookup-qemu-platforms "arm"))
24206 (guix-support? #t)))
24212 guix build -s armhf-linux inkscape
24216 and it will build Inkscape for ARMv7 @emph{as if it were a native
24217 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
24218 if you'd like to test a package build for an architecture you don't have
24221 @item @code{qemu} (default: @code{qemu})
24222 The QEMU package to use.
24226 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
24227 Return the list of QEMU platform objects corresponding to
24228 @var{platforms}@dots{}. @var{platforms} must be a list of strings
24229 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
24230 @code{"mips64el"}, and so on.
24233 @deffn {Scheme Procedure} qemu-platform? @var{obj}
24234 Return true if @var{obj} is a platform object.
24237 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
24238 Return the name of @var{platform}---a string such as @code{"arm"}.
24241 @node Version Control Services
24242 @subsection Version Control Services
24244 The @code{(gnu services version-control)} module provides a service to
24245 allow remote access to local Git repositories. There are three options:
24246 the @code{git-daemon-service}, which provides access to repositories via
24247 the @code{git://} unsecured TCP-based protocol, extending the
24248 @code{nginx} web server to proxy some requests to
24249 @code{git-http-backend}, or providing a web interface with
24250 @code{cgit-service-type}.
24252 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
24254 Return a service that runs @command{git daemon}, a simple TCP server to
24255 expose repositories over the Git protocol for anonymous access.
24257 The optional @var{config} argument should be a
24258 @code{<git-daemon-configuration>} object, by default it allows read-only
24259 access to exported@footnote{By creating the magic file
24260 @file{git-daemon-export-ok} in the repository directory.} repositories under
24265 @deftp {Data Type} git-daemon-configuration
24266 Data type representing the configuration for @code{git-daemon-service}.
24269 @item @code{package} (default: @var{git})
24270 Package object of the Git distributed version control system.
24272 @item @code{export-all?} (default: @var{#f})
24273 Whether to allow access for all Git repositories, even if they do not
24274 have the @file{git-daemon-export-ok} file.
24276 @item @code{base-path} (default: @file{/srv/git})
24277 Whether to remap all the path requests as relative to the given path.
24278 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
24279 then if you later try to pull @code{git://example.com/hello.git}, git
24280 daemon will interpret the path as @code{/srv/git/hello.git}.
24282 @item @code{user-path} (default: @var{#f})
24283 Whether to allow @code{~user} notation to be used in requests. When
24284 specified with empty string, requests to @code{git://host/~alice/foo} is
24285 taken as a request to access @code{foo} repository in the home directory
24286 of user @code{alice}. If @var{(user-path "path")} is specified, the
24287 same request is taken as a request to access @code{path/foo} repository
24288 in the home directory of user @code{alice}.
24290 @item @code{listen} (default: @var{'()})
24291 Whether to listen on specific IP addresses or hostnames, defaults to
24294 @item @code{port} (default: @var{#f})
24295 Whether to listen on an alternative port, which defaults to 9418.
24297 @item @code{whitelist} (default: @var{'()})
24298 If not empty, only allow access to this list of directories.
24300 @item @code{extra-options} (default: @var{'()})
24301 Extra options will be passed to @code{git daemon}, please run
24302 @command{man git-daemon} for more information.
24307 The @code{git://} protocol lacks authentication. When you pull from a
24308 repository fetched via @code{git://}, you don't know whether the data you
24309 receive was modified or is even coming from the specified host, and your
24310 connection is subject to eavesdropping. It's better to use an authenticated
24311 and encrypted transport, such as @code{https}. Although Git allows you
24312 to serve repositories using unsophisticated file-based web servers,
24313 there is a faster protocol implemented by the @code{git-http-backend}
24314 program. This program is the back-end of a proper Git web service. It
24315 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
24316 on running the necessary @code{fcgiwrap} daemon.
24318 Guix has a separate configuration data type for serving Git repositories
24321 @deftp {Data Type} git-http-configuration
24322 Data type representing the configuration for @code{git-http-service}.
24325 @item @code{package} (default: @var{git})
24326 Package object of the Git distributed version control system.
24328 @item @code{git-root} (default: @file{/srv/git})
24329 Directory containing the Git repositories to expose to the world.
24331 @item @code{export-all?} (default: @var{#f})
24332 Whether to expose access for all Git repositories in @var{git-root},
24333 even if they do not have the @file{git-daemon-export-ok} file.
24335 @item @code{uri-path} (default: @file{/git/})
24336 Path prefix for Git access. With the default @code{/git/} prefix, this
24337 will map @code{http://@var{server}/git/@var{repo}.git} to
24338 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
24339 with this prefix are not passed on to this Git instance.
24341 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
24342 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
24347 There is no @code{git-http-service-type}, currently; instead you can
24348 create an @code{nginx-location-configuration} from a
24349 @code{git-http-configuration} and then add that location to a web
24352 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
24353 [config=(git-http-configuration)]
24354 Compute an @code{nginx-location-configuration} that corresponds to the
24355 given Git http configuration. An example nginx service definition to
24356 serve the default @file{/srv/git} over HTTPS might be:
24359 (service nginx-service-type
24360 (nginx-configuration
24363 (nginx-server-configuration
24364 (listen '("443 ssl"))
24365 (server-name "git.my-host.org")
24367 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
24368 (ssl-certificate-key
24369 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
24372 (git-http-nginx-location-configuration
24373 (git-http-configuration (uri-path "/"))))))))))
24376 This example assumes that you are using Let's Encrypt to get your TLS
24377 certificate. @xref{Certificate Services}. The default @code{certbot}
24378 service will redirect all HTTP traffic on @code{git.my-host.org} to
24379 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
24380 system services. @xref{Web Services}.
24383 @subsubheading Cgit Service
24385 @cindex Cgit service
24386 @cindex Git, web interface
24387 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
24388 repositories written in C.
24390 The following example will configure the service with default values.
24391 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
24394 (service cgit-service-type)
24397 The @code{file-object} type designates either a file-like object
24398 (@pxref{G-Expressions, file-like objects}) or a string.
24400 @c %start of fragment
24402 Available @code{cgit-configuration} fields are:
24404 @deftypevr {@code{cgit-configuration} parameter} package package
24409 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
24410 NGINX configuration.
24414 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
24415 Specifies a command which will be invoked to format the content of about
24416 pages (both top-level and for each repository).
24418 Defaults to @samp{""}.
24422 @deftypevr {@code{cgit-configuration} parameter} string agefile
24423 Specifies a path, relative to each repository path, which can be used to
24424 specify the date and time of the youngest commit in the repository.
24426 Defaults to @samp{""}.
24430 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
24431 Specifies a command that will be invoked for authenticating repository
24434 Defaults to @samp{""}.
24438 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
24439 Flag which, when set to @samp{age}, enables date ordering in the branch
24440 ref list, and when set @samp{name} enables ordering by branch name.
24442 Defaults to @samp{"name"}.
24446 @deftypevr {@code{cgit-configuration} parameter} string cache-root
24447 Path used to store the cgit cache entries.
24449 Defaults to @samp{"/var/cache/cgit"}.
24453 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
24454 Number which specifies the time-to-live, in minutes, for the cached
24455 version of repository pages accessed with a fixed SHA1.
24457 Defaults to @samp{-1}.
24461 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
24462 Number which specifies the time-to-live, in minutes, for the cached
24463 version of repository pages accessed without a fixed SHA1.
24465 Defaults to @samp{5}.
24469 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
24470 Number which specifies the time-to-live, in minutes, for the cached
24471 version of the repository summary page.
24473 Defaults to @samp{5}.
24477 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
24478 Number which specifies the time-to-live, in minutes, for the cached
24479 version of the repository index page.
24481 Defaults to @samp{5}.
24485 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
24486 Number which specifies the time-to-live, in minutes, for the result of
24487 scanning a path for Git repositories.
24489 Defaults to @samp{15}.
24493 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
24494 Number which specifies the time-to-live, in minutes, for the cached
24495 version of the repository about page.
24497 Defaults to @samp{15}.
24501 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
24502 Number which specifies the time-to-live, in minutes, for the cached
24503 version of snapshots.
24505 Defaults to @samp{5}.
24509 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
24510 The maximum number of entries in the cgit cache. When set to @samp{0},
24511 caching is disabled.
24513 Defaults to @samp{0}.
24517 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
24518 Sort items in the repo list case sensitively.
24520 Defaults to @samp{#t}.
24524 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
24525 List of common prefixes which, when combined with a repository URL,
24526 generates valid clone URLs for the repository.
24528 Defaults to @samp{()}.
24532 @deftypevr {@code{cgit-configuration} parameter} list clone-url
24533 List of @code{clone-url} templates.
24535 Defaults to @samp{()}.
24539 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
24540 Command which will be invoked to format commit messages.
24542 Defaults to @samp{""}.
24546 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
24547 Flag which, when set to @samp{date}, enables strict date ordering in the
24548 commit log, and when set to @samp{topo} enables strict topological
24551 Defaults to @samp{"git log"}.
24555 @deftypevr {@code{cgit-configuration} parameter} file-object css
24556 URL which specifies the css document to include in all cgit pages.
24558 Defaults to @samp{"/share/cgit/cgit.css"}.
24562 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
24563 Specifies a command which will be invoked to format names and email
24564 address of committers, authors, and taggers, as represented in various
24565 places throughout the cgit interface.
24567 Defaults to @samp{""}.
24571 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
24572 Flag which, when set to @samp{#t}, will make cgit generate a HTML
24573 fragment suitable for embedding in other HTML pages.
24575 Defaults to @samp{#f}.
24579 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
24580 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
24581 commit history graph to the left of the commit messages in the
24582 repository log page.
24584 Defaults to @samp{#f}.
24588 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
24589 Flag which, when set to @samp{#t}, allows all filter settings to be
24590 overridden in repository-specific cgitrc files.
24592 Defaults to @samp{#f}.
24596 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
24597 Flag which, when set to @samp{#t}, allows users to follow a file in the
24600 Defaults to @samp{#f}.
24604 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
24605 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
24608 Defaults to @samp{#t}.
24612 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
24613 Flag which, when set to @samp{#t}, will make cgit generate extra links
24614 "summary", "commit", "tree" for each repo in the repository index.
24616 Defaults to @samp{#f}.
24620 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
24621 Flag which, when set to @samp{#t}, will make cgit display the owner of
24622 each repo in the repository index.
24624 Defaults to @samp{#t}.
24628 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
24629 Flag which, when set to @samp{#t}, will make cgit print the number of
24630 modified files for each commit on the repository log page.
24632 Defaults to @samp{#f}.
24636 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
24637 Flag which, when set to @samp{#t}, will make cgit print the number of
24638 added and removed lines for each commit on the repository log page.
24640 Defaults to @samp{#f}.
24644 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
24645 Flag which, when set to @code{#t}, will make cgit display remote
24646 branches in the summary and refs views.
24648 Defaults to @samp{#f}.
24652 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
24653 Flag which, when set to @code{1}, will make cgit use the subject of the
24654 parent commit as link text when generating links to parent commits in
24657 Defaults to @samp{#f}.
24661 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
24662 Flag which, when set to @samp{#t}, will make cgit use the subject of the
24663 parent commit as link text when generating links to parent commits in
24666 Defaults to @samp{#f}.
24670 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
24671 Flag which, when set to @samp{#t}, will make cgit generate linenumber
24672 links for plaintext blobs printed in the tree view.
24674 Defaults to @samp{#t}.
24678 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
24679 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
24680 set any repo specific settings.
24682 Defaults to @samp{#f}.
24686 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
24687 URL used as link to a shortcut icon for cgit.
24689 Defaults to @samp{"/favicon.ico"}.
24693 @deftypevr {@code{cgit-configuration} parameter} string footer
24694 The content of the file specified with this option will be included
24695 verbatim at the bottom of all pages (i.e.@: it replaces the standard
24696 "generated by..."@: message).
24698 Defaults to @samp{""}.
24702 @deftypevr {@code{cgit-configuration} parameter} string head-include
24703 The content of the file specified with this option will be included
24704 verbatim in the HTML HEAD section on all pages.
24706 Defaults to @samp{""}.
24710 @deftypevr {@code{cgit-configuration} parameter} string header
24711 The content of the file specified with this option will be included
24712 verbatim at the top of all pages.
24714 Defaults to @samp{""}.
24718 @deftypevr {@code{cgit-configuration} parameter} file-object include
24719 Name of a configfile to include before the rest of the current config-
24722 Defaults to @samp{""}.
24726 @deftypevr {@code{cgit-configuration} parameter} string index-header
24727 The content of the file specified with this option will be included
24728 verbatim above the repository index.
24730 Defaults to @samp{""}.
24734 @deftypevr {@code{cgit-configuration} parameter} string index-info
24735 The content of the file specified with this option will be included
24736 verbatim below the heading on the repository index page.
24738 Defaults to @samp{""}.
24742 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
24743 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
24744 in the servers timezone.
24746 Defaults to @samp{#f}.
24750 @deftypevr {@code{cgit-configuration} parameter} file-object logo
24751 URL which specifies the source of an image which will be used as a logo
24754 Defaults to @samp{"/share/cgit/cgit.png"}.
24758 @deftypevr {@code{cgit-configuration} parameter} string logo-link
24759 URL loaded when clicking on the cgit logo image.
24761 Defaults to @samp{""}.
24765 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
24766 Command which will be invoked to format the Owner column of the main
24769 Defaults to @samp{""}.
24773 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
24774 Number of items to display in atom feeds view.
24776 Defaults to @samp{10}.
24780 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
24781 Number of entries to list per page in "log" view.
24783 Defaults to @samp{50}.
24787 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
24788 Number of commit message characters to display in "log" view.
24790 Defaults to @samp{80}.
24794 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
24795 Specifies the number of entries to list per page on the repository index
24798 Defaults to @samp{50}.
24802 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24803 Specifies the maximum number of repo description characters to display
24804 on the repository index page.
24806 Defaults to @samp{80}.
24810 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24811 Specifies the maximum size of a blob to display HTML for in KBytes.
24813 Defaults to @samp{0}.
24817 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24818 Maximum statistics period. Valid values are @samp{week},@samp{month},
24819 @samp{quarter} and @samp{year}.
24821 Defaults to @samp{""}.
24825 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24826 Mimetype for the specified filename extension.
24828 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24829 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24830 "image/png") (svg "image/svg+xml"))}.
24834 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24835 Specifies the file to use for automatic mimetype lookup.
24837 Defaults to @samp{""}.
24841 @deftypevr {@code{cgit-configuration} parameter} string module-link
24842 Text which will be used as the formatstring for a hyperlink when a
24843 submodule is printed in a directory listing.
24845 Defaults to @samp{""}.
24849 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24850 If set to the value @samp{#t} caching will be disabled.
24852 Defaults to @samp{#f}.
24856 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24857 If set to @samp{#t} showing full author email addresses will be
24860 Defaults to @samp{#f}.
24864 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24865 Flag which, when set to @samp{#t}, will make cgit omit the standard
24866 header on all pages.
24868 Defaults to @samp{#f}.
24872 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24873 A list of subdirectories inside of @code{repository-directory}, relative
24874 to it, that should loaded as Git repositories. An empty list means that
24875 all subdirectories will be loaded.
24877 Defaults to @samp{()}.
24881 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24882 Text which will be used as default value for @code{cgit-repo-readme}.
24884 Defaults to @samp{""}.
24888 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24889 If set to @code{#t} and @code{repository-directory} is enabled, if any
24890 repositories are found with a suffix of @code{.git}, this suffix will be
24891 removed for the URL and name.
24893 Defaults to @samp{#f}.
24897 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24898 Maximum number of files to consider when detecting renames.
24900 Defaults to @samp{-1}.
24904 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24905 The way in which repositories in each section are sorted.
24907 Defaults to @samp{""}.
24911 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24912 Text used as content for the @code{robots} meta-tag.
24914 Defaults to @samp{("noindex" "nofollow")}.
24918 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24919 Text printed below the heading on the repository index page.
24921 Defaults to @samp{"a fast webinterface for the git dscm"}.
24925 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24926 The content of the file specified with this option will be included
24927 verbatim below the ``about'' link on the repository index page.
24929 Defaults to @samp{""}.
24933 @deftypevr {@code{cgit-configuration} parameter} string root-title
24934 Text printed as heading on the repository index page.
24936 Defaults to @samp{""}.
24940 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24941 If set to @samp{#t} and repository-directory is enabled,
24942 repository-directory will recurse into directories whose name starts
24943 with a period. Otherwise, repository-directory will stay away from such
24944 directories, considered as ``hidden''. Note that this does not apply to
24945 the @file{.git} directory in non-bare repos.
24947 Defaults to @samp{#f}.
24951 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24952 Text which specifies the default set of snapshot formats that cgit
24953 generates links for.
24955 Defaults to @samp{()}.
24959 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24960 Name of the directory to scan for repositories (represents
24963 Defaults to @samp{"/srv/git"}.
24967 @deftypevr {@code{cgit-configuration} parameter} string section
24968 The name of the current repository section - all repositories defined
24969 after this option will inherit the current section name.
24971 Defaults to @samp{""}.
24975 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24976 Flag which, when set to @samp{1}, will sort the sections on the
24977 repository listing by name.
24979 Defaults to @samp{""}.
24983 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24984 A number which, if defined prior to repository-directory, specifies how
24985 many path elements from each repo path to use as a default section name.
24987 Defaults to @samp{0}.
24991 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24992 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24995 Defaults to @samp{#f}.
24999 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
25000 Specifies a command which will be invoked to format plaintext blobs in
25003 Defaults to @samp{""}.
25007 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
25008 Specifies the number of branches to display in the repository ``summary''
25011 Defaults to @samp{10}.
25015 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
25016 Specifies the number of log entries to display in the repository
25019 Defaults to @samp{10}.
25023 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
25024 Specifies the number of tags to display in the repository ``summary''
25027 Defaults to @samp{10}.
25031 @deftypevr {@code{cgit-configuration} parameter} string strict-export
25032 Filename which, if specified, needs to be present within the repository
25033 for cgit to allow access to that repository.
25035 Defaults to @samp{""}.
25039 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
25040 URL which, if specified, will be used as root for all cgit links.
25042 Defaults to @samp{"/"}.
25046 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
25047 A list of @dfn{cgit-repo} records to use with config.
25049 Defaults to @samp{()}.
25051 Available @code{repository-cgit-configuration} fields are:
25053 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
25054 A mask of snapshot formats for this repo that cgit generates links for,
25055 restricted by the global @code{snapshots} setting.
25057 Defaults to @samp{()}.
25061 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
25062 Override the default @code{source-filter}.
25064 Defaults to @samp{""}.
25068 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
25069 The relative URL used to access the repository.
25071 Defaults to @samp{""}.
25075 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
25076 Override the default @code{about-filter}.
25078 Defaults to @samp{""}.
25082 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
25083 Flag which, when set to @samp{age}, enables date ordering in the branch
25084 ref list, and when set to @samp{name} enables ordering by branch name.
25086 Defaults to @samp{""}.
25090 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
25091 A list of URLs which can be used to clone repo.
25093 Defaults to @samp{()}.
25097 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
25098 Override the default @code{commit-filter}.
25100 Defaults to @samp{""}.
25104 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
25105 Flag which, when set to @samp{date}, enables strict date ordering in the
25106 commit log, and when set to @samp{topo} enables strict topological
25109 Defaults to @samp{""}.
25113 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
25114 The name of the default branch for this repository. If no such branch
25115 exists in the repository, the first branch name (when sorted) is used as
25116 default instead. By default branch pointed to by HEAD, or ``master'' if
25117 there is no suitable HEAD.
25119 Defaults to @samp{""}.
25123 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
25124 The value to show as repository description.
25126 Defaults to @samp{""}.
25130 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
25131 The value to show as repository homepage.
25133 Defaults to @samp{""}.
25137 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
25138 Override the default @code{email-filter}.
25140 Defaults to @samp{""}.
25144 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
25145 A flag which can be used to disable the global setting
25146 @code{enable-commit-graph?}.
25148 Defaults to @samp{disabled}.
25152 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
25153 A flag which can be used to disable the global setting
25154 @code{enable-log-filecount?}.
25156 Defaults to @samp{disabled}.
25160 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
25161 A flag which can be used to disable the global setting
25162 @code{enable-log-linecount?}.
25164 Defaults to @samp{disabled}.
25168 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
25169 Flag which, when set to @code{#t}, will make cgit display remote
25170 branches in the summary and refs views.
25172 Defaults to @samp{disabled}.
25176 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
25177 A flag which can be used to override the global setting
25178 @code{enable-subject-links?}.
25180 Defaults to @samp{disabled}.
25184 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
25185 A flag which can be used to override the global setting
25186 @code{enable-html-serving?}.
25188 Defaults to @samp{disabled}.
25192 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
25193 Flag which, when set to @code{#t}, hides the repository from the
25196 Defaults to @samp{#f}.
25200 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
25201 Flag which, when set to @samp{#t}, ignores the repository.
25203 Defaults to @samp{#f}.
25207 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
25208 URL which specifies the source of an image which will be used as a logo
25209 on this repo’s pages.
25211 Defaults to @samp{""}.
25215 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
25216 URL loaded when clicking on the cgit logo image.
25218 Defaults to @samp{""}.
25222 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
25223 Override the default @code{owner-filter}.
25225 Defaults to @samp{""}.
25229 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
25230 Text which will be used as the formatstring for a hyperlink when a
25231 submodule is printed in a directory listing. The arguments for the
25232 formatstring are the path and SHA1 of the submodule commit.
25234 Defaults to @samp{""}.
25238 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
25239 Text which will be used as the formatstring for a hyperlink when a
25240 submodule with the specified subdirectory path is printed in a directory
25243 Defaults to @samp{()}.
25247 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
25248 Override the default maximum statistics period.
25250 Defaults to @samp{""}.
25254 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
25255 The value to show as repository name.
25257 Defaults to @samp{""}.
25261 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
25262 A value used to identify the owner of the repository.
25264 Defaults to @samp{""}.
25268 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
25269 An absolute path to the repository directory.
25271 Defaults to @samp{""}.
25275 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
25276 A path (relative to repo) which specifies a file to include verbatim as
25277 the ``About'' page for this repo.
25279 Defaults to @samp{""}.
25283 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
25284 The name of the current repository section - all repositories defined
25285 after this option will inherit the current section name.
25287 Defaults to @samp{""}.
25291 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
25292 Extra options will be appended to cgitrc file.
25294 Defaults to @samp{()}.
25300 @deftypevr {@code{cgit-configuration} parameter} list extra-options
25301 Extra options will be appended to cgitrc file.
25303 Defaults to @samp{()}.
25308 @c %end of fragment
25310 However, it could be that you just want to get a @code{cgitrc} up and
25311 running. In that case, you can pass an @code{opaque-cgit-configuration}
25312 as a record to @code{cgit-service-type}. As its name indicates, an
25313 opaque configuration does not have easy reflective capabilities.
25315 Available @code{opaque-cgit-configuration} fields are:
25317 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
25321 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
25322 The contents of the @code{cgitrc}, as a string.
25325 For example, if your @code{cgitrc} is just the empty string, you
25326 could instantiate a cgit service like this:
25329 (service cgit-service-type
25330 (opaque-cgit-configuration
25334 @subsubheading Gitolite Service
25336 @cindex Gitolite service
25337 @cindex Git, hosting
25338 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
25339 repositories on a central server.
25341 Gitolite can handle multiple repositories and users, and supports flexible
25342 configuration of the permissions for the users on the repositories.
25344 The following example will configure Gitolite using the default @code{git}
25345 user, and the provided SSH public key.
25348 (service gitolite-service-type
25349 (gitolite-configuration
25350 (admin-pubkey (plain-file
25352 "ssh-rsa AAAA... guix@@example.com"))))
25355 Gitolite is configured through a special admin repository which you can clone,
25356 for example, if you setup Gitolite on @code{example.com}, you would run the
25357 following command to clone the admin repository.
25360 git clone git@@example.com:gitolite-admin
25363 When the Gitolite service is activated, the provided @code{admin-pubkey} will
25364 be inserted in to the @file{keydir} directory in the gitolite-admin
25365 repository. If this results in a change in the repository, it will be
25366 committed using the message ``gitolite setup by GNU Guix''.
25368 @deftp {Data Type} gitolite-configuration
25369 Data type representing the configuration for @code{gitolite-service-type}.
25372 @item @code{package} (default: @var{gitolite})
25373 Gitolite package to use.
25375 @item @code{user} (default: @var{git})
25376 User to use for Gitolite. This will be user that you use when accessing
25379 @item @code{group} (default: @var{git})
25380 Group to use for Gitolite.
25382 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
25383 Directory in which to store the Gitolite configuration and repositories.
25385 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
25386 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
25387 representing the configuration for Gitolite.
25389 @item @code{admin-pubkey} (default: @var{#f})
25390 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
25391 setup Gitolite. This will be inserted in to the @file{keydir} directory
25392 within the gitolite-admin repository.
25394 To specify the SSH key as a string, use the @code{plain-file} function.
25397 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
25403 @deftp {Data Type} gitolite-rc-file
25404 Data type representing the Gitolite RC file.
25407 @item @code{umask} (default: @code{#o0077})
25408 This controls the permissions Gitolite sets on the repositories and their
25411 A value like @code{#o0027} will give read access to the group used by Gitolite
25412 (by default: @code{git}). This is necessary when using Gitolite with software
25413 like cgit or gitweb.
25415 @item @code{git-config-keys} (default: @code{""})
25416 Gitolite allows you to set git config values using the @samp{config} keyword. This
25417 setting allows control over the config keys to accept.
25419 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
25420 Set the role names allowed to be used by users running the perms command.
25422 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
25423 This setting controls the commands and features to enable within Gitolite.
25429 @node Game Services
25430 @subsection Game Services
25432 @subsubheading The Battle for Wesnoth Service
25434 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
25435 based tactical strategy game, with several single player campaigns, and
25436 multiplayer games (both networked and local).
25438 @defvar {Scheme Variable} wesnothd-service-type
25439 Service type for the wesnothd service. Its value must be a
25440 @code{wesnothd-configuration} object. To run wesnothd in the default
25441 configuration, instantiate it as:
25444 (service wesnothd-service-type)
25448 @deftp {Data Type} wesnothd-configuration
25449 Data type representing the configuration of @command{wesnothd}.
25452 @item @code{package} (default: @code{wesnoth-server})
25453 The wesnoth server package to use.
25455 @item @code{port} (default: @code{15000})
25456 The port to bind the server to.
25461 @node PAM Mount Service
25462 @subsection PAM Mount Service
25465 The @code{(gnu services pam-mount)} module provides a service allowing
25466 users to mount volumes when they log in. It should be able to mount any
25467 volume format supported by the system.
25469 @defvar {Scheme Variable} pam-mount-service-type
25470 Service type for PAM Mount support.
25473 @deftp {Data Type} pam-mount-configuration
25474 Data type representing the configuration of PAM Mount.
25476 It takes the following parameters:
25480 The configuration rules that will be used to generate
25481 @file{/etc/security/pam_mount.conf.xml}.
25483 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
25484 Guile Reference Manual}), and the the default ones don't mount anything
25485 for anyone at login:
25488 `((debug (@@ (enable "0")))
25489 (mntoptions (@@ (allow ,(string-join
25490 '("nosuid" "nodev" "loop"
25491 "encryption" "fsck" "nonempty"
25492 "allow_root" "allow_other")
25494 (mntoptions (@@ (require "nosuid,nodev")))
25495 (logout (@@ (wait "0")
25499 (mkmountpoint (@@ (enable "1")
25503 Some @code{volume} elements must be added to automatically mount volumes
25504 at login. Here's an example allowing the user @code{alice} to mount her
25505 encrypted @code{HOME} directory and allowing the user @code{bob} to mount
25506 the partition where he stores his data:
25509 (define pam-mount-rules
25510 `((debug (@@ (enable "0")))
25511 (volume (@@ (user "alice")
25514 (mountpoint "/home/alice")))
25515 (volume (@@ (user "bob")
25518 (mountpoint "/home/bob/data")
25519 (options "defaults,autodefrag,compress")))
25520 (mntoptions (@@ (allow ,(string-join
25521 '("nosuid" "nodev" "loop"
25522 "encryption" "fsck" "nonempty"
25523 "allow_root" "allow_other")
25525 (mntoptions (@@ (require "nosuid,nodev")))
25526 (logout (@@ (wait "0")
25530 (mkmountpoint (@@ (enable "1")
25531 (remove "true")))))
25533 (service pam-mount-service-type
25534 (pam-mount-configuration
25535 (rules pam-mount-rules)))
25538 The complete list of possible options can be found in the man page for
25539 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
25544 @node Guix Services
25545 @subsection Guix Services
25547 @subsubheading Guix Data Service
25548 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
25549 and provides data about GNU Guix. This includes information about
25550 packages, derivations and lint warnings.
25552 The data is stored in a PostgreSQL database, and available through a web
25555 @defvar {Scheme Variable} guix-data-service-type
25556 Service type for the Guix Data Service. Its value must be a
25557 @code{guix-data-service-configuration} object. The service optionally
25558 extends the getmail service, as the guix-commits mailing list is used to
25559 find out about changes in the Guix git repository.
25562 @deftp {Data Type} guix-data-service-configuration
25563 Data type representing the configuration of the Guix Data Service.
25566 @item @code{package} (default: @code{guix-data-service})
25567 The Guix Data Service package to use.
25569 @item @code{user} (default: @code{"guix-data-service"})
25570 The system user to run the service as.
25572 @item @code{group} (default: @code{"guix-data-service"})
25573 The system group to run the service as.
25575 @item @code{port} (default: @code{8765})
25576 The port to bind the web service to.
25578 @item @code{host} (default: @code{"127.0.0.1"})
25579 The host to bind the web service to.
25581 @item @code{getmail-idle-mailboxes} (default: @code{#f})
25582 If set, this is the list of mailboxes that the getmail service will be
25583 configured to listen to.
25585 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
25586 If set, this is the @code{getmail-retriever-configuration} object with
25587 which to configure getmail to fetch mail from the guix-commits mailing
25590 @item @code{extra-options} (default: @var{'()})
25591 Extra command line options for @code{guix-data-service}.
25593 @item @code{extra-process-jobs-options} (default: @var{'()})
25594 Extra command line options for @code{guix-data-service-process-jobs}.
25599 @node Linux Services
25600 @subsection Linux Services
25603 @cindex out of memory killer
25605 @cindex early out of memory daemon
25606 @subsubheading Early OOM Service
25608 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
25609 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
25610 space and provides a more responsive and configurable alternative to the
25611 in-kernel OOM killer. It is useful to prevent the system from becoming
25612 unresponsive when it runs out of memory.
25614 @deffn {Scheme Variable} earlyoom-service-type
25615 The service type for running @command{earlyoom}, the Early OOM daemon.
25616 Its value must be a @code{earlyoom-configuration} object, described
25617 below. The service can be instantiated in its default configuration
25621 (service earlyoom-service-type)
25625 @deftp {Data Type} earlyoom-configuration
25626 This is the configuration record for the @code{earlyoom-service-type}.
25629 @item @code{earlyoom} (default: @var{earlyoom})
25630 The Earlyoom package to use.
25632 @item @code{minimum-available-memory} (default: @code{10})
25633 The threshold for the minimum @emph{available} memory, in percentages.
25635 @item @code{minimum-free-swap} (default: @code{10})
25636 The threshold for the minimum free swap memory, in percentages.
25638 @item @code{prefer-regexp} (default: @code{#f})
25639 A regular expression (as a string) to match the names of the processes
25640 that should be preferably killed.
25642 @item @code{avoid-regexp} (default: @code{#f})
25643 A regular expression (as a string) to match the names of the processes
25644 that should @emph{not} be killed.
25646 @item @code{memory-report-interval} (default: @code{0})
25647 The interval in seconds at which a memory report is printed. It is
25648 disabled by default.
25650 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
25651 A boolean indicating whether the positive adjustments set in
25652 @file{/proc/*/oom_score_adj}.
25654 @item @code{show-debug-messages?} (default: @code{#f})
25655 A boolean indicating whether debug messages should be printed. The logs
25656 are saved at @file{/var/log/earlyoom.log}.
25658 @item @code{send-notification-command} (default: @code{#f})
25659 This can be used to provide a custom command used for sending
25665 @cindex kernel module loader
25666 @subsubheading Kernel Module Loader Service
25668 The kernel module loader service allows one to load loadable kernel
25669 modules at boot. This is especially useful for modules that don't
25670 autoload and need to be manually loaded, as it's the case with
25673 @deffn {Scheme Variable} kernel-module-loader-service-type
25674 The service type for loading loadable kernel modules at boot with
25675 @command{modprobe}. Its value must be a list of strings representing
25676 module names. For example loading the drivers provided by
25677 @code{ddcci-driver-linux}, in debugging mode by passing some module
25678 parameters, can be done as follow:
25681 (use-modules (gnu) (gnu services))
25682 (use-package-modules linux)
25683 (use-service-modules linux)
25685 (define ddcci-config
25686 (plain-file "ddcci.conf"
25687 "options ddcci dyndbg delay=120"))
25691 (services (cons* (service kernel-module-loader-service-type
25692 '("ddcci" "ddcci_backlight"))
25693 (simple-service 'ddcci-config etc-service-type
25694 (list `("modprobe.d/ddcci.conf"
25697 (kernel-loadable-modules (list ddcci-driver-linux)))
25701 @node Miscellaneous Services
25702 @subsection Miscellaneous Services
25704 @cindex fingerprint
25705 @subsubheading Fingerprint Service
25707 The @code{(gnu services authentication)} module provides a DBus service to
25708 read and identify fingerprints via a fingerprint sensor.
25710 @defvr {Scheme Variable} fprintd-service-type
25711 The service type for @command{fprintd}, which provides the fingerprint
25712 reading capability.
25715 (service fprintd-service-type)
25720 @subsubheading System Control Service
25722 The @code{(gnu services sysctl)} provides a service to configure kernel
25723 parameters at boot.
25725 @defvr {Scheme Variable} sysctl-service-type
25726 The service type for @command{sysctl}, which modifies kernel parameters
25727 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
25731 (service sysctl-service-type
25732 (sysctl-configuration
25733 (settings '(("net.ipv4.ip_forward" . "1")))))
25737 @deftp {Data Type} sysctl-configuration
25738 The data type representing the configuration of @command{sysctl}.
25741 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
25742 The @command{sysctl} executable to use.
25744 @item @code{settings} (default: @code{'()})
25745 An association list specifies kernel parameters and their values.
25750 @subsubheading PC/SC Smart Card Daemon Service
25752 The @code{(gnu services security-token)} module provides the following service
25753 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
25754 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
25755 manager that coordinates communications with smart card readers, smart cards
25756 and cryptographic tokens that are connected to the system.
25758 @defvr {Scheme Variable} pcscd-service-type
25759 Service type for the @command{pcscd} service. Its value must be a
25760 @code{pcscd-configuration} object. To run pcscd in the default
25761 configuration, instantiate it as:
25764 (service pcscd-service-type)
25768 @deftp {Data Type} pcscd-configuration
25769 The data type representing the configuration of @command{pcscd}.
25772 @item @code{pcsc-lite} (default: @code{pcsc-lite})
25773 The pcsc-lite package that provides pcscd.
25774 @item @code{usb-drivers} (default: @code{(list ccid)})
25775 List of packages that provide USB drivers to pcscd. Drivers are expected to be
25776 under @file{pcsc/drivers} in the store directory of the package.
25781 @subsubheading Lirc Service
25783 The @code{(gnu services lirc)} module provides the following service.
25785 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
25786 [#:device #f] [#:driver #f] [#:config-file #f] @
25787 [#:extra-options '()]
25788 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
25789 decodes infrared signals from remote controls.
25791 Optionally, @var{device}, @var{driver} and @var{config-file}
25792 (configuration file name) may be specified. See @command{lircd} manual
25795 Finally, @var{extra-options} is a list of additional command-line options
25796 passed to @command{lircd}.
25800 @subsubheading Spice Service
25802 The @code{(gnu services spice)} module provides the following service.
25804 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
25805 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
25806 that enables sharing the clipboard with a vm and setting the guest display
25807 resolution when the graphical console window resizes.
25810 @cindex inputattach
25811 @subsubheading inputattach Service
25813 @cindex tablet input, for Xorg
25814 @cindex touchscreen input, for Xorg
25815 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
25816 use input devices such as Wacom tablets, touchscreens, or joysticks with the
25817 Xorg display server.
25819 @deffn {Scheme Variable} inputattach-service-type
25820 Type of a service that runs @command{inputattach} on a device and
25821 dispatches events from it.
25824 @deftp {Data Type} inputattach-configuration
25826 @item @code{device-type} (default: @code{"wacom"})
25827 The type of device to connect to. Run @command{inputattach --help}, from the
25828 @code{inputattach} package, to see the list of supported device types.
25830 @item @code{device} (default: @code{"/dev/ttyS0"})
25831 The device file to connect to the device.
25833 @item @code{baud-rate} (default: @code{#f})
25834 Baud rate to use for the serial connection.
25835 Should be a number or @code{#f}.
25837 @item @code{log-file} (default: @code{#f})
25838 If true, this must be the name of a file to log messages to.
25842 @subsubheading Dictionary Service
25844 The @code{(gnu services dict)} module provides the following service:
25846 @defvr {Scheme Variable} dicod-service-type
25847 This is the type of the service that runs the @command{dicod} daemon, an
25848 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25851 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
25852 Return a service that runs the @command{dicod} daemon, an implementation
25853 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
25855 The optional @var{config} argument specifies the configuration for
25856 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
25857 default it serves the GNU Collaborative International Dictionary of English.
25859 You can add @command{open localhost} to your @file{~/.dico} file to make
25860 @code{localhost} the default server for @command{dico} client
25861 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
25864 @deftp {Data Type} dicod-configuration
25865 Data type representing the configuration of dicod.
25868 @item @code{dico} (default: @var{dico})
25869 Package object of the GNU Dico dictionary server.
25871 @item @code{interfaces} (default: @var{'("localhost")})
25872 This is the list of IP addresses and ports and possibly socket file
25873 names to listen to (@pxref{Server Settings, @code{listen} directive,,
25874 dico, GNU Dico Manual}).
25876 @item @code{handlers} (default: @var{'()})
25877 List of @code{<dicod-handler>} objects denoting handlers (module instances).
25879 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
25880 List of @code{<dicod-database>} objects denoting dictionaries to be served.
25884 @deftp {Data Type} dicod-handler
25885 Data type representing a dictionary handler (module instance).
25889 Name of the handler (module instance).
25891 @item @code{module} (default: @var{#f})
25892 Name of the dicod module of the handler (instance). If it is @code{#f},
25893 the module has the same name as the handler.
25894 (@pxref{Modules,,, dico, GNU Dico Manual}).
25896 @item @code{options}
25897 List of strings or gexps representing the arguments for the module handler
25901 @deftp {Data Type} dicod-database
25902 Data type representing a dictionary database.
25906 Name of the database, will be used in DICT commands.
25908 @item @code{handler}
25909 Name of the dicod handler (module instance) used by this database
25910 (@pxref{Handlers,,, dico, GNU Dico Manual}).
25912 @item @code{complex?} (default: @var{#f})
25913 Whether the database configuration complex. The complex configuration
25914 will need a corresponding @code{<dicod-handler>} object, otherwise not.
25916 @item @code{options}
25917 List of strings or gexps representing the arguments for the database
25918 (@pxref{Databases,,, dico, GNU Dico Manual}).
25922 @defvr {Scheme Variable} %dicod-database:gcide
25923 A @code{<dicod-database>} object serving the GNU Collaborative International
25924 Dictionary of English using the @code{gcide} package.
25927 The following is an example @code{dicod-service} configuration.
25930 (dicod-service #:config
25931 (dicod-configuration
25932 (handlers (list (dicod-handler
25936 (list #~(string-append "dbdir=" #$wordnet))))))
25937 (databases (list (dicod-database
25940 (handler "wordnet")
25941 (options '("database=wn")))
25942 %dicod-database:gcide))))
25946 @subsubheading Docker Service
25948 The @code{(gnu services docker)} module provides the following services.
25950 @defvr {Scheme Variable} docker-service-type
25952 This is the type of the service that runs @url{https://www.docker.com,Docker},
25953 a daemon that can execute application bundles (sometimes referred to as
25954 ``containers'') in isolated environments.
25958 @deftp {Data Type} docker-configuration
25959 This is the data type representing the configuration of Docker and Containerd.
25963 @item @code{package} (default: @code{docker})
25964 The Docker package to use.
25966 @item @code{containerd} (default: @var{containerd})
25967 The Containerd package to use.
25973 @subsubheading Auditd Service
25975 The @code{(gnu services auditd)} module provides the following service.
25977 @defvr {Scheme Variable} auditd-service-type
25979 This is the type of the service that runs
25980 @url{https://people.redhat.com/sgrubb/audit/,auditd},
25981 a daemon that tracks security-relevant information on your system.
25983 Examples of things that can be tracked:
25993 Failed login attempts
26000 @command{auditctl} from the @code{audit} package can be used in order
26001 to add or remove events to be tracked (until the next reboot).
26002 In order to permanently track events, put the command line arguments
26003 of auditctl into @file{/etc/audit/audit.rules}.
26004 @command{aureport} from the @code{audit} package can be used in order
26005 to view a report of all recorded events.
26006 The audit daemon usually logs into the directory @file{/var/log/audit}.
26010 @deftp {Data Type} auditd-configuration
26011 This is the data type representing the configuration of auditd.
26015 @item @code{audit} (default: @code{audit})
26016 The audit package to use.
26021 @defvr {Scheme Variable} singularity-service-type
26022 This is the type of the service that allows you to run
26023 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
26024 create and run application bundles (aka. ``containers''). The value for this
26025 service is the Singularity package to use.
26027 The service does not install a daemon; instead, it installs helper programs as
26028 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
26029 @command{singularity run} and similar commands.
26033 @subsubheading Nix service
26035 The @code{(gnu services nix)} module provides the following service.
26037 @defvr {Scheme Variable} nix-service-type
26039 This is the type of the service that runs build daemon of the
26040 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
26044 (use-modules (gnu))
26045 (use-service-modules nix)
26046 (use-package-modules package-management)
26050 (packages (append (list nix)
26053 (services (append (list (service nix-service-type))
26057 After @command{guix system reconfigure} configure Nix for your user:
26060 @item Add a Nix channel and update it. See
26061 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
26063 @item Create a symlink to your profile and activate Nix profile:
26067 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
26068 $ source /run/current-system/profile/etc/profile.d/nix.sh
26073 @node Setuid Programs
26074 @section Setuid Programs
26076 @cindex setuid programs
26077 Some programs need to run with ``root'' privileges, even when they are
26078 launched by unprivileged users. A notorious example is the
26079 @command{passwd} program, which users can run to change their
26080 password, and which needs to access the @file{/etc/passwd} and
26081 @file{/etc/shadow} files---something normally restricted to root, for
26082 obvious security reasons. To address that, these executables are
26083 @dfn{setuid-root}, meaning that they always run with root privileges
26084 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
26085 for more info about the setuid mechanism.)
26087 The store itself @emph{cannot} contain setuid programs: that would be a
26088 security issue since any user on the system can write derivations that
26089 populate the store (@pxref{The Store}). Thus, a different mechanism is
26090 used: instead of changing the setuid bit directly on files that are in
26091 the store, we let the system administrator @emph{declare} which programs
26092 should be setuid root.
26094 The @code{setuid-programs} field of an @code{operating-system}
26095 declaration contains a list of G-expressions denoting the names of
26096 programs to be setuid-root (@pxref{Using the Configuration System}).
26097 For instance, the @command{passwd} program, which is part of the Shadow
26098 package, can be designated by this G-expression (@pxref{G-Expressions}):
26101 #~(string-append #$shadow "/bin/passwd")
26104 A default set of setuid programs is defined by the
26105 @code{%setuid-programs} variable of the @code{(gnu system)} module.
26107 @defvr {Scheme Variable} %setuid-programs
26108 A list of G-expressions denoting common programs that are setuid-root.
26110 The list includes commands such as @command{passwd}, @command{ping},
26111 @command{su}, and @command{sudo}.
26114 Under the hood, the actual setuid programs are created in the
26115 @file{/run/setuid-programs} directory at system activation time. The
26116 files in this directory refer to the ``real'' binaries, which are in the
26119 @node X.509 Certificates
26120 @section X.509 Certificates
26122 @cindex HTTPS, certificates
26123 @cindex X.509 certificates
26125 Web servers available over HTTPS (that is, HTTP over the transport-layer
26126 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
26127 that the client can then use to @emph{authenticate} the server. To do
26128 that, clients verify that the server's certificate is signed by a
26129 so-called @dfn{certificate authority} (CA). But to verify the CA's
26130 signature, clients must have first acquired the CA's certificate.
26132 Web browsers such as GNU@tie{}IceCat include their own set of CA
26133 certificates, such that they are able to verify CA signatures
26136 However, most other programs that can talk HTTPS---@command{wget},
26137 @command{git}, @command{w3m}, etc.---need to be told where CA
26138 certificates can be found.
26140 @cindex @code{nss-certs}
26141 In Guix, this is done by adding a package that provides certificates
26142 to the @code{packages} field of the @code{operating-system} declaration
26143 (@pxref{operating-system Reference}). Guix includes one such package,
26144 @code{nss-certs}, which is a set of CA certificates provided as part of
26145 Mozilla's Network Security Services.
26147 Note that it is @emph{not} part of @code{%base-packages}, so you need to
26148 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
26149 most applications and libraries look for certificates by default, points
26150 to the certificates installed globally.
26152 Unprivileged users, including users of Guix on a foreign distro,
26153 can also install their own certificate package in
26154 their profile. A number of environment variables need to be defined so
26155 that applications and libraries know where to find them. Namely, the
26156 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
26157 variables. Some applications add their own environment variables; for
26158 instance, the Git version control system honors the certificate bundle
26159 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
26160 would typically run something like:
26163 guix install nss-certs
26164 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
26165 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
26166 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
26169 As another example, R requires the @code{CURL_CA_BUNDLE} environment
26170 variable to point to a certificate bundle, so you would have to run
26171 something like this:
26174 guix install nss-certs
26175 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
26178 For other applications you may want to look up the required environment
26179 variable in the relevant documentation.
26182 @node Name Service Switch
26183 @section Name Service Switch
26185 @cindex name service switch
26187 The @code{(gnu system nss)} module provides bindings to the
26188 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
26189 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
26190 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
26191 extended with new ``name'' lookup methods for system databases, which
26192 includes host names, service names, user accounts, and more (@pxref{Name
26193 Service Switch, System Databases and Name Service Switch,, libc, The GNU
26194 C Library Reference Manual}).
26196 The NSS configuration specifies, for each system database, which lookup
26197 method is to be used, and how the various methods are chained
26198 together---for instance, under which circumstances NSS should try the
26199 next method in the list. The NSS configuration is given in the
26200 @code{name-service-switch} field of @code{operating-system} declarations
26201 (@pxref{operating-system Reference, @code{name-service-switch}}).
26204 @cindex .local, host name lookup
26205 As an example, the declaration below configures the NSS to use the
26206 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
26207 back-end}, which supports host name lookups over multicast DNS (mDNS)
26208 for host names ending in @code{.local}:
26211 (name-service-switch
26212 (hosts (list %files ;first, check /etc/hosts
26214 ;; If the above did not succeed, try
26215 ;; with 'mdns_minimal'.
26217 (name "mdns_minimal")
26219 ;; 'mdns_minimal' is authoritative for
26220 ;; '.local'. When it returns "not found",
26221 ;; no need to try the next methods.
26222 (reaction (lookup-specification
26223 (not-found => return))))
26225 ;; Then fall back to DNS.
26229 ;; Finally, try with the "full" 'mdns'.
26234 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
26235 contains this configuration, so you will not have to type it if all you
26236 want is to have @code{.local} host lookup working.
26238 Note that, in this case, in addition to setting the
26239 @code{name-service-switch} of the @code{operating-system} declaration,
26240 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
26241 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
26242 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
26243 to the name service cache daemon (@pxref{Base Services,
26244 @code{nscd-service}}).
26246 For convenience, the following variables provide typical NSS
26249 @defvr {Scheme Variable} %default-nss
26250 This is the default name service switch configuration, a
26251 @code{name-service-switch} object.
26254 @defvr {Scheme Variable} %mdns-host-lookup-nss
26255 This is the name service switch configuration with support for host name
26256 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
26259 The reference for name service switch configuration is given below. It
26260 is a direct mapping of the configuration file format of the C library , so
26261 please refer to the C library manual for more information (@pxref{NSS
26262 Configuration File,,, libc, The GNU C Library Reference Manual}).
26263 Compared to the configuration file format of libc NSS, it has the advantage
26264 not only of adding this warm parenthetic feel that we like, but also
26265 static checks: you will know about syntax errors and typos as soon as you
26266 run @command{guix system}.
26268 @deftp {Data Type} name-service-switch
26270 This is the data type representation the configuration of libc's name
26271 service switch (NSS). Each field below represents one of the supported
26288 The system databases handled by the NSS. Each of these fields must be a
26289 list of @code{<name-service>} objects (see below).
26293 @deftp {Data Type} name-service
26295 This is the data type representing an actual name service and the
26296 associated lookup action.
26300 A string denoting the name service (@pxref{Services in the NSS
26301 configuration,,, libc, The GNU C Library Reference Manual}).
26303 Note that name services listed here must be visible to nscd. This is
26304 achieved by passing the @code{#:name-services} argument to
26305 @code{nscd-service} the list of packages providing the needed name
26306 services (@pxref{Base Services, @code{nscd-service}}).
26309 An action specified using the @code{lookup-specification} macro
26310 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
26311 Reference Manual}). For example:
26314 (lookup-specification (unavailable => continue)
26315 (success => return))
26320 @node Initial RAM Disk
26321 @section Initial RAM Disk
26324 @cindex initial RAM disk
26325 For bootstrapping purposes, the Linux-Libre kernel is passed an
26326 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
26327 root file system as well as an initialization script. The latter is
26328 responsible for mounting the real root file system, and for loading any
26329 kernel modules that may be needed to achieve that.
26331 The @code{initrd-modules} field of an @code{operating-system}
26332 declaration allows you to specify Linux-libre kernel modules that must
26333 be available in the initrd. In particular, this is where you would list
26334 modules needed to actually drive the hard disk where your root partition
26335 is---although the default value of @code{initrd-modules} should cover
26336 most use cases. For example, assuming you need the @code{megaraid_sas}
26337 module in addition to the default modules to be able to access your root
26338 file system, you would write:
26343 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
26346 @defvr {Scheme Variable} %base-initrd-modules
26347 This is the list of kernel modules included in the initrd by default.
26350 Furthermore, if you need lower-level customization, the @code{initrd}
26351 field of an @code{operating-system} declaration allows
26352 you to specify which initrd you would like to use. The @code{(gnu
26353 system linux-initrd)} module provides three ways to build an initrd: the
26354 high-level @code{base-initrd} procedure and the low-level
26355 @code{raw-initrd} and @code{expression->initrd} procedures.
26357 The @code{base-initrd} procedure is intended to cover most common uses.
26358 For example, if you want to add a bunch of kernel modules to be loaded
26359 at boot time, you can define the @code{initrd} field of the operating
26360 system declaration like this:
26363 (initrd (lambda (file-systems . rest)
26364 ;; Create a standard initrd but set up networking
26365 ;; with the parameters QEMU expects by default.
26366 (apply base-initrd file-systems
26367 #:qemu-networking? #t
26371 The @code{base-initrd} procedure also handles common use cases that
26372 involves using the system as a QEMU guest, or as a ``live'' system with
26373 volatile root file system.
26375 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
26376 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
26377 such as trying to guess which kernel modules and packages should be included
26378 to the initrd. An example use of @code{raw-initrd} is when a user has
26379 a custom Linux kernel configuration and default kernel modules included by
26380 @code{base-initrd} are not available.
26382 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
26383 honors several options passed on the Linux kernel command line
26384 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
26385 @code{-append} option of QEMU), notably:
26388 @item --load=@var{boot}
26389 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
26390 program, once it has mounted the root file system.
26392 Guix uses this option to yield control to a boot program that runs the
26393 service activation programs and then spawns the GNU@tie{}Shepherd, the
26394 initialization system.
26396 @item --root=@var{root}
26397 Mount @var{root} as the root file system. @var{root} can be a
26398 device name like @code{/dev/sda1}, a file system label, or a file system
26401 @item --system=@var{system}
26402 Have @file{/run/booted-system} and @file{/run/current-system} point to
26405 @item modprobe.blacklist=@var{modules}@dots{}
26406 @cindex module, black-listing
26407 @cindex black list, of kernel modules
26408 Instruct the initial RAM disk as well as the @command{modprobe} command
26409 (from the kmod package) to refuse to load @var{modules}. @var{modules}
26410 must be a comma-separated list of module names---e.g.,
26411 @code{usbkbd,9pnet}.
26414 Start a read-eval-print loop (REPL) from the initial RAM disk before it
26415 tries to load kernel modules and to mount the root file system. Our
26416 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
26417 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
26418 Manual}, for more information on Guile's REPL.
26422 Now that you know all the features that initial RAM disks produced by
26423 @code{base-initrd} and @code{raw-initrd} provide,
26424 here is how to use it and customize it further.
26427 @cindex initial RAM disk
26428 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
26429 [#:linux-modules '()] [#:mapped-devices '()] @
26430 [#:keyboard-layout #f] @
26431 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
26432 Return a derivation that builds a raw initrd. @var{file-systems} is
26433 a list of file systems to be mounted by the initrd, possibly in addition to
26434 the root file system specified on the kernel command line via @code{--root}.
26435 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
26436 @var{mapped-devices} is a list of device mappings to realize before
26437 @var{file-systems} are mounted (@pxref{Mapped Devices}).
26438 @var{helper-packages} is a list of packages to be copied in the initrd. It may
26439 include @code{e2fsck/static} or other packages needed by the initrd to check
26440 the root file system.
26442 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26443 the desired console keyboard layout. This is done before @var{mapped-devices}
26444 are set up and before @var{file-systems} are mounted such that, should the
26445 user need to enter a passphrase or use the REPL, this happens using the
26446 intended keyboard layout.
26448 When @var{qemu-networking?} is true, set up networking with the standard QEMU
26449 parameters. When @var{virtio?} is true, load additional modules so that the
26450 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
26452 When @var{volatile-root?} is true, the root file system is writable but any changes
26456 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
26457 [#:mapped-devices '()] [#:keyboard-layout #f] @
26458 [#:qemu-networking? #f] [#:volatile-root? #f] @
26459 [#:linux-modules '()]
26460 Return as a file-like object a generic initrd, with kernel
26461 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
26462 mounted by the initrd, possibly in addition to the root file system specified
26463 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
26464 mappings to realize before @var{file-systems} are mounted.
26466 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
26467 the desired console keyboard layout. This is done before @var{mapped-devices}
26468 are set up and before @var{file-systems} are mounted such that, should the
26469 user need to enter a passphrase or use the REPL, this happens using the
26470 intended keyboard layout.
26472 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
26474 The initrd is automatically populated with all the kernel modules necessary
26475 for @var{file-systems} and for the given options. Additional kernel
26476 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
26477 loaded at boot time in the order in which they appear.
26480 Needless to say, the initrds we produce and use embed a
26481 statically-linked Guile, and the initialization program is a Guile
26482 program. That gives a lot of flexibility. The
26483 @code{expression->initrd} procedure builds such an initrd, given the
26484 program to run in that initrd.
26486 @deffn {Scheme Procedure} expression->initrd @var{exp} @
26487 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
26488 Return as a file-like object a Linux initrd (a gzipped cpio archive)
26489 containing @var{guile} and that evaluates @var{exp}, a G-expression,
26490 upon booting. All the derivations referenced by @var{exp} are
26491 automatically copied to the initrd.
26494 @node Bootloader Configuration
26495 @section Bootloader Configuration
26498 @cindex boot loader
26500 The operating system supports multiple bootloaders. The bootloader is
26501 configured using @code{bootloader-configuration} declaration. All the
26502 fields of this structure are bootloader agnostic except for one field,
26503 @code{bootloader} that indicates the bootloader to be configured and
26506 Some of the bootloaders do not honor every field of
26507 @code{bootloader-configuration}. For instance, the extlinux
26508 bootloader does not support themes and thus ignores the @code{theme}
26511 @deftp {Data Type} bootloader-configuration
26512 The type of a bootloader configuration declaration.
26516 @item @code{bootloader}
26517 @cindex EFI, bootloader
26518 @cindex UEFI, bootloader
26519 @cindex BIOS, bootloader
26520 The bootloader to use, as a @code{bootloader} object. For now
26521 @code{grub-bootloader}, @code{grub-efi-bootloader},
26522 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
26524 @vindex grub-efi-bootloader
26525 @code{grub-efi-bootloader} allows to boot on modern systems using the
26526 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
26527 use if the installation image contains a @file{/sys/firmware/efi} directory
26528 when you boot it on your system.
26530 @vindex grub-bootloader
26531 @code{grub-bootloader} allows you to boot in particular Intel-based machines
26532 in ``legacy'' BIOS mode.
26534 @cindex ARM, bootloaders
26535 @cindex AArch64, bootloaders
26536 Available bootloaders are described in @code{(gnu bootloader @dots{})}
26537 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
26538 of bootloaders for a wide range of ARM and AArch64 systems, using the
26539 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
26541 @item @code{target}
26542 This is a string denoting the target onto which to install the
26545 The interpretation depends on the bootloader in question. For
26546 @code{grub-bootloader}, for example, it should be a device name understood by
26547 the bootloader @command{installer} command, such as @code{/dev/sda} or
26548 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
26549 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
26550 system, usually @file{/boot/efi}.
26552 @item @code{menu-entries} (default: @code{()})
26553 A possibly empty list of @code{menu-entry} objects (see below), denoting
26554 entries to appear in the bootloader menu, in addition to the current
26555 system entry and the entry pointing to previous system generations.
26557 @item @code{default-entry} (default: @code{0})
26558 The index of the default boot menu entry. Index 0 is for the entry of the
26561 @item @code{timeout} (default: @code{5})
26562 The number of seconds to wait for keyboard input before booting. Set to
26563 0 to boot immediately, and to -1 to wait indefinitely.
26565 @cindex keyboard layout, for the bootloader
26566 @item @code{keyboard-layout} (default: @code{#f})
26567 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
26568 layout, usually US@tie{}English (``qwerty'').
26570 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
26574 This option is currently ignored by bootloaders other than @code{grub} and
26578 @item @code{theme} (default: @var{#f})
26579 The bootloader theme object describing the theme to use. If no theme
26580 is provided, some bootloaders might use a default theme, that's true
26583 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
26584 The output terminals used for the bootloader boot menu, as a list of
26585 symbols. GRUB accepts the values: @code{console}, @code{serial},
26586 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
26587 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
26588 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
26589 configuration,,, grub,GNU GRUB manual}).
26591 @item @code{terminal-inputs} (default: @code{'()})
26592 The input terminals used for the bootloader boot menu, as a list of
26593 symbols. For GRUB, the default is the native platform terminal as
26594 determined at run-time. GRUB accepts the values: @code{console},
26595 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
26596 @code{usb_keyboard}. This field corresponds to the GRUB variable
26597 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
26600 @item @code{serial-unit} (default: @code{#f})
26601 The serial unit used by the bootloader, as an integer from 0 to 3.
26602 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
26603 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26605 @item @code{serial-speed} (default: @code{#f})
26606 The speed of the serial interface, as an integer. For GRUB, the
26607 default value is chosen at run-time; currently GRUB chooses
26608 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
26615 Should you want to list additional boot menu entries @i{via} the
26616 @code{menu-entries} field above, you will need to create them with the
26617 @code{menu-entry} form. For example, imagine you want to be able to
26618 boot another distro (hard to imagine!), you can define a menu entry
26623 (label "The Other Distro")
26624 (linux "/boot/old/vmlinux-2.6.32")
26625 (linux-arguments '("root=/dev/sda2"))
26626 (initrd "/boot/old/initrd"))
26631 @deftp {Data Type} menu-entry
26632 The type of an entry in the bootloader menu.
26637 The label to show in the menu---e.g., @code{"GNU"}.
26640 The Linux kernel image to boot, for example:
26643 (file-append linux-libre "/bzImage")
26646 For GRUB, it is also possible to specify a device explicitly in the
26647 file path using GRUB's device naming convention (@pxref{Naming
26648 convention,,, grub, GNU GRUB manual}), for example:
26651 "(hd0,msdos1)/boot/vmlinuz"
26654 If the device is specified explicitly as above, then the @code{device}
26655 field is ignored entirely.
26657 @item @code{linux-arguments} (default: @code{()})
26658 The list of extra Linux kernel command-line arguments---e.g.,
26659 @code{("console=ttyS0")}.
26661 @item @code{initrd}
26662 A G-Expression or string denoting the file name of the initial RAM disk
26663 to use (@pxref{G-Expressions}).
26664 @item @code{device} (default: @code{#f})
26665 The device where the kernel and initrd are to be found---i.e., for GRUB,
26666 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
26668 This may be a file system label (a string), a file system UUID (a
26669 bytevector, @pxref{File Systems}), or @code{#f}, in which case
26670 the bootloader will search the device containing the file specified by
26671 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
26672 must @emph{not} be an OS device name such as @file{/dev/sda1}.
26680 @c FIXME: Write documentation once it's stable.
26681 For now only GRUB has theme support. GRUB themes are created using
26682 the @code{grub-theme} form, which is not fully documented yet.
26684 @deftp {Data Type} grub-theme
26685 Data type representing the configuration of the GRUB theme.
26688 @item @code{gfxmode} (default: @code{'("auto")})
26689 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
26690 @pxref{gfxmode,,, grub, GNU GRUB manual}).
26694 @defvr {Scheme Variable} %default-theme
26695 This is the default GRUB theme used by the operating system if no
26696 @code{theme} field is specified in @code{bootloader-configuration}
26699 It comes with a fancy background image displaying the GNU and Guix
26703 For example, to override the default resolution, you may use something
26708 (bootloader-configuration
26711 (inherit %default-theme)
26712 (gfxmode '("1024x786x32" "auto"))))))
26715 @node Invoking guix system
26716 @section Invoking @code{guix system}
26718 Once you have written an operating system declaration as seen in the
26719 previous section, it can be @dfn{instantiated} using the @command{guix
26720 system} command. The synopsis is:
26723 guix system @var{options}@dots{} @var{action} @var{file}
26726 @var{file} must be the name of a file containing an
26727 @code{operating-system} declaration. @var{action} specifies how the
26728 operating system is instantiated. Currently the following values are
26733 Display available service type definitions that match the given regular
26734 expressions, sorted by relevance:
26740 $ guix system search console
26741 name: console-fonts
26742 location: gnu/services/base.scm:806:2
26743 extends: shepherd-root
26744 description: Install the given fonts on the specified ttys (fonts are per
26745 + virtual console on GNU/Linux). The value of this service is a list of
26746 + tty/font pairs. The font can be the name of a font provided by the `kbd'
26747 + package or any valid argument to `setfont', as in this example:
26749 + '(("tty1" . "LatGrkCyr-8x16")
26750 + ("tty2" . (file-append
26752 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
26753 + ("tty3" . (file-append
26755 + "/share/consolefonts/ter-132n"))) ; for HDPI
26759 location: gnu/services/base.scm:1190:2
26760 extends: shepherd-root
26761 description: Provide console login using the `mingetty' program.
26765 location: gnu/services/base.scm:860:2
26767 description: Provide a console log-in service as specified by its
26768 + configuration value, a `login-configuration' object.
26774 As for @command{guix package --search}, the result is written in
26775 @code{recutils} format, which makes it easy to filter the output
26776 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
26779 Build the operating system described in @var{file}, activate it, and
26780 switch to it@footnote{This action (and the related actions
26781 @code{switch-generation} and @code{roll-back}) are usable only on
26782 systems already running Guix System.}.
26785 @c The paragraph below refers to the problem discussed at
26786 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
26787 It is highly recommended to run @command{guix pull} once before you run
26788 @command{guix system reconfigure} for the first time (@pxref{Invoking
26789 guix pull}). Failing to do that you would see an older version of Guix
26790 once @command{reconfigure} has completed.
26793 This effects all the configuration specified in @var{file}: user
26794 accounts, system services, global package list, setuid programs, etc.
26795 The command starts system services specified in @var{file} that are not
26796 currently running; if a service is currently running this command will
26797 arrange for it to be upgraded the next time it is stopped (e.g.@: by
26798 @code{herd stop X} or @code{herd restart X}).
26800 This command creates a new generation whose number is one greater than
26801 the current generation (as reported by @command{guix system
26802 list-generations}). If that generation already exists, it will be
26803 overwritten. This behavior mirrors that of @command{guix package}
26804 (@pxref{Invoking guix package}).
26806 It also adds a bootloader menu entry for the new OS configuration,
26807 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
26808 entries for older configurations to a submenu, allowing you to choose
26809 an older system generation at boot time should you need it.
26811 @cindex provenance tracking, of the operating system
26812 Upon completion, the new system is deployed under
26813 @file{/run/current-system}. This directory contains @dfn{provenance
26814 meta-data}: the list of channels in use (@pxref{Channels}) and
26815 @var{file} itself, when available. This information is useful should
26816 you later want to inspect how this particular generation was built.
26818 In fact, assuming @var{file} is self-contained, you can later rebuild
26819 generation @var{n} of your operating system with:
26822 guix time-machine \
26823 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
26824 system reconfigure \
26825 /var/guix/profiles/system-@var{n}-link/configuration.scm
26828 You can think of it as some sort of built-in version control! Your
26829 system is not just a binary artifact: @emph{it carries its own source}.
26830 @xref{Service Reference, @code{provenance-service-type}}, for more
26831 information on provenance tracking.
26833 @item switch-generation
26834 @cindex generations
26835 Switch to an existing system generation. This action atomically
26836 switches the system profile to the specified system generation. It
26837 also rearranges the system's existing bootloader menu entries. It
26838 makes the menu entry for the specified system generation the default,
26839 and it moves the entries for the other generations to a submenu, if
26840 supported by the bootloader being used. The next time the system
26841 boots, it will use the specified system generation.
26843 The bootloader itself is not being reinstalled when using this
26844 command. Thus, the installed bootloader is used with an updated
26845 configuration file.
26847 The target generation can be specified explicitly by its generation
26848 number. For example, the following invocation would switch to system
26852 guix system switch-generation 7
26855 The target generation can also be specified relative to the current
26856 generation with the form @code{+N} or @code{-N}, where @code{+3} means
26857 ``3 generations ahead of the current generation,'' and @code{-1} means
26858 ``1 generation prior to the current generation.'' When specifying a
26859 negative value such as @code{-1}, you must precede it with @code{--} to
26860 prevent it from being parsed as an option. For example:
26863 guix system switch-generation -- -1
26866 Currently, the effect of invoking this action is @emph{only} to switch
26867 the system profile to an existing generation and rearrange the
26868 bootloader menu entries. To actually start using the target system
26869 generation, you must reboot after running this action. In the future,
26870 it will be updated to do the same things as @command{reconfigure},
26871 like activating and deactivating services.
26873 This action will fail if the specified generation does not exist.
26876 @cindex rolling back
26877 Switch to the preceding system generation. The next time the system
26878 boots, it will use the preceding system generation. This is the inverse
26879 of @command{reconfigure}, and it is exactly the same as invoking
26880 @command{switch-generation} with an argument of @code{-1}.
26882 Currently, as with @command{switch-generation}, you must reboot after
26883 running this action to actually start using the preceding system
26886 @item delete-generations
26887 @cindex deleting system generations
26888 @cindex saving space
26889 Delete system generations, making them candidates for garbage collection
26890 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
26893 This works in the same way as @command{guix package --delete-generations}
26894 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
26895 arguments, all system generations but the current one are deleted:
26898 guix system delete-generations
26901 You can also select the generations you want to delete. The example below
26902 deletes all the system generations that are more than two month old:
26905 guix system delete-generations 2m
26908 Running this command automatically reinstalls the bootloader with an updated
26909 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
26910 longer lists the generations that have been deleted.
26913 Build the derivation of the operating system, which includes all the
26914 configuration files and programs needed to boot and run the system.
26915 This action does not actually install anything.
26918 Populate the given directory with all the files necessary to run the
26919 operating system specified in @var{file}. This is useful for first-time
26920 installations of Guix System. For instance:
26923 guix system init my-os-config.scm /mnt
26926 copies to @file{/mnt} all the store items required by the configuration
26927 specified in @file{my-os-config.scm}. This includes configuration
26928 files, packages, and so on. It also creates other essential files
26929 needed for the system to operate correctly---e.g., the @file{/etc},
26930 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
26932 This command also installs bootloader on the target specified in
26933 @file{my-os-config}, unless the @option{--no-bootloader} option was
26937 @cindex virtual machine
26939 @anchor{guix system vm}
26940 Build a virtual machine that contains the operating system declared in
26941 @var{file}, and return a script to run that virtual machine (VM).
26944 The @code{vm} action and others below
26945 can use KVM support in the Linux-libre kernel. Specifically, if the
26946 machine has hardware virtualization support, the corresponding
26947 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
26948 must exist and be readable and writable by the user and by the
26949 build users of the daemon (@pxref{Build Environment Setup}).
26952 Arguments given to the script are passed to QEMU as in the example
26953 below, which enables networking and requests 1@tie{}GiB of RAM for the
26957 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
26960 The VM shares its store with the host system.
26962 Additional file systems can be shared between the host and the VM using
26963 the @code{--share} and @code{--expose} command-line options: the former
26964 specifies a directory to be shared with write access, while the latter
26965 provides read-only access to the shared directory.
26967 The example below creates a VM in which the user's home directory is
26968 accessible read-only, and where the @file{/exchange} directory is a
26969 read-write mapping of @file{$HOME/tmp} on the host:
26972 guix system vm my-config.scm \
26973 --expose=$HOME --share=$HOME/tmp=/exchange
26976 On GNU/Linux, the default is to boot directly to the kernel; this has
26977 the advantage of requiring only a very tiny root disk image since the
26978 store of the host can then be mounted.
26980 The @code{--full-boot} option forces a complete boot sequence, starting
26981 with the bootloader. This requires more disk space since a root image
26982 containing at least the kernel, initrd, and bootloader data files must
26983 be created. The @code{--image-size} option can be used to specify the
26986 @cindex System images, creation in various formats
26987 @cindex Creating system images in various formats
26990 @itemx docker-image
26991 Return a virtual machine, disk image, or Docker image of the operating
26992 system declared in @var{file} that stands alone. By default,
26993 @command{guix system} estimates the size of the image needed to store
26994 the system, but you can use the @option{--image-size} option to specify
26995 a value. Docker images are built to contain exactly what they need, so
26996 the @option{--image-size} option is ignored in the case of
26997 @code{docker-image}.
26999 You can specify the root file system type by using the
27000 @option{--file-system-type} option. It defaults to @code{ext4}.
27002 When using @code{vm-image}, the returned image is in qcow2 format, which
27003 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
27004 for more information on how to run the image in a virtual machine.
27006 When using @code{disk-image}, a raw disk image is produced; it can be
27007 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
27008 the device corresponding to a USB stick, one can copy the image to it
27009 using the following command:
27012 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
27015 When using @code{docker-image}, a Docker image is produced. Guix builds
27016 the image from scratch, not from a pre-existing Docker base image. As a
27017 result, it contains @emph{exactly} what you define in the operating
27018 system configuration file. You can then load the image and launch a
27019 Docker container using commands like the following:
27022 image_id="`docker load < guix-system-docker-image.tar.gz`"
27023 container_id="`docker create $image_id`"
27024 docker start $container_id
27027 This command starts a new Docker container from the specified image. It
27028 will boot the Guix system in the usual manner, which means it will
27029 start any services you have defined in the operating system
27030 configuration. You can get an interactive shell running in the container
27031 using @command{docker exec}:
27034 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
27037 Depending on what you run in the Docker container, it
27038 may be necessary to give the container additional permissions. For
27039 example, if you intend to build software using Guix inside of the Docker
27040 container, you may need to pass the @option{--privileged} option to
27041 @code{docker create}.
27044 Return a script to run the operating system declared in @var{file}
27045 within a container. Containers are a set of lightweight isolation
27046 mechanisms provided by the kernel Linux-libre. Containers are
27047 substantially less resource-demanding than full virtual machines since
27048 the kernel, shared objects, and other resources can be shared with the
27049 host system; this also means they provide thinner isolation.
27051 Currently, the script must be run as root in order to support more than
27052 a single user and group. The container shares its store with the host
27055 As with the @code{vm} action (@pxref{guix system vm}), additional file
27056 systems to be shared between the host and container can be specified
27057 using the @option{--share} and @option{--expose} options:
27060 guix system container my-config.scm \
27061 --expose=$HOME --share=$HOME/tmp=/exchange
27065 This option requires Linux-libre 3.19 or newer.
27070 @var{options} can contain any of the common build options (@pxref{Common
27071 Build Options}). In addition, @var{options} can contain one of the
27075 @item --expression=@var{expr}
27076 @itemx -e @var{expr}
27077 Consider the operating-system @var{expr} evaluates to.
27078 This is an alternative to specifying a file which evaluates to an
27080 This is used to generate the Guix system installer @pxref{Building the
27081 Installation Image}).
27083 @item --system=@var{system}
27084 @itemx -s @var{system}
27085 Attempt to build for @var{system} instead of the host system type.
27086 This works as per @command{guix build} (@pxref{Invoking guix build}).
27090 Return the derivation file name of the given operating system without
27093 @cindex provenance tracking, of the operating system
27094 @item --save-provenance
27095 As discussed above, @command{guix system init} and @command{guix system
27096 reconfigure} always save provenance information @i{via} a dedicated
27097 service (@pxref{Service Reference, @code{provenance-service-type}}).
27098 However, other commands don't do that by default. If you wish to, say,
27099 create a virtual machine image that contains provenance information, you
27103 guix system vm-image --save-provenance config.scm
27106 That way, the resulting image will effectively ``embed its own source''
27107 in the form of meta-data in @file{/run/current-system}. With that
27108 information, one can rebuild the image to make sure it really contains
27109 what it pretends to contain; or they could use that to derive a variant
27112 @item --file-system-type=@var{type}
27113 @itemx -t @var{type}
27114 For the @code{disk-image} action, create a file system of the given
27115 @var{type} on the image.
27117 When this option is omitted, @command{guix system} uses @code{ext4}.
27119 @cindex ISO-9660 format
27120 @cindex CD image format
27121 @cindex DVD image format
27122 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
27123 for burning on CDs and DVDs.
27125 @item --image-size=@var{size}
27126 For the @code{vm-image} and @code{disk-image} actions, create an image
27127 of the given @var{size}. @var{size} may be a number of bytes, or it may
27128 include a unit as a suffix (@pxref{Block size, size specifications,,
27129 coreutils, GNU Coreutils}).
27131 When this option is omitted, @command{guix system} computes an estimate
27132 of the image size as a function of the size of the system declared in
27137 For the @code{container} action, allow containers to access the host network,
27138 that is, do not create a network namespace.
27140 @item --root=@var{file}
27141 @itemx -r @var{file}
27142 Make @var{file} a symlink to the result, and register it as a garbage
27145 @item --skip-checks
27146 Skip pre-installation safety checks.
27148 By default, @command{guix system init} and @command{guix system
27149 reconfigure} perform safety checks: they make sure the file systems that
27150 appear in the @code{operating-system} declaration actually exist
27151 (@pxref{File Systems}), and that any Linux kernel modules that may be
27152 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
27153 RAM Disk}). Passing this option skips these tests altogether.
27156 @cindex on-error strategy
27157 @cindex error strategy
27158 @item --on-error=@var{strategy}
27159 Apply @var{strategy} when an error occurs when reading @var{file}.
27160 @var{strategy} may be one of the following:
27163 @item nothing-special
27164 Report the error concisely and exit. This is the default strategy.
27167 Likewise, but also display a backtrace.
27170 Report the error and enter Guile's debugger. From there, you can run
27171 commands such as @code{,bt} to get a backtrace, @code{,locals} to
27172 display local variable values, and more generally inspect the state of the
27173 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
27174 a list of available debugging commands.
27178 Once you have built, configured, re-configured, and re-re-configured
27179 your Guix installation, you may find it useful to list the operating
27180 system generations available on disk---and that you can choose from the
27181 bootloader boot menu:
27186 Describe the current system generation: its file name, the kernel and
27187 bootloader used, etc., as well as provenance information when available.
27189 @item list-generations
27190 List a summary of each generation of the operating system available on
27191 disk, in a human-readable way. This is similar to the
27192 @option{--list-generations} option of @command{guix package}
27193 (@pxref{Invoking guix package}).
27195 Optionally, one can specify a pattern, with the same syntax that is used
27196 in @command{guix package --list-generations}, to restrict the list of
27197 generations displayed. For instance, the following command displays
27198 generations that are up to 10 days old:
27201 $ guix system list-generations 10d
27206 The @command{guix system} command has even more to offer! The following
27207 sub-commands allow you to visualize how your system services relate to
27210 @anchor{system-extension-graph}
27213 @item extension-graph
27214 Emit in Dot/Graphviz format to standard output the @dfn{service
27215 extension graph} of the operating system defined in @var{file}
27216 (@pxref{Service Composition}, for more information on service
27222 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
27225 produces a PDF file showing the extension relations among services.
27227 @anchor{system-shepherd-graph}
27228 @item shepherd-graph
27229 Emit in Dot/Graphviz format to standard output the @dfn{dependency
27230 graph} of shepherd services of the operating system defined in
27231 @var{file}. @xref{Shepherd Services}, for more information and for an
27236 @node Invoking guix deploy
27237 @section Invoking @code{guix deploy}
27239 We've already seen @code{operating-system} declarations used to manage a
27240 machine's configuration locally. Suppose you need to configure multiple
27241 machines, though---perhaps you're managing a service on the web that's
27242 comprised of several servers. @command{guix deploy} enables you to use those
27243 same @code{operating-system} declarations to manage multiple remote hosts at
27244 once as a logical ``deployment''.
27247 The functionality described in this section is still under development
27248 and is subject to change. Get in touch with us on
27249 @email{guix-devel@@gnu.org}!
27253 guix deploy @var{file}
27256 Such an invocation will deploy the machines that the code within @var{file}
27257 evaluates to. As an example, @var{file} might contain a definition like this:
27260 ;; This is a Guix deployment of a "bare bones" setup, with
27261 ;; no X11 display server, to a machine with an SSH daemon
27262 ;; listening on localhost:2222. A configuration such as this
27263 ;; may be appropriate for virtual machine with ports
27264 ;; forwarded to the host's loopback interface.
27266 (use-service-modules networking ssh)
27267 (use-package-modules bootloaders)
27271 (host-name "gnu-deployed")
27272 (timezone "Etc/UTC")
27273 (bootloader (bootloader-configuration
27274 (bootloader grub-bootloader)
27275 (target "/dev/vda")
27276 (terminal-outputs '(console))))
27277 (file-systems (cons (file-system
27279 (device "/dev/vda1")
27281 %base-file-systems))
27283 (append (list (service dhcp-client-service-type)
27284 (service openssh-service-type
27285 (openssh-configuration
27286 (permit-root-login #t)
27287 (allow-empty-passwords? #t))))
27291 (operating-system %system)
27292 (environment managed-host-environment-type)
27293 (configuration (machine-ssh-configuration
27294 (host-name "localhost")
27295 (system "x86_64-linux")
27297 (identity "./id_rsa")
27301 The file should evaluate to a list of @var{machine} objects. This example,
27302 upon being deployed, will create a new generation on the remote system
27303 realizing the @code{operating-system} declaration @code{%system}.
27304 @code{environment} and @code{configuration} specify how the machine should be
27305 provisioned---that is, how the computing resources should be created and
27306 managed. The above example does not create any resources, as a
27307 @code{'managed-host} is a machine that is already running the Guix system and
27308 available over the network. This is a particularly simple case; a more
27309 complex deployment may involve, for example, starting virtual machines through
27310 a Virtual Private Server (VPS) provider. In such a case, a different
27311 @var{environment} type would be used.
27313 Do note that you first need to generate a key pair on the coordinator machine
27314 to allow the daemon to export signed archives of files from the store
27315 (@pxref{Invoking guix archive}).
27318 # guix archive --generate-key
27322 Each target machine must authorize the key of the master machine so that it
27323 accepts store items it receives from the coordinator:
27326 # guix archive --authorize < coordinator-public-key.txt
27329 @code{user}, in this example, specifies the name of the user account to log in
27330 as to perform the deployment. Its default value is @code{root}, but root
27331 login over SSH may be forbidden in some cases. To work around this,
27332 @command{guix deploy} can log in as an unprivileged user and employ
27333 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
27334 currently installed on the remote and can be invoked non-interactively as
27335 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
27336 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
27337 be accomplished with the following operating system configuration snippet:
27341 (gnu system)) ;for %sudoers-specification
27343 (define %user "username")
27348 (plain-file "sudoers"
27349 (string-append (plain-file-content %sudoers-specification)
27350 (format #f "~a ALL = NOPASSWD: ALL~%"
27355 For more information regarding the format of the @file{sudoers} file,
27356 consult @command{man sudoers}.
27358 @deftp {Data Type} machine
27359 This is the data type representing a single machine in a heterogeneous Guix
27363 @item @code{operating-system}
27364 The object of the operating system configuration to deploy.
27366 @item @code{environment}
27367 An @code{environment-type} describing how the machine should be provisioned.
27369 @item @code{configuration} (default: @code{#f})
27370 An object describing the configuration for the machine's @code{environment}.
27371 If the @code{environment} has a default configuration, @code{#f} may be used.
27372 If @code{#f} is used for an environment with no default configuration,
27373 however, an error will be thrown.
27377 @deftp {Data Type} machine-ssh-configuration
27378 This is the data type representing the SSH client parameters for a machine
27379 with an @code{environment} of @code{managed-host-environment-type}.
27382 @item @code{host-name}
27383 @item @code{build-locally?} (default: @code{#t})
27384 If false, system derivations will be built on the machine being deployed to.
27385 @item @code{system}
27386 The system type describing the architecture of the machine being deployed
27387 to---e.g., @code{"x86_64-linux"}.
27388 @item @code{authorize?} (default: @code{#t})
27389 If true, the coordinator's signing key will be added to the remote's ACL
27391 @item @code{port} (default: @code{22})
27392 @item @code{user} (default: @code{"root"})
27393 @item @code{identity} (default: @code{#f})
27394 If specified, the path to the SSH private key to use to authenticate with the
27397 @item @code{host-key} (default: @code{#f})
27398 This should be the SSH host key of the machine, which looks like this:
27401 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
27404 When @code{host-key} is @code{#f}, the server is authenticated against
27405 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
27411 @deftp {Data Type} digital-ocean-configuration
27412 This is the data type describing the Droplet that should be created for a
27413 machine with an @code{environment} of @code{digital-ocean-environment-type}.
27416 @item @code{ssh-key}
27417 The path to the SSH private key to use to authenticate with the remote
27418 host. In the future, this field may not exist.
27420 A list of string ``tags'' that uniquely identify the machine. Must be given
27421 such that no two machines in the deployment have the same set of tags.
27422 @item @code{region}
27423 A Digital Ocean region slug, such as @code{"nyc3"}.
27425 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
27426 @item @code{enable-ipv6?}
27427 Whether or not the droplet should be created with IPv6 networking.
27431 @node Running Guix in a VM
27432 @section Running Guix in a Virtual Machine
27434 @cindex virtual machine
27435 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
27437 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
27438 This image is a compressed image in QCOW format. You will first need to
27439 decompress with @command{xz -d}, and then you can pass it to an emulator such
27440 as QEMU (see below for details).
27442 This image boots the Xfce graphical environment and it contains some
27443 commonly-used tools. You can install more software in the image by running
27444 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
27445 also reconfigure the system based on its initial configuration file available
27446 as @file{/run/current-system/configuration.scm} (@pxref{Using the
27447 Configuration System}).
27449 Instead of using this pre-built image, one can also build their own virtual
27450 machine image using @command{guix system vm-image} (@pxref{Invoking guix
27451 system}). The returned image is in qcow2 format, which the
27452 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
27455 If you built your own image, you must copy it out of the store
27456 (@pxref{The Store}) and give yourself permission to write to the copy
27457 before you can use it. When invoking QEMU, you must choose a system
27458 emulator that is suitable for your hardware platform. Here is a minimal
27459 QEMU invocation that will boot the result of @command{guix system
27460 vm-image} on x86_64 hardware:
27463 $ qemu-system-x86_64 \
27464 -nic user,model=virtio-net-pci \
27465 -enable-kvm -m 1024 \
27466 -device virtio-blk,drive=myhd \
27467 -drive if=none,file=/tmp/qemu-image,id=myhd
27470 Here is what each of these options means:
27473 @item qemu-system-x86_64
27474 This specifies the hardware platform to emulate. This should match the
27477 @item -nic user,model=virtio-net-pci
27478 Enable the unprivileged user-mode network stack. The guest OS can
27479 access the host but not vice versa. This is the simplest way to get the
27480 guest OS online. @code{model} specifies which network device to emulate:
27481 @code{virtio-net-pci} is a special device made for virtualized operating
27482 systems and recommended for most uses. Assuming your hardware platform is
27483 x86_64, you can get a list of available NIC models by running
27484 @command{qemu-system-x86_64 -nic model=help}.
27487 If your system has hardware virtualization extensions, enabling the
27488 virtual machine support (KVM) of the Linux kernel will make things run
27491 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
27493 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
27494 which may be insufficient for some operations.
27496 @item -device virtio-blk,drive=myhd
27497 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
27498 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
27499 better performance than if it were emulating a complete disk drive. See the
27500 QEMU and KVM documentation for more info.
27502 @item -drive if=none,file=/tmp/qemu-image,id=myhd
27503 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
27504 the ``myhd'' drive.
27507 The default @command{run-vm.sh} script that is returned by an invocation of
27508 @command{guix system vm} does not add a @command{-nic user} flag by default.
27509 To get network access from within the vm add the @code{(dhcp-client-service)}
27510 to your system definition and start the VM using
27511 @command{`guix system vm config.scm` -nic user}. An important caveat of using
27512 @command{-nic user} for networking is that @command{ping} will not work, because
27513 it uses the ICMP protocol. You'll have to use a different command to check for
27514 network connectivity, for example @command{guix download}.
27516 @subsection Connecting Through SSH
27520 To enable SSH inside a VM you need to add an SSH server like
27521 @code{openssh-service-type} to your VM (@pxref{Networking Services,
27522 @code{openssh-service-type}}). In addition you need to forward the SSH port,
27523 22 by default, to the host. You can do this with
27526 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
27529 To connect to the VM you can run
27532 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
27535 The @command{-p} tells @command{ssh} the port you want to connect to.
27536 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
27537 every time you modify your @command{config.scm} file and the
27538 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
27539 connection to an unknown host every time you connect.
27541 @subsection Using @command{virt-viewer} with Spice
27543 As an alternative to the default @command{qemu} graphical client you can
27544 use the @command{remote-viewer} from the @command{virt-viewer} package. To
27545 connect pass the @command{-spice port=5930,disable-ticketing} flag to
27546 @command{qemu}. See previous section for further information on how to do this.
27548 Spice also allows you to do some nice stuff like share your clipboard with your
27549 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
27552 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
27553 -chardev spicevmc,name=vdagent,id=vdagent
27554 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
27555 name=com.redhat.spice.0
27558 You'll also need to add the @code{(spice-vdagent-service)} to your
27559 system definition (@pxref{Miscellaneous Services, Spice service}).
27561 @node Defining Services
27562 @section Defining Services
27564 The previous sections show the available services and how one can combine
27565 them in an @code{operating-system} declaration. But how do we define
27566 them in the first place? And what is a service anyway?
27569 * Service Composition:: The model for composing services.
27570 * Service Types and Services:: Types and services.
27571 * Service Reference:: API reference.
27572 * Shepherd Services:: A particular type of service.
27575 @node Service Composition
27576 @subsection Service Composition
27580 Here we define a @dfn{service} as, broadly, something that extends the
27581 functionality of the operating system. Often a service is a process---a
27582 @dfn{daemon}---started when the system boots: a secure shell server, a
27583 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
27584 whose execution can be triggered by another daemon---e.g., an FTP server
27585 started by @command{inetd} or a D-Bus service activated by
27586 @command{dbus-daemon}. Occasionally, a service does not map to a
27587 daemon. For instance, the ``account'' service collects user accounts
27588 and makes sure they exist when the system runs; the ``udev'' service
27589 collects device management rules and makes them available to the eudev
27590 daemon; the @file{/etc} service populates the @file{/etc} directory
27593 @cindex service extensions
27594 Guix system services are connected by @dfn{extensions}. For instance, the
27595 secure shell service @emph{extends} the Shepherd---the
27596 initialization system, running as PID@tie{}1---by giving it the command
27597 lines to start and stop the secure shell daemon (@pxref{Networking
27598 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
27599 service by passing it its @file{.service} specification, and extends the
27600 udev service by passing it device management rules (@pxref{Desktop
27601 Services, @code{upower-service}}); the Guix daemon service extends the
27602 Shepherd by passing it the command lines to start and stop the daemon,
27603 and extends the account service by passing it a list of required build
27604 user accounts (@pxref{Base Services}).
27606 All in all, services and their ``extends'' relations form a directed
27607 acyclic graph (DAG). If we represent services as boxes and extensions
27608 as arrows, a typical system might provide something like this:
27610 @image{images/service-graph,,5in,Typical service extension graph.}
27612 @cindex system service
27613 At the bottom, we see the @dfn{system service}, which produces the
27614 directory containing everything to run and boot the system, as returned
27615 by the @command{guix system build} command. @xref{Service Reference},
27616 to learn about the other service types shown here.
27617 @xref{system-extension-graph, the @command{guix system extension-graph}
27618 command}, for information on how to generate this representation for a
27619 particular operating system definition.
27621 @cindex service types
27622 Technically, developers can define @dfn{service types} to express these
27623 relations. There can be any number of services of a given type on the
27624 system---for instance, a system running two instances of the GNU secure
27625 shell server (lsh) has two instances of @code{lsh-service-type}, with
27626 different parameters.
27628 The following section describes the programming interface for service
27629 types and services.
27631 @node Service Types and Services
27632 @subsection Service Types and Services
27634 A @dfn{service type} is a node in the DAG described above. Let us start
27635 with a simple example, the service type for the Guix build daemon
27636 (@pxref{Invoking guix-daemon}):
27639 (define guix-service-type
27643 (list (service-extension shepherd-root-service-type guix-shepherd-service)
27644 (service-extension account-service-type guix-accounts)
27645 (service-extension activation-service-type guix-activation)))
27646 (default-value (guix-configuration))))
27650 It defines three things:
27654 A name, whose sole purpose is to make inspection and debugging easier.
27657 A list of @dfn{service extensions}, where each extension designates the
27658 target service type and a procedure that, given the parameters of the
27659 service, returns a list of objects to extend the service of that type.
27661 Every service type has at least one service extension. The only
27662 exception is the @dfn{boot service type}, which is the ultimate service.
27665 Optionally, a default value for instances of this type.
27668 In this example, @code{guix-service-type} extends three services:
27671 @item shepherd-root-service-type
27672 The @code{guix-shepherd-service} procedure defines how the Shepherd
27673 service is extended. Namely, it returns a @code{<shepherd-service>}
27674 object that defines how @command{guix-daemon} is started and stopped
27675 (@pxref{Shepherd Services}).
27677 @item account-service-type
27678 This extension for this service is computed by @code{guix-accounts},
27679 which returns a list of @code{user-group} and @code{user-account}
27680 objects representing the build user accounts (@pxref{Invoking
27683 @item activation-service-type
27684 Here @code{guix-activation} is a procedure that returns a gexp, which is
27685 a code snippet to run at ``activation time''---e.g., when the service is
27689 A service of this type is instantiated like this:
27692 (service guix-service-type
27693 (guix-configuration
27695 (use-substitutes? #f)))
27698 The second argument to the @code{service} form is a value representing
27699 the parameters of this specific service instance.
27700 @xref{guix-configuration-type, @code{guix-configuration}}, for
27701 information about the @code{guix-configuration} data type. When the
27702 value is omitted, the default value specified by
27703 @code{guix-service-type} is used:
27706 (service guix-service-type)
27709 @code{guix-service-type} is quite simple because it extends other
27710 services but is not extensible itself.
27712 @c @subsubsubsection Extensible Service Types
27714 The service type for an @emph{extensible} service looks like this:
27717 (define udev-service-type
27718 (service-type (name 'udev)
27720 (list (service-extension shepherd-root-service-type
27721 udev-shepherd-service)))
27723 (compose concatenate) ;concatenate the list of rules
27724 (extend (lambda (config rules)
27726 (($ <udev-configuration> udev initial-rules)
27727 (udev-configuration
27728 (udev udev) ;the udev package to use
27729 (rules (append initial-rules rules)))))))))
27732 This is the service type for the
27733 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
27734 management daemon}. Compared to the previous example, in addition to an
27735 extension of @code{shepherd-root-service-type}, we see two new fields:
27739 This is the procedure to @dfn{compose} the list of extensions to
27740 services of this type.
27742 Services can extend the udev service by passing it lists of rules; we
27743 compose those extensions simply by concatenating them.
27746 This procedure defines how the value of the service is @dfn{extended} with
27747 the composition of the extensions.
27749 Udev extensions are composed into a list of rules, but the udev service
27750 value is itself a @code{<udev-configuration>} record. So here, we
27751 extend that record by appending the list of rules it contains to the
27752 list of contributed rules.
27755 This is a string giving an overview of the service type. The string can
27756 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
27757 @command{guix system search} command searches these strings and displays
27758 them (@pxref{Invoking guix system}).
27761 There can be only one instance of an extensible service type such as
27762 @code{udev-service-type}. If there were more, the
27763 @code{service-extension} specifications would be ambiguous.
27765 Still here? The next section provides a reference of the programming
27766 interface for services.
27768 @node Service Reference
27769 @subsection Service Reference
27771 We have seen an overview of service types (@pxref{Service Types and
27772 Services}). This section provides a reference on how to manipulate
27773 services and service types. This interface is provided by the
27774 @code{(gnu services)} module.
27776 @deffn {Scheme Procedure} service @var{type} [@var{value}]
27777 Return a new service of @var{type}, a @code{<service-type>} object (see
27778 below.) @var{value} can be any object; it represents the parameters of
27779 this particular service instance.
27781 When @var{value} is omitted, the default value specified by @var{type}
27782 is used; if @var{type} does not specify a default value, an error is
27785 For instance, this:
27788 (service openssh-service-type)
27792 is equivalent to this:
27795 (service openssh-service-type
27796 (openssh-configuration))
27799 In both cases the result is an instance of @code{openssh-service-type}
27800 with the default configuration.
27803 @deffn {Scheme Procedure} service? @var{obj}
27804 Return true if @var{obj} is a service.
27807 @deffn {Scheme Procedure} service-kind @var{service}
27808 Return the type of @var{service}---i.e., a @code{<service-type>} object.
27811 @deffn {Scheme Procedure} service-value @var{service}
27812 Return the value associated with @var{service}. It represents its
27816 Here is an example of how a service is created and manipulated:
27820 (service nginx-service-type
27821 (nginx-configuration
27823 (log-directory log-directory)
27824 (run-directory run-directory)
27825 (file config-file))))
27830 (eq? (service-kind s) nginx-service-type)
27834 The @code{modify-services} form provides a handy way to change the
27835 parameters of some of the services of a list such as
27836 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
27837 evaluates to a list of services. Of course, you could always use
27838 standard list combinators such as @code{map} and @code{fold} to do that
27839 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
27840 @code{modify-services} simply provides a more concise form for this
27843 @deffn {Scheme Syntax} modify-services @var{services} @
27844 (@var{type} @var{variable} => @var{body}) @dots{}
27846 Modify the services listed in @var{services} according to the given
27847 clauses. Each clause has the form:
27850 (@var{type} @var{variable} => @var{body})
27853 where @var{type} is a service type---e.g.,
27854 @code{guix-service-type}---and @var{variable} is an identifier that is
27855 bound within the @var{body} to the service parameters---e.g., a
27856 @code{guix-configuration} instance---of the original service of that
27859 The @var{body} should evaluate to the new service parameters, which will
27860 be used to configure the new service. This new service will replace the
27861 original in the resulting list. Because a service's service parameters
27862 are created using @code{define-record-type*}, you can write a succinct
27863 @var{body} that evaluates to the new service parameters by using the
27864 @code{inherit} feature that @code{define-record-type*} provides.
27866 @xref{Using the Configuration System}, for example usage.
27870 Next comes the programming interface for service types. This is
27871 something you want to know when writing new service definitions, but not
27872 necessarily when simply looking for ways to customize your
27873 @code{operating-system} declaration.
27875 @deftp {Data Type} service-type
27876 @cindex service type
27877 This is the representation of a @dfn{service type} (@pxref{Service Types
27882 This is a symbol, used only to simplify inspection and debugging.
27884 @item @code{extensions}
27885 A non-empty list of @code{<service-extension>} objects (see below).
27887 @item @code{compose} (default: @code{#f})
27888 If this is @code{#f}, then the service type denotes services that cannot
27889 be extended---i.e., services that do not receive ``values'' from other
27892 Otherwise, it must be a one-argument procedure. The procedure is called
27893 by @code{fold-services} and is passed a list of values collected from
27894 extensions. It may return any single value.
27896 @item @code{extend} (default: @code{#f})
27897 If this is @code{#f}, services of this type cannot be extended.
27899 Otherwise, it must be a two-argument procedure: @code{fold-services}
27900 calls it, passing it the initial value of the service as the first
27901 argument and the result of applying @code{compose} to the extension
27902 values as the second argument. It must return a value that is a valid
27903 parameter value for the service instance.
27906 @xref{Service Types and Services}, for examples.
27909 @deffn {Scheme Procedure} service-extension @var{target-type} @
27911 Return a new extension for services of type @var{target-type}.
27912 @var{compute} must be a one-argument procedure: @code{fold-services}
27913 calls it, passing it the value associated with the service that provides
27914 the extension; it must return a valid value for the target service.
27917 @deffn {Scheme Procedure} service-extension? @var{obj}
27918 Return true if @var{obj} is a service extension.
27921 Occasionally, you might want to simply extend an existing service. This
27922 involves creating a new service type and specifying the extension of
27923 interest, which can be verbose; the @code{simple-service} procedure
27924 provides a shorthand for this.
27926 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
27927 Return a service that extends @var{target} with @var{value}. This works
27928 by creating a singleton service type @var{name}, of which the returned
27929 service is an instance.
27931 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
27935 (simple-service 'my-mcron-job mcron-service-type
27936 #~(job '(next-hour (3)) "guix gc -F 2G"))
27940 At the core of the service abstraction lies the @code{fold-services}
27941 procedure, which is responsible for ``compiling'' a list of services
27942 down to a single directory that contains everything needed to boot and
27943 run the system---the directory shown by the @command{guix system build}
27944 command (@pxref{Invoking guix system}). In essence, it propagates
27945 service extensions down the service graph, updating each node parameters
27946 on the way, until it reaches the root node.
27948 @deffn {Scheme Procedure} fold-services @var{services} @
27949 [#:target-type @var{system-service-type}]
27950 Fold @var{services} by propagating their extensions down to the root of
27951 type @var{target-type}; return the root service adjusted accordingly.
27954 Lastly, the @code{(gnu services)} module also defines several essential
27955 service types, some of which are listed below.
27957 @defvr {Scheme Variable} system-service-type
27958 This is the root of the service graph. It produces the system directory
27959 as returned by the @command{guix system build} command.
27962 @defvr {Scheme Variable} boot-service-type
27963 The type of the ``boot service'', which produces the @dfn{boot script}.
27964 The boot script is what the initial RAM disk runs when booting.
27967 @defvr {Scheme Variable} etc-service-type
27968 The type of the @file{/etc} service. This service is used to create
27969 files under @file{/etc} and can be extended by
27970 passing it name/file tuples such as:
27973 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
27976 In this example, the effect would be to add an @file{/etc/issue} file
27977 pointing to the given file.
27980 @defvr {Scheme Variable} setuid-program-service-type
27981 Type for the ``setuid-program service''. This service collects lists of
27982 executable file names, passed as gexps, and adds them to the set of
27983 setuid-root programs on the system (@pxref{Setuid Programs}).
27986 @defvr {Scheme Variable} profile-service-type
27987 Type of the service that populates the @dfn{system profile}---i.e., the
27988 programs under @file{/run/current-system/profile}. Other services can
27989 extend it by passing it lists of packages to add to the system profile.
27992 @cindex provenance tracking, of the operating system
27993 @defvr {Scheme Variable} provenance-service-type
27994 This is the type of the service that records @dfn{provenance meta-data}
27995 in the system itself. It creates several files under
27996 @file{/run/current-system}:
28000 This is a ``channel file'' that can be passed to @command{guix pull -C}
28001 or @command{guix time-machine -C}, and which describes the channels used
28002 to build the system, if that information was available
28003 (@pxref{Channels}).
28005 @item configuration.scm
28006 This is the file that was passed as the value for this
28007 @code{provenance-service-type} service. By default, @command{guix
28008 system reconfigure} automatically passes the OS configuration file it
28009 received on the command line.
28012 This contains the same information as the two other files but in a
28013 format that is more readily processable.
28016 In general, these two pieces of information (channels and configuration
28017 file) are enough to reproduce the operating system ``from source''.
28020 This information is necessary to rebuild your operating system, but it
28021 is not always sufficient. In particular, @file{configuration.scm}
28022 itself is insufficient if it is not self-contained---if it refers to
28023 external Guile modules or to extra files. If you want
28024 @file{configuration.scm} to be self-contained, we recommend that modules
28025 or files it refers to be part of a channel.
28027 Besides, provenance meta-data is ``silent'' in the sense that it does
28028 not change the bits contained in your system, @emph{except for the
28029 meta-data bits themselves}. Two different OS configurations or sets of
28030 channels can lead to the same system, bit-for-bit; when
28031 @code{provenance-service-type} is used, these two systems will have
28032 different meta-data and thus different store file names, which makes
28033 comparison less trivial.
28036 This service is automatically added to your operating system
28037 configuration when you use @command{guix system reconfigure},
28038 @command{guix system init}, or @command{guix deploy}.
28041 @node Shepherd Services
28042 @subsection Shepherd Services
28044 @cindex shepherd services
28046 @cindex init system
28047 The @code{(gnu services shepherd)} module provides a way to define
28048 services managed by the GNU@tie{}Shepherd, which is the
28049 initialization system---the first process that is started when the
28050 system boots, also known as PID@tie{}1
28051 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
28053 Services in the Shepherd can depend on each other. For instance, the
28054 SSH daemon may need to be started after the syslog daemon has been
28055 started, which in turn can only happen once all the file systems have
28056 been mounted. The simple operating system defined earlier (@pxref{Using
28057 the Configuration System}) results in a service graph like this:
28059 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
28061 You can actually generate such a graph for any operating system
28062 definition using the @command{guix system shepherd-graph} command
28063 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
28065 The @code{%shepherd-root-service} is a service object representing
28066 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
28067 by passing it lists of @code{<shepherd-service>} objects.
28069 @deftp {Data Type} shepherd-service
28070 The data type representing a service managed by the Shepherd.
28073 @item @code{provision}
28074 This is a list of symbols denoting what the service provides.
28076 These are the names that may be passed to @command{herd start},
28077 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
28078 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
28079 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
28081 @item @code{requirement} (default: @code{'()})
28082 List of symbols denoting the Shepherd services this one depends on.
28084 @cindex one-shot services, for the Shepherd
28085 @item @code{one-shot?} (default: @code{#f})
28086 Whether this service is @dfn{one-shot}. One-shot services stop immediately
28087 after their @code{start} action has completed. @xref{Slots of services,,,
28088 shepherd, The GNU Shepherd Manual}, for more info.
28090 @item @code{respawn?} (default: @code{#t})
28091 Whether to restart the service when it stops, for instance when the
28092 underlying process dies.
28095 @itemx @code{stop} (default: @code{#~(const #f)})
28096 The @code{start} and @code{stop} fields refer to the Shepherd's
28097 facilities to start and stop processes (@pxref{Service De- and
28098 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
28099 G-expressions that get expanded in the Shepherd configuration file
28100 (@pxref{G-Expressions}).
28102 @item @code{actions} (default: @code{'()})
28103 @cindex actions, of Shepherd services
28104 This is a list of @code{shepherd-action} objects (see below) defining
28105 @dfn{actions} supported by the service, in addition to the standard
28106 @code{start} and @code{stop} actions. Actions listed here become available as
28107 @command{herd} sub-commands:
28110 herd @var{action} @var{service} [@var{arguments}@dots{}]
28113 @item @code{auto-start?} (default: @code{#t})
28114 Whether this service should be started automatically by the Shepherd. If it
28115 is @code{#f} the service has to be started manually with @code{herd start}.
28117 @item @code{documentation}
28118 A documentation string, as shown when running:
28121 herd doc @var{service-name}
28124 where @var{service-name} is one of the symbols in @code{provision}
28125 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
28127 @item @code{modules} (default: @code{%default-modules})
28128 This is the list of modules that must be in scope when @code{start} and
28129 @code{stop} are evaluated.
28134 @deftp {Data Type} shepherd-action
28135 This is the data type that defines additional actions implemented by a
28136 Shepherd service (see above).
28140 Symbol naming the action.
28142 @item documentation
28143 This is a documentation string for the action. It can be viewed by running:
28146 herd doc @var{service} action @var{action}
28150 This should be a gexp that evaluates to a procedure of at least one argument,
28151 which is the ``running value'' of the service (@pxref{Slots of services,,,
28152 shepherd, The GNU Shepherd Manual}).
28155 The following example defines an action called @code{say-hello} that kindly
28161 (documentation "Say hi!")
28162 (procedure #~(lambda (running . args)
28163 (format #t "Hello, friend! arguments: ~s\n"
28168 Assuming this action is added to the @code{example} service, then you can do:
28171 # herd say-hello example
28172 Hello, friend! arguments: ()
28173 # herd say-hello example a b c
28174 Hello, friend! arguments: ("a" "b" "c")
28177 This, as you can see, is a fairly sophisticated way to say hello.
28178 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
28182 @defvr {Scheme Variable} shepherd-root-service-type
28183 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
28185 This is the service type that extensions target when they want to create
28186 shepherd services (@pxref{Service Types and Services}, for an example).
28187 Each extension must pass a list of @code{<shepherd-service>}.
28190 @defvr {Scheme Variable} %shepherd-root-service
28191 This service represents PID@tie{}1.
28195 @node Documentation
28196 @chapter Documentation
28198 @cindex documentation, searching for
28199 @cindex searching for documentation
28200 @cindex Info, documentation format
28202 @cindex manual pages
28203 In most cases packages installed with Guix come with documentation.
28204 There are two main documentation formats: ``Info'', a browseable
28205 hypertext format used for GNU software, and ``manual pages'' (or ``man
28206 pages''), the linear documentation format traditionally found on Unix.
28207 Info manuals are accessed with the @command{info} command or with Emacs,
28208 and man pages are accessed using @command{man}.
28210 You can look for documentation of software installed on your system by
28211 keyword. For example, the following command searches for information
28212 about ``TLS'' in Info manuals:
28216 "(emacs)Network Security" -- STARTTLS
28217 "(emacs)Network Security" -- TLS
28218 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
28219 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
28224 The command below searches for the same keyword in man pages:
28228 SSL (7) - OpenSSL SSL/TLS library
28229 certtool (1) - GnuTLS certificate tool
28233 These searches are purely local to your computer so you have the
28234 guarantee that documentation you find corresponds to what you have
28235 actually installed, you can access it off-line, and your privacy is
28238 Once you have these results, you can view the relevant documentation by
28242 $ info "(gnutls)Core TLS API"
28252 Info manuals contain sections and indices as well as hyperlinks like
28253 those found in Web pages. The @command{info} reader (@pxref{Top, Info
28254 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
28255 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
28256 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
28257 Introduction}, for an introduction to Info navigation.
28259 @node Installing Debugging Files
28260 @chapter Installing Debugging Files
28262 @cindex debugging files
28263 Program binaries, as produced by the GCC compilers for instance, are
28264 typically written in the ELF format, with a section containing
28265 @dfn{debugging information}. Debugging information is what allows the
28266 debugger, GDB, to map binary code to source code; it is required to
28267 debug a compiled program in good conditions.
28269 The problem with debugging information is that is takes up a fair amount
28270 of disk space. For example, debugging information for the GNU C Library
28271 weighs in at more than 60 MiB. Thus, as a user, keeping all the
28272 debugging info of all the installed programs is usually not an option.
28273 Yet, space savings should not come at the cost of an impediment to
28274 debugging---especially in the GNU system, which should make it easier
28275 for users to exert their computing freedom (@pxref{GNU Distribution}).
28277 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
28278 mechanism that allows users to get the best of both worlds: debugging
28279 information can be stripped from the binaries and stored in separate
28280 files. GDB is then able to load debugging information from those files,
28281 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
28284 The GNU distribution takes advantage of this by storing debugging
28285 information in the @code{lib/debug} sub-directory of a separate package
28286 output unimaginatively called @code{debug} (@pxref{Packages with
28287 Multiple Outputs}). Users can choose to install the @code{debug} output
28288 of a package when they need it. For instance, the following command
28289 installs the debugging information for the GNU C Library and for GNU
28293 guix install glibc:debug guile:debug
28296 GDB must then be told to look for debug files in the user's profile, by
28297 setting the @code{debug-file-directory} variable (consider setting it
28298 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
28302 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
28305 From there on, GDB will pick up debugging information from the
28306 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
28308 In addition, you will most likely want GDB to be able to show the source
28309 code being debugged. To do that, you will have to unpack the source
28310 code of the package of interest (obtained with @code{guix build
28311 --source}, @pxref{Invoking guix build}), and to point GDB to that source
28312 directory using the @code{directory} command (@pxref{Source Path,
28313 @code{directory},, gdb, Debugging with GDB}).
28315 @c XXX: keep me up-to-date
28316 The @code{debug} output mechanism in Guix is implemented by the
28317 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
28318 opt-in---debugging information is available only for the packages
28319 with definitions explicitly declaring a @code{debug} output. This may be
28320 changed to opt-out in the future if our build farm servers can handle
28321 the load. To check whether a package has a @code{debug} output, use
28322 @command{guix package --list-available} (@pxref{Invoking guix package}).
28325 @node Security Updates
28326 @chapter Security Updates
28328 @cindex security updates
28329 @cindex security vulnerabilities
28330 Occasionally, important security vulnerabilities are discovered in software
28331 packages and must be patched. Guix developers try hard to keep track of
28332 known vulnerabilities and to apply fixes as soon as possible in the
28333 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
28334 containing only security updates.) The @command{guix lint} tool helps
28335 developers find out about vulnerable versions of software packages in the
28340 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
28341 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
28342 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
28346 @xref{Invoking guix lint}, for more information.
28348 Guix follows a functional
28349 package management discipline (@pxref{Introduction}), which implies
28350 that, when a package is changed, @emph{every package that depends on it}
28351 must be rebuilt. This can significantly slow down the deployment of
28352 fixes in core packages such as libc or Bash, since basically the whole
28353 distribution would need to be rebuilt. Using pre-built binaries helps
28354 (@pxref{Substitutes}), but deployment may still take more time than
28358 To address this, Guix implements @dfn{grafts}, a mechanism that allows
28359 for fast deployment of critical updates without the costs associated
28360 with a whole-distribution rebuild. The idea is to rebuild only the
28361 package that needs to be patched, and then to ``graft'' it onto packages
28362 explicitly installed by the user and that were previously referring to
28363 the original package. The cost of grafting is typically very low, and
28364 order of magnitudes lower than a full rebuild of the dependency chain.
28366 @cindex replacements of packages, for grafts
28367 For instance, suppose a security update needs to be applied to Bash.
28368 Guix developers will provide a package definition for the ``fixed''
28369 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
28370 Packages}). Then, the original package definition is augmented with a
28371 @code{replacement} field pointing to the package containing the bug fix:
28378 (replacement bash-fixed)))
28381 From there on, any package depending directly or indirectly on Bash---as
28382 reported by @command{guix gc --requisites} (@pxref{Invoking guix
28383 gc})---that is installed is automatically ``rewritten'' to refer to
28384 @code{bash-fixed} instead of @code{bash}. This grafting process takes
28385 time proportional to the size of the package, usually less than a
28386 minute for an ``average'' package on a recent machine. Grafting is
28387 recursive: when an indirect dependency requires grafting, then grafting
28388 ``propagates'' up to the package that the user is installing.
28390 Currently, the length of the name and version of the graft and that of
28391 the package it replaces (@code{bash-fixed} and @code{bash} in the example
28392 above) must be equal. This restriction mostly comes from the fact that
28393 grafting works by patching files, including binary files, directly.
28394 Other restrictions may apply: for instance, when adding a graft to a
28395 package providing a shared library, the original shared library and its
28396 replacement must have the same @code{SONAME} and be binary-compatible.
28398 The @option{--no-grafts} command-line option allows you to forcefully
28399 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
28403 guix build bash --no-grafts
28407 returns the store file name of the original Bash, whereas:
28414 returns the store file name of the ``fixed'', replacement Bash. This
28415 allows you to distinguish between the two variants of Bash.
28417 To verify which Bash your whole profile refers to, you can run
28418 (@pxref{Invoking guix gc}):
28421 guix gc -R `readlink -f ~/.guix-profile` | grep bash
28425 @dots{} and compare the store file names that you get with those above.
28426 Likewise for a complete Guix system generation:
28429 guix gc -R `guix system build my-config.scm` | grep bash
28432 Lastly, to check which Bash running processes are using, you can use the
28433 @command{lsof} command:
28436 lsof | grep /gnu/store/.*bash
28440 @node Bootstrapping
28441 @chapter Bootstrapping
28443 @c Adapted from the ELS 2013 paper.
28445 @cindex bootstrapping
28447 Bootstrapping in our context refers to how the distribution gets built
28448 ``from nothing''. Remember that the build environment of a derivation
28449 contains nothing but its declared inputs (@pxref{Introduction}). So
28450 there's an obvious chicken-and-egg problem: how does the first package
28451 get built? How does the first compiler get compiled? Note that this is
28452 a question of interest only to the curious hacker, not to the regular
28453 user, so you can shamelessly skip this section if you consider yourself
28454 a ``regular user''.
28456 @cindex bootstrap binaries
28457 The GNU system is primarily made of C code, with libc at its core. The
28458 GNU build system itself assumes the availability of a Bourne shell and
28459 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
28460 `grep'. Furthermore, build programs---programs that run
28461 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
28462 (@pxref{Derivations}). Consequently, to be able to build anything at
28463 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
28464 Binutils, libc, and the other packages mentioned above---the
28465 @dfn{bootstrap binaries}.
28467 These bootstrap binaries are ``taken for granted'', though we can also
28468 re-create them if needed (more on that later).
28470 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
28471 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
28474 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
28475 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
28478 @node Reduced Binary Seed Bootstrap
28479 @section The Reduced Binary Seed Bootstrap
28481 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
28482 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
28483 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
28484 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
28485 ``taken for granted.''
28487 Taking these binaries for granted means that we consider them to be a correct
28488 and trustworthy `seed' for building the complete system. Therein lies a
28489 problem: the current combined size of these bootstrap binaries is about 250MB
28490 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
28491 these is next to impossible.
28493 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
28494 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
28495 Bootstrap'' and while we are working towards that goal it would be hyperbole
28496 to use that term for what we do now.}.
28498 The Reduced Binary Seed bootstrap removes the most critical tools---from a
28499 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
28500 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
28501 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
28502 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
28503 these new binary seeds and a new set of
28505 packages@footnote{@c
28520 gcc-mesboot1-wrapper,
28521 glibc-headers-mesboot,
28525 gcc-mesboot-wrapper.
28528 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
28529 From here on the more traditional bootstrap process resumes. This approach
28530 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
28531 reduce this further. If you are interested, join us on @code{#bootstrappable}
28532 on the Freenode IRC network.
28534 @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
28535 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
28537 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
28538 compiler used to build the rest of GuixSD.
28540 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
28542 @node Preparing to Use the Bootstrap Binaries
28543 @section Preparing to Use the Bootstrap Binaries
28545 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
28546 @c large image, it's hard to scroll. Oh well.
28547 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
28549 The figure above shows the very beginning of the dependency graph of the
28550 distribution, corresponding to the package definitions of the @code{(gnu
28551 packages bootstrap)} module. A similar figure can be generated with
28552 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
28555 guix graph -t derivation \
28556 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
28557 | dot -Tps > gcc.ps
28560 or, for the Reduced Binary Seed bootstrap
28563 guix graph -t derivation \
28564 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
28565 | dot -Tps > mes.ps
28568 At this level of detail, things are
28569 slightly complex. First, Guile itself consists of an ELF executable,
28570 along with many source and compiled Scheme files that are dynamically
28571 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
28572 tarball shown in this graph. This tarball is part of Guix's ``source''
28573 distribution, and gets inserted into the store with @code{add-to-store}
28574 (@pxref{The Store}).
28576 But how do we write a derivation that unpacks this tarball and adds it
28577 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
28578 derivation---the first one that gets built---uses @code{bash} as its
28579 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
28580 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
28581 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
28582 the Guix source distribution, whose sole purpose is to allow the Guile
28583 tarball to be unpacked.
28585 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
28586 Guile that can be used to run subsequent build programs. Its first task
28587 is to download tarballs containing the other pre-built binaries---this
28588 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
28589 @code{ftp-client.scm} are used for this purpose. The
28590 @code{module-import.drv} derivations import those modules in a directory
28591 in the store, using the original layout. The
28592 @code{module-import-compiled.drv} derivations compile those modules, and
28593 write them in an output directory with the right layout. This
28594 corresponds to the @code{#:modules} argument of
28595 @code{build-expression->derivation} (@pxref{Derivations}).
28597 Finally, the various tarballs are unpacked by the derivations
28598 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
28599 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
28600 point we have a working C tool chain.
28602 @unnumberedsec Building the Build Tools
28604 Bootstrapping is complete when we have a full tool chain that does not
28605 depend on the pre-built bootstrap tools discussed above. This
28606 no-dependency requirement is verified by checking whether the files of
28607 the final tool chain contain references to the @file{/gnu/store}
28608 directories of the bootstrap inputs. The process that leads to this
28609 ``final'' tool chain is described by the package definitions found in
28610 the @code{(gnu packages commencement)} module.
28612 The @command{guix graph} command allows us to ``zoom out'' compared to
28613 the graph above, by looking at the level of package objects instead of
28614 individual derivations---remember that a package may translate to
28615 several derivations, typically one derivation to download its source,
28616 one to build the Guile modules it needs, and one to actually build the
28617 package from source. The command:
28620 guix graph -t bag \
28621 -e '(@@@@ (gnu packages commencement)
28622 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
28626 produces the dependency graph leading to the ``final'' C
28627 library@footnote{You may notice the @code{glibc-intermediate} label,
28628 suggesting that it is not @emph{quite} final, but as a good
28629 approximation, we will consider it final.}, depicted below.
28631 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
28633 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
28634 The first tool that gets built with the bootstrap binaries is
28635 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
28636 for all the following packages. From there Findutils and Diffutils get
28639 Then come the first-stage Binutils and GCC, built as pseudo cross
28640 tools---i.e., with @code{--target} equal to @code{--host}. They are
28641 used to build libc. Thanks to this cross-build trick, this libc is
28642 guaranteed not to hold any reference to the initial tool chain.
28644 From there the final Binutils and GCC (not shown above) are built.
28646 from the final Binutils, and links programs against the just-built libc.
28647 This tool chain is used to build the other packages used by Guix and by
28648 the GNU Build System: Guile, Bash, Coreutils, etc.
28650 And voilà! At this point we have the complete set of build tools that
28651 the GNU Build System expects. These are in the @code{%final-inputs}
28652 variable of the @code{(gnu packages commencement)} module, and are
28653 implicitly used by any package that uses @code{gnu-build-system}
28654 (@pxref{Build Systems, @code{gnu-build-system}}).
28657 @unnumberedsec Building the Bootstrap Binaries
28659 @cindex bootstrap binaries
28660 Because the final tool chain does not depend on the bootstrap binaries,
28661 those rarely need to be updated. Nevertheless, it is useful to have an
28662 automated way to produce them, should an update occur, and this is what
28663 the @code{(gnu packages make-bootstrap)} module provides.
28665 The following command builds the tarballs containing the bootstrap binaries
28666 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
28667 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
28668 and Guile, and a tarball containing a mixture of Coreutils and other basic
28669 command-line tools):
28672 guix build bootstrap-tarballs
28675 The generated tarballs are those that should be referred to in the
28676 @code{(gnu packages bootstrap)} module mentioned at the beginning of
28679 Still here? Then perhaps by now you've started to wonder: when do we
28680 reach a fixed point? That is an interesting question! The answer is
28681 unknown, but if you would like to investigate further (and have
28682 significant computational and storage resources to do so), then let us
28685 @unnumberedsec Reducing the Set of Bootstrap Binaries
28687 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
28688 binary code! Why is that a problem? It's a problem because these big chunks
28689 of binary code are practically non-auditable, which makes it hard to establish
28690 what source code produced them. Every unauditable binary also leaves us
28691 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
28692 paper @emph{Reflections on Trusting Trust}.
28694 This is mitigated by the fact that our bootstrap binaries were generated
28695 from an earlier Guix revision. Nevertheless it lacks the level of
28696 transparency that we get in the rest of the package dependency graph,
28697 where Guix always gives us a source-to-binary mapping. Thus, our goal
28698 is to reduce the set of bootstrap binaries to the bare minimum.
28700 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
28701 on-going projects to do that. One of these is about replacing the
28702 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
28703 of increasing complexity, which could be built from source starting from
28704 a simple and auditable assembler.
28706 Our first major achievement is the replacement of of GCC, the GNU C Library
28707 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
28708 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
28709 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
28710 bootstrapped yet and thus we inject them as binary seeds. We call this the
28711 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
28712 binaries! Also, it has eliminated the C compiler binary; i686-linux and
28713 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
28715 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
28716 also looking at any other bootstrap binaries. Your help is welcome!
28719 @chapter Porting to a New Platform
28721 As discussed above, the GNU distribution is self-contained, and
28722 self-containment is achieved by relying on pre-built ``bootstrap
28723 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
28724 operating system kernel, CPU architecture, and application binary
28725 interface (ABI). Thus, to port the distribution to a platform that is
28726 not yet supported, one must build those bootstrap binaries, and update
28727 the @code{(gnu packages bootstrap)} module to use them on that platform.
28729 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
28730 When everything goes well, and assuming the GNU tool chain supports the
28731 target platform, this can be as simple as running a command like this
28735 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
28738 For this to work, the @code{glibc-dynamic-linker} procedure in
28739 @code{(gnu packages bootstrap)} must be augmented to return the right
28740 file name for libc's dynamic linker on that platform; likewise,
28741 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
28742 taught about the new platform.
28744 Once these are built, the @code{(gnu packages bootstrap)} module needs
28745 to be updated to refer to these binaries on the target platform. That
28746 is, the hashes and URLs of the bootstrap tarballs for the new platform
28747 must be added alongside those of the currently supported platforms. The
28748 bootstrap Guile tarball is treated specially: it is expected to be
28749 available locally, and @file{gnu/local.mk} has rules to download it for
28750 the supported architectures; a rule for the new platform must be added
28753 In practice, there may be some complications. First, it may be that the
28754 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
28755 above) is not recognized by all the GNU tools. Typically, glibc
28756 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
28757 configure flag (see @code{gcc.scm} for examples of how to handle this).
28758 Second, some of the required packages could fail to build for that
28759 platform. Lastly, the generated binaries could be broken for some
28762 @c *********************************************************************
28763 @include contributing.texi
28765 @c *********************************************************************
28766 @node Acknowledgments
28767 @chapter Acknowledgments
28769 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
28770 which was designed and
28771 implemented by Eelco Dolstra, with contributions from other people (see
28772 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
28773 management, and promoted unprecedented features, such as transactional
28774 package upgrades and rollbacks, per-user profiles, and referentially
28775 transparent build processes. Without this work, Guix would not exist.
28777 The Nix-based software distributions, Nixpkgs and NixOS, have also been
28778 an inspiration for Guix.
28780 GNU@tie{}Guix itself is a collective work with contributions from a
28781 number of people. See the @file{AUTHORS} file in Guix for more
28782 information on these fine people. The @file{THANKS} file lists people
28783 who have helped by reporting bugs, taking care of the infrastructure,
28784 providing artwork and themes, making suggestions, and more---thank you!
28787 @c *********************************************************************
28788 @node GNU Free Documentation License
28789 @appendix GNU Free Documentation License
28790 @cindex license, GNU Free Documentation License
28791 @include fdl-1.3.texi
28793 @c *********************************************************************
28794 @node Concept Index
28795 @unnumbered Concept Index
28798 @node Programming Index
28799 @unnumbered Programming Index
28800 @syncodeindex tp fn
28801 @syncodeindex vr fn
28806 @c Local Variables:
28807 @c ispell-local-dictionary: "american";