6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017, 2019 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 ng0@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018 Marius Bakke@*
50 Copyright @copyright{} 2017 Hartmut Goebel@*
51 Copyright @copyright{} 2017 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
70 Permission is granted to copy, distribute and/or modify this document
71 under the terms of the GNU Free Documentation License, Version 1.3 or
72 any later version published by the Free Software Foundation; with no
73 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
74 copy of the license is included in the section entitled ``GNU Free
75 Documentation License''.
78 @dircategory System administration
80 * Guix: (guix). Manage installed software and system configuration.
81 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
82 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
83 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
84 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
85 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
88 @dircategory Software development
90 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
91 * guix build: (guix)Invoking guix build. Building packages.
92 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
96 @title GNU Guix Reference Manual
97 @subtitle Using the GNU Guix Functional Package Manager
98 @author The GNU Guix Developers
101 @vskip 0pt plus 1filll
102 Edition @value{EDITION} @*
110 @c *********************************************************************
114 This document describes GNU Guix version @value{VERSION}, a functional
115 package management tool written for the GNU system.
117 @c TRANSLATORS: You can replace the following paragraph with information on
118 @c how to join your own translation team and how to report issues with the
120 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
121 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
122 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
123 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
124 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
125 would like to translate it in your native language, consider joining the
126 @uref{https://translationproject.org/domain/guix-manual.html, Translation
130 * Introduction:: What is Guix about?
131 * Installation:: Installing Guix.
132 * System Installation:: Installing the whole operating system.
133 * Package Management:: Package installation, upgrade, etc.
134 * Development:: Guix-aided software development.
135 * Programming Interface:: Using Guix in Scheme.
136 * Utilities:: Package management commands.
137 * System Configuration:: Configuring the operating system.
138 * Documentation:: Browsing software user manuals.
139 * Installing Debugging Files:: Feeding the debugger.
140 * Security Updates:: Deploying security fixes quickly.
141 * Bootstrapping:: GNU/Linux built from scratch.
142 * Porting:: Targeting another platform or kernel.
143 * Contributing:: Your help needed!
145 * Acknowledgments:: Thanks!
146 * GNU Free Documentation License:: The license of this manual.
147 * Concept Index:: Concepts.
148 * Programming Index:: Data types, functions, and variables.
151 --- The Detailed Node Listing ---
155 * Managing Software the Guix Way:: What's special.
156 * GNU Distribution:: The packages and tools.
160 * Binary Installation:: Getting Guix running in no time!
161 * Requirements:: Software needed to build and run Guix.
162 * Running the Test Suite:: Testing Guix.
163 * Setting Up the Daemon:: Preparing the build daemon's environment.
164 * Invoking guix-daemon:: Running the build daemon.
165 * Application Setup:: Application-specific setup.
167 Setting Up the Daemon
169 * Build Environment Setup:: Preparing the isolated build environment.
170 * Daemon Offload Setup:: Offloading builds to remote machines.
171 * SELinux Support:: Using an SELinux policy for the daemon.
175 * Limitations:: What you can expect.
176 * Hardware Considerations:: Supported hardware.
177 * USB Stick and DVD Installation:: Preparing the installation medium.
178 * Preparing for Installation:: Networking, partitioning, etc.
179 * Guided Graphical Installation:: Easy graphical installation.
180 * Manual Installation:: Manual installation for wizards.
181 * After System Installation:: When installation succeeded.
182 * Installing Guix in a VM:: Guix System playground.
183 * Building the Installation Image:: How this comes to be.
187 * Keyboard Layout and Networking and Partitioning:: Initial setup.
188 * Proceeding with the Installation:: Installing.
192 * Features:: How Guix will make your life brighter.
193 * Invoking guix package:: Package installation, removal, etc.
194 * Substitutes:: Downloading pre-built binaries.
195 * Packages with Multiple Outputs:: Single source package, multiple outputs.
196 * Invoking guix gc:: Running the garbage collector.
197 * Invoking guix pull:: Fetching the latest Guix and distribution.
198 * Channels:: Customizing the package collection.
199 * Inferiors:: Interacting with another revision of Guix.
200 * Invoking guix describe:: Display information about your Guix revision.
201 * Invoking guix archive:: Exporting and importing store files.
205 * Official Substitute Server:: One particular source of substitutes.
206 * Substitute Server Authorization:: How to enable or disable substitutes.
207 * Substitute Authentication:: How Guix verifies substitutes.
208 * Proxy Settings:: How to get substitutes via proxy.
209 * Substitution Failure:: What happens when substitution fails.
210 * On Trusting Binaries:: How can you trust that binary blob?
214 * Invoking guix environment:: Setting up development environments.
215 * Invoking guix pack:: Creating software bundles.
217 Programming Interface
219 * Package Modules:: Packages from the programmer's viewpoint.
220 * Defining Packages:: Defining new packages.
221 * Build Systems:: Specifying how packages are built.
222 * The Store:: Manipulating the package store.
223 * Derivations:: Low-level interface to package derivations.
224 * The Store Monad:: Purely functional interface to the store.
225 * G-Expressions:: Manipulating build expressions.
226 * Invoking guix repl:: Fiddling with Guix interactively.
230 * package Reference:: The package data type.
231 * origin Reference:: The origin data type.
235 * Invoking guix build:: Building packages from the command line.
236 * Invoking guix edit:: Editing package definitions.
237 * Invoking guix download:: Downloading a file and printing its hash.
238 * Invoking guix hash:: Computing the cryptographic hash of a file.
239 * Invoking guix import:: Importing package definitions.
240 * Invoking guix refresh:: Updating package definitions.
241 * Invoking guix lint:: Finding errors in package definitions.
242 * Invoking guix size:: Profiling disk usage.
243 * Invoking guix graph:: Visualizing the graph of packages.
244 * Invoking guix publish:: Sharing substitutes.
245 * Invoking guix challenge:: Challenging substitute servers.
246 * Invoking guix copy:: Copying to and from a remote store.
247 * Invoking guix container:: Process isolation.
248 * Invoking guix weather:: Assessing substitute availability.
249 * Invoking guix processes:: Listing client processes.
251 Invoking @command{guix build}
253 * Common Build Options:: Build options for most commands.
254 * Package Transformation Options:: Creating variants of packages.
255 * Additional Build Options:: Options specific to 'guix build'.
256 * Debugging Build Failures:: Real life packaging experience.
260 * Using the Configuration System:: Customizing your GNU system.
261 * operating-system Reference:: Detail of operating-system declarations.
262 * File Systems:: Configuring file system mounts.
263 * Mapped Devices:: Block device extra processing.
264 * User Accounts:: Specifying user accounts.
265 * Keyboard Layout:: How the system interprets key strokes.
266 * Locales:: Language and cultural convention settings.
267 * Services:: Specifying system services.
268 * Setuid Programs:: Programs running with root privileges.
269 * X.509 Certificates:: Authenticating HTTPS servers.
270 * Name Service Switch:: Configuring libc's name service switch.
271 * Initial RAM Disk:: Linux-Libre bootstrapping.
272 * Bootloader Configuration:: Configuring the boot loader.
273 * Invoking guix system:: Instantiating a system configuration.
274 * Invoking guix deploy:: Deploying a system configuration to a remote host.
275 * Running Guix in a VM:: How to run Guix System in a virtual machine.
276 * Defining Services:: Adding new service definitions.
280 * Base Services:: Essential system services.
281 * Scheduled Job Execution:: The mcron service.
282 * Log Rotation:: The rottlog service.
283 * Networking Services:: Network setup, SSH daemon, etc.
284 * X Window:: Graphical display.
285 * Printing Services:: Local and remote printer support.
286 * Desktop Services:: D-Bus and desktop services.
287 * Sound Services:: ALSA and Pulseaudio services.
288 * Database Services:: SQL databases, key-value stores, etc.
289 * Mail Services:: IMAP, POP3, SMTP, and all that.
290 * Messaging Services:: Messaging services.
291 * Telephony Services:: Telephony services.
292 * Monitoring Services:: Monitoring services.
293 * Kerberos Services:: Kerberos services.
294 * Web Services:: Web servers.
295 * Certificate Services:: TLS certificates via Let's Encrypt.
296 * DNS Services:: DNS daemons.
297 * VPN Services:: VPN daemons.
298 * Network File System:: NFS related services.
299 * Continuous Integration:: The Cuirass service.
300 * Power Management Services:: Extending battery life.
301 * Audio Services:: The MPD.
302 * Virtualization Services:: Virtualization services.
303 * Version Control Services:: Providing remote access to Git repositories.
304 * Game Services:: Game servers.
305 * Miscellaneous Services:: Other services.
309 * Service Composition:: The model for composing services.
310 * Service Types and Services:: Types and services.
311 * Service Reference:: API reference.
312 * Shepherd Services:: A particular type of service.
317 @c *********************************************************************
319 @chapter Introduction
322 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
323 using the international phonetic alphabet (IPA).} is a package
324 management tool for and distribution of the GNU system.
325 Guix makes it easy for unprivileged
326 users to install, upgrade, or remove software packages, to roll back to a
327 previous package set, to build packages from source, and generally
328 assists with the creation and maintenance of software environments.
331 @cindex GuixSD, now Guix System
332 @cindex Guix System Distribution, now Guix System
333 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
334 complements the available tools without interference (@pxref{Installation}),
335 or you can use it as a standalone operating system distribution,
336 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
337 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
338 group everything under the ``Guix'' banner since, after all, Guix System is
339 readily available through the @command{guix system} command, even if you're
340 using a different distro underneath!}. @xref{GNU Distribution}.
343 * Managing Software the Guix Way:: What's special.
344 * GNU Distribution:: The packages and tools.
347 @node Managing Software the Guix Way
348 @section Managing Software the Guix Way
350 @cindex user interfaces
351 Guix provides a command-line package management interface
352 (@pxref{Package Management}), tools to help with software development
353 (@pxref{Development}), command-line utilities for more advanced usage,
354 (@pxref{Utilities}), as well as Scheme programming interfaces
355 (@pxref{Programming Interface}).
357 Its @dfn{build daemon} is responsible for building packages on behalf of
358 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
359 binaries from authorized sources (@pxref{Substitutes}).
361 @cindex extensibility of the distribution
362 @cindex customization, of packages
363 Guix includes package definitions for many GNU and non-GNU packages, all
364 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
365 user's computing freedom}. It is @emph{extensible}: users can write
366 their own package definitions (@pxref{Defining Packages}) and make them
367 available as independent package modules (@pxref{Package Modules}). It
368 is also @emph{customizable}: users can @emph{derive} specialized package
369 definitions from existing ones, including from the command line
370 (@pxref{Package Transformation Options}).
372 @cindex functional package management
374 Under the hood, Guix implements the @dfn{functional package management}
375 discipline pioneered by Nix (@pxref{Acknowledgments}).
376 In Guix, the package build and installation process is seen
377 as a @emph{function}, in the mathematical sense. That function takes inputs,
378 such as build scripts, a compiler, and libraries, and
379 returns an installed package. As a pure function, its result depends
380 solely on its inputs---for instance, it cannot refer to software or
381 scripts that were not explicitly passed as inputs. A build function
382 always produces the same result when passed a given set of inputs. It
383 cannot alter the environment of the running system in
384 any way; for instance, it cannot create, modify, or delete files outside
385 of its build and installation directories. This is achieved by running
386 build processes in isolated environments (or @dfn{containers}), where only their
387 explicit inputs are visible.
390 The result of package build functions is @dfn{cached} in the file
391 system, in a special directory called @dfn{the store} (@pxref{The
392 Store}). Each package is installed in a directory of its own in the
393 store---by default under @file{/gnu/store}. The directory name contains
394 a hash of all the inputs used to build that package; thus, changing an
395 input yields a different directory name.
397 This approach is the foundation for the salient features of Guix: support
398 for transactional package upgrade and rollback, per-user installation, and
399 garbage collection of packages (@pxref{Features}).
402 @node GNU Distribution
403 @section GNU Distribution
406 Guix comes with a distribution of the GNU system consisting entirely of
407 free software@footnote{The term ``free'' here refers to the
408 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
409 users of that software}.}. The
410 distribution can be installed on its own (@pxref{System Installation}),
411 but it is also possible to install Guix as a package manager on top of
412 an installed GNU/Linux system (@pxref{Installation}). When we need to
413 distinguish between the two, we refer to the standalone distribution as
416 The distribution provides core GNU packages such as GNU libc, GCC, and
417 Binutils, as well as many GNU and non-GNU applications. The complete
418 list of available packages can be browsed
419 @url{https://www.gnu.org/software/guix/packages,on-line} or by
420 running @command{guix package} (@pxref{Invoking guix package}):
423 guix package --list-available
426 Our goal is to provide a practical 100% free software distribution of
427 Linux-based and other variants of GNU, with a focus on the promotion and
428 tight integration of GNU components, and an emphasis on programs and
429 tools that help users exert that freedom.
431 Packages are currently available on the following platforms:
436 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
439 Intel 32-bit architecture (IA32), Linux-Libre kernel;
442 ARMv7-A architecture with hard float, Thumb-2 and NEON,
443 using the EABI hard-float application binary interface (ABI),
444 and Linux-Libre kernel.
447 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
450 little-endian 64-bit MIPS processors, specifically the Loongson series,
451 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
452 supported; in particular, the project's build farms no longer provide
453 substitutes for this architecture.
457 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
458 configuration and Guix takes care of instantiating the configuration in a
459 transactional, reproducible, and stateless fashion (@pxref{System
460 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
461 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
462 Manual}), the well-known GNU utilities and tool chain, as well as the
463 graphical environment or system services of your choice.
465 Guix System is available on all the above platforms except
466 @code{mips64el-linux}.
469 For information on porting to other architectures or kernels,
472 Building this distribution is a cooperative effort, and you are invited
473 to join! @xref{Contributing}, for information about how you can help.
476 @c *********************************************************************
478 @chapter Installation
480 @cindex installing Guix
483 We recommend the use of this
484 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
485 shell installer script} to install Guix on top of a running GNU/Linux system,
486 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
487 with the installation of the package manager, which can be done on top of a
488 running GNU/Linux system. If, instead, you want to install the complete GNU
489 operating system, @pxref{System Installation}.} The script automates the
490 download, installation, and initial configuration of Guix. It should be run
494 @cindex foreign distro
495 @cindex directories related to foreign distro
496 When installed on a foreign distro, GNU@tie{}Guix complements the available
497 tools without interference. Its data lives exclusively in two directories,
498 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
499 such as @file{/etc}, are left untouched.
501 Once installed, Guix can be updated by running @command{guix pull}
502 (@pxref{Invoking guix pull}).
504 If you prefer to perform the installation steps manually or want to tweak
505 them, you may find the following subsections useful. They describe the
506 software requirements of Guix, as well as how to install it manually and get
510 * Binary Installation:: Getting Guix running in no time!
511 * Requirements:: Software needed to build and run Guix.
512 * Running the Test Suite:: Testing Guix.
513 * Setting Up the Daemon:: Preparing the build daemon's environment.
514 * Invoking guix-daemon:: Running the build daemon.
515 * Application Setup:: Application-specific setup.
518 @node Binary Installation
519 @section Binary Installation
521 @cindex installing Guix from binaries
522 @cindex installer script
523 This section describes how to install Guix on an arbitrary system from a
524 self-contained tarball providing binaries for Guix and for all its
525 dependencies. This is often quicker than installing from source, which
526 is described in the next sections. The only requirement is to have
529 @c Note duplicated from the ``Installation'' node.
531 We recommend the use of this
532 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
533 shell installer script}. The script automates the download, installation, and
534 initial configuration steps described below. It should be run as the root
538 Installing goes along these lines:
542 @cindex downloading Guix binary
543 Download the binary tarball from
544 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
545 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
546 already running the kernel Linux, and so on.
548 @c The following is somewhat duplicated in ``System Installation''.
549 Make sure to download the associated @file{.sig} file and to verify the
550 authenticity of the tarball against it, along these lines:
553 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
554 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
557 If that command fails because you do not have the required public key,
558 then run this command to import it:
561 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
562 -qO - | gpg --import -
566 and rerun the @code{gpg --verify} command.
568 Take note that a warning like ``This key is not certified with a trusted
569 signature!'' is normal.
571 @c end authentication part
574 Now, you need to become the @code{root} user. Depending on your distribution,
575 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
579 # tar --warning=no-timestamp -xf \
580 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
581 # mv var/guix /var/ && mv gnu /
584 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
585 The latter contains a ready-to-use profile for @code{root} (see next
588 Do @emph{not} unpack the tarball on a working Guix system since that
589 would overwrite its own essential files.
591 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
592 not emit warnings about ``implausibly old time stamps'' (such
593 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
595 They stem from the fact that all the
596 files in the archive have their modification time set to zero (which
597 means January 1st, 1970.) This is done on purpose to make sure the
598 archive content is independent of its creation time, thus making it
602 Make the profile available under @file{~root/.config/guix/current}, which is
603 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
606 # mkdir -p ~root/.config/guix
607 # ln -sf /var/guix/profiles/per-user/root/current-guix \
608 ~root/.config/guix/current
611 Source @file{etc/profile} to augment @code{PATH} and other relevant
612 environment variables:
615 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
616 source $GUIX_PROFILE/etc/profile
620 Create the group and user accounts for build users as explained below
621 (@pxref{Build Environment Setup}).
624 Run the daemon, and set it to automatically start on boot.
626 If your host distro uses the systemd init system, this can be achieved
629 @c Versions of systemd that supported symlinked service files are not
630 @c yet widely deployed, so we should suggest that users copy the service
633 @c See this thread for more information:
634 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
637 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
639 # systemctl start guix-daemon && systemctl enable guix-daemon
642 If your host distro uses the Upstart init system:
645 # initctl reload-configuration
646 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
651 Otherwise, you can still start the daemon manually with:
654 # ~root/.config/guix/current/bin/guix-daemon \
655 --build-users-group=guixbuild
659 Make the @command{guix} command available to other users on the machine,
663 # mkdir -p /usr/local/bin
665 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
668 It is also a good idea to make the Info version of this manual available
672 # mkdir -p /usr/local/share/info
673 # cd /usr/local/share/info
674 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
678 That way, assuming @file{/usr/local/share/info} is in the search path,
679 running @command{info guix} will open this manual (@pxref{Other Info
680 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
684 @cindex substitutes, authorization thereof
685 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
686 (@pxref{Substitutes}), authorize them:
689 # guix archive --authorize < \
690 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
694 Each user may need to perform a few additional steps to make their Guix
695 environment ready for use, @pxref{Application Setup}.
698 Voilà, the installation is complete!
700 You can confirm that Guix is working by installing a sample package into
707 The binary installation tarball can be (re)produced and verified simply
708 by running the following command in the Guix source tree:
711 make guix-binary.@var{system}.tar.xz
715 ...@: which, in turn, runs:
718 guix pack -s @var{system} --localstatedir \
719 --profile-name=current-guix guix
722 @xref{Invoking guix pack}, for more info on this handy tool.
725 @section Requirements
727 This section lists requirements when building Guix from source. The
728 build procedure for Guix is the same as for other GNU software, and is
729 not covered here. Please see the files @file{README} and @file{INSTALL}
730 in the Guix source tree for additional details.
732 @cindex official website
733 GNU Guix is available for download from its website at
734 @url{https://www.gnu.org/software/guix/}.
736 GNU Guix depends on the following packages:
739 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
740 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
743 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
744 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
745 Guile,, gnutls-guile, GnuTLS-Guile});
747 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
750 @c FIXME: Specify a version number once a release has been made.
751 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
753 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
754 @item @url{https://zlib.net, zlib};
755 @item @url{https://www.gnu.org/software/make/, GNU Make}.
758 The following dependencies are optional:
762 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
763 Support for build offloading (@pxref{Daemon Offload Setup}) and
764 @command{guix copy} (@pxref{Invoking guix copy}) depends on
765 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
766 version 0.10.2 or later.
769 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
770 substitutes can be used and @command{guix publish} can compress substitutes
774 When @url{http://www.bzip.org, libbz2} is available,
775 @command{guix-daemon} can use it to compress build logs.
778 Unless @code{--disable-daemon} was passed to @command{configure}, the
779 following packages are also needed:
782 @item @url{https://gnupg.org/, GNU libgcrypt};
783 @item @url{https://sqlite.org, SQLite 3};
784 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
788 @cindex state directory
789 When configuring Guix on a system that already has a Guix installation,
790 be sure to specify the same state directory as the existing installation
791 using the @code{--localstatedir} option of the @command{configure}
792 script (@pxref{Directory Variables, @code{localstatedir},, standards,
793 GNU Coding Standards}). The @command{configure} script protects against
794 unintended misconfiguration of @var{localstatedir} so you do not
795 inadvertently corrupt your store (@pxref{The Store}).
797 @cindex Nix, compatibility
798 When a working installation of @url{https://nixos.org/nix/, the Nix package
799 manager} is available, you
800 can instead configure Guix with @code{--disable-daemon}. In that case,
801 Nix replaces the three dependencies above.
803 Guix is compatible with Nix, so it is possible to share the same store
804 between both. To do so, you must pass @command{configure} not only the
805 same @code{--with-store-dir} value, but also the same
806 @code{--localstatedir} value. The latter is essential because it
807 specifies where the database that stores metadata about the store is
808 located, among other things. The default values for Nix are
809 @code{--with-store-dir=/nix/store} and @code{--localstatedir=/nix/var}.
810 Note that @code{--disable-daemon} is not required if
811 your goal is to share the store with Nix.
813 @node Running the Test Suite
814 @section Running the Test Suite
817 After a successful @command{configure} and @code{make} run, it is a good
818 idea to run the test suite. It can help catch issues with the setup or
819 environment, or bugs in Guix itself---and really, reporting test
820 failures is a good way to help improve the software. To run the test
827 Test cases can run in parallel: you can use the @code{-j} option of
828 GNU@tie{}make to speed things up. The first run may take a few minutes
829 on a recent machine; subsequent runs will be faster because the store
830 that is created for test purposes will already have various things in
833 It is also possible to run a subset of the tests by defining the
834 @code{TESTS} makefile variable as in this example:
837 make check TESTS="tests/store.scm tests/cpio.scm"
840 By default, tests results are displayed at a file level. In order to
841 see the details of every individual test cases, it is possible to define
842 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
845 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
848 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
849 @file{test-suite.log} file. Please specify the Guix version being used
850 as well as version numbers of the dependencies (@pxref{Requirements}) in
853 Guix also comes with a whole-system test suite that tests complete
854 Guix System instances. It can only run on systems where
855 Guix is already installed, using:
862 or, again, by defining @code{TESTS} to select a subset of tests to run:
865 make check-system TESTS="basic mcron"
868 These system tests are defined in the @code{(gnu tests @dots{})}
869 modules. They work by running the operating systems under test with
870 lightweight instrumentation in a virtual machine (VM). They can be
871 computationally intensive or rather cheap, depending on whether
872 substitutes are available for their dependencies (@pxref{Substitutes}).
873 Some of them require a lot of storage space to hold VM images.
875 Again in case of test failures, please send @email{bug-guix@@gnu.org}
878 @node Setting Up the Daemon
879 @section Setting Up the Daemon
882 Operations such as building a package or running the garbage collector
883 are all performed by a specialized process, the @dfn{build daemon}, on
884 behalf of clients. Only the daemon may access the store and its
885 associated database. Thus, any operation that manipulates the store
886 goes through the daemon. For instance, command-line tools such as
887 @command{guix package} and @command{guix build} communicate with the
888 daemon (@i{via} remote procedure calls) to instruct it what to do.
890 The following sections explain how to prepare the build daemon's
891 environment. See also @ref{Substitutes}, for information on how to allow
892 the daemon to download pre-built binaries.
895 * Build Environment Setup:: Preparing the isolated build environment.
896 * Daemon Offload Setup:: Offloading builds to remote machines.
897 * SELinux Support:: Using an SELinux policy for the daemon.
900 @node Build Environment Setup
901 @subsection Build Environment Setup
903 @cindex build environment
904 In a standard multi-user setup, Guix and its daemon---the
905 @command{guix-daemon} program---are installed by the system
906 administrator; @file{/gnu/store} is owned by @code{root} and
907 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
908 Guix tools to build packages or otherwise access the store, and the
909 daemon will do it on their behalf, ensuring that the store is kept in a
910 consistent state, and allowing built packages to be shared among users.
913 When @command{guix-daemon} runs as @code{root}, you may not want package
914 build processes themselves to run as @code{root} too, for obvious
915 security reasons. To avoid that, a special pool of @dfn{build users}
916 should be created for use by build processes started by the daemon.
917 These build users need not have a shell and a home directory: they will
918 just be used when the daemon drops @code{root} privileges in build
919 processes. Having several such users allows the daemon to launch
920 distinct build processes under separate UIDs, which guarantees that they
921 do not interfere with each other---an essential feature since builds are
922 regarded as pure functions (@pxref{Introduction}).
924 On a GNU/Linux system, a build user pool may be created like this (using
925 Bash syntax and the @code{shadow} commands):
927 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
928 @c for why `-G' is needed.
930 # groupadd --system guixbuild
931 # for i in `seq -w 1 10`;
933 useradd -g guixbuild -G guixbuild \
934 -d /var/empty -s `which nologin` \
935 -c "Guix build user $i" --system \
941 The number of build users determines how many build jobs may run in
942 parallel, as specified by the @option{--max-jobs} option
943 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
944 @command{guix system vm} and related commands, you may need to add the
945 build users to the @code{kvm} group so they can access @file{/dev/kvm},
946 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
947 (@pxref{Invoking guix system}).
949 The @code{guix-daemon} program may then be run as @code{root} with the
950 following command@footnote{If your machine uses the systemd init system,
951 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
952 file in @file{/etc/systemd/system} will ensure that
953 @command{guix-daemon} is automatically started. Similarly, if your
954 machine uses the Upstart init system, drop the
955 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
956 file in @file{/etc/init}.}:
959 # guix-daemon --build-users-group=guixbuild
964 This way, the daemon starts build processes in a chroot, under one of
965 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
966 environment contains nothing but:
968 @c Keep this list in sync with libstore/build.cc! -----------------------
971 a minimal @code{/dev} directory, created mostly independently from the
972 host @code{/dev}@footnote{``Mostly'', because while the set of files
973 that appear in the chroot's @code{/dev} is fixed, most of these files
974 can only be created if the host has them.};
977 the @code{/proc} directory; it only shows the processes of the container
978 since a separate PID name space is used;
981 @file{/etc/passwd} with an entry for the current user and an entry for
985 @file{/etc/group} with an entry for the user's group;
988 @file{/etc/hosts} with an entry that maps @code{localhost} to
992 a writable @file{/tmp} directory.
995 You can influence the directory where the daemon stores build trees
996 @i{via} the @code{TMPDIR} environment variable. However, the build tree
997 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
998 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
999 This way, the value of @code{TMPDIR} does not leak inside build
1000 environments, which avoids discrepancies in cases where build processes
1001 capture the name of their build tree.
1004 The daemon also honors the @code{http_proxy} environment variable for
1005 HTTP downloads it performs, be it for fixed-output derivations
1006 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
1008 If you are installing Guix as an unprivileged user, it is still possible
1009 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
1010 However, build processes will not be isolated from one another, and not
1011 from the rest of the system. Thus, build processes may interfere with
1012 each other, and may access programs, libraries, and other files
1013 available on the system---making it much harder to view them as
1014 @emph{pure} functions.
1017 @node Daemon Offload Setup
1018 @subsection Using the Offload Facility
1022 When desired, the build daemon can @dfn{offload} derivation builds to
1023 other machines running Guix, using the @code{offload} @dfn{build
1024 hook}@footnote{This feature is available only when
1025 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1026 present.}. When that
1027 feature is enabled, a list of user-specified build machines is read from
1028 @file{/etc/guix/machines.scm}; every time a build is requested, for
1029 instance via @code{guix build}, the daemon attempts to offload it to one
1030 of the machines that satisfy the constraints of the derivation, in
1031 particular its system type---e.g., @file{x86_64-linux}. Missing
1032 prerequisites for the build are copied over SSH to the target machine,
1033 which then proceeds with the build; upon success the output(s) of the
1034 build are copied back to the initial machine.
1036 The @file{/etc/guix/machines.scm} file typically looks like this:
1039 (list (build-machine
1040 (name "eightysix.example.org")
1041 (system "x86_64-linux")
1042 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1044 (speed 2.)) ;incredibly fast!
1047 (name "meeps.example.org")
1048 (system "mips64el-linux")
1049 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1052 (string-append (getenv "HOME")
1053 "/.ssh/identity-for-guix"))))
1057 In the example above we specify a list of two build machines, one for
1058 the @code{x86_64} architecture and one for the @code{mips64el}
1061 In fact, this file is---not surprisingly!---a Scheme file that is
1062 evaluated when the @code{offload} hook is started. Its return value
1063 must be a list of @code{build-machine} objects. While this example
1064 shows a fixed list of build machines, one could imagine, say, using
1065 DNS-SD to return a list of potential build machines discovered in the
1066 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1067 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1070 @deftp {Data Type} build-machine
1071 This data type represents build machines to which the daemon may offload
1072 builds. The important fields are:
1077 The host name of the remote machine.
1080 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1083 The user account to use when connecting to the remote machine over SSH.
1084 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1085 allow non-interactive logins.
1088 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1089 This is used to authenticate the machine when we connect to it. It is a
1090 long string that looks like this:
1093 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1096 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1097 key can be found in a file such as
1098 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1100 If the machine is running the SSH daemon of GNU@tie{}lsh,
1101 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1102 similar file. It can be converted to the OpenSSH format using
1103 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1106 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1107 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1112 A number of optional fields may be specified:
1116 @item @code{port} (default: @code{22})
1117 Port number of SSH server on the machine.
1119 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1120 The SSH private key file to use when connecting to the machine, in
1121 OpenSSH format. This key must not be protected with a passphrase.
1123 Note that the default value is the private key @emph{of the root
1124 account}. Make sure it exists if you use the default.
1126 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1127 @itemx @code{compression-level} (default: @code{3})
1128 The SSH-level compression methods and compression level requested.
1130 Note that offloading relies on SSH compression to reduce bandwidth usage
1131 when transferring files to and from build machines.
1133 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1134 File name of the Unix-domain socket @command{guix-daemon} is listening
1137 @item @code{parallel-builds} (default: @code{1})
1138 The number of builds that may run in parallel on the machine.
1140 @item @code{speed} (default: @code{1.0})
1141 A ``relative speed factor''. The offload scheduler will tend to prefer
1142 machines with a higher speed factor.
1144 @item @code{features} (default: @code{'()})
1145 A list of strings denoting specific features supported by the machine.
1146 An example is @code{"kvm"} for machines that have the KVM Linux modules
1147 and corresponding hardware support. Derivations can request features by
1148 name, and they will be scheduled on matching build machines.
1153 The @command{guix} command must be in the search path on the build
1154 machines. You can check whether this is the case by running:
1157 ssh build-machine guix repl --version
1160 There is one last thing to do once @file{machines.scm} is in place. As
1161 explained above, when offloading, files are transferred back and forth
1162 between the machine stores. For this to work, you first need to
1163 generate a key pair on each machine to allow the daemon to export signed
1164 archives of files from the store (@pxref{Invoking guix archive}):
1167 # guix archive --generate-key
1171 Each build machine must authorize the key of the master machine so that
1172 it accepts store items it receives from the master:
1175 # guix archive --authorize < master-public-key.txt
1179 Likewise, the master machine must authorize the key of each build machine.
1181 All the fuss with keys is here to express pairwise mutual trust
1182 relations between the master and the build machines. Concretely, when
1183 the master receives files from a build machine (and @i{vice versa}), its
1184 build daemon can make sure they are genuine, have not been tampered
1185 with, and that they are signed by an authorized key.
1187 @cindex offload test
1188 To test whether your setup is operational, run this command on the
1195 This will attempt to connect to each of the build machines specified in
1196 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1197 available on each machine, attempt to export to the machine and import
1198 from it, and report any error in the process.
1200 If you want to test a different machine file, just specify it on the
1204 # guix offload test machines-qualif.scm
1207 Last, you can test the subset of the machines whose name matches a
1208 regular expression like this:
1211 # guix offload test machines.scm '\.gnu\.org$'
1214 @cindex offload status
1215 To display the current load of all build hosts, run this command on the
1219 # guix offload status
1223 @node SELinux Support
1224 @subsection SELinux Support
1226 @cindex SELinux, daemon policy
1227 @cindex mandatory access control, SELinux
1228 @cindex security, guix-daemon
1229 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1230 can be installed on a system where SELinux is enabled, in order to label
1231 Guix files and to specify the expected behavior of the daemon. Since
1232 Guix System does not provide an SELinux base policy, the daemon policy cannot
1233 be used on Guix System.
1235 @subsubsection Installing the SELinux policy
1236 @cindex SELinux, policy installation
1237 To install the policy run this command as root:
1240 semodule -i etc/guix-daemon.cil
1243 Then relabel the file system with @code{restorecon} or by a different
1244 mechanism provided by your system.
1246 Once the policy is installed, the file system has been relabeled, and
1247 the daemon has been restarted, it should be running in the
1248 @code{guix_daemon_t} context. You can confirm this with the following
1252 ps -Zax | grep guix-daemon
1255 Monitor the SELinux log files as you run a command like @code{guix build
1256 hello} to convince yourself that SELinux permits all necessary
1259 @subsubsection Limitations
1260 @cindex SELinux, limitations
1262 This policy is not perfect. Here is a list of limitations or quirks
1263 that should be considered when deploying the provided SELinux policy for
1268 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1269 operations involve contexts that have anything to do with
1270 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1271 but it would be preferrable to define socket rules for only this label.
1274 @code{guix gc} cannot access arbitrary links to profiles. By design,
1275 the file label of the destination of a symlink is independent of the
1276 file label of the link itself. Although all profiles under
1277 $localstatedir are labelled, the links to these profiles inherit the
1278 label of the directory they are in. For links in the user’s home
1279 directory this will be @code{user_home_t}. But for links from the root
1280 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1281 directory, etc, this won’t work. @code{guix gc} would be prevented from
1282 reading and following these links.
1285 The daemon’s feature to listen for TCP connections might no longer work.
1286 This might require extra rules, because SELinux treats network sockets
1287 differently from files.
1290 Currently all files with a name matching the regular expression
1291 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1292 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1293 that name in any profile would be permitted to run in the
1294 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1295 build a package that provides this executable and convince a user to
1296 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1297 At that point SELinux could not prevent it from accessing files that are
1298 allowed for processes in that domain.
1300 We could generate a much more restrictive policy at installation time,
1301 so that only the @emph{exact} file name of the currently installed
1302 @code{guix-daemon} executable would be labelled with
1303 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1304 The downside is that root would have to install or upgrade the policy at
1305 installation time whenever the Guix package that provides the
1306 effectively running @code{guix-daemon} executable is upgraded.
1309 @node Invoking guix-daemon
1310 @section Invoking @command{guix-daemon}
1312 The @command{guix-daemon} program implements all the functionality to
1313 access the store. This includes launching build processes, running the
1314 garbage collector, querying the availability of a build result, etc. It
1315 is normally run as @code{root} like this:
1318 # guix-daemon --build-users-group=guixbuild
1322 For details on how to set it up, @pxref{Setting Up the Daemon}.
1325 @cindex container, build environment
1326 @cindex build environment
1327 @cindex reproducible builds
1328 By default, @command{guix-daemon} launches build processes under
1329 different UIDs, taken from the build group specified with
1330 @code{--build-users-group}. In addition, each build process is run in a
1331 chroot environment that only contains the subset of the store that the
1332 build process depends on, as specified by its derivation
1333 (@pxref{Programming Interface, derivation}), plus a set of specific
1334 system directories. By default, the latter contains @file{/dev} and
1335 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1336 @dfn{container}: in addition to having its own file system tree, it has
1337 a separate mount name space, its own PID name space, network name space,
1338 etc. This helps achieve reproducible builds (@pxref{Features}).
1340 When the daemon performs a build on behalf of the user, it creates a
1341 build directory under @file{/tmp} or under the directory specified by
1342 its @code{TMPDIR} environment variable. This directory is shared with
1343 the container for the duration of the build, though within the container,
1344 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1346 The build directory is automatically deleted upon completion, unless the
1347 build failed and the client specified @option{--keep-failed}
1348 (@pxref{Invoking guix build, @option{--keep-failed}}).
1350 The daemon listens for connections and spawns one sub-process for each session
1351 started by a client (one of the @command{guix} sub-commands.) The
1352 @command{guix processes} command allows you to get an overview of the activity
1353 on your system by viewing each of the active sessions and clients.
1354 @xref{Invoking guix processes}, for more information.
1356 The following command-line options are supported:
1359 @item --build-users-group=@var{group}
1360 Take users from @var{group} to run build processes (@pxref{Setting Up
1361 the Daemon, build users}).
1363 @item --no-substitutes
1365 Do not use substitutes for build products. That is, always build things
1366 locally instead of allowing downloads of pre-built binaries
1367 (@pxref{Substitutes}).
1369 When the daemon runs with @code{--no-substitutes}, clients can still
1370 explicitly enable substitution @i{via} the @code{set-build-options}
1371 remote procedure call (@pxref{The Store}).
1373 @item --substitute-urls=@var{urls}
1374 @anchor{daemon-substitute-urls}
1375 Consider @var{urls} the default whitespace-separated list of substitute
1376 source URLs. When this option is omitted,
1377 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1379 This means that substitutes may be downloaded from @var{urls}, as long
1380 as they are signed by a trusted signature (@pxref{Substitutes}).
1383 @item --no-build-hook
1384 Do not use the @dfn{build hook}.
1386 The build hook is a helper program that the daemon can start and to
1387 which it submits build requests. This mechanism is used to offload
1388 builds to other machines (@pxref{Daemon Offload Setup}).
1390 @item --cache-failures
1391 Cache build failures. By default, only successful builds are cached.
1393 When this option is used, @command{guix gc --list-failures} can be used
1394 to query the set of store items marked as failed; @command{guix gc
1395 --clear-failures} removes store items from the set of cached failures.
1396 @xref{Invoking guix gc}.
1398 @item --cores=@var{n}
1400 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1403 The default value is @code{0}, but it may be overridden by clients, such
1404 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1407 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1408 in the build process, which can then use it to exploit internal
1409 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1411 @item --max-jobs=@var{n}
1413 Allow at most @var{n} build jobs in parallel. The default value is
1414 @code{1}. Setting it to @code{0} means that no builds will be performed
1415 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1416 Setup}), or simply fail.
1418 @item --max-silent-time=@var{seconds}
1419 When the build or substitution process remains silent for more than
1420 @var{seconds}, terminate it and report a build failure.
1422 The default value is @code{0}, which disables the timeout.
1424 The value specified here can be overridden by clients (@pxref{Common
1425 Build Options, @code{--max-silent-time}}).
1427 @item --timeout=@var{seconds}
1428 Likewise, when the build or substitution process lasts 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{--timeout}}).
1436 @item --rounds=@var{N}
1437 Build each derivation @var{n} times in a row, and raise an error if
1438 consecutive build results are not bit-for-bit identical. Note that this
1439 setting can be overridden by clients such as @command{guix build}
1440 (@pxref{Invoking guix build}).
1442 When used in conjunction with @option{--keep-failed}, the differing
1443 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1444 This makes it easy to look for differences between the two results.
1447 Produce debugging output.
1449 This is useful to debug daemon start-up issues, but then it may be
1450 overridden by clients, for example the @code{--verbosity} option of
1451 @command{guix build} (@pxref{Invoking guix build}).
1453 @item --chroot-directory=@var{dir}
1454 Add @var{dir} to the build chroot.
1456 Doing this may change the result of build processes---for instance if
1457 they use optional dependencies found in @var{dir} when it is available,
1458 and not otherwise. For that reason, it is not recommended to do so.
1459 Instead, make sure that each derivation declares all the inputs that it
1462 @item --disable-chroot
1463 Disable chroot builds.
1465 Using this option is not recommended since, again, it would allow build
1466 processes to gain access to undeclared dependencies. It is necessary,
1467 though, when @command{guix-daemon} is running under an unprivileged user
1470 @item --log-compression=@var{type}
1471 Compress build logs according to @var{type}, one of @code{gzip},
1472 @code{bzip2}, or @code{none}.
1474 Unless @code{--lose-logs} is used, all the build logs are kept in the
1475 @var{localstatedir}. To save space, the daemon automatically compresses
1476 them with bzip2 by default.
1478 @item --disable-deduplication
1479 @cindex deduplication
1480 Disable automatic file ``deduplication'' in the store.
1482 By default, files added to the store are automatically ``deduplicated'':
1483 if a newly added file is identical to another one found in the store,
1484 the daemon makes the new file a hard link to the other file. This can
1485 noticeably reduce disk usage, at the expense of slightly increased
1486 input/output load at the end of a build process. This option disables
1489 @item --gc-keep-outputs[=yes|no]
1490 Tell whether the garbage collector (GC) must keep outputs of live
1494 @cindex garbage collector roots
1495 When set to ``yes'', the GC will keep the outputs of any live derivation
1496 available in the store---the @code{.drv} files. The default is ``no'',
1497 meaning that derivation outputs are kept only if they are reachable from a GC
1498 root. @xref{Invoking guix gc}, for more on GC roots.
1500 @item --gc-keep-derivations[=yes|no]
1501 Tell whether the garbage collector (GC) must keep derivations
1502 corresponding to live outputs.
1504 When set to ``yes'', as is the case by default, the GC keeps
1505 derivations---i.e., @code{.drv} files---as long as at least one of their
1506 outputs is live. This allows users to keep track of the origins of
1507 items in their store. Setting it to ``no'' saves a bit of disk space.
1509 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1510 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1511 ``yes'' causes liveness to flow from derivations to outputs. When both are
1512 set to ``yes'', the effect is to keep all the build prerequisites (the
1513 sources, compiler, libraries, and other build-time tools) of live objects in
1514 the store, regardless of whether these prerequisites are reachable from a GC
1515 root. This is convenient for developers since it saves rebuilds or downloads.
1517 @item --impersonate-linux-2.6
1518 On Linux-based systems, impersonate Linux 2.6. This means that the
1519 kernel's @code{uname} system call will report 2.6 as the release number.
1521 This might be helpful to build programs that (usually wrongfully) depend
1522 on the kernel version number.
1525 Do not keep build logs. By default they are kept under
1526 @code{@var{localstatedir}/guix/log}.
1528 @item --system=@var{system}
1529 Assume @var{system} as the current system type. By default it is the
1530 architecture/kernel pair found at configure time, such as
1531 @code{x86_64-linux}.
1533 @item --listen=@var{endpoint}
1534 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1535 as the file name of a Unix-domain socket if it starts with
1536 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1537 host name or host name and port to listen to. Here are a few examples:
1540 @item --listen=/gnu/var/daemon
1541 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1542 creating it if needed.
1544 @item --listen=localhost
1545 @cindex daemon, remote access
1546 @cindex remote access to the daemon
1547 @cindex daemon, cluster setup
1548 @cindex clusters, daemon setup
1549 Listen for TCP connections on the network interface corresponding to
1550 @code{localhost}, on port 44146.
1552 @item --listen=128.0.0.42:1234
1553 Listen for TCP connections on the network interface corresponding to
1554 @code{128.0.0.42}, on port 1234.
1557 This option can be repeated multiple times, in which case
1558 @command{guix-daemon} accepts connections on all the specified
1559 endpoints. Users can tell client commands what endpoint to connect to
1560 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1561 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1564 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1565 @code{--listen=@var{host}} is suitable on local networks, such as
1566 clusters, where only trusted nodes may connect to the build daemon. In
1567 other cases where remote access to the daemon is needed, we recommend
1568 using Unix-domain sockets along with SSH.
1571 When @code{--listen} is omitted, @command{guix-daemon} listens for
1572 connections on the Unix-domain socket located at
1573 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1577 @node Application Setup
1578 @section Application Setup
1580 @cindex foreign distro
1581 When using Guix on top of GNU/Linux distribution other than Guix System---a
1582 so-called @dfn{foreign distro}---a few additional steps are needed to
1583 get everything in place. Here are some of them.
1587 @anchor{locales-and-locpath}
1588 @cindex locales, when not on Guix System
1590 @vindex GUIX_LOCPATH
1591 Packages installed @i{via} Guix will not use the locale data of the
1592 host system. Instead, you must first install one of the locale packages
1593 available with Guix and then define the @code{GUIX_LOCPATH} environment
1597 $ guix install glibc-locales
1598 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1601 Note that the @code{glibc-locales} package contains data for all the
1602 locales supported by the GNU@tie{}libc and weighs in at around
1603 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1604 limited to a few UTF-8 locales.
1606 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1607 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1608 Manual}). There are two important differences though:
1612 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1613 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1614 to make sure the programs of the foreign distro will not end up loading
1615 incompatible locale data.
1618 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1619 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1620 should your Guix profile contain a mixture of programs linked against
1621 different libc version, each libc version will only try to load locale
1622 data in the right format.
1625 This is important because the locale data format used by different libc
1626 versions may be incompatible.
1628 @subsection Name Service Switch
1630 @cindex name service switch, glibc
1631 @cindex NSS (name service switch), glibc
1632 @cindex nscd (name service caching daemon)
1633 @cindex name service caching daemon (nscd)
1634 When using Guix on a foreign distro, we @emph{strongly recommend} that
1635 the system run the GNU C library's @dfn{name service cache daemon},
1636 @command{nscd}, which should be listening on the
1637 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1638 installed with Guix may fail to look up host names or user accounts, or
1639 may even crash. The next paragraphs explain why.
1641 @cindex @file{nsswitch.conf}
1642 The GNU C library implements a @dfn{name service switch} (NSS), which is
1643 an extensible mechanism for ``name lookups'' in general: host name
1644 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1645 The GNU C Library Reference Manual}).
1647 @cindex Network information service (NIS)
1648 @cindex NIS (Network information service)
1649 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1650 lookup implementations: for example, the @code{nss-mdns} plugin allow
1651 resolution of @code{.local} host names, the @code{nis} plugin allows
1652 user account lookup using the Network information service (NIS), and so
1653 on. These extra ``lookup services'' are configured system-wide in
1654 @file{/etc/nsswitch.conf}, and all the programs running on the system
1655 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1658 When they perform a name lookup---for instance by calling the
1659 @code{getaddrinfo} function in C---applications first try to connect to
1660 the nscd; on success, nscd performs name lookups on their behalf. If
1661 the nscd is not running, then they perform the name lookup by
1662 themselves, by loading the name lookup services into their own address
1663 space and running it. These name lookup services---the
1664 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1665 the host system's C library, rather than from the C library the
1666 application is linked against (the C library coming from Guix).
1668 And this is where the problem is: if your application is linked against
1669 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1670 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1671 likely crash or have its name lookups fail unexpectedly.
1673 Running @command{nscd} on the system, among other advantages, eliminates
1674 this binary incompatibility problem because those @code{libnss_*.so}
1675 files are loaded in the @command{nscd} process, not in applications
1678 @subsection X11 Fonts
1681 The majority of graphical applications use Fontconfig to locate and
1682 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1683 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1684 by default. Thus, to allow graphical applications installed with Guix
1685 to display fonts, you have to install fonts with Guix as well.
1686 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1687 @code{font-gnu-freefont-ttf}.
1689 To display text written in Chinese languages, Japanese, or Korean in
1690 graphical applications, consider installing
1691 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1692 has multiple outputs, one per language family (@pxref{Packages with
1693 Multiple Outputs}). For instance, the following command installs fonts
1694 for Chinese languages:
1697 guix install font-adobe-source-han-sans:cn
1700 @cindex @code{xterm}
1701 Older programs such as @command{xterm} do not use Fontconfig and instead
1702 rely on server-side font rendering. Such programs require to specify a
1703 full name of a font using XLFD (X Logical Font Description), like this:
1706 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1709 To be able to use such full names for the TrueType fonts installed in
1710 your Guix profile, you need to extend the font path of the X server:
1712 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1713 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1715 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1718 @cindex @code{xlsfonts}
1719 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1720 to make sure your TrueType fonts are listed there.
1722 @cindex @code{fc-cache}
1724 After installing fonts you may have to refresh the font cache to use
1725 them in applications. The same applies when applications installed via
1726 Guix do not seem to find fonts. To force rebuilding of the font cache
1727 run @code{fc-cache -f}. The @code{fc-cache} command is provided by the
1728 @code{fontconfig} package.
1730 @subsection X.509 Certificates
1732 @cindex @code{nss-certs}
1733 The @code{nss-certs} package provides X.509 certificates, which allow
1734 programs to authenticate Web servers accessed over HTTPS.
1736 When using Guix on a foreign distro, you can install this package and
1737 define the relevant environment variables so that packages know where to
1738 look for certificates. @xref{X.509 Certificates}, for detailed
1741 @subsection Emacs Packages
1743 @cindex @code{emacs}
1744 When you install Emacs packages with Guix, the elisp files may be placed
1745 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1747 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1748 directory exists because potentially there may exist thousands of Emacs
1749 packages and storing all their files in a single directory may not be
1750 reliable (because of name conflicts). So we think using a separate
1751 directory for each package is a good idea. It is very similar to how
1752 the Emacs package system organizes the file structure (@pxref{Package
1753 Files,,, emacs, The GNU Emacs Manual}).
1755 By default, Emacs (installed with Guix) ``knows'' where these packages
1756 are placed, so you do not need to perform any configuration. If, for
1757 some reason, you want to avoid auto-loading Emacs packages installed
1758 with Guix, you can do so by running Emacs with @code{--no-site-file}
1759 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1761 @subsection The GCC toolchain
1766 Guix offers individual compiler packages such as @code{gcc} but if you
1767 are in need of a complete toolchain for compiling and linking source
1768 code what you really want is the @code{gcc-toolchain} package. This
1769 package provides a complete GCC toolchain for C/C++ development,
1770 including GCC itself, the GNU C Library (headers and binaries, plus
1771 debugging symbols in the @code{debug} output), Binutils, and a linker
1774 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1775 passed to the linker, add corresponding @code{-rpath} arguments, and
1776 invoke the actual linker with this new set of arguments. You can instruct the
1777 wrapper to refuse to link against libraries not in the store by setting the
1778 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1782 @c *********************************************************************
1783 @node System Installation
1784 @chapter System Installation
1786 @cindex installing Guix System
1787 @cindex Guix System, installation
1788 This section explains how to install Guix System
1789 on a machine. Guix, as a package manager, can
1790 also be installed on top of a running GNU/Linux system,
1791 @pxref{Installation}.
1795 @c This paragraph is for people reading this from tty2 of the
1796 @c installation image.
1797 You are reading this documentation with an Info reader. For details on
1798 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1799 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1800 Info}. Hit @kbd{l} afterwards to come back here.
1802 Alternately, run @command{info info} in another tty to keep the manual
1808 * Limitations:: What you can expect.
1809 * Hardware Considerations:: Supported hardware.
1810 * USB Stick and DVD Installation:: Preparing the installation medium.
1811 * Preparing for Installation:: Networking, partitioning, etc.
1812 * Guided Graphical Installation:: Easy graphical installation.
1813 * Manual Installation:: Manual installation for wizards.
1814 * After System Installation:: When installation succeeded.
1815 * Installing Guix in a VM:: Guix System playground.
1816 * Building the Installation Image:: How this comes to be.
1820 @section Limitations
1822 We consider Guix System to be ready for a wide range of ``desktop'' and server
1823 use cases. The reliability guarantees it provides---transactional upgrades
1824 and rollbacks, reproducibility---make it a solid foundation.
1826 Nevertheless, before you proceed with the installation, be aware of the
1827 following noteworthy limitations applicable to version @value{VERSION}:
1831 Support for the Logical Volume Manager (LVM) is missing.
1834 More and more system services are provided (@pxref{Services}), but some
1838 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1839 as well as a number of X11 window managers. However, KDE is currently
1843 More than a disclaimer, this is an invitation to report issues (and success
1844 stories!), and to join us in improving it. @xref{Contributing}, for more
1848 @node Hardware Considerations
1849 @section Hardware Considerations
1851 @cindex hardware support on Guix System
1852 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1853 builds around the kernel Linux-libre, which means that only hardware for
1854 which free software drivers and firmware exist is supported. Nowadays,
1855 a wide range of off-the-shelf hardware is supported on
1856 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1857 Ethernet controllers. Unfortunately, there are still areas where
1858 hardware vendors deny users control over their own computing, and such
1859 hardware is not supported on Guix System.
1861 @cindex WiFi, hardware support
1862 One of the main areas where free drivers or firmware are lacking is WiFi
1863 devices. WiFi devices known to work include those using Atheros chips
1864 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1865 driver, and those using Broadcom/AirForce chips (BCM43xx with
1866 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1867 Linux-libre driver. Free firmware exists for both and is available
1868 out-of-the-box on Guix System, as part of @code{%base-firmware}
1869 (@pxref{operating-system Reference, @code{firmware}}).
1871 @cindex RYF, Respects Your Freedom
1872 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1873 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1874 certification program for hardware products that respect your freedom
1875 and your privacy and ensure that you have control over your device. We
1876 encourage you to check the list of RYF-certified devices.
1878 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1879 web site. It contains a catalog of hardware devices with information
1880 about their support in GNU/Linux.
1883 @node USB Stick and DVD Installation
1884 @section USB Stick and DVD Installation
1886 An ISO-9660 installation image that can be written to a USB stick or
1887 burnt to a DVD can be downloaded from
1888 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1889 where @var{system} is one of:
1893 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1896 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1899 @c start duplication of authentication part from ``Binary Installation''
1900 Make sure to download the associated @file{.sig} file and to verify the
1901 authenticity of the image against it, along these lines:
1904 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1905 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1908 If that command fails because you do not have the required public key,
1909 then run this command to import it:
1912 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1913 -qO - | gpg --import -
1917 and rerun the @code{gpg --verify} command.
1919 Take note that a warning like ``This key is not certified with a trusted
1920 signature!'' is normal.
1924 This image contains the tools necessary for an installation.
1925 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1927 @unnumberedsubsec Copying to a USB Stick
1929 To copy the image to a USB stick, follow these steps:
1933 Decompress the image using the @command{xz} command:
1936 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1940 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1941 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1942 copy the image with:
1945 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1949 Access to @file{/dev/sdX} usually requires root privileges.
1952 @unnumberedsubsec Burning on a DVD
1954 To copy the image to a DVD, follow these steps:
1958 Decompress the image using the @command{xz} command:
1961 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1965 Insert a blank DVD into your machine, and determine
1966 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1967 copy the image with:
1970 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1973 Access to @file{/dev/srX} usually requires root privileges.
1976 @unnumberedsubsec Booting
1978 Once this is done, you should be able to reboot the system and boot from
1979 the USB stick or DVD. The latter usually requires you to get in the
1980 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
1982 @xref{Installing Guix in a VM}, if, instead, you would like to install
1983 Guix System in a virtual machine (VM).
1986 @node Preparing for Installation
1987 @section Preparing for Installation
1989 Once you have booted, you can use the guided graphical installer, which makes
1990 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
1991 if you are already familiar with GNU/Linux and if you want more control than
1992 what the graphical installer provides, you can choose the ``manual''
1993 installation process (@pxref{Manual Installation}).
1995 The graphical installer is available on TTY1. You can obtain root shells on
1996 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
1997 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
1998 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
1999 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2000 which allows you to select text with the left mouse button and to paste it
2001 with the middle button.
2004 Installation requires access to the Internet so that any missing
2005 dependencies of your system configuration can be downloaded. See the
2006 ``Networking'' section below.
2009 @node Guided Graphical Installation
2010 @section Guided Graphical Installation
2012 The graphical installer is a text-based user interface. It will guide you,
2013 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2015 The first dialog boxes allow you to set up the system as you use it during the
2016 installation: you can choose the language, keyboard layout, and set up
2017 networking, which will be used during the installation. The image below shows
2018 the networking dialog.
2020 @image{images/installer-network,5in,, networking setup with the graphical installer}
2022 Later steps allow you to partition your hard disk, as shown in the image
2023 below, to choose whether or not to use encrypted file systems, to enter the
2024 host name and root password, and to create an additional account, among other
2027 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2029 Note that, at any time, the installer allows you to exit the current
2030 installation step and resume at a previous step, as show in the image below.
2032 @image{images/installer-resume,5in,, resuming the installation process}
2034 Once you're done, the installer produces an operating system configuration and
2035 displays it (@pxref{Using the Configuration System}). At that point you can
2036 hit ``OK'' and installation will proceed. On success, you can reboot into the
2037 new system and enjoy. @xref{After System Installation}, for what's next!
2040 @node Manual Installation
2041 @section Manual Installation
2043 This section describes how you would ``manually'' install GNU@tie{}Guix System
2044 on your machine. This option requires familiarity with GNU/Linux, with the
2045 shell, and with common administration tools. If you think this is not for
2046 you, consider using the guided graphical installer (@pxref{Guided Graphical
2049 The installation system provides root shells on TTYs 3 to 6; press
2050 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2051 many common tools needed to install the system. But it is also a full-blown
2052 Guix System, which means that you can install additional packages, should you
2053 need it, using @command{guix package} (@pxref{Invoking guix package}).
2056 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2057 * Proceeding with the Installation:: Installing.
2060 @node Keyboard Layout and Networking and Partitioning
2061 @subsection Keyboard Layout, Networking, and Partitioning
2063 Before you can install the system, you may want to adjust the keyboard layout,
2064 set up networking, and partition your target hard disk. This section will
2065 guide you through this.
2067 @subsubsection Keyboard Layout
2069 @cindex keyboard layout
2070 The installation image uses the US qwerty keyboard layout. If you want
2071 to change it, you can use the @command{loadkeys} command. For example,
2072 the following command selects the Dvorak keyboard layout:
2078 See the files under @file{/run/current-system/profile/share/keymaps} for
2079 a list of available keyboard layouts. Run @command{man loadkeys} for
2082 @subsubsection Networking
2084 Run the following command to see what your network interfaces are called:
2091 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2097 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2098 Wired interfaces have a name starting with @samp{e}; for example, the
2099 interface corresponding to the first on-board Ethernet controller is
2100 called @samp{eno1}. Wireless interfaces have a name starting with
2101 @samp{w}, like @samp{w1p2s0}.
2104 @item Wired connection
2105 To configure a wired network run the following command, substituting
2106 @var{interface} with the name of the wired interface you want to use.
2109 ifconfig @var{interface} up
2112 @item Wireless connection
2115 To configure wireless networking, you can create a configuration file
2116 for the @command{wpa_supplicant} configuration tool (its location is not
2117 important) using one of the available text editors such as
2121 nano wpa_supplicant.conf
2124 As an example, the following stanza can go to this file and will work
2125 for many wireless networks, provided you give the actual SSID and
2126 passphrase for the network you are connecting to:
2130 ssid="@var{my-ssid}"
2132 psk="the network's secret passphrase"
2136 Start the wireless service and run it in the background with the
2137 following command (substitute @var{interface} with the name of the
2138 network interface you want to use):
2141 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2144 Run @command{man wpa_supplicant} for more information.
2148 At this point, you need to acquire an IP address. On a network where IP
2149 addresses are automatically assigned @i{via} DHCP, you can run:
2152 dhclient -v @var{interface}
2155 Try to ping a server to see if networking is up and running:
2161 Setting up network access is almost always a requirement because the
2162 image does not contain all the software and tools that may be needed.
2164 @cindex installing over SSH
2165 If you want to, you can continue the installation remotely by starting
2169 herd start ssh-daemon
2172 Make sure to either set a password with @command{passwd}, or configure
2173 OpenSSH public key authentication before logging in.
2175 @subsubsection Disk Partitioning
2177 Unless this has already been done, the next step is to partition, and
2178 then format the target partition(s).
2180 The installation image includes several partitioning tools, including
2181 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2182 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2183 the partition layout you want:
2189 If your disk uses the GUID Partition Table (GPT) format and you plan to
2190 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2191 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2194 @cindex EFI, installation
2195 @cindex UEFI, installation
2196 @cindex ESP, EFI system partition
2197 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2198 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2199 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2202 parted /dev/sda set 1 esp on
2206 @vindex grub-bootloader
2207 @vindex grub-efi-bootloader
2208 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2209 @file{/sys/firmware/efi} exists in the installation image, then you should
2210 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2211 Otherwise you should use the BIOS-based GRUB, known as
2212 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2216 Once you are done partitioning the target hard disk drive, you have to
2217 create a file system on the relevant partition(s)@footnote{Currently
2218 Guix System only supports ext4 and btrfs file systems. In particular, code
2219 that reads file system UUIDs and labels only works for these file system
2220 types.}. For the ESP, if you have one and assuming it is
2221 @file{/dev/sda1}, run:
2224 mkfs.fat -F32 /dev/sda1
2227 Preferably, assign file systems a label so that you can easily and
2228 reliably refer to them in @code{file-system} declarations (@pxref{File
2229 Systems}). This is typically done using the @code{-L} option of
2230 @command{mkfs.ext4} and related commands. So, assuming the target root
2231 partition lives at @file{/dev/sda2}, a file system with the label
2232 @code{my-root} can be created with:
2235 mkfs.ext4 -L my-root /dev/sda2
2238 @cindex encrypted disk
2239 If you are instead planning to encrypt the root partition, you can use
2240 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2241 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2242 @code{man cryptsetup}} for more information.) Assuming you want to
2243 store the root partition on @file{/dev/sda2}, the command sequence would
2244 be along these lines:
2247 cryptsetup luksFormat /dev/sda2
2248 cryptsetup open --type luks /dev/sda2 my-partition
2249 mkfs.ext4 -L my-root /dev/mapper/my-partition
2252 Once that is done, mount the target file system under @file{/mnt}
2253 with a command like (again, assuming @code{my-root} is the label of the
2257 mount LABEL=my-root /mnt
2260 Also mount any other file systems you would like to use on the target
2261 system relative to this path. If you have opted for @file{/boot/efi} as an
2262 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2263 found by @code{guix system init} afterwards.
2265 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2266 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2267 sure to initialize them with @command{mkswap}. Assuming you have one
2268 swap partition on @file{/dev/sda3}, you would run:
2275 Alternatively, you may use a swap file. For example, assuming that in
2276 the new system you want to use the file @file{/swapfile} as a swap file,
2277 you would run@footnote{This example will work for many types of file
2278 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2279 btrfs), the required steps may be different. For details, see the
2280 manual pages for @command{mkswap} and @command{swapon}.}:
2283 # This is 10 GiB of swap space. Adjust "count" to change the size.
2284 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2285 # For security, make the file readable and writable only by root.
2286 chmod 600 /mnt/swapfile
2287 mkswap /mnt/swapfile
2288 swapon /mnt/swapfile
2291 Note that if you have encrypted the root partition and created a swap
2292 file in its file system as described above, then the encryption also
2293 protects the swap file, just like any other file in that file system.
2295 @node Proceeding with the Installation
2296 @subsection Proceeding with the Installation
2298 With the target partitions ready and the target root mounted on
2299 @file{/mnt}, we're ready to go. First, run:
2302 herd start cow-store /mnt
2305 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2306 during the installation phase are written to the target disk on @file{/mnt}
2307 rather than kept in memory. This is necessary because the first phase of
2308 the @command{guix system init} command (see below) entails downloads or
2309 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2311 Next, you have to edit a file and
2312 provide the declaration of the operating system to be installed. To
2313 that end, the installation system comes with three text editors. We
2314 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2315 supports syntax highlighting and parentheses matching; other editors
2316 include GNU Zile (an Emacs clone), and
2317 nvi (a clone of the original BSD @command{vi} editor).
2318 We strongly recommend storing that file on the target root file system, say,
2319 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2320 configuration file once you have rebooted into the newly-installed system.
2322 @xref{Using the Configuration System}, for an overview of the
2323 configuration file. The example configurations discussed in that
2324 section are available under @file{/etc/configuration} in the
2325 installation image. Thus, to get started with a system configuration
2326 providing a graphical display server (a ``desktop'' system), you can run
2327 something along these lines:
2331 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2332 # nano /mnt/etc/config.scm
2335 You should pay attention to what your configuration file contains, and
2340 Make sure the @code{bootloader-configuration} form refers to the target
2341 you want to install GRUB on. It should mention @code{grub-bootloader} if
2342 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2343 for newer UEFI systems. For legacy systems, the @code{target} field
2344 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2345 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2346 currently mounted and a @code{file-system} entry is specified in your
2350 Be sure that your file system labels match the value of their respective
2351 @code{device} fields in your @code{file-system} configuration, assuming
2352 your @code{file-system} configuration uses the @code{file-system-label}
2353 procedure in its @code{device} field.
2356 If there are encrypted or RAID partitions, make sure to add a
2357 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2360 Once you are done preparing the configuration file, the new system must
2361 be initialized (remember that the target root file system is mounted
2365 guix system init /mnt/etc/config.scm /mnt
2369 This copies all the necessary files and installs GRUB on
2370 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2371 more information, @pxref{Invoking guix system}. This command may trigger
2372 downloads or builds of missing packages, which can take some time.
2374 Once that command has completed---and hopefully succeeded!---you can run
2375 @command{reboot} and boot into the new system. The @code{root} password
2376 in the new system is initially empty; other users' passwords need to be
2377 initialized by running the @command{passwd} command as @code{root},
2378 unless your configuration specifies otherwise
2379 (@pxref{user-account-password, user account passwords}).
2380 @xref{After System Installation}, for what's next!
2383 @node After System Installation
2384 @section After System Installation
2386 Success, you've now booted into Guix System! From then on, you can update the
2387 system whenever you want by running, say:
2391 sudo guix system reconfigure /etc/config.scm
2395 This builds a new system generation with the latest packages and services
2396 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2397 your system includes the latest security updates (@pxref{Security Updates}).
2399 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2401 @cindex sudo vs. @command{guix pull}
2402 Note that @command{sudo guix} runs your user's @command{guix} command and
2403 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2404 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2407 Join us on @code{#guix} on the Freenode IRC network or on
2408 @email{guix-devel@@gnu.org} to share your experience!
2411 @node Installing Guix in a VM
2412 @section Installing Guix in a Virtual Machine
2414 @cindex virtual machine, Guix System installation
2415 @cindex virtual private server (VPS)
2416 @cindex VPS (virtual private server)
2417 If you'd like to install Guix System in a virtual machine (VM) or on a
2418 virtual private server (VPS) rather than on your beloved machine, this
2421 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2422 disk image, follow these steps:
2426 First, retrieve and decompress the Guix system installation image as
2427 described previously (@pxref{USB Stick and DVD Installation}).
2430 Create a disk image that will hold the installed system. To make a
2431 qcow2-formatted disk image, use the @command{qemu-img} command:
2434 qemu-img create -f qcow2 guixsd.img 50G
2437 The resulting file will be much smaller than 50 GB (typically less than
2438 1 MB), but it will grow as the virtualized storage device is filled up.
2441 Boot the USB installation image in an VM:
2444 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2445 -net user -net nic,model=virtio -boot menu=on \
2446 -drive file=guix-system-install-@value{VERSION}.@var{system}.iso \
2447 -drive file=guixsd.img
2450 The ordering of the drives matters. @code{-enable-kvm} is optional, but
2451 significantly improves performance, @pxref{Running Guix in a VM}.
2453 In the VM console, quickly press the @kbd{F12} key to enter the boot
2454 menu. Then press the @kbd{2} key and the @kbd{RET} key to validate your
2458 You're now root in the VM, proceed with the installation process.
2459 @xref{Preparing for Installation}, and follow the instructions.
2462 Once installation is complete, you can boot the system that's on your
2463 @file{guixsd.img} image. @xref{Running Guix in a VM}, for how to do
2466 @node Building the Installation Image
2467 @section Building the Installation Image
2469 @cindex installation image
2470 The installation image described above was built using the @command{guix
2471 system} command, specifically:
2474 guix system disk-image --file-system-type=iso9660 \
2475 gnu/system/install.scm
2478 Have a look at @file{gnu/system/install.scm} in the source tree,
2479 and see also @ref{Invoking guix system} for more information
2480 about the installation image.
2482 @section Building the Installation Image for ARM Boards
2484 Many ARM boards require a specific variant of the
2485 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2487 If you build a disk image and the bootloader is not available otherwise
2488 (on another boot drive etc), it's advisable to build an image that
2489 includes the bootloader, specifically:
2492 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2495 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2496 board, a list of possible boards will be printed.
2498 @c *********************************************************************
2499 @node Package Management
2500 @chapter Package Management
2503 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2504 remove software packages, without having to know about their build
2505 procedures or dependencies. Guix also goes beyond this obvious set of
2508 This chapter describes the main features of Guix, as well as the
2509 package management tools it provides. Along with the command-line
2510 interface described below (@pxref{Invoking guix package, @code{guix
2511 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2512 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2513 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2517 guix install emacs-guix
2521 * Features:: How Guix will make your life brighter.
2522 * Invoking guix package:: Package installation, removal, etc.
2523 * Substitutes:: Downloading pre-built binaries.
2524 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2525 * Invoking guix gc:: Running the garbage collector.
2526 * Invoking guix pull:: Fetching the latest Guix and distribution.
2527 * Channels:: Customizing the package collection.
2528 * Inferiors:: Interacting with another revision of Guix.
2529 * Invoking guix describe:: Display information about your Guix revision.
2530 * Invoking guix archive:: Exporting and importing store files.
2536 When using Guix, each package ends up in the @dfn{package store}, in its
2537 own directory---something that resembles
2538 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2540 Instead of referring to these directories, users have their own
2541 @dfn{profile}, which points to the packages that they actually want to
2542 use. These profiles are stored within each user's home directory, at
2543 @code{$HOME/.guix-profile}.
2545 For example, @code{alice} installs GCC 4.7.2. As a result,
2546 @file{/home/alice/.guix-profile/bin/gcc} points to
2547 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2548 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2549 simply continues to point to
2550 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2551 coexist on the same system without any interference.
2553 The @command{guix package} command is the central tool to manage
2554 packages (@pxref{Invoking guix package}). It operates on the per-user
2555 profiles, and can be used @emph{with normal user privileges}.
2557 @cindex transactions
2558 The command provides the obvious install, remove, and upgrade
2559 operations. Each invocation is actually a @emph{transaction}: either
2560 the specified operation succeeds, or nothing happens. Thus, if the
2561 @command{guix package} process is terminated during the transaction,
2562 or if a power outage occurs during the transaction, then the user's
2563 profile remains in its previous state, and remains usable.
2565 In addition, any package transaction may be @emph{rolled back}. So, if,
2566 for example, an upgrade installs a new version of a package that turns
2567 out to have a serious bug, users may roll back to the previous instance
2568 of their profile, which was known to work well. Similarly, the global
2569 system configuration on Guix is subject to
2570 transactional upgrades and roll-back
2571 (@pxref{Using the Configuration System}).
2573 All packages in the package store may be @emph{garbage-collected}.
2574 Guix can determine which packages are still referenced by user
2575 profiles, and remove those that are provably no longer referenced
2576 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2577 generations of their profile so that the packages they refer to can be
2580 @cindex reproducibility
2581 @cindex reproducible builds
2582 Guix takes a @dfn{purely functional} approach to package
2583 management, as described in the introduction (@pxref{Introduction}).
2584 Each @file{/gnu/store} package directory name contains a hash of all the
2585 inputs that were used to build that package---compiler, libraries, build
2586 scripts, etc. This direct correspondence allows users to make sure a
2587 given package installation matches the current state of their
2588 distribution. It also helps maximize @dfn{build reproducibility}:
2589 thanks to the isolated build environments that are used, a given build
2590 is likely to yield bit-identical files when performed on different
2591 machines (@pxref{Invoking guix-daemon, container}).
2594 This foundation allows Guix to support @dfn{transparent binary/source
2595 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2596 available from an external source---a @dfn{substitute}, Guix just
2597 downloads it and unpacks it;
2598 otherwise, it builds the package from source, locally
2599 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2600 reproducible, users do not have to trust servers that provide
2601 substitutes: they can force a local build and @emph{challenge} providers
2602 (@pxref{Invoking guix challenge}).
2604 Control over the build environment is a feature that is also useful for
2605 developers. The @command{guix environment} command allows developers of
2606 a package to quickly set up the right development environment for their
2607 package, without having to manually install the dependencies of the
2608 package into their profile (@pxref{Invoking guix environment}).
2610 @cindex replication, of software environments
2611 @cindex provenance tracking, of software artifacts
2612 All of Guix and its package definitions is version-controlled, and
2613 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2614 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2615 Guix instance on a different machine or at a later point in time, which in
2616 turn allows you to @emph{replicate complete software environments}, while
2617 retaining precise @dfn{provenance tracking} of the software.
2619 @node Invoking guix package
2620 @section Invoking @command{guix package}
2622 @cindex installing packages
2623 @cindex removing packages
2624 @cindex package installation
2625 @cindex package removal
2626 The @command{guix package} command is the tool that allows users to
2627 install, upgrade, and remove packages, as well as rolling back to
2628 previous configurations. It operates only on the user's own profile,
2629 and works with normal user privileges (@pxref{Features}). Its syntax
2633 guix package @var{options}
2636 @cindex transactions
2637 Primarily, @var{options} specifies the operations to be performed during
2638 the transaction. Upon completion, a new profile is created, but
2639 previous @dfn{generations} of the profile remain available, should the user
2642 For example, to remove @code{lua} and install @code{guile} and
2643 @code{guile-cairo} in a single transaction:
2646 guix package -r lua -i guile guile-cairo
2649 @cindex aliases, for @command{guix package}
2650 For your convenience, we also provide the following aliases:
2654 @command{guix search} is an alias for @command{guix package -s},
2656 @command{guix install} is an alias for @command{guix package -i},
2658 @command{guix remove} is an alias for @command{guix package -r},
2660 and @command{guix upgrade} is an alias for @command{guix package -u}.
2663 These aliases are less expressive than @command{guix package} and provide
2664 fewer options, so in some cases you'll probably want to use @command{guix
2667 @command{guix package} also supports a @dfn{declarative approach}
2668 whereby the user specifies the exact set of packages to be available and
2669 passes it @i{via} the @option{--manifest} option
2670 (@pxref{profile-manifest, @option{--manifest}}).
2673 For each user, a symlink to the user's default profile is automatically
2674 created in @file{$HOME/.guix-profile}. This symlink always points to the
2675 current generation of the user's default profile. Thus, users can add
2676 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2677 variable, and so on.
2678 @cindex search paths
2679 If you are not using Guix System, consider adding the
2680 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2681 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2682 shells get all the right environment variable definitions:
2685 GUIX_PROFILE="$HOME/.guix-profile" ; \
2686 source "$HOME/.guix-profile/etc/profile"
2689 In a multi-user setup, user profiles are stored in a place registered as
2690 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2691 to (@pxref{Invoking guix gc}). That directory is normally
2692 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2693 @var{localstatedir} is the value passed to @code{configure} as
2694 @code{--localstatedir}, and @var{user} is the user name. The
2695 @file{per-user} directory is created when @command{guix-daemon} is
2696 started, and the @var{user} sub-directory is created by @command{guix
2699 The @var{options} can be among the following:
2703 @item --install=@var{package} @dots{}
2704 @itemx -i @var{package} @dots{}
2705 Install the specified @var{package}s.
2707 Each @var{package} may specify either a simple package name, such as
2708 @code{guile}, or a package name followed by an at-sign and version number,
2709 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2710 case, the newest version prefixed by @code{1.8} is selected.)
2712 If no version number is specified, the
2713 newest available version will be selected. In addition, @var{package}
2714 may contain a colon, followed by the name of one of the outputs of the
2715 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2716 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2717 name (and optionally version) are searched for among the GNU
2718 distribution modules (@pxref{Package Modules}).
2720 @cindex propagated inputs
2721 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2722 that automatically get installed along with the required package
2723 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2724 @code{package} objects}, for information about propagated inputs in
2725 package definitions).
2727 @anchor{package-cmd-propagated-inputs}
2728 An example is the GNU MPC library: its C header files refer to those of
2729 the GNU MPFR library, which in turn refer to those of the GMP library.
2730 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2731 in the profile; removing MPC also removes MPFR and GMP---unless they had
2732 also been explicitly installed by the user.
2734 Besides, packages sometimes rely on the definition of environment
2735 variables for their search paths (see explanation of
2736 @code{--search-paths} below). Any missing or possibly incorrect
2737 environment variable definitions are reported here.
2739 @item --install-from-expression=@var{exp}
2741 Install the package @var{exp} evaluates to.
2743 @var{exp} must be a Scheme expression that evaluates to a
2744 @code{<package>} object. This option is notably useful to disambiguate
2745 between same-named variants of a package, with expressions such as
2746 @code{(@@ (gnu packages base) guile-final)}.
2748 Note that this option installs the first output of the specified
2749 package, which may be insufficient when needing a specific output of a
2750 multiple-output package.
2752 @item --install-from-file=@var{file}
2753 @itemx -f @var{file}
2754 Install the package that the code within @var{file} evaluates to.
2756 As an example, @var{file} might contain a definition like this
2757 (@pxref{Defining Packages}):
2760 @verbatiminclude package-hello.scm
2763 Developers may find it useful to include such a @file{guix.scm} file
2764 in the root of their project source tree that can be used to test
2765 development snapshots and create reproducible development environments
2766 (@pxref{Invoking guix environment}).
2768 @item --remove=@var{package} @dots{}
2769 @itemx -r @var{package} @dots{}
2770 Remove the specified @var{package}s.
2772 As for @code{--install}, each @var{package} may specify a version number
2773 and/or output name in addition to the package name. For instance,
2774 @code{-r glibc:debug} would remove the @code{debug} output of
2777 @item --upgrade[=@var{regexp} @dots{}]
2778 @itemx -u [@var{regexp} @dots{}]
2779 @cindex upgrading packages
2780 Upgrade all the installed packages. If one or more @var{regexp}s are
2781 specified, upgrade only installed packages whose name matches a
2782 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2784 Note that this upgrades package to the latest version of packages found
2785 in the distribution currently installed. To update your distribution,
2786 you should regularly run @command{guix pull} (@pxref{Invoking guix
2789 @item --do-not-upgrade[=@var{regexp} @dots{}]
2790 When used together with the @code{--upgrade} option, do @emph{not}
2791 upgrade any packages whose name matches a @var{regexp}. For example, to
2792 upgrade all packages in the current profile except those containing the
2793 substring ``emacs'':
2796 $ guix package --upgrade . --do-not-upgrade emacs
2799 @item @anchor{profile-manifest}--manifest=@var{file}
2800 @itemx -m @var{file}
2801 @cindex profile declaration
2802 @cindex profile manifest
2803 Create a new generation of the profile from the manifest object
2804 returned by the Scheme code in @var{file}.
2806 This allows you to @emph{declare} the profile's contents rather than
2807 constructing it through a sequence of @code{--install} and similar
2808 commands. The advantage is that @var{file} can be put under version
2809 control, copied to different machines to reproduce the same profile, and
2812 @c FIXME: Add reference to (guix profile) documentation when available.
2813 @var{file} must return a @dfn{manifest} object, which is roughly a list
2816 @findex packages->manifest
2818 (use-package-modules guile emacs)
2823 ;; Use a specific package output.
2824 (list guile-2.0 "debug")))
2827 @findex specifications->manifest
2828 In this example we have to know which modules define the @code{emacs}
2829 and @code{guile-2.0} variables to provide the right
2830 @code{use-package-modules} line, which can be cumbersome. We can
2831 instead provide regular package specifications and let
2832 @code{specifications->manifest} look up the corresponding package
2836 (specifications->manifest
2837 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2841 @cindex rolling back
2842 @cindex undoing transactions
2843 @cindex transactions, undoing
2844 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2845 the last transaction.
2847 When combined with options such as @code{--install}, roll back occurs
2848 before any other actions.
2850 When rolling back from the first generation that actually contains
2851 installed packages, the profile is made to point to the @dfn{zeroth
2852 generation}, which contains no files apart from its own metadata.
2854 After having rolled back, installing, removing, or upgrading packages
2855 overwrites previous future generations. Thus, the history of the
2856 generations in a profile is always linear.
2858 @item --switch-generation=@var{pattern}
2859 @itemx -S @var{pattern}
2861 Switch to a particular generation defined by @var{pattern}.
2863 @var{pattern} may be either a generation number or a number prefixed
2864 with ``+'' or ``-''. The latter means: move forward/backward by a
2865 specified number of generations. For example, if you want to return to
2866 the latest generation after @code{--roll-back}, use
2867 @code{--switch-generation=+1}.
2869 The difference between @code{--roll-back} and
2870 @code{--switch-generation=-1} is that @code{--switch-generation} will
2871 not make a zeroth generation, so if a specified generation does not
2872 exist, the current generation will not be changed.
2874 @item --search-paths[=@var{kind}]
2875 @cindex search paths
2876 Report environment variable definitions, in Bash syntax, that may be
2877 needed in order to use the set of installed packages. These environment
2878 variables are used to specify @dfn{search paths} for files used by some
2879 of the installed packages.
2881 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2882 environment variables to be defined so it can look for headers and
2883 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2884 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2885 library are installed in the profile, then @code{--search-paths} will
2886 suggest setting these variables to @code{@var{profile}/include} and
2887 @code{@var{profile}/lib}, respectively.
2889 The typical use case is to define these environment variables in the
2893 $ eval `guix package --search-paths`
2896 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2897 meaning that the returned environment variable definitions will either
2898 be exact settings, or prefixes or suffixes of the current value of these
2899 variables. When omitted, @var{kind} defaults to @code{exact}.
2901 This option can also be used to compute the @emph{combined} search paths
2902 of several profiles. Consider this example:
2905 $ guix package -p foo -i guile
2906 $ guix package -p bar -i guile-json
2907 $ guix package -p foo -p bar --search-paths
2910 The last command above reports about the @code{GUILE_LOAD_PATH}
2911 variable, even though, taken individually, neither @file{foo} nor
2912 @file{bar} would lead to that recommendation.
2915 @item --profile=@var{profile}
2916 @itemx -p @var{profile}
2917 Use @var{profile} instead of the user's default profile.
2919 @cindex collisions, in a profile
2920 @cindex colliding packages in profiles
2921 @cindex profile collisions
2922 @item --allow-collisions
2923 Allow colliding packages in the new profile. Use at your own risk!
2925 By default, @command{guix package} reports as an error @dfn{collisions}
2926 in the profile. Collisions happen when two or more different versions
2927 or variants of a given package end up in the profile.
2930 Use the bootstrap Guile to build the profile. This option is only
2931 useful to distribution developers.
2935 In addition to these actions, @command{guix package} supports the
2936 following options to query the current state of a profile, or the
2937 availability of packages:
2941 @item --search=@var{regexp}
2942 @itemx -s @var{regexp}
2943 @cindex searching for packages
2944 List the available packages whose name, synopsis, or description matches
2945 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
2946 Print all the metadata of matching packages in
2947 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
2948 GNU recutils manual}).
2950 This allows specific fields to be extracted using the @command{recsel}
2951 command, for instance:
2954 $ guix package -s malloc | recsel -p name,version,relevance
2968 Similarly, to show the name of all the packages available under the
2969 terms of the GNU@tie{}LGPL version 3:
2972 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
2979 It is also possible to refine search results using several @code{-s} flags to
2980 @command{guix package}, or several arguments to @command{guix search}. For
2981 example, the following command returns a list of board games (this time using
2982 the @command{guix search} alias):
2985 $ guix search '\<board\>' game | recsel -p name
2990 If we were to omit @code{-s game}, we would also get software packages
2991 that deal with printed circuit boards; removing the angle brackets
2992 around @code{board} would further add packages that have to do with
2995 And now for a more elaborate example. The following command searches
2996 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
2997 libraries, and prints the name and synopsis of the matching packages:
3000 $ guix search crypto library | \
3001 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3005 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3006 information on @dfn{selection expressions} for @code{recsel -e}.
3008 @item --show=@var{package}
3009 Show details about @var{package}, taken from the list of available packages, in
3010 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3014 $ guix package --show=python | recsel -p name,version
3022 You may also specify the full name of a package to only get details about a
3023 specific version of it:
3025 $ guix package --show=python@@3.4 | recsel -p name,version
3032 @item --list-installed[=@var{regexp}]
3033 @itemx -I [@var{regexp}]
3034 List the currently installed packages in the specified profile, with the
3035 most recently installed packages shown last. When @var{regexp} is
3036 specified, list only installed packages whose name matches @var{regexp}.
3038 For each installed package, print the following items, separated by
3039 tabs: the package name, its version string, the part of the package that
3040 is installed (for instance, @code{out} for the default output,
3041 @code{include} for its headers, etc.), and the path of this package in
3044 @item --list-available[=@var{regexp}]
3045 @itemx -A [@var{regexp}]
3046 List packages currently available in the distribution for this system
3047 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3048 installed packages whose name matches @var{regexp}.
3050 For each package, print the following items separated by tabs: its name,
3051 its version string, the parts of the package (@pxref{Packages with
3052 Multiple Outputs}), and the source location of its definition.
3054 @item --list-generations[=@var{pattern}]
3055 @itemx -l [@var{pattern}]
3057 Return a list of generations along with their creation dates; for each
3058 generation, show the installed packages, with the most recently
3059 installed packages shown last. Note that the zeroth generation is never
3062 For each installed package, print the following items, separated by
3063 tabs: the name of a package, its version string, the part of the package
3064 that is installed (@pxref{Packages with Multiple Outputs}), and the
3065 location of this package in the store.
3067 When @var{pattern} is used, the command returns only matching
3068 generations. Valid patterns include:
3071 @item @emph{Integers and comma-separated integers}. Both patterns denote
3072 generation numbers. For instance, @code{--list-generations=1} returns
3075 And @code{--list-generations=1,8,2} outputs three generations in the
3076 specified order. Neither spaces nor trailing commas are allowed.
3078 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3079 specified generations and everything in between. Note that the start of
3080 a range must be smaller than its end.
3082 It is also possible to omit the endpoint. For example,
3083 @code{--list-generations=2..}, returns all generations starting from the
3086 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3087 or months by passing an integer along with the first letter of the
3088 duration. For example, @code{--list-generations=20d} lists generations
3089 that are up to 20 days old.
3092 @item --delete-generations[=@var{pattern}]
3093 @itemx -d [@var{pattern}]
3094 When @var{pattern} is omitted, delete all generations except the current
3097 This command accepts the same patterns as @option{--list-generations}.
3098 When @var{pattern} is specified, delete the matching generations. When
3099 @var{pattern} specifies a duration, generations @emph{older} than the
3100 specified duration match. For instance, @code{--delete-generations=1m}
3101 deletes generations that are more than one month old.
3103 If the current generation matches, it is @emph{not} deleted. Also, the
3104 zeroth generation is never deleted.
3106 Note that deleting generations prevents rolling back to them.
3107 Consequently, this command must be used with care.
3111 Finally, since @command{guix package} may actually start build
3112 processes, it supports all the common build options (@pxref{Common Build
3113 Options}). It also supports package transformation options, such as
3114 @option{--with-source} (@pxref{Package Transformation Options}).
3115 However, note that package transformations are lost when upgrading; to
3116 preserve transformations across upgrades, you should define your own
3117 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3118 (@pxref{Defining Packages}).
3121 @section Substitutes
3124 @cindex pre-built binaries
3125 Guix supports transparent source/binary deployment, which means that it
3126 can either build things locally, or download pre-built items from a
3127 server, or both. We call these pre-built items @dfn{substitutes}---they
3128 are substitutes for local build results. In many cases, downloading a
3129 substitute is much faster than building things locally.
3131 Substitutes can be anything resulting from a derivation build
3132 (@pxref{Derivations}). Of course, in the common case, they are
3133 pre-built package binaries, but source tarballs, for instance, which
3134 also result from derivation builds, can be available as substitutes.
3137 * Official Substitute Server:: One particular source of substitutes.
3138 * Substitute Server Authorization:: How to enable or disable substitutes.
3139 * Substitute Authentication:: How Guix verifies substitutes.
3140 * Proxy Settings:: How to get substitutes via proxy.
3141 * Substitution Failure:: What happens when substitution fails.
3142 * On Trusting Binaries:: How can you trust that binary blob?
3145 @node Official Substitute Server
3146 @subsection Official Substitute Server
3149 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3150 that builds packages from Guix continuously for some
3151 architectures, and makes them available as substitutes. This is the
3152 default source of substitutes; it can be overridden by passing the
3153 @option{--substitute-urls} option either to @command{guix-daemon}
3154 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3155 or to client tools such as @command{guix package}
3156 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3159 Substitute URLs can be either HTTP or HTTPS.
3160 HTTPS is recommended because communications are encrypted; conversely,
3161 using HTTP makes all communications visible to an eavesdropper, who
3162 could use the information gathered to determine, for instance, whether
3163 your system has unpatched security vulnerabilities.
3165 Substitutes from the official build farm are enabled by default when
3166 using Guix System (@pxref{GNU Distribution}). However,
3167 they are disabled by default when using Guix on a foreign distribution,
3168 unless you have explicitly enabled them via one of the recommended
3169 installation steps (@pxref{Installation}). The following paragraphs
3170 describe how to enable or disable substitutes for the official build
3171 farm; the same procedure can also be used to enable substitutes for any
3172 other substitute server.
3174 @node Substitute Server Authorization
3175 @subsection Substitute Server Authorization
3178 @cindex substitutes, authorization thereof
3179 @cindex access control list (ACL), for substitutes
3180 @cindex ACL (access control list), for substitutes
3181 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3183 must add its public key to the access control list (ACL) of archive
3184 imports, using the @command{guix archive} command (@pxref{Invoking guix
3185 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3186 be compromised and to serve genuine substitutes.
3188 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3189 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3190 the installation prefix of Guix. If you installed Guix from source,
3191 make sure you checked the GPG signature of
3192 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3193 Then, you can run something like this:
3196 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3199 Once this is in place, the output of a command like @code{guix build}
3200 should change from something like:
3203 $ guix build emacs --dry-run
3204 The following derivations would be built:
3205 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3206 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3207 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3208 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3216 $ guix build emacs --dry-run
3217 112.3 MB would be downloaded:
3218 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3219 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3220 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3221 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3226 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3227 will be downloaded, when possible, for future builds.
3229 @cindex substitutes, how to disable
3230 The substitute mechanism can be disabled globally by running
3231 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3232 guix-daemon}). It can also be disabled temporarily by passing the
3233 @code{--no-substitutes} option to @command{guix package}, @command{guix
3234 build}, and other command-line tools.
3236 @node Substitute Authentication
3237 @subsection Substitute Authentication
3239 @cindex digital signatures
3240 Guix detects and raises an error when attempting to use a substitute
3241 that has been tampered with. Likewise, it ignores substitutes that are
3242 not signed, or that are not signed by one of the keys listed in the ACL.
3244 There is one exception though: if an unauthorized server provides
3245 substitutes that are @emph{bit-for-bit identical} to those provided by
3246 an authorized server, then the unauthorized server becomes eligible for
3247 downloads. For example, assume we have chosen two substitute servers
3251 --substitute-urls="https://a.example.org https://b.example.org"
3255 @cindex reproducible builds
3256 If the ACL contains only the key for @code{b.example.org}, and if
3257 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3258 then Guix will download substitutes from @code{a.example.org} because it
3259 comes first in the list and can be considered a mirror of
3260 @code{b.example.org}. In practice, independent build machines usually
3261 produce the same binaries, thanks to bit-reproducible builds (see
3264 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3265 (in other words, the server is not authenticated), contrary to what
3266 HTTPS clients such as Web browsers usually do. This is because Guix
3267 authenticates substitute information itself, as explained above, which
3268 is what we care about (whereas X.509 certificates are about
3269 authenticating bindings between domain names and public keys.)
3271 @node Proxy Settings
3272 @subsection Proxy Settings
3275 Substitutes are downloaded over HTTP or HTTPS.
3276 The @code{http_proxy} environment
3277 variable can be set in the environment of @command{guix-daemon} and is
3278 honored for downloads of substitutes. Note that the value of
3279 @code{http_proxy} in the environment where @command{guix build},
3280 @command{guix package}, and other client commands are run has
3281 @emph{absolutely no effect}.
3283 @node Substitution Failure
3284 @subsection Substitution Failure
3286 Even when a substitute for a derivation is available, sometimes the
3287 substitution attempt will fail. This can happen for a variety of
3288 reasons: the substitute server might be offline, the substitute may
3289 recently have been deleted, the connection might have been interrupted,
3292 When substitutes are enabled and a substitute for a derivation is
3293 available, but the substitution attempt fails, Guix will attempt to
3294 build the derivation locally depending on whether or not
3295 @code{--fallback} was given (@pxref{fallback-option,, common build
3296 option @code{--fallback}}). Specifically, if @code{--fallback} was
3297 omitted, then no local build will be performed, and the derivation is
3298 considered to have failed. However, if @code{--fallback} was given,
3299 then Guix will attempt to build the derivation locally, and the success
3300 or failure of the derivation depends on the success or failure of the
3301 local build. Note that when substitutes are disabled or no substitute
3302 is available for the derivation in question, a local build will
3303 @emph{always} be performed, regardless of whether or not
3304 @code{--fallback} was given.
3306 To get an idea of how many substitutes are available right now, you can
3307 try running the @command{guix weather} command (@pxref{Invoking guix
3308 weather}). This command provides statistics on the substitutes provided
3311 @node On Trusting Binaries
3312 @subsection On Trusting Binaries
3314 @cindex trust, of pre-built binaries
3315 Today, each individual's control over their own computing is at the
3316 mercy of institutions, corporations, and groups with enough power and
3317 determination to subvert the computing infrastructure and exploit its
3318 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3319 convenient, we encourage users to also build on their own, or even run
3320 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3321 interesting target. One way to help is by publishing the software you
3322 build using @command{guix publish} so that others have one more choice
3323 of server to download substitutes from (@pxref{Invoking guix publish}).
3325 Guix has the foundations to maximize build reproducibility
3326 (@pxref{Features}). In most cases, independent builds of a given
3327 package or derivation should yield bit-identical results. Thus, through
3328 a diverse set of independent package builds, we can strengthen the
3329 integrity of our systems. The @command{guix challenge} command aims to
3330 help users assess substitute servers, and to assist developers in
3331 finding out about non-deterministic package builds (@pxref{Invoking guix
3332 challenge}). Similarly, the @option{--check} option of @command{guix
3333 build} allows users to check whether previously-installed substitutes
3334 are genuine by rebuilding them locally (@pxref{build-check,
3335 @command{guix build --check}}).
3337 In the future, we want Guix to have support to publish and retrieve
3338 binaries to/from other users, in a peer-to-peer fashion. If you would
3339 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3341 @node Packages with Multiple Outputs
3342 @section Packages with Multiple Outputs
3344 @cindex multiple-output packages
3345 @cindex package outputs
3348 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3349 source package leads to exactly one directory in the store. When running
3350 @command{guix install glibc}, one installs the default output of the
3351 GNU libc package; the default output is called @code{out}, but its name
3352 can be omitted as shown in this command. In this particular case, the
3353 default output of @code{glibc} contains all the C header files, shared
3354 libraries, static libraries, Info documentation, and other supporting
3357 Sometimes it is more appropriate to separate the various types of files
3358 produced from a single source package into separate outputs. For
3359 instance, the GLib C library (used by GTK+ and related packages)
3360 installs more than 20 MiB of reference documentation as HTML pages.
3361 To save space for users who do not need it, the documentation goes to a
3362 separate output, called @code{doc}. To install the main GLib output,
3363 which contains everything but the documentation, one would run:
3369 @cindex documentation
3370 The command to install its documentation is:
3373 guix install glib:doc
3376 Some packages install programs with different ``dependency footprints''.
3377 For instance, the WordNet package installs both command-line tools and
3378 graphical user interfaces (GUIs). The former depend solely on the C
3379 library, whereas the latter depend on Tcl/Tk and the underlying X
3380 libraries. In this case, we leave the command-line tools in the default
3381 output, whereas the GUIs are in a separate output. This allows users
3382 who do not need the GUIs to save space. The @command{guix size} command
3383 can help find out about such situations (@pxref{Invoking guix size}).
3384 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3386 There are several such multiple-output packages in the GNU distribution.
3387 Other conventional output names include @code{lib} for libraries and
3388 possibly header files, @code{bin} for stand-alone programs, and
3389 @code{debug} for debugging information (@pxref{Installing Debugging
3390 Files}). The outputs of a packages are listed in the third column of
3391 the output of @command{guix package --list-available} (@pxref{Invoking
3395 @node Invoking guix gc
3396 @section Invoking @command{guix gc}
3398 @cindex garbage collector
3400 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3401 The @command{guix gc} command allows users to explicitly run the garbage
3402 collector to reclaim space from the @file{/gnu/store} directory. It is
3403 the @emph{only} way to remove files from @file{/gnu/store}---removing
3404 files or directories manually may break it beyond repair!
3407 @cindex garbage collector roots
3408 The garbage collector has a set of known @dfn{roots}: any file under
3409 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3410 cannot be deleted; any other file is considered @dfn{dead} and may be
3411 deleted. The set of garbage collector roots (``GC roots'' for short)
3412 includes default user profiles; by default, the symlinks under
3413 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3414 added with @command{guix build --root}, for example (@pxref{Invoking
3415 guix build}). The @command{guix gc --list-roots} command lists them.
3417 Prior to running @code{guix gc --collect-garbage} to make space, it is
3418 often useful to remove old generations from user profiles; that way, old
3419 package builds referenced by those generations can be reclaimed. This
3420 is achieved by running @code{guix package --delete-generations}
3421 (@pxref{Invoking guix package}).
3423 Our recommendation is to run a garbage collection periodically, or when
3424 you are short on disk space. For instance, to guarantee that at least
3425 5@tie{}GB are available on your disk, simply run:
3431 It is perfectly safe to run as a non-interactive periodic job
3432 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3433 Running @command{guix gc} with no arguments will collect as
3434 much garbage as it can, but that is often inconvenient: you may find
3435 yourself having to rebuild or re-download software that is ``dead'' from
3436 the GC viewpoint but that is necessary to build other pieces of
3437 software---e.g., the compiler tool chain.
3439 The @command{guix gc} command has three modes of operation: it can be
3440 used to garbage-collect any dead files (the default), to delete specific
3441 files (the @code{--delete} option), to print garbage-collector
3442 information, or for more advanced queries. The garbage collection
3443 options are as follows:
3446 @item --collect-garbage[=@var{min}]
3447 @itemx -C [@var{min}]
3448 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3449 sub-directories. This is the default operation when no option is
3452 When @var{min} is given, stop once @var{min} bytes have been collected.
3453 @var{min} may be a number of bytes, or it may include a unit as a
3454 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3455 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3457 When @var{min} is omitted, collect all the garbage.
3459 @item --free-space=@var{free}
3460 @itemx -F @var{free}
3461 Collect garbage until @var{free} space is available under
3462 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3463 as @code{500MiB}, as described above.
3465 When @var{free} or more is already available in @file{/gnu/store}, do
3466 nothing and exit immediately.
3468 @item --delete-generations[=@var{duration}]
3469 @itemx -d [@var{duration}]
3470 Before starting the garbage collection process, delete all the generations
3471 older than @var{duration}, for all the user profiles; when run as root, this
3472 applies to all the profiles @emph{of all the users}.
3474 For example, this command deletes all the generations of all your profiles
3475 that are older than 2 months (except generations that are current), and then
3476 proceeds to free space until at least 10 GiB are available:
3479 guix gc -d 2m -F 10G
3484 Attempt to delete all the store files and directories specified as
3485 arguments. This fails if some of the files are not in the store, or if
3486 they are still live.
3488 @item --list-failures
3489 List store items corresponding to cached build failures.
3491 This prints nothing unless the daemon was started with
3492 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3493 @option{--cache-failures}}).
3496 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3499 @item --clear-failures
3500 Remove the specified store items from the failed-build cache.
3502 Again, this option only makes sense when the daemon is started with
3503 @option{--cache-failures}. Otherwise, it does nothing.
3506 Show the list of dead files and directories still present in the
3507 store---i.e., files and directories no longer reachable from any root.
3510 Show the list of live store files and directories.
3514 In addition, the references among existing store files can be queried:
3520 @cindex package dependencies
3521 List the references (respectively, the referrers) of store files given
3527 List the requisites of the store files passed as arguments. Requisites
3528 include the store files themselves, their references, and the references
3529 of these, recursively. In other words, the returned list is the
3530 @dfn{transitive closure} of the store files.
3532 @xref{Invoking guix size}, for a tool to profile the size of the closure
3533 of an element. @xref{Invoking guix graph}, for a tool to visualize
3534 the graph of references.
3538 Return the derivation(s) leading to the given store items
3539 (@pxref{Derivations}).
3541 For example, this command:
3544 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3548 returns the @file{.drv} file(s) leading to the @code{emacs} package
3549 installed in your profile.
3551 Note that there may be zero matching @file{.drv} files, for instance
3552 because these files have been garbage-collected. There can also be more
3553 than one matching @file{.drv} due to fixed-output derivations.
3556 Lastly, the following options allow you to check the integrity of the
3557 store and to control disk usage.
3561 @item --verify[=@var{options}]
3562 @cindex integrity, of the store
3563 @cindex integrity checking
3564 Verify the integrity of the store.
3566 By default, make sure that all the store items marked as valid in the
3567 database of the daemon actually exist in @file{/gnu/store}.
3569 When provided, @var{options} must be a comma-separated list containing one
3570 or more of @code{contents} and @code{repair}.
3572 When passing @option{--verify=contents}, the daemon computes the
3573 content hash of each store item and compares it against its hash in the
3574 database. Hash mismatches are reported as data corruptions. Because it
3575 traverses @emph{all the files in the store}, this command can take a
3576 long time, especially on systems with a slow disk drive.
3578 @cindex repairing the store
3579 @cindex corruption, recovering from
3580 Using @option{--verify=repair} or @option{--verify=contents,repair}
3581 causes the daemon to try to repair corrupt store items by fetching
3582 substitutes for them (@pxref{Substitutes}). Because repairing is not
3583 atomic, and thus potentially dangerous, it is available only to the
3584 system administrator. A lightweight alternative, when you know exactly
3585 which items in the store are corrupt, is @command{guix build --repair}
3586 (@pxref{Invoking guix build}).
3589 @cindex deduplication
3590 Optimize the store by hard-linking identical files---this is
3591 @dfn{deduplication}.
3593 The daemon performs deduplication after each successful build or archive
3594 import, unless it was started with @code{--disable-deduplication}
3595 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3596 this option is primarily useful when the daemon was running with
3597 @code{--disable-deduplication}.
3601 @node Invoking guix pull
3602 @section Invoking @command{guix pull}
3604 @cindex upgrading Guix
3605 @cindex updating Guix
3606 @cindex @command{guix pull}
3608 Packages are installed or upgraded to the latest version available in
3609 the distribution currently available on your local machine. To update
3610 that distribution, along with the Guix tools, you must run @command{guix
3611 pull}: the command downloads the latest Guix source code and package
3612 descriptions, and deploys it. Source code is downloaded from a
3613 @uref{https://git-scm.com, Git} repository, by default the official
3614 GNU@tie{}Guix repository, though this can be customized.
3616 On completion, @command{guix package} will use packages and package
3617 versions from this just-retrieved copy of Guix. Not only that, but all
3618 the Guix commands and Scheme modules will also be taken from that latest
3619 version. New @command{guix} sub-commands added by the update also
3622 Any user can update their Guix copy using @command{guix pull}, and the
3623 effect is limited to the user who run @command{guix pull}. For
3624 instance, when user @code{root} runs @command{guix pull}, this has no
3625 effect on the version of Guix that user @code{alice} sees, and vice
3628 The result of running @command{guix pull} is a @dfn{profile} available
3629 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3630 make sure to add it to the beginning of your search path so that you use
3631 the latest version, and similarly for the Info manual
3632 (@pxref{Documentation}):
3635 export PATH="$HOME/.config/guix/current/bin:$PATH"
3636 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3639 The @code{--list-generations} or @code{-l} option lists past generations
3640 produced by @command{guix pull}, along with details about their provenance:
3644 Generation 1 Jun 10 2018 00:18:18
3646 repository URL: https://git.savannah.gnu.org/git/guix.git
3647 branch: origin/master
3648 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3650 Generation 2 Jun 11 2018 11:02:49
3652 repository URL: https://git.savannah.gnu.org/git/guix.git
3653 branch: origin/master
3654 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3655 2 new packages: keepalived, libnfnetlink
3656 6 packages upgraded: emacs-nix-mode@@2.0.4,
3657 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3658 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3660 Generation 3 Jun 13 2018 23:31:07 (current)
3662 repository URL: https://git.savannah.gnu.org/git/guix.git
3663 branch: origin/master
3664 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3665 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3666 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3669 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3670 describe the current status of Guix.
3672 This @code{~/.config/guix/current} profile works like any other profile
3673 created by @command{guix package} (@pxref{Invoking guix package}). That
3674 is, you can list generations, roll back to the previous
3675 generation---i.e., the previous Guix---and so on:
3678 $ guix package -p ~/.config/guix/current --roll-back
3679 switched from generation 3 to 2
3680 $ guix package -p ~/.config/guix/current --delete-generations=1
3681 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3684 The @command{guix pull} command is usually invoked with no arguments,
3685 but it supports the following options:
3688 @item --url=@var{url}
3689 @itemx --commit=@var{commit}
3690 @itemx --branch=@var{branch}
3691 Download code for the @code{guix} channel from the specified @var{url}, at the
3692 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3693 string), or @var{branch}.
3695 @cindex @file{channels.scm}, configuration file
3696 @cindex configuration file for channels
3697 These options are provided for convenience, but you can also specify your
3698 configuration in the @file{~/.config/guix/channels.scm} file or using the
3699 @option{--channels} option (see below).
3701 @item --channels=@var{file}
3702 @itemx -C @var{file}
3703 Read the list of channels from @var{file} instead of
3704 @file{~/.config/guix/channels.scm}. @var{file} must contain Scheme code that
3705 evaluates to a list of channel objects. @xref{Channels}, for more
3710 Display the list of packages added or upgraded since the previous generation.
3712 This is the same information as displayed upon @command{guix pull} completion,
3713 but without ellipses; it is also similar to the output of @command{guix pull
3714 -l} for the last generation (see below).
3716 @item --list-generations[=@var{pattern}]
3717 @itemx -l [@var{pattern}]
3718 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3719 is provided, the subset of generations that match @var{pattern}.
3720 The syntax of @var{pattern} is the same as with @code{guix package
3721 --list-generations} (@pxref{Invoking guix package}).
3723 @xref{Invoking guix describe}, for a way to display information about the
3724 current generation only.
3726 @item --profile=@var{profile}
3727 @itemx -p @var{profile}
3728 Use @var{profile} instead of @file{~/.config/guix/current}.
3732 Show which channel commit(s) would be used and what would be built or
3733 substituted but do not actually do it.
3735 @item --system=@var{system}
3736 @itemx -s @var{system}
3737 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3738 the system type of the build host.
3741 Produce verbose output, writing build logs to the standard error output.
3744 Use the bootstrap Guile to build the latest Guix. This option is only
3745 useful to Guix developers.
3748 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3749 repository and branch to pull from, as well as @emph{additional} repositories
3750 containing package modules that should be deployed. @xref{Channels}, for more
3753 In addition, @command{guix pull} supports all the common build options
3754 (@pxref{Common Build Options}).
3760 @cindex @file{channels.scm}, configuration file
3761 @cindex configuration file for channels
3762 @cindex @command{guix pull}, configuration file
3763 @cindex configuration of @command{guix pull}
3764 Guix and its package collection are updated by running @command{guix pull}
3765 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3766 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3767 customized by defining @dfn{channels} in the
3768 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3769 of a Git repository to be deployed, and @command{guix pull} can be instructed
3770 to pull from one or more channels. In other words, channels can be used to
3771 @emph{customize} and to @emph{extend} Guix, as we will see below.
3773 @subsection Using a Custom Guix Channel
3775 The channel called @code{guix} specifies where Guix itself---its command-line
3776 tools as well as its package collection---should be downloaded. For instance,
3777 suppose you want to update from your own copy of the Guix repository at
3778 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3779 write in @code{~/.config/guix/channels.scm} this specification:
3782 ;; Tell 'guix pull' to use my own repo.
3785 (url "https://example.org/my-guix.git")
3786 (branch "super-hacks")))
3790 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3791 branch of the repository at @code{example.org}.
3793 @subsection Specifying Additional Channels
3795 @cindex extending the package collection (channels)
3796 @cindex personal packages (channels)
3797 @cindex channels, for personal packages
3798 You can also specify @emph{additional channels} to pull from. Let's say you
3799 have a bunch of custom package variants or personal packages that you think
3800 would make little sense to contribute to the Guix project, but would like to
3801 have these packages transparently available to you at the command line. You
3802 would first write modules containing those package definitions (@pxref{Package
3803 Modules}), maintain them in a Git repository, and then you and anyone else can
3804 use it as an additional channel to get packages from. Neat, no?
3806 @c What follows stems from discussions at
3807 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3808 @c earlier discussions on guix-devel@gnu.org.
3810 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3811 publish your personal channel to the world, we would like to share a few words
3816 Before publishing a channel, please consider contributing your package
3817 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3818 to free software of all sorts, and packages in Guix proper are readily
3819 available to all Guix users and benefit from the project's quality assurance
3823 When you maintain package definitions outside Guix, we, Guix developers,
3824 consider that @emph{the compatibility burden is on you}. Remember that
3825 package modules and package definitions are just Scheme code that uses various
3826 programming interfaces (APIs). We want to remain free to change these APIs to
3827 keep improving Guix, possibly in ways that break your channel. We never
3828 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3832 Corollary: if you're using an external channel and that channel breaks, please
3833 @emph{report the issue to the channel authors}, not to the Guix project.
3836 You've been warned! Having said this, we believe external channels are a
3837 practical way to exert your freedom to augment Guix' package collection and to
3838 share your improvements, which are basic tenets of
3839 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3840 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3843 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3844 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3847 @vindex %default-channels
3849 ;; Add my personal packages to those Guix provides.
3851 (name 'my-personal-packages)
3852 (url "https://example.org/personal-packages.git"))
3857 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3858 add a channel the list of channels that the variable @code{%default-channels}
3859 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3860 Manual}). With this file in place, @command{guix pull} builds not only Guix
3861 but also the package modules from your own repository. The result in
3862 @file{~/.config/guix/current} is the union of Guix with your own package
3866 $ guix pull --list-generations
3868 Generation 19 Aug 27 2018 16:20:48
3870 repository URL: https://git.savannah.gnu.org/git/guix.git
3872 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3873 my-personal-packages dd3df5e
3874 repository URL: https://example.org/personal-packages.git
3876 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
3877 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
3878 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
3882 The output of @command{guix pull} above shows that Generation@tie{}19 includes
3883 both Guix and packages from the @code{my-personal-packages} channel. Among
3884 the new and upgraded packages that are listed, some like @code{my-gimp} and
3885 @code{my-emacs-with-cool-features} might come from
3886 @code{my-personal-packages}, while others come from the Guix default channel.
3888 To create a channel, create a Git repository containing your own package
3889 modules and make it available. The repository can contain anything, but a
3890 useful channel will contain Guile modules that export packages. Once you
3891 start using a channel, Guix will behave as if the root directory of that
3892 channel's Git repository has been added to the Guile load path (@pxref{Load
3893 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
3894 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
3895 module, then the module will be available under the name @code{(my-packages
3896 my-tools)}, and you will be able to use it like any other module
3897 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
3899 @cindex dependencies, channels
3900 @cindex meta-data, channels
3901 @subsection Declaring Channel Dependencies
3903 Channel authors may decide to augment a package collection provided by other
3904 channels. They can declare their channel to be dependent on other channels in
3905 a meta-data file @file{.guix-channel}, which is to be placed in the root of
3906 the channel repository.
3908 The meta-data file should contain a simple S-expression like this:
3915 (name some-collection)
3916 (url "https://example.org/first-collection.git"))
3918 (name some-other-collection)
3919 (url "https://example.org/second-collection.git")
3920 (branch "testing"))))
3923 In the above example this channel is declared to depend on two other channels,
3924 which will both be fetched automatically. The modules provided by the channel
3925 will be compiled in an environment where the modules of all these declared
3926 channels are available.
3928 For the sake of reliability and maintainability, you should avoid dependencies
3929 on channels that you don't control, and you should aim to keep the number of
3930 dependencies to a minimum.
3932 @cindex subdirectory, channels
3933 @subsection Package Modules in a Sub-directory
3935 As a channel author, you may want to keep your channel modules in a
3936 sub-directory. If your modules are in the sub-directory @file{guix}, you must
3937 add a meta-data file @file{.guix-channel} that contains:
3945 @subsection Replicating Guix
3947 @cindex pinning, channels
3948 @cindex replicating Guix
3949 @cindex reproducibility, of Guix
3950 The @command{guix pull --list-generations} output above shows precisely which
3951 commits were used to build this instance of Guix. We can thus replicate it,
3952 say, on another machine, by providing a channel specification in
3953 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
3956 ;; Deploy specific commits of my channels of interest.
3959 (url "https://git.savannah.gnu.org/git/guix.git")
3960 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
3962 (name 'my-personal-packages)
3963 (url "https://example.org/personal-packages.git")
3964 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
3967 The @command{guix describe --format=channels} command can even generate this
3968 list of channels directly (@pxref{Invoking guix describe}).
3970 At this point the two machines run the @emph{exact same Guix}, with access to
3971 the @emph{exact same packages}. The output of @command{guix build gimp} on
3972 one machine will be exactly the same, bit for bit, as the output of the same
3973 command on the other machine. It also means both machines have access to all
3974 the source code of Guix and, transitively, to all the source code of every
3977 This gives you super powers, allowing you to track the provenance of binary
3978 artifacts with very fine grain, and to reproduce software environments at
3979 will---some sort of ``meta reproducibility'' capabilities, if you will.
3980 @xref{Inferiors}, for another way to take advantage of these super powers.
3985 @c TODO: Remove this once we're more confident about API stability.
3987 The functionality described here is a ``technology preview'' as of version
3988 @value{VERSION}. As such, the interface is subject to change.
3992 @cindex composition of Guix revisions
3993 Sometimes you might need to mix packages from the revision of Guix you're
3994 currently running with packages available in a different revision of Guix.
3995 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
3996 revisions in arbitrary ways.
3998 @cindex inferior packages
3999 Technically, an ``inferior'' is essentially a separate Guix process connected
4000 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4001 @code{(guix inferior)} module allows you to create inferiors and to
4002 communicate with them. It also provides a high-level interface to browse and
4003 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4005 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4006 to interact with a separate revision of Guix. For example, let's assume you
4007 want to install in your profile the current @code{guile} package, along with
4008 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4009 because the newer @code{guile-json} has an incompatible API and you want to
4010 run your code against the old API@. To do that, you could write a manifest for
4011 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4012 manifest, you would create an inferior for that old Guix revision you care
4013 about, and you would look up the @code{guile-json} package in the inferior:
4016 (use-modules (guix inferior) (guix channels)
4017 (srfi srfi-1)) ;for 'first'
4020 ;; This is the old revision from which we want to
4021 ;; extract guile-json.
4024 (url "https://git.savannah.gnu.org/git/guix.git")
4026 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4029 ;; An inferior representing the above revision.
4030 (inferior-for-channels channels))
4032 ;; Now create a manifest with the current "guile" package
4033 ;; and the old "guile-json" package.
4035 (list (first (lookup-inferior-packages inferior "guile-json"))
4036 (specification->package "guile")))
4039 On its first run, @command{guix package --manifest} might have to build the
4040 channel you specified before it can create the inferior; subsequent runs will
4041 be much faster because the Guix revision will be cached.
4043 The @code{(guix inferior)} module provides the following procedures to open an
4046 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4047 [#:cache-directory] [#:ttl]
4048 Return an inferior for @var{channels}, a list of channels. Use the cache at
4049 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4050 This procedure opens a new connection to the build daemon.
4052 As a side effect, this procedure may build or substitute binaries for
4053 @var{channels}, which can take time.
4056 @deffn {Scheme Procedure} open-inferior @var{directory} @
4057 [#:command "bin/guix"]
4058 Open the inferior Guix in @var{directory}, running
4059 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4060 the inferior could not be launched.
4063 @cindex inferior packages
4064 The procedures listed below allow you to obtain and manipulate inferior
4067 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4068 Return the list of packages known to @var{inferior}.
4071 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4073 Return the sorted list of inferior packages matching @var{name} in
4074 @var{inferior}, with highest version numbers first. If @var{version} is true,
4075 return only packages with a version number prefixed by @var{version}.
4078 @deffn {Scheme Procedure} inferior-package? @var{obj}
4079 Return true if @var{obj} is an inferior package.
4082 @deffn {Scheme Procedure} inferior-package-name @var{package}
4083 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4084 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4085 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4086 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4087 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4088 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4089 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4090 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4091 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4092 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4093 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4094 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4095 These procedures are the counterpart of package record accessors
4096 (@pxref{package Reference}). Most of them work by querying the inferior
4097 @var{package} comes from, so the inferior must still be live when you call
4101 Inferior packages can be used transparently like any other package or
4102 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4103 transparently handled by the @code{packages->manifest} procedure, which is
4104 commonly use in manifests (@pxref{Invoking guix package, the
4105 @option{--manifest} option of @command{guix package}}). Thus you can insert
4106 an inferior package pretty much anywhere you would insert a regular package:
4107 in manifests, in the @code{packages} field of your @code{operating-system}
4108 declaration, and so on.
4110 @node Invoking guix describe
4111 @section Invoking @command{guix describe}
4113 @cindex reproducibility
4114 @cindex replicating Guix
4115 Often you may want to answer questions like: ``Which revision of Guix am I
4116 using?'' or ``Which channels am I using?'' This is useful information in many
4117 situations: if you want to @emph{replicate} an environment on a different
4118 machine or user account, if you want to report a bug or to determine what
4119 change in the channels you are using caused it, or if you want to record your
4120 system state for reproducibility purposes. The @command{guix describe}
4121 command answers these questions.
4123 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4124 displays the channel(s) that it was built from, including their repository URL
4125 and commit IDs (@pxref{Channels}):
4129 Generation 10 Sep 03 2018 17:32:44 (current)
4131 repository URL: https://git.savannah.gnu.org/git/guix.git
4133 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4136 If you're familiar with the Git version control system, this is similar in
4137 spirit to @command{git describe}; the output is also similar to that of
4138 @command{guix pull --list-generations}, but limited to the current generation
4139 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4140 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4141 information is all it takes to describe the revision of Guix you're using, and
4142 also to replicate it.
4144 To make it easier to replicate Guix, @command{guix describe} can also be asked
4145 to return a list of channels instead of the human-readable description above:
4148 $ guix describe -f channels
4151 (url "https://git.savannah.gnu.org/git/guix.git")
4153 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4157 You can save this to a file and feed it to @command{guix pull -C} on some
4158 other machine or at a later point in time, which will instantiate @emph{this
4159 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4160 From there on, since you're able to deploy the same revision of Guix, you can
4161 just as well @emph{replicate a complete software environment}. We humbly
4162 think that this is @emph{awesome}, and we hope you'll like it too!
4164 The details of the options supported by @command{guix describe} are as
4168 @item --format=@var{format}
4169 @itemx -f @var{format}
4170 Produce output in the specified @var{format}, one of:
4174 produce human-readable output;
4176 produce a list of channel specifications that can be passed to @command{guix
4177 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4181 produce a list of channel specifications in JSON format;
4183 produce a list of channel specifications in Recutils format.
4186 @item --profile=@var{profile}
4187 @itemx -p @var{profile}
4188 Display information about @var{profile}.
4191 @node Invoking guix archive
4192 @section Invoking @command{guix archive}
4194 @cindex @command{guix archive}
4196 The @command{guix archive} command allows users to @dfn{export} files
4197 from the store into a single archive, and to later @dfn{import} them on
4198 a machine that runs Guix.
4199 In particular, it allows store files to be transferred from one machine
4200 to the store on another machine.
4203 If you're looking for a way to produce archives in a format suitable for
4204 tools other than Guix, @pxref{Invoking guix pack}.
4207 @cindex exporting store items
4208 To export store files as an archive to standard output, run:
4211 guix archive --export @var{options} @var{specifications}...
4214 @var{specifications} may be either store file names or package
4215 specifications, as for @command{guix package} (@pxref{Invoking guix
4216 package}). For instance, the following command creates an archive
4217 containing the @code{gui} output of the @code{git} package and the main
4218 output of @code{emacs}:
4221 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4224 If the specified packages are not built yet, @command{guix archive}
4225 automatically builds them. The build process may be controlled with the
4226 common build options (@pxref{Common Build Options}).
4228 To transfer the @code{emacs} package to a machine connected over SSH,
4232 guix archive --export -r emacs | ssh the-machine guix archive --import
4236 Similarly, a complete user profile may be transferred from one machine
4237 to another like this:
4240 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4241 ssh the-machine guix archive --import
4245 However, note that, in both examples, all of @code{emacs} and the
4246 profile as well as all of their dependencies are transferred (due to
4247 @code{-r}), regardless of what is already available in the store on the
4248 target machine. The @code{--missing} option can help figure out which
4249 items are missing from the target store. The @command{guix copy}
4250 command simplifies and optimizes this whole process, so this is probably
4251 what you should use in this case (@pxref{Invoking guix copy}).
4253 @cindex nar, archive format
4254 @cindex normalized archive (nar)
4255 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4256 comparable in spirit to `tar', but with differences
4257 that make it more appropriate for our purposes. First, rather than
4258 recording all Unix metadata for each file, the nar format only mentions
4259 the file type (regular, directory, or symbolic link); Unix permissions
4260 and owner/group are dismissed. Second, the order in which directory
4261 entries are stored always follows the order of file names according to
4262 the C locale collation order. This makes archive production fully
4265 When exporting, the daemon digitally signs the contents of the archive,
4266 and that digital signature is appended. When importing, the daemon
4267 verifies the signature and rejects the import in case of an invalid
4268 signature or if the signing key is not authorized.
4269 @c FIXME: Add xref to daemon doc about signatures.
4271 The main options are:
4275 Export the specified store files or packages (see below.) Write the
4276 resulting archive to the standard output.
4278 Dependencies are @emph{not} included in the output, unless
4279 @code{--recursive} is passed.
4283 When combined with @code{--export}, this instructs @command{guix
4284 archive} to include dependencies of the given items in the archive.
4285 Thus, the resulting archive is self-contained: it contains the closure
4286 of the exported store items.
4289 Read an archive from the standard input, and import the files listed
4290 therein into the store. Abort if the archive has an invalid digital
4291 signature, or if it is signed by a public key not among the authorized
4292 keys (see @code{--authorize} below.)
4295 Read a list of store file names from the standard input, one per line,
4296 and write on the standard output the subset of these files missing from
4299 @item --generate-key[=@var{parameters}]
4300 @cindex signing, archives
4301 Generate a new key pair for the daemon. This is a prerequisite before
4302 archives can be exported with @code{--export}. Note that this operation
4303 usually takes time, because it needs to gather enough entropy to
4304 generate the key pair.
4306 The generated key pair is typically stored under @file{/etc/guix}, in
4307 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4308 key, which must be kept secret.) When @var{parameters} is omitted,
4309 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4310 versions before 1.6.0, it is a 4096-bit RSA key.
4311 Alternatively, @var{parameters} can specify
4312 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4313 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4314 Libgcrypt Reference Manual}).
4317 @cindex authorizing, archives
4318 Authorize imports signed by the public key passed on standard input.
4319 The public key must be in ``s-expression advanced format''---i.e., the
4320 same format as the @file{signing-key.pub} file.
4322 The list of authorized keys is kept in the human-editable file
4323 @file{/etc/guix/acl}. The file contains
4324 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4325 s-expressions''} and is structured as an access-control list in the
4326 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4329 @item --extract=@var{directory}
4330 @itemx -x @var{directory}
4331 Read a single-item archive as served by substitute servers
4332 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4333 low-level operation needed in only very narrow use cases; see below.
4335 For example, the following command extracts the substitute for Emacs
4336 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4340 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4341 | bunzip2 | guix archive -x /tmp/emacs
4344 Single-item archives are different from multiple-item archives produced
4345 by @command{guix archive --export}; they contain a single store item,
4346 and they do @emph{not} embed a signature. Thus this operation does
4347 @emph{no} signature verification and its output should be considered
4350 The primary purpose of this operation is to facilitate inspection of
4351 archive contents coming from possibly untrusted substitute servers.
4356 @c *********************************************************************
4358 @chapter Development
4360 @cindex software development
4361 If you are a software developer, Guix provides tools that you should find
4362 helpful---independently of the language you're developing in. This is what
4363 this chapter is about.
4365 The @command{guix environment} command provides a convenient way to set up
4366 @dfn{development environments} containing all the dependencies and tools
4367 necessary to work on the software package of your choice. The @command{guix
4368 pack} command allows you to create @dfn{application bundles} that can be
4369 easily distributed to users who do not run Guix.
4372 * Invoking guix environment:: Setting up development environments.
4373 * Invoking guix pack:: Creating software bundles.
4376 @node Invoking guix environment
4377 @section Invoking @command{guix environment}
4379 @cindex reproducible build environments
4380 @cindex development environments
4381 @cindex @command{guix environment}
4382 @cindex environment, package build environment
4383 The purpose of @command{guix environment} is to assist hackers in
4384 creating reproducible development environments without polluting their
4385 package profile. The @command{guix environment} tool takes one or more
4386 packages, builds all of their inputs, and creates a shell
4387 environment to use them.
4389 The general syntax is:
4392 guix environment @var{options} @var{package}@dots{}
4395 The following example spawns a new shell set up for the development of
4399 guix environment guile
4402 If the needed dependencies are not built yet, @command{guix environment}
4403 automatically builds them. The environment of the new shell is an augmented
4404 version of the environment that @command{guix environment} was run in.
4405 It contains the necessary search paths for building the given package
4406 added to the existing environment variables. To create a ``pure''
4407 environment, in which the original environment variables have been unset,
4408 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4409 environment variables such as @code{PATH} in their @file{~/.bashrc}
4410 file. As a consequence, when @code{guix environment} launches it, Bash
4411 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4412 environment variables. It is an error to define such environment
4413 variables in @file{.bashrc}; instead, they should be defined in
4414 @file{.bash_profile}, which is sourced only by log-in shells.
4415 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4416 details on Bash start-up files.}.
4418 @vindex GUIX_ENVIRONMENT
4419 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4420 variable in the shell it spawns; its value is the file name of the
4421 profile of this environment. This allows users to, say, define a
4422 specific prompt for development environments in their @file{.bashrc}
4423 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4426 if [ -n "$GUIX_ENVIRONMENT" ]
4428 export PS1="\u@@\h \w [dev]\$ "
4433 ...@: or to browse the profile:
4436 $ ls "$GUIX_ENVIRONMENT/bin"
4439 Additionally, more than one package may be specified, in which case the
4440 union of the inputs for the given packages are used. For example, the
4441 command below spawns a shell where all of the dependencies of both Guile
4442 and Emacs are available:
4445 guix environment guile emacs
4448 Sometimes an interactive shell session is not desired. An arbitrary
4449 command may be invoked by placing the @code{--} token to separate the
4450 command from the rest of the arguments:
4453 guix environment guile -- make -j4
4456 In other situations, it is more convenient to specify the list of
4457 packages needed in the environment. For example, the following command
4458 runs @command{python} from an environment containing Python@tie{}2.7 and
4462 guix environment --ad-hoc python2-numpy python-2.7 -- python
4465 Furthermore, one might want the dependencies of a package and also some
4466 additional packages that are not build-time or runtime dependencies, but
4467 are useful when developing nonetheless. Because of this, the
4468 @code{--ad-hoc} flag is positional. Packages appearing before
4469 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4470 added to the environment. Packages appearing after are interpreted as
4471 packages that will be added to the environment directly. For example,
4472 the following command creates a Guix development environment that
4473 additionally includes Git and strace:
4476 guix environment guix --ad-hoc git strace
4479 Sometimes it is desirable to isolate the environment as much as
4480 possible, for maximal purity and reproducibility. In particular, when
4481 using Guix on a host distro that is not Guix System, it is desirable to
4482 prevent access to @file{/usr/bin} and other system-wide resources from
4483 the development environment. For example, the following command spawns
4484 a Guile REPL in a ``container'' where only the store and the current
4485 working directory are mounted:
4488 guix environment --ad-hoc --container guile -- guile
4492 The @code{--container} option requires Linux-libre 3.19 or newer.
4495 The available options are summarized below.
4498 @item --root=@var{file}
4499 @itemx -r @var{file}
4500 @cindex persistent environment
4501 @cindex garbage collector root, for environments
4502 Make @var{file} a symlink to the profile for this environment, and
4503 register it as a garbage collector root.
4505 This is useful if you want to protect your environment from garbage
4506 collection, to make it ``persistent''.
4508 When this option is omitted, the environment is protected from garbage
4509 collection only for the duration of the @command{guix environment}
4510 session. This means that next time you recreate the same environment,
4511 you could have to rebuild or re-download packages. @xref{Invoking guix
4512 gc}, for more on GC roots.
4514 @item --expression=@var{expr}
4515 @itemx -e @var{expr}
4516 Create an environment for the package or list of packages that
4517 @var{expr} evaluates to.
4519 For example, running:
4522 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4525 starts a shell with the environment for this specific variant of the
4531 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4534 starts a shell with all the base system packages available.
4536 The above commands only use the default output of the given packages.
4537 To select other outputs, two element tuples can be specified:
4540 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4543 @item --load=@var{file}
4544 @itemx -l @var{file}
4545 Create an environment for the package or list of packages that the code
4546 within @var{file} evaluates to.
4548 As an example, @var{file} might contain a definition like this
4549 (@pxref{Defining Packages}):
4552 @verbatiminclude environment-gdb.scm
4555 @item --manifest=@var{file}
4556 @itemx -m @var{file}
4557 Create an environment for the packages contained in the manifest object
4558 returned by the Scheme code in @var{file}.
4560 This is similar to the same-named option in @command{guix package}
4561 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4565 Include all specified packages in the resulting environment, as if an
4566 @i{ad hoc} package were defined with them as inputs. This option is
4567 useful for quickly creating an environment without having to write a
4568 package expression to contain the desired inputs.
4570 For instance, the command:
4573 guix environment --ad-hoc guile guile-sdl -- guile
4576 runs @command{guile} in an environment where Guile and Guile-SDL are
4579 Note that this example implicitly asks for the default output of
4580 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4581 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4582 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4584 This option may be composed with the default behavior of @command{guix
4585 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4586 as packages whose dependencies will be added to the environment, the
4587 default behavior. Packages appearing after are interpreted as packages
4588 that will be added to the environment directly.
4591 Unset existing environment variables when building the new environment, except
4592 those specified with @option{--preserve} (see below.) This has the effect of
4593 creating an environment in which search paths only contain package inputs.
4595 @item --preserve=@var{regexp}
4596 @itemx -E @var{regexp}
4597 When used alongside @option{--pure}, preserve the environment variables
4598 matching @var{regexp}---in other words, put them on a ``white list'' of
4599 environment variables that must be preserved. This option can be repeated
4603 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4607 This example runs @command{mpirun} in a context where the only environment
4608 variables defined are @code{PATH}, environment variables whose name starts
4609 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4612 @item --search-paths
4613 Display the environment variable definitions that make up the
4616 @item --system=@var{system}
4617 @itemx -s @var{system}
4618 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4623 Run @var{command} within an isolated container. The current working
4624 directory outside the container is mapped inside the container.
4625 Additionally, unless overridden with @code{--user}, a dummy home
4626 directory is created that matches the current user's home directory, and
4627 @file{/etc/passwd} is configured accordingly.
4629 The spawned process runs as the current user outside the container. Inside
4630 the container, it has the same UID and GID as the current user, unless
4631 @option{--user} is passed (see below.)
4635 For containers, share the network namespace with the host system.
4636 Containers created without this flag only have access to the loopback
4639 @item --link-profile
4641 For containers, link the environment profile to
4642 @file{~/.guix-profile} within the container. This is equivalent to
4643 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4644 within the container. Linking will fail and abort the environment if
4645 the directory already exists, which will certainly be the case if
4646 @command{guix environment} was invoked in the user's home directory.
4648 Certain packages are configured to look in
4649 @code{~/.guix-profile} for configuration files and data;@footnote{For
4650 example, the @code{fontconfig} package inspects
4651 @file{~/.guix-profile/share/fonts} for additional fonts.}
4652 @code{--link-profile} allows these programs to behave as expected within
4655 @item --user=@var{user}
4656 @itemx -u @var{user}
4657 For containers, use the username @var{user} in place of the current
4658 user. The generated @file{/etc/passwd} entry within the container will
4659 contain the name @var{user}, the home directory will be
4660 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4661 the UID and GID inside the container are 1000. @var{user}
4662 need not exist on the system.
4664 Additionally, any shared or exposed path (see @code{--share} and
4665 @code{--expose} respectively) whose target is within the current user's
4666 home directory will be remapped relative to @file{/home/USER}; this
4667 includes the automatic mapping of the current working directory.
4670 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4672 guix environment --container --user=foo \
4673 --expose=$HOME/test \
4674 --expose=/tmp/target=$HOME/target
4677 While this will limit the leaking of user identity through home paths
4678 and each of the user fields, this is only one useful component of a
4679 broader privacy/anonymity solution---not one in and of itself.
4682 For containers, the default behavior is to share the current working
4683 directory with the isolated container and immediately change to that
4684 directory within the container. If this is undesirable, @code{--no-cwd}
4685 will cause the current working directory to @emph{not} be automatically
4686 shared and will change to the user's home directory within the container
4687 instead. See also @code{--user}.
4689 @item --expose=@var{source}[=@var{target}]
4690 For containers, expose the file system @var{source} from the host system
4691 as the read-only file system @var{target} within the container. If
4692 @var{target} is not specified, @var{source} is used as the target mount
4693 point in the container.
4695 The example below spawns a Guile REPL in a container in which the user's
4696 home directory is accessible read-only via the @file{/exchange}
4700 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4703 @item --share=@var{source}[=@var{target}]
4704 For containers, share the file system @var{source} from the host system
4705 as the writable file system @var{target} within the container. If
4706 @var{target} is not specified, @var{source} is used as the target mount
4707 point in the container.
4709 The example below spawns a Guile REPL in a container in which the user's
4710 home directory is accessible for both reading and writing via the
4711 @file{/exchange} directory:
4714 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4718 @command{guix environment}
4719 also supports all of the common build options that @command{guix
4720 build} supports (@pxref{Common Build Options}) as well as package
4721 transformation options (@pxref{Package Transformation Options}).
4723 @node Invoking guix pack
4724 @section Invoking @command{guix pack}
4726 Occasionally you want to pass software to people who are not (yet!)
4727 lucky enough to be using Guix. You'd tell them to run @command{guix
4728 package -i @var{something}}, but that's not possible in this case. This
4729 is where @command{guix pack} comes in.
4732 If you are looking for ways to exchange binaries among machines that
4733 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4734 publish}, and @ref{Invoking guix archive}.
4739 @cindex application bundle
4740 @cindex software bundle
4741 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4742 @dfn{software bundle}: it creates a tarball or some other archive
4743 containing the binaries of the software you're interested in, and all
4744 its dependencies. The resulting archive can be used on any machine that
4745 does not have Guix, and people can run the exact same binaries as those
4746 you have with Guix. The pack itself is created in a bit-reproducible
4747 fashion, so anyone can verify that it really contains the build results
4748 that you pretend to be shipping.
4750 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4751 their dependencies, you can run:
4754 $ guix pack guile emacs geiser
4756 /gnu/store/@dots{}-pack.tar.gz
4759 The result here is a tarball containing a @file{/gnu/store} directory
4760 with all the relevant packages. The resulting tarball contains a
4761 @dfn{profile} with the three packages of interest; the profile is the
4762 same as would be created by @command{guix package -i}. It is this
4763 mechanism that is used to create Guix's own standalone binary tarball
4764 (@pxref{Binary Installation}).
4766 Users of this pack would have to run
4767 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
4768 find inconvenient. To work around it, you can create, say, a
4769 @file{/opt/gnu/bin} symlink to the profile:
4772 guix pack -S /opt/gnu/bin=bin guile emacs geiser
4776 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
4778 @cindex relocatable binaries, with @command{guix pack}
4779 What if the recipient of your pack does not have root privileges on
4780 their machine, and thus cannot unpack it in the root file system? In
4781 that case, you will want to use the @code{--relocatable} option (see
4782 below). This option produces @dfn{relocatable binaries}, meaning they
4783 they can be placed anywhere in the file system hierarchy: in the example
4784 above, users can unpack your tarball in their home directory and
4785 directly run @file{./opt/gnu/bin/guile}.
4787 @cindex Docker, build an image with guix pack
4788 Alternatively, you can produce a pack in the Docker image format using
4789 the following command:
4792 guix pack -f docker guile emacs geiser
4796 The result is a tarball that can be passed to the @command{docker load}
4798 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
4799 documentation} for more information.
4801 @cindex Singularity, build an image with guix pack
4802 @cindex SquashFS, build an image with guix pack
4803 Yet another option is to produce a SquashFS image with the following
4807 guix pack -f squashfs guile emacs geiser
4811 The result is a SquashFS file system image that can either be mounted or
4812 directly be used as a file system container image with the
4813 @uref{https://singularity.lbl.gov, Singularity container execution
4814 environment}, using commands like @command{singularity shell} or
4815 @command{singularity exec}.
4817 Several command-line options allow you to customize your pack:
4820 @item --format=@var{format}
4821 @itemx -f @var{format}
4822 Produce a pack in the given @var{format}.
4824 The available formats are:
4828 This is the default format. It produces a tarball containing all the
4829 specified binaries and symlinks.
4832 This produces a tarball that follows the
4833 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
4834 Docker Image Specification}.
4837 This produces a SquashFS image containing all the specified binaries and
4838 symlinks, as well as empty mount points for virtual file systems like
4842 @cindex relocatable binaries
4845 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
4846 anywhere in the file system hierarchy and run from there.
4848 When this option is passed once, the resulting binaries require support for
4849 @dfn{user namespaces} in the kernel Linux; when passed
4850 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
4851 PRoot support, can be thought of as the abbreviation of ``Really
4852 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
4853 if user namespaces are unavailable, and essentially work anywhere---see below
4854 for the implications.
4856 For example, if you create a pack containing Bash with:
4859 guix pack -RR -S /mybin=bin bash
4863 ...@: you can copy that pack to a machine that lacks Guix, and from your
4864 home directory as a normal user, run:
4872 In that shell, if you type @code{ls /gnu/store}, you'll notice that
4873 @file{/gnu/store} shows up and contains all the dependencies of
4874 @code{bash}, even though the machine actually lacks @file{/gnu/store}
4875 altogether! That is probably the simplest way to deploy Guix-built
4876 software on a non-Guix machine.
4879 By default, relocatable binaries rely on the @dfn{user namespace} feature of
4880 the kernel Linux, which allows unprivileged users to mount or change root.
4881 Old versions of Linux did not support it, and some GNU/Linux distributions
4884 To produce relocatable binaries that work even in the absence of user
4885 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
4886 case, binaries will try user namespace support and fall back to PRoot if user
4887 namespaces are not supported.
4889 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
4890 support for file system virtualization. It achieves that by using the
4891 @code{ptrace} system call on the running program. This approach has the
4892 advantage to work without requiring special kernel support, but it incurs
4893 run-time overhead every time a system call is made.
4896 @cindex entry point, for Docker images
4897 @item --entry-point=@var{command}
4898 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
4899 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
4900 support it. @var{command} must be relative to the profile contained in the
4903 The entry point specifies the command that tools like @code{docker run} or
4904 @code{singularity run} automatically start by default. For example, you can
4908 guix pack -f docker --entry-point=bin/guile guile
4911 The resulting pack can easily be loaded and @code{docker run} with no extra
4912 arguments will spawn @code{bin/guile}:
4915 docker load -i pack.tar.gz
4916 docker run @var{image-id}
4919 @item --expression=@var{expr}
4920 @itemx -e @var{expr}
4921 Consider the package @var{expr} evaluates to.
4923 This has the same purpose as the same-named option in @command{guix
4924 build} (@pxref{Additional Build Options, @code{--expression} in
4925 @command{guix build}}).
4927 @item --manifest=@var{file}
4928 @itemx -m @var{file}
4929 Use the packages contained in the manifest object returned by the Scheme
4932 This has a similar purpose as the same-named option in @command{guix
4933 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
4934 same manifest files. It allows you to define a collection of packages
4935 once and use it both for creating profiles and for creating archives
4936 for use on machines that do not have Guix installed. Note that you can
4937 specify @emph{either} a manifest file @emph{or} a list of packages,
4940 @item --system=@var{system}
4941 @itemx -s @var{system}
4942 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4943 the system type of the build host.
4945 @item --target=@var{triplet}
4946 @cindex cross-compilation
4947 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
4948 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
4949 configuration triplets,, autoconf, Autoconf}).
4951 @item --compression=@var{tool}
4952 @itemx -C @var{tool}
4953 Compress the resulting tarball using @var{tool}---one of @code{gzip},
4954 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
4956 @item --symlink=@var{spec}
4957 @itemx -S @var{spec}
4958 Add the symlinks specified by @var{spec} to the pack. This option can
4959 appear several times.
4961 @var{spec} has the form @code{@var{source}=@var{target}}, where
4962 @var{source} is the symlink that will be created and @var{target} is the
4965 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
4966 symlink pointing to the @file{bin} sub-directory of the profile.
4968 @item --save-provenance
4969 Save provenance information for the packages passed on the command line.
4970 Provenance information includes the URL and commit of the channels in use
4973 Provenance information is saved in the
4974 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
4975 usual package metadata---the name and version of each package, their
4976 propagated inputs, and so on. It is useful information to the recipient of
4977 the pack, who then knows how the pack was (supposedly) obtained.
4979 This option is not enabled by default because, like timestamps, provenance
4980 information contributes nothing to the build process. In other words, there
4981 is an infinity of channel URLs and commit IDs that can lead to the same pack.
4982 Recording such ``silent'' metadata in the output thus potentially breaks the
4983 source-to-binary bitwise reproducibility property.
4985 @item --root=@var{file}
4986 @itemx -r @var{file}
4987 @cindex garbage collector root, for packs
4988 Make @var{file} a symlink to the resulting pack, and register it as a garbage
4991 @item --localstatedir
4992 @itemx --profile-name=@var{name}
4993 Include the ``local state directory'', @file{/var/guix}, in the resulting
4994 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
4995 profile---by default @var{name} is @code{guix-profile}, which corresponds to
4996 @file{~root/.guix-profile}.
4998 @file{/var/guix} contains the store database (@pxref{The Store}) as well
4999 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5000 the pack means that the store is ``complete'' and manageable by Guix;
5001 not providing it pack means that the store is ``dead'': items cannot be
5002 added to it or removed from it after extraction of the pack.
5004 One use case for this is the Guix self-contained binary tarball
5005 (@pxref{Binary Installation}).
5008 Use the bootstrap binaries to build the pack. This option is only
5009 useful to Guix developers.
5012 In addition, @command{guix pack} supports all the common build options
5013 (@pxref{Common Build Options}) and all the package transformation
5014 options (@pxref{Package Transformation Options}).
5017 @c *********************************************************************
5018 @node Programming Interface
5019 @chapter Programming Interface
5021 GNU Guix provides several Scheme programming interfaces (APIs) to
5022 define, build, and query packages. The first interface allows users to
5023 write high-level package definitions. These definitions refer to
5024 familiar packaging concepts, such as the name and version of a package,
5025 its build system, and its dependencies. These definitions can then be
5026 turned into concrete build actions.
5028 Build actions are performed by the Guix daemon, on behalf of users. In a
5029 standard setup, the daemon has write access to the store---the
5030 @file{/gnu/store} directory---whereas users do not. The recommended
5031 setup also has the daemon perform builds in chroots, under a specific
5032 build users, to minimize interference with the rest of the system.
5035 Lower-level APIs are available to interact with the daemon and the
5036 store. To instruct the daemon to perform a build action, users actually
5037 provide it with a @dfn{derivation}. A derivation is a low-level
5038 representation of the build actions to be taken, and the environment in
5039 which they should occur---derivations are to package definitions what
5040 assembly is to C programs. The term ``derivation'' comes from the fact
5041 that build results @emph{derive} from them.
5043 This chapter describes all these APIs in turn, starting from high-level
5044 package definitions.
5047 * Package Modules:: Packages from the programmer's viewpoint.
5048 * Defining Packages:: Defining new packages.
5049 * Build Systems:: Specifying how packages are built.
5050 * The Store:: Manipulating the package store.
5051 * Derivations:: Low-level interface to package derivations.
5052 * The Store Monad:: Purely functional interface to the store.
5053 * G-Expressions:: Manipulating build expressions.
5054 * Invoking guix repl:: Fiddling with Guix interactively.
5057 @node Package Modules
5058 @section Package Modules
5060 From a programming viewpoint, the package definitions of the
5061 GNU distribution are provided by Guile modules in the @code{(gnu packages
5062 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5063 packages @dots{})} module name space are not necessarily ``GNU
5064 packages''. This module naming scheme follows the usual Guile module
5065 naming convention: @code{gnu} means that these modules are distributed
5066 as part of the GNU system, and @code{packages} identifies modules that
5067 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5068 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5069 module exports a variable named @code{emacs}, which is bound to a
5070 @code{<package>} object (@pxref{Defining Packages}).
5072 The @code{(gnu packages @dots{})} module name space is
5073 automatically scanned for packages by the command-line tools. For
5074 instance, when running @code{guix install emacs}, all the @code{(gnu
5075 packages @dots{})} modules are scanned until one that exports a package
5076 object whose name is @code{emacs} is found. This package search
5077 facility is implemented in the @code{(gnu packages)} module.
5079 @cindex customization, of packages
5080 @cindex package module search path
5081 Users can store package definitions in modules with different
5082 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5083 name and module name must match. For instance, the @code{(my-packages
5084 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5085 relative to the load path specified with @option{--load-path} or
5086 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5087 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5088 these package definitions visible to the user interfaces:
5092 By adding the directory containing your package modules to the search path
5093 with the @code{-L} flag of @command{guix package} and other commands
5094 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5095 environment variable described below.
5098 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5099 pulls from it. A channel is essentially a Git repository containing package
5100 modules. @xref{Channels}, for more information on how to define and use
5104 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5106 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5107 This is a colon-separated list of directories to search for additional
5108 package modules. Directories listed in this variable take precedence
5109 over the own modules of the distribution.
5112 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5113 each package is built based solely on other packages in the
5114 distribution. The root of this dependency graph is a small set of
5115 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5116 bootstrap)} module. For more information on bootstrapping,
5117 @pxref{Bootstrapping}.
5119 @node Defining Packages
5120 @section Defining Packages
5122 The high-level interface to package definitions is implemented in the
5123 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5124 example, the package definition, or @dfn{recipe}, for the GNU Hello
5125 package looks like this:
5128 (define-module (gnu packages hello)
5129 #:use-module (guix packages)
5130 #:use-module (guix download)
5131 #:use-module (guix build-system gnu)
5132 #:use-module (guix licenses)
5133 #:use-module (gnu packages gawk))
5135 (define-public hello
5141 (uri (string-append "mirror://gnu/hello/hello-" version
5145 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5146 (build-system gnu-build-system)
5147 (arguments '(#:configure-flags '("--enable-silent-rules")))
5148 (inputs `(("gawk" ,gawk)))
5149 (synopsis "Hello, GNU world: An example GNU package")
5150 (description "Guess what GNU Hello prints!")
5151 (home-page "https://www.gnu.org/software/hello/")
5156 Without being a Scheme expert, the reader may have guessed the meaning
5157 of the various fields here. This expression binds the variable
5158 @code{hello} to a @code{<package>} object, which is essentially a record
5159 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5160 This package object can be inspected using procedures found in the
5161 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5162 returns---surprise!---@code{"hello"}.
5164 With luck, you may be able to import part or all of the definition of
5165 the package you are interested in from another repository, using the
5166 @code{guix import} command (@pxref{Invoking guix import}).
5168 In the example above, @var{hello} is defined in a module of its own,
5169 @code{(gnu packages hello)}. Technically, this is not strictly
5170 necessary, but it is convenient to do so: all the packages defined in
5171 modules under @code{(gnu packages @dots{})} are automatically known to
5172 the command-line tools (@pxref{Package Modules}).
5174 There are a few points worth noting in the above package definition:
5178 The @code{source} field of the package is an @code{<origin>} object
5179 (@pxref{origin Reference}, for the complete reference).
5180 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5181 meaning that the source is a file to be downloaded over FTP or HTTP.
5183 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5184 the GNU mirrors defined in @code{(guix download)}.
5186 The @code{sha256} field specifies the expected SHA256 hash of the file
5187 being downloaded. It is mandatory, and allows Guix to check the
5188 integrity of the file. The @code{(base32 @dots{})} form introduces the
5189 base32 representation of the hash. You can obtain this information with
5190 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5191 hash} (@pxref{Invoking guix hash}).
5194 When needed, the @code{origin} form can also have a @code{patches} field
5195 listing patches to be applied, and a @code{snippet} field giving a
5196 Scheme expression to modify the source code.
5199 @cindex GNU Build System
5200 The @code{build-system} field specifies the procedure to build the
5201 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5202 represents the familiar GNU Build System, where packages may be
5203 configured, built, and installed with the usual @code{./configure &&
5204 make && make check && make install} command sequence.
5207 The @code{arguments} field specifies options for the build system
5208 (@pxref{Build Systems}). Here it is interpreted by
5209 @var{gnu-build-system} as a request run @file{configure} with the
5210 @code{--enable-silent-rules} flag.
5216 What about these quote (@code{'}) characters? They are Scheme syntax to
5217 introduce a literal list; @code{'} is synonymous with @code{quote}.
5218 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5219 for details. Here the value of the @code{arguments} field is a list of
5220 arguments passed to the build system down the road, as with @code{apply}
5221 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5224 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5225 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5226 @code{#:configure-flags} is a keyword used to pass a keyword argument
5227 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5231 The @code{inputs} field specifies inputs to the build process---i.e.,
5232 build-time or run-time dependencies of the package. Here, we define an
5233 input called @code{"gawk"} whose value is that of the @var{gawk}
5234 variable; @var{gawk} is itself bound to a @code{<package>} object.
5236 @cindex backquote (quasiquote)
5239 @cindex comma (unquote)
5243 @findex unquote-splicing
5244 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5245 us to introduce a literal list in the @code{inputs} field, while
5246 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5247 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5250 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5251 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5252 of ensuring that they are present (@pxref{Build Systems}).
5254 However, any other dependencies need to be specified in the
5255 @code{inputs} field. Any dependency not specified here will simply be
5256 unavailable to the build process, possibly leading to a build failure.
5259 @xref{package Reference}, for a full description of possible fields.
5261 Once a package definition is in place, the
5262 package may actually be built using the @code{guix build} command-line
5263 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5264 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5265 package definition using the @command{guix edit} command
5266 (@pxref{Invoking guix edit}).
5267 @xref{Packaging Guidelines}, for
5268 more information on how to test package definitions, and
5269 @ref{Invoking guix lint}, for information on how to check a definition
5270 for style conformance.
5271 @vindex GUIX_PACKAGE_PATH
5272 Lastly, @pxref{Channels}, for information
5273 on how to extend the distribution by adding your own package definitions
5276 Finally, updating the package definition to a new upstream version
5277 can be partly automated by the @command{guix refresh} command
5278 (@pxref{Invoking guix refresh}).
5280 Behind the scenes, a derivation corresponding to the @code{<package>}
5281 object is first computed by the @code{package-derivation} procedure.
5282 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5283 The build actions it prescribes may then be realized by using the
5284 @code{build-derivations} procedure (@pxref{The Store}).
5286 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5287 Return the @code{<derivation>} object of @var{package} for @var{system}
5288 (@pxref{Derivations}).
5290 @var{package} must be a valid @code{<package>} object, and @var{system}
5291 must be a string denoting the target system type---e.g.,
5292 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5293 must be a connection to the daemon, which operates on the store
5294 (@pxref{The Store}).
5298 @cindex cross-compilation
5299 Similarly, it is possible to compute a derivation that cross-builds a
5300 package for some other system:
5302 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5303 @var{package} @var{target} [@var{system}]
5304 Return the @code{<derivation>} object of @var{package} cross-built from
5305 @var{system} to @var{target}.
5307 @var{target} must be a valid GNU triplet denoting the target hardware
5308 and operating system, such as @code{"mips64el-linux-gnu"}
5309 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5312 @cindex package transformations
5313 @cindex input rewriting
5314 @cindex dependency tree rewriting
5315 Packages can be manipulated in arbitrary ways. An example of a useful
5316 transformation is @dfn{input rewriting}, whereby the dependency tree of
5317 a package is rewritten by replacing specific inputs by others:
5319 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5320 [@var{rewrite-name}]
5321 Return a procedure that, when passed a package, replaces its direct and
5322 indirect dependencies (but not its implicit inputs) according to
5323 @var{replacements}. @var{replacements} is a list of package pairs; the
5324 first element of each pair is the package to replace, and the second one
5327 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5328 the name of a package and returns its new name after rewrite.
5332 Consider this example:
5335 (define libressl-instead-of-openssl
5336 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5338 (package-input-rewriting `((,openssl . ,libressl))))
5340 (define git-with-libressl
5341 (libressl-instead-of-openssl git))
5345 Here we first define a rewriting procedure that replaces @var{openssl}
5346 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5347 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5348 This is exactly what the @option{--with-input} command-line option does
5349 (@pxref{Package Transformation Options, @option{--with-input}}).
5351 The following variant of @code{package-input-rewriting} can match packages to
5352 be replaced by name rather than by identity.
5354 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5355 Return a procedure that, given a package, applies the given @var{replacements} to
5356 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5357 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5358 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5359 replacement for that package.
5362 The example above could be rewritten this way:
5365 (define libressl-instead-of-openssl
5366 ;; Replace all the packages called "openssl" with LibreSSL.
5367 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5370 The key difference here is that, this time, packages are matched by spec and
5371 not by identity. In other words, any package in the graph that is called
5372 @code{openssl} will be replaced.
5374 A more generic procedure to rewrite a package dependency graph is
5375 @code{package-mapping}: it supports arbitrary changes to nodes in the
5378 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5379 Return a procedure that, given a package, applies @var{proc} to all the packages
5380 depended on and returns the resulting package. The procedure stops recursion
5381 when @var{cut?} returns true for a given package.
5385 * package Reference:: The package data type.
5386 * origin Reference:: The origin data type.
5390 @node package Reference
5391 @subsection @code{package} Reference
5393 This section summarizes all the options available in @code{package}
5394 declarations (@pxref{Defining Packages}).
5396 @deftp {Data Type} package
5397 This is the data type representing a package recipe.
5401 The name of the package, as a string.
5403 @item @code{version}
5404 The version of the package, as a string.
5407 An object telling how the source code for the package should be
5408 acquired. Most of the time, this is an @code{origin} object, which
5409 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5410 can also be any other ``file-like'' object such as a @code{local-file},
5411 which denotes a file from the local file system (@pxref{G-Expressions,
5412 @code{local-file}}).
5414 @item @code{build-system}
5415 The build system that should be used to build the package (@pxref{Build
5418 @item @code{arguments} (default: @code{'()})
5419 The arguments that should be passed to the build system. This is a
5420 list, typically containing sequential keyword-value pairs.
5422 @item @code{inputs} (default: @code{'()})
5423 @itemx @code{native-inputs} (default: @code{'()})
5424 @itemx @code{propagated-inputs} (default: @code{'()})
5425 @cindex inputs, of packages
5426 These fields list dependencies of the package. Each one is a list of
5427 tuples, where each tuple has a label for the input (a string) as its
5428 first element, a package, origin, or derivation as its second element,
5429 and optionally the name of the output thereof that should be used, which
5430 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5431 more on package outputs). For example, the list below specifies three
5435 `(("libffi" ,libffi)
5436 ("libunistring" ,libunistring)
5437 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5440 @cindex cross compilation, package dependencies
5441 The distinction between @code{native-inputs} and @code{inputs} is
5442 necessary when considering cross-compilation. When cross-compiling,
5443 dependencies listed in @code{inputs} are built for the @emph{target}
5444 architecture; conversely, dependencies listed in @code{native-inputs}
5445 are built for the architecture of the @emph{build} machine.
5447 @code{native-inputs} is typically used to list tools needed at
5448 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5449 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5450 this area (@pxref{Invoking guix lint}).
5452 @anchor{package-propagated-inputs}
5453 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5454 specified packages will be automatically installed alongside the package
5455 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5456 package}}, for information on how @command{guix package} deals with
5459 For example this is necessary when a C/C++ library needs headers of
5460 another library to compile, or when a pkg-config file refers to another
5461 one @i{via} its @code{Requires} field.
5463 Another example where @code{propagated-inputs} is useful is for languages
5464 that lack a facility to record the run-time search path akin to the
5465 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5466 more. To ensure that libraries written in those languages can find
5467 library code they depend on at run time, run-time dependencies must be
5468 listed in @code{propagated-inputs} rather than @code{inputs}.
5470 @item @code{outputs} (default: @code{'("out")})
5471 The list of output names of the package. @xref{Packages with Multiple
5472 Outputs}, for typical uses of additional outputs.
5474 @item @code{native-search-paths} (default: @code{'()})
5475 @itemx @code{search-paths} (default: @code{'()})
5476 A list of @code{search-path-specification} objects describing
5477 search-path environment variables honored by the package.
5479 @item @code{replacement} (default: @code{#f})
5480 This must be either @code{#f} or a package object that will be used as a
5481 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5484 @item @code{synopsis}
5485 A one-line description of the package.
5487 @item @code{description}
5488 A more elaborate description of the package.
5490 @item @code{license}
5491 @cindex license, of packages
5492 The license of the package; a value from @code{(guix licenses)},
5493 or a list of such values.
5495 @item @code{home-page}
5496 The URL to the home-page of the package, as a string.
5498 @item @code{supported-systems} (default: @var{%supported-systems})
5499 The list of systems supported by the package, as strings of the form
5500 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5502 @item @code{maintainers} (default: @code{'()})
5503 The list of maintainers of the package, as @code{maintainer} objects.
5505 @item @code{location} (default: source location of the @code{package} form)
5506 The source location of the package. It is useful to override this when
5507 inheriting from another package, in which case this field is not
5508 automatically corrected.
5512 @deffn {Scheme Syntax} this-package
5513 When used in the @emph{lexical scope} of a package field definition, this
5514 identifier resolves to the package being defined.
5516 The example below shows how to add a package as a native input of itself when
5524 ;; When cross-compiled, Guile, for example, depends on
5525 ;; a native version of itself. Add it here.
5526 (native-inputs (if (%current-target-system)
5527 `(("self" ,this-package))
5531 It is an error to refer to @code{this-package} outside a package definition.
5534 @node origin Reference
5535 @subsection @code{origin} Reference
5537 This section summarizes all the options available in @code{origin}
5538 declarations (@pxref{Defining Packages}).
5540 @deftp {Data Type} origin
5541 This is the data type representing a source code origin.
5545 An object containing the URI of the source. The object type depends on
5546 the @code{method} (see below). For example, when using the
5547 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5548 values are: a URL represented as a string, or a list thereof.
5551 A procedure that handles the URI.
5556 @item @var{url-fetch} from @code{(guix download)}
5557 download a file from the HTTP, HTTPS, or FTP URL specified in the
5561 @item @var{git-fetch} from @code{(guix git-download)}
5562 clone the Git version control repository, and check out the revision
5563 specified in the @code{uri} field as a @code{git-reference} object; a
5564 @code{git-reference} looks like this:
5568 (url "git://git.debian.org/git/pkg-shadow/shadow")
5569 (commit "v4.1.5.1"))
5574 A bytevector containing the SHA-256 hash of the source. Typically the
5575 @code{base32} form is used here to generate the bytevector from a
5578 You can obtain this information using @code{guix download}
5579 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5582 @item @code{file-name} (default: @code{#f})
5583 The file name under which the source code should be saved. When this is
5584 @code{#f}, a sensible default value will be used in most cases. In case
5585 the source is fetched from a URL, the file name from the URL will be
5586 used. For version control checkouts, it is recommended to provide the
5587 file name explicitly because the default is not very descriptive.
5589 @item @code{patches} (default: @code{'()})
5590 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5591 file-like objects}) pointing to patches to be applied to the source.
5593 This list of patches must be unconditional. In particular, it cannot
5594 depend on the value of @code{%current-system} or
5595 @code{%current-target-system}.
5597 @item @code{snippet} (default: @code{#f})
5598 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5599 in the source directory. This is a convenient way to modify the source,
5600 sometimes more convenient than a patch.
5602 @item @code{patch-flags} (default: @code{'("-p1")})
5603 A list of command-line flags that should be passed to the @code{patch}
5606 @item @code{patch-inputs} (default: @code{#f})
5607 Input packages or derivations to the patching process. When this is
5608 @code{#f}, the usual set of inputs necessary for patching are provided,
5609 such as GNU@tie{}Patch.
5611 @item @code{modules} (default: @code{'()})
5612 A list of Guile modules that should be loaded during the patching
5613 process and while running the code in the @code{snippet} field.
5615 @item @code{patch-guile} (default: @code{#f})
5616 The Guile package that should be used in the patching process. When
5617 this is @code{#f}, a sensible default is used.
5623 @section Build Systems
5625 @cindex build system
5626 Each package definition specifies a @dfn{build system} and arguments for
5627 that build system (@pxref{Defining Packages}). This @code{build-system}
5628 field represents the build procedure of the package, as well as implicit
5629 dependencies of that build procedure.
5631 Build systems are @code{<build-system>} objects. The interface to
5632 create and manipulate them is provided by the @code{(guix build-system)}
5633 module, and actual build systems are exported by specific modules.
5635 @cindex bag (low-level package representation)
5636 Under the hood, build systems first compile package objects to
5637 @dfn{bags}. A @dfn{bag} is like a package, but with less
5638 ornamentation---in other words, a bag is a lower-level representation of
5639 a package, which includes all the inputs of that package, including some
5640 that were implicitly added by the build system. This intermediate
5641 representation is then compiled to a derivation (@pxref{Derivations}).
5643 Build systems accept an optional list of @dfn{arguments}. In package
5644 definitions, these are passed @i{via} the @code{arguments} field
5645 (@pxref{Defining Packages}). They are typically keyword arguments
5646 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5647 Guile Reference Manual}). The value of these arguments is usually
5648 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5649 by the daemon (@pxref{Derivations}).
5651 The main build system is @var{gnu-build-system}, which implements the
5652 standard build procedure for GNU and many other packages. It
5653 is provided by the @code{(guix build-system gnu)} module.
5655 @defvr {Scheme Variable} gnu-build-system
5656 @var{gnu-build-system} represents the GNU Build System, and variants
5657 thereof (@pxref{Configuration, configuration and makefile conventions,,
5658 standards, GNU Coding Standards}).
5660 @cindex build phases
5661 In a nutshell, packages using it are configured, built, and installed with
5662 the usual @code{./configure && make && make check && make install}
5663 command sequence. In practice, a few additional steps are often needed.
5664 All these steps are split up in separate @dfn{phases},
5665 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5666 modules for more details about the build phases.}:
5670 Unpack the source tarball, and change the current directory to the
5671 extracted source tree. If the source is actually a directory, copy it
5672 to the build tree, and enter that directory.
5674 @item patch-source-shebangs
5675 Patch shebangs encountered in source files so they refer to the right
5676 store file names. For instance, this changes @code{#!/bin/sh} to
5677 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5680 Run the @file{configure} script with a number of default options, such
5681 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5682 by the @code{#:configure-flags} argument.
5685 Run @code{make} with the list of flags specified with
5686 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5687 (the default), build with @code{make -j}.
5690 Run @code{make check}, or some other target specified with
5691 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5692 @code{#:parallel-tests?} argument is true (the default), run @code{make
5696 Run @code{make install} with the flags listed in @code{#:make-flags}.
5698 @item patch-shebangs
5699 Patch shebangs on the installed executable files.
5702 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5703 is false), copying them to the @code{debug} output when available
5704 (@pxref{Installing Debugging Files}).
5707 @vindex %standard-phases
5708 The build-side module @code{(guix build gnu-build-system)} defines
5709 @var{%standard-phases} as the default list of build phases.
5710 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5711 procedure implements the actual phase.
5713 The list of phases used for a particular package can be changed with the
5714 @code{#:phases} parameter. For instance, passing:
5717 #:phases (modify-phases %standard-phases (delete 'configure))
5720 means that all the phases described above will be used, except the
5721 @code{configure} phase.
5723 In addition, this build system ensures that the ``standard'' environment
5724 for GNU packages is available. This includes tools such as GCC, libc,
5725 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5726 build-system gnu)} module for a complete list). We call these the
5727 @dfn{implicit inputs} of a package, because package definitions do not
5728 have to mention them.
5731 Other @code{<build-system>} objects are defined to support other
5732 conventions and tools used by free software packages. They inherit most
5733 of @var{gnu-build-system}, and differ mainly in the set of inputs
5734 implicitly added to the build process, and in the list of phases
5735 executed. Some of these build systems are listed below.
5737 @defvr {Scheme Variable} ant-build-system
5738 This variable is exported by @code{(guix build-system ant)}. It
5739 implements the build procedure for Java packages that can be built with
5740 @url{https://ant.apache.org/, Ant build tool}.
5742 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5743 provided by the @code{icedtea} package to the set of inputs. Different
5744 packages can be specified with the @code{#:ant} and @code{#:jdk}
5745 parameters, respectively.
5747 When the original package does not provide a suitable Ant build file,
5748 the parameter @code{#:jar-name} can be used to generate a minimal Ant
5749 build file @file{build.xml} with tasks to build the specified jar
5750 archive. In this case the parameter @code{#:source-dir} can be used to
5751 specify the source sub-directory, defaulting to ``src''.
5753 The @code{#:main-class} parameter can be used with the minimal ant
5754 buildfile to specify the main class of the resulting jar. This makes the
5755 jar file executable. The @code{#:test-include} parameter can be used to
5756 specify the list of junit tests to run. It defaults to
5757 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
5758 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
5759 because abstract classes cannot be run as tests.
5761 The parameter @code{#:build-target} can be used to specify the Ant task
5762 that should be run during the @code{build} phase. By default the
5763 ``jar'' task will be run.
5767 @defvr {Scheme Variable} android-ndk-build-system
5768 @cindex Android distribution
5769 @cindex Android NDK build system
5770 This variable is exported by @code{(guix build-system android-ndk)}. It
5771 implements a build procedure for Android NDK (native development kit)
5772 packages using a Guix-specific build process.
5774 The build system assumes that packages install their public interface
5775 (header) files to the subdirectory "include" of the "out" output and
5776 their libraries to the subdirectory "lib" of the "out" output.
5778 It's also assumed that the union of all the dependencies of a package
5779 has no conflicting files.
5781 For the time being, cross-compilation is not supported - so right now
5782 the libraries and header files are assumed to be host tools.
5786 @defvr {Scheme Variable} asdf-build-system/source
5787 @defvrx {Scheme Variable} asdf-build-system/sbcl
5788 @defvrx {Scheme Variable} asdf-build-system/ecl
5790 These variables, exported by @code{(guix build-system asdf)}, implement
5791 build procedures for Common Lisp packages using
5792 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
5793 definition facility for Common Lisp programs and libraries.
5795 The @code{asdf-build-system/source} system installs the packages in
5796 source form, and can be loaded using any common lisp implementation, via
5797 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
5798 systems in the format which a particular implementation understands.
5799 These build systems can also be used to produce executable programs, or
5800 lisp images which contain a set of packages pre-loaded.
5802 The build system uses naming conventions. For binary packages, the
5803 package name should be prefixed with the lisp implementation, such as
5804 @code{sbcl-} for @code{asdf-build-system/sbcl}.
5806 Additionally, the corresponding source package should be labeled using
5807 the same convention as python packages (see @ref{Python Modules}), using
5808 the @code{cl-} prefix.
5810 For binary packages, each system should be defined as a Guix package.
5811 If one package @code{origin} contains several systems, package variants
5812 can be created in order to build all the systems. Source packages,
5813 which use @code{asdf-build-system/source}, may contain several systems.
5815 In order to create executable programs and images, the build-side
5816 procedures @code{build-program} and @code{build-image} can be used.
5817 They should be called in a build phase after the @code{create-symlinks}
5818 phase, so that the system which was just built can be used within the
5819 resulting image. @code{build-program} requires a list of Common Lisp
5820 expressions to be passed as the @code{#:entry-program} argument.
5822 If the system is not defined within its own @code{.asd} file of the same
5823 name, then the @code{#:asd-file} parameter should be used to specify
5824 which file the system is defined in. Furthermore, if the package
5825 defines a system for its tests in a separate file, it will be loaded
5826 before the tests are run if it is specified by the
5827 @code{#:test-asd-file} parameter. If it is not set, the files
5828 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
5829 and @code{test.asd} will be tried if they exist.
5831 If for some reason the package must be named in a different way than the
5832 naming conventions suggest, the @code{#:asd-system-name} parameter can
5833 be used to specify the name of the system.
5837 @defvr {Scheme Variable} cargo-build-system
5838 @cindex Rust programming language
5839 @cindex Cargo (Rust build system)
5840 This variable is exported by @code{(guix build-system cargo)}. It
5841 supports builds of packages using Cargo, the build tool of the
5842 @uref{https://www.rust-lang.org, Rust programming language}.
5844 It adds @code{rustc} and @code{cargo} to the set of inputs.
5845 A different Rust package can be specified with the @code{#:rust} parameter.
5847 Regular cargo dependencies should be added to the package definition via the
5848 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
5849 spec can be a package or a source definition. Note that the spec must
5850 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
5851 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
5852 should be added to the package definition via the
5853 @code{#:cargo-development-inputs} parameter.
5855 In its @code{configure} phase, this build system will make any source inputs
5856 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
5857 parameters available to cargo. The @code{update-cargo-lock} phase will,
5858 when there is a @code{Cargo.lock} file, update the @code{Cargo.lock} file
5859 with the inputs and their versions available at build time. The
5860 @code{install} phase installs any crate the binaries if they are defined by
5864 @cindex Clojure (programming language)
5865 @cindex simple Clojure build system
5866 @defvr {Scheme Variable} clojure-build-system
5867 This variable is exported by @code{(guix build-system clojure)}. It implements
5868 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
5869 using plain old @code{compile} in Clojure. Cross-compilation is not supported
5872 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
5873 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
5874 @code{#:zip} parameters, respectively.
5876 A list of source directories, test directories and jar names can be specified
5877 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
5878 parameters, respectively. Compile directory and main class can be specified
5879 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
5880 Other parameters are documented below.
5882 This build system is an extension of @var{ant-build-system}, but with the
5883 following phases changed:
5888 This phase calls @code{compile} in Clojure to compile source files and runs
5889 @command{jar} to create jars from both source files and compiled files
5890 according to the include list and exclude list specified in
5891 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
5892 has priority over the include list. These lists consist of symbols
5893 representing Clojure libraries or the special keyword @code{#:all} representing
5894 all Clojure libraries found under the source directories. The parameter
5895 @code{#:omit-source?} decides if source should be included into the jars.
5898 This phase runs tests according to the include list and exclude list specified
5899 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
5900 meanings are analogous to that of @code{#:aot-include} and
5901 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
5902 stands for all Clojure libraries found under the test directories. The
5903 parameter @code{#:tests?} decides if tests should be run.
5906 This phase installs all jars built previously.
5909 Apart from the above, this build system also contains an additional phase:
5914 This phase installs all top-level files with base name matching
5915 @var{%doc-regex}. A different regex can be specified with the
5916 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
5917 directories specified in @code{#:doc-dirs} are installed as well.
5921 @defvr {Scheme Variable} cmake-build-system
5922 This variable is exported by @code{(guix build-system cmake)}. It
5923 implements the build procedure for packages using the
5924 @url{https://www.cmake.org, CMake build tool}.
5926 It automatically adds the @code{cmake} package to the set of inputs.
5927 Which package is used can be specified with the @code{#:cmake}
5930 The @code{#:configure-flags} parameter is taken as a list of flags
5931 passed to the @command{cmake} command. The @code{#:build-type}
5932 parameter specifies in abstract terms the flags passed to the compiler;
5933 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
5934 debugging information''), which roughly means that code is compiled with
5935 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
5938 @defvr {Scheme Variable} dune-build-system
5939 This variable is exported by @code{(guix build-system dune)}. It
5940 supports builds of packages using @uref{https://dune.build/, Dune}, a build
5941 tool for the OCaml programming language. It is implemented as an extension
5942 of the @code{ocaml-build-system} which is described below. As such, the
5943 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
5946 It automatically adds the @code{dune} package to the set of inputs.
5947 Which package is used can be specified with the @code{#:dune}
5950 There is no @code{configure} phase because dune packages typically don't
5951 need to be configured. The @code{#:build-flags} parameter is taken as a
5952 list of flags passed to the @code{dune} command during the build.
5954 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
5955 command instead of the more recent @code{dune} command while building
5956 a package. Its default value is @code{#f}.
5958 The @code{#:package} parameter can be passed to specify a package name, which
5959 is useful when a package contains multiple packages and you want to build
5960 only one of them. This is equivalent to passing the @code{-p} argument to
5964 @defvr {Scheme Variable} go-build-system
5965 This variable is exported by @code{(guix build-system go)}. It
5966 implements a build procedure for Go packages using the standard
5967 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
5968 Go build mechanisms}.
5970 The user is expected to provide a value for the key @code{#:import-path}
5971 and, in some cases, @code{#:unpack-path}. The
5972 @url{https://golang.org/doc/code.html#ImportPaths, import path}
5973 corresponds to the file system path expected by the package's build
5974 scripts and any referring packages, and provides a unique way to
5975 refer to a Go package. It is typically based on a combination of the
5976 package source code's remote URI and file system hierarchy structure. In
5977 some cases, you will need to unpack the package's source code to a
5978 different directory structure than the one indicated by the import path,
5979 and @code{#:unpack-path} should be used in such cases.
5981 Packages that provide Go libraries should install their source code into
5982 the built output. The key @code{#:install-source?}, which defaults to
5983 @code{#t}, controls whether or not the source code is installed. It can
5984 be set to @code{#f} for packages that only provide executable files.
5987 @defvr {Scheme Variable} glib-or-gtk-build-system
5988 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
5989 is intended for use with packages making use of GLib or GTK+.
5991 This build system adds the following two phases to the ones defined by
5992 @var{gnu-build-system}:
5995 @item glib-or-gtk-wrap
5996 The phase @code{glib-or-gtk-wrap} ensures that programs in
5997 @file{bin/} are able to find GLib ``schemas'' and
5998 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
5999 modules}. This is achieved by wrapping the programs in launch scripts
6000 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6001 environment variables.
6003 It is possible to exclude specific package outputs from that wrapping
6004 process by listing their names in the
6005 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6006 when an output is known not to contain any GLib or GTK+ binaries, and
6007 where wrapping would gratuitously add a dependency of that output on
6010 @item glib-or-gtk-compile-schemas
6011 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6012 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6013 GSettings schemas} of GLib are compiled. Compilation is performed by the
6014 @command{glib-compile-schemas} program. It is provided by the package
6015 @code{glib:bin} which is automatically imported by the build system.
6016 The @code{glib} package providing @command{glib-compile-schemas} can be
6017 specified with the @code{#:glib} parameter.
6020 Both phases are executed after the @code{install} phase.
6023 @defvr {Scheme Variable} guile-build-system
6024 This build system is for Guile packages that consist exclusively of Scheme
6025 code and that are so lean that they don't even have a makefile, let alone a
6026 @file{configure} script. It compiles Scheme code using @command{guild
6027 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6028 installs the @file{.scm} and @file{.go} files in the right place. It also
6029 installs documentation.
6031 This build system supports cross-compilation by using the @code{--target}
6032 option of @command{guild compile}.
6034 Packages built with @code{guile-build-system} must provide a Guile package in
6035 their @code{native-inputs} field.
6038 @defvr {Scheme Variable} minify-build-system
6039 This variable is exported by @code{(guix build-system minify)}. It
6040 implements a minification procedure for simple JavaScript packages.
6042 It adds @code{uglify-js} to the set of inputs and uses it to compress
6043 all JavaScript files in the @file{src} directory. A different minifier
6044 package can be specified with the @code{#:uglify-js} parameter, but it
6045 is expected that the package writes the minified code to the standard
6048 When the input JavaScript files are not all located in the @file{src}
6049 directory, the parameter @code{#:javascript-files} can be used to
6050 specify a list of file names to feed to the minifier.
6053 @defvr {Scheme Variable} ocaml-build-system
6054 This variable is exported by @code{(guix build-system ocaml)}. It implements
6055 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6056 of choosing the correct set of commands to run for each package. OCaml
6057 packages can expect many different commands to be run. This build system will
6060 When the package has a @file{setup.ml} file present at the top-level, it will
6061 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6062 @code{ocaml setup.ml -install}. The build system will assume that this file
6063 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6064 care of setting the prefix and enabling tests if they are not disabled. You
6065 can pass configure and build flags with the @code{#:configure-flags} and
6066 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6067 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6068 bypass this system in the build and install phases.
6070 When the package has a @file{configure} file, it is assumed that it is a
6071 hand-made configure script that requires a different argument format than
6072 in the @code{gnu-build-system}. You can add more flags with the
6073 @code{#:configure-flags} key.
6075 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6076 @code{#t}), it will be used and more flags can be passed to the build and
6077 install phases with the @code{#:make-flags} key.
6079 Finally, some packages do not have these files and use a somewhat standard
6080 location for its build system. In that case, the build system will run
6081 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6082 providing the path to the required findlib module. Additional flags can
6083 be passed via the @code{#:build-flags} key. Install is taken care of by
6084 @command{opam-installer}. In this case, the @code{opam} package must
6085 be added to the @code{native-inputs} field of the package definition.
6087 Note that most OCaml packages assume they will be installed in the same
6088 directory as OCaml, which is not what we want in guix. In particular, they
6089 will install @file{.so} files in their module's directory, which is usually
6090 fine because it is in the OCaml compiler directory. In guix though, these
6091 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6092 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6093 @file{.so} libraries should be installed.
6096 @defvr {Scheme Variable} python-build-system
6097 This variable is exported by @code{(guix build-system python)}. It
6098 implements the more or less standard build procedure used by Python
6099 packages, which consists in running @code{python setup.py build} and
6100 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6102 For packages that install stand-alone Python programs under @code{bin/},
6103 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6104 environment variable points to all the Python libraries they depend on.
6106 Which Python package is used to perform the build can be specified with
6107 the @code{#:python} parameter. This is a useful way to force a package
6108 to be built for a specific version of the Python interpreter, which
6109 might be necessary if the package is only compatible with a single
6110 interpreter version.
6112 By default guix calls @code{setup.py} under control of
6113 @code{setuptools}, much like @command{pip} does. Some packages are not
6114 compatible with setuptools (and pip), thus you can disable this by
6115 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6118 @defvr {Scheme Variable} perl-build-system
6119 This variable is exported by @code{(guix build-system perl)}. It
6120 implements the standard build procedure for Perl packages, which either
6121 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6122 followed by @code{Build} and @code{Build install}; or in running
6123 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6124 @code{make} and @code{make install}, depending on which of
6125 @code{Build.PL} or @code{Makefile.PL} is present in the package
6126 distribution. Preference is given to the former if both @code{Build.PL}
6127 and @code{Makefile.PL} exist in the package distribution. This
6128 preference can be reversed by specifying @code{#t} for the
6129 @code{#:make-maker?} parameter.
6131 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6132 passes flags specified by the @code{#:make-maker-flags} or
6133 @code{#:module-build-flags} parameter, respectively.
6135 Which Perl package is used can be specified with @code{#:perl}.
6138 @defvr {Scheme Variable} r-build-system
6139 This variable is exported by @code{(guix build-system r)}. It
6140 implements the build procedure used by @uref{https://r-project.org, R}
6141 packages, which essentially is little more than running @code{R CMD
6142 INSTALL --library=/gnu/store/@dots{}} in an environment where
6143 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6144 are run after installation using the R function
6145 @code{tools::testInstalledPackage}.
6148 @defvr {Scheme Variable} rakudo-build-system
6149 This variable is exported by @code{(guix build-system rakudo)}. It
6150 implements the build procedure used by @uref{https://rakudo.org/,
6151 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6152 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6153 installs the binaries, library files and the resources, as well as wrap
6154 the files under the @code{bin/} directory. Tests can be skipped by
6155 passing @code{#f} to the @code{tests?} parameter.
6157 Which rakudo package is used can be specified with @code{rakudo}.
6158 Which perl6-tap-harness package used for the tests can be specified with
6159 @code{#:prove6} or removed by passing @code{#f} to the
6160 @code{with-prove6?} parameter.
6161 Which perl6-zef package used for tests and installing can be specified
6162 with @code{#:zef} or removed by passing @code{#f} to the
6163 @code{with-zef?} parameter.
6166 @defvr {Scheme Variable} texlive-build-system
6167 This variable is exported by @code{(guix build-system texlive)}. It is
6168 used to build TeX packages in batch mode with a specified engine. The
6169 build system sets the @code{TEXINPUTS} variable to find all TeX source
6170 files in the inputs.
6172 By default it runs @code{luatex} on all files ending on @code{ins}. A
6173 different engine and format can be specified with the
6174 @code{#:tex-format} argument. Different build targets can be specified
6175 with the @code{#:build-targets} argument, which expects a list of file
6176 names. The build system adds only @code{texlive-bin} and
6177 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6178 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6179 and @code{#:texlive-latex-base}, respectively.
6181 The @code{#:tex-directory} parameter tells the build system where to
6182 install the built files under the texmf tree.
6185 @defvr {Scheme Variable} ruby-build-system
6186 This variable is exported by @code{(guix build-system ruby)}. It
6187 implements the RubyGems build procedure used by Ruby packages, which
6188 involves running @code{gem build} followed by @code{gem install}.
6190 The @code{source} field of a package that uses this build system
6191 typically references a gem archive, since this is the format that Ruby
6192 developers use when releasing their software. The build system unpacks
6193 the gem archive, potentially patches the source, runs the test suite,
6194 repackages the gem, and installs it. Additionally, directories and
6195 tarballs may be referenced to allow building unreleased gems from Git or
6196 a traditional source release tarball.
6198 Which Ruby package is used can be specified with the @code{#:ruby}
6199 parameter. A list of additional flags to be passed to the @command{gem}
6200 command can be specified with the @code{#:gem-flags} parameter.
6203 @defvr {Scheme Variable} waf-build-system
6204 This variable is exported by @code{(guix build-system waf)}. It
6205 implements a build procedure around the @code{waf} script. The common
6206 phases---@code{configure}, @code{build}, and @code{install}---are
6207 implemented by passing their names as arguments to the @code{waf}
6210 The @code{waf} script is executed by the Python interpreter. Which
6211 Python package is used to run the script can be specified with the
6212 @code{#:python} parameter.
6215 @defvr {Scheme Variable} scons-build-system
6216 This variable is exported by @code{(guix build-system scons)}. It
6217 implements the build procedure used by the SCons software construction
6218 tool. This build system runs @code{scons} to build the package,
6219 @code{scons test} to run tests, and then @code{scons install} to install
6222 Additional flags to be passed to @code{scons} can be specified with the
6223 @code{#:scons-flags} parameter. The version of Python used to run SCons
6224 can be specified by selecting the appropriate SCons package with the
6225 @code{#:scons} parameter.
6228 @defvr {Scheme Variable} haskell-build-system
6229 This variable is exported by @code{(guix build-system haskell)}. It
6230 implements the Cabal build procedure used by Haskell packages, which
6231 involves running @code{runhaskell Setup.hs configure
6232 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6233 Instead of installing the package by running @code{runhaskell Setup.hs
6234 install}, to avoid trying to register libraries in the read-only
6235 compiler store directory, the build system uses @code{runhaskell
6236 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6237 addition, the build system generates the package documentation by
6238 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6239 is passed. Optional Haddock parameters can be passed with the help of
6240 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6241 not found, the build system looks for @code{Setup.lhs} instead.
6243 Which Haskell compiler is used can be specified with the @code{#:haskell}
6244 parameter which defaults to @code{ghc}.
6247 @defvr {Scheme Variable} dub-build-system
6248 This variable is exported by @code{(guix build-system dub)}. It
6249 implements the Dub build procedure used by D packages, which
6250 involves running @code{dub build} and @code{dub run}.
6251 Installation is done by copying the files manually.
6253 Which D compiler is used can be specified with the @code{#:ldc}
6254 parameter which defaults to @code{ldc}.
6257 @defvr {Scheme Variable} emacs-build-system
6258 This variable is exported by @code{(guix build-system emacs)}. It
6259 implements an installation procedure similar to the packaging system
6260 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6262 It first creates the @code{@var{package}-autoloads.el} file, then it
6263 byte compiles all Emacs Lisp files. Differently from the Emacs
6264 packaging system, the Info documentation files are moved to the standard
6265 documentation directory and the @file{dir} file is deleted. Each
6266 package is installed in its own directory under
6267 @file{share/emacs/site-lisp/guix.d}.
6270 @defvr {Scheme Variable} font-build-system
6271 This variable is exported by @code{(guix build-system font)}. It
6272 implements an installation procedure for font packages where upstream
6273 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6274 need to be copied into place. It copies font files to standard
6275 locations in the output directory.
6278 @defvr {Scheme Variable} meson-build-system
6279 This variable is exported by @code{(guix build-system meson)}. It
6280 implements the build procedure for packages that use
6281 @url{https://mesonbuild.com, Meson} as their build system.
6283 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6284 of inputs, and they can be changed with the parameters @code{#:meson}
6285 and @code{#:ninja} if needed. The default Meson is
6286 @code{meson-for-build}, which is special because it doesn't clear the
6287 @code{RUNPATH} of binaries and libraries when they are installed.
6289 This build system is an extension of @var{gnu-build-system}, but with the
6290 following phases changed to some specific for Meson:
6295 The phase runs @code{meson} with the flags specified in
6296 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6297 @code{plain} unless something else is specified in @code{#:build-type}.
6300 The phase runs @code{ninja} to build the package in parallel by default, but
6301 this can be changed with @code{#:parallel-build?}.
6304 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6305 which is @code{"test"} by default.
6308 The phase runs @code{ninja install} and can not be changed.
6311 Apart from that, the build system also adds the following phases:
6316 This phase ensures that all binaries can find the libraries they need.
6317 It searches for required libraries in subdirectories of the package being
6318 built, and adds those to @code{RUNPATH} where needed. It also removes
6319 references to libraries left over from the build phase by
6320 @code{meson-for-build}, such as test dependencies, that aren't actually
6321 required for the program to run.
6323 @item glib-or-gtk-wrap
6324 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6325 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6327 @item glib-or-gtk-compile-schemas
6328 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6329 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6333 @defvr {Scheme Variable} linux-module-build-system
6334 @var{linux-module-build-system} allows building Linux kernel modules.
6336 @cindex build phases
6337 This build system is an extension of @var{gnu-build-system}, but with the
6338 following phases changed:
6343 This phase configures the environment so that the Linux kernel's Makefile
6344 can be used to build the external kernel module.
6347 This phase uses the Linux kernel's Makefile in order to build the external
6351 This phase uses the Linux kernel's Makefile in order to install the external
6355 It is possible and useful to specify the Linux kernel to use for building
6356 the module (in the "arguments" form of a package using the
6357 linux-module-build-system, use the key #:linux to specify it).
6360 @defvr {Scheme Variable} node-build-system
6361 This variable is exported by @code{(guix build-system node)}. It
6362 implements the build procedure used by @uref{http://nodejs.org,
6363 Node.js}, which implements an approximation of the @code{npm install}
6364 command, followed by an @code{npm test} command.
6366 Which Node.js package is used to interpret the @code{npm} commands can
6367 be specified with the @code{#:node} parameter which defaults to
6371 Lastly, for packages that do not need anything as sophisticated, a
6372 ``trivial'' build system is provided. It is trivial in the sense that
6373 it provides basically no support: it does not pull any implicit inputs,
6374 and does not have a notion of build phases.
6376 @defvr {Scheme Variable} trivial-build-system
6377 This variable is exported by @code{(guix build-system trivial)}.
6379 This build system requires a @code{#:builder} argument. This argument
6380 must be a Scheme expression that builds the package output(s)---as
6381 with @code{build-expression->derivation} (@pxref{Derivations,
6382 @code{build-expression->derivation}}).
6392 Conceptually, the @dfn{store} is the place where derivations that have
6393 been built successfully are stored---by default, @file{/gnu/store}.
6394 Sub-directories in the store are referred to as @dfn{store items} or
6395 sometimes @dfn{store paths}. The store has an associated database that
6396 contains information such as the store paths referred to by each store
6397 path, and the list of @emph{valid} store items---results of successful
6398 builds. This database resides in @file{@var{localstatedir}/guix/db},
6399 where @var{localstatedir} is the state directory specified @i{via}
6400 @option{--localstatedir} at configure time, usually @file{/var}.
6402 The store is @emph{always} accessed by the daemon on behalf of its clients
6403 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6404 connect to the daemon over a Unix-domain socket, send requests to it,
6405 and read the result---these are remote procedure calls, or RPCs.
6408 Users must @emph{never} modify files under @file{/gnu/store} directly.
6409 This would lead to inconsistencies and break the immutability
6410 assumptions of Guix's functional model (@pxref{Introduction}).
6412 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6413 how to check the integrity of the store and attempt recovery from
6414 accidental modifications.
6417 The @code{(guix store)} module provides procedures to connect to the
6418 daemon, and to perform RPCs. These are described below. By default,
6419 @code{open-connection}, and thus all the @command{guix} commands,
6420 connect to the local daemon or to the URI specified by the
6421 @code{GUIX_DAEMON_SOCKET} environment variable.
6423 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6424 When set, the value of this variable should be a file name or a URI
6425 designating the daemon endpoint. When it is a file name, it denotes a
6426 Unix-domain socket to connect to. In addition to file names, the
6427 supported URI schemes are:
6432 These are for Unix-domain sockets.
6433 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6434 @file{/var/guix/daemon-socket/socket}.
6437 @cindex daemon, remote access
6438 @cindex remote access to the daemon
6439 @cindex daemon, cluster setup
6440 @cindex clusters, daemon setup
6441 These URIs denote connections over TCP/IP, without encryption nor
6442 authentication of the remote host. The URI must specify the host name
6443 and optionally a port number (by default port 44146 is used):
6446 guix://master.guix.example.org:1234
6449 This setup is suitable on local networks, such as clusters, where only
6450 trusted nodes may connect to the build daemon at
6451 @code{master.guix.example.org}.
6453 The @code{--listen} option of @command{guix-daemon} can be used to
6454 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6458 @cindex SSH access to build daemons
6459 These URIs allow you to connect to a remote daemon over
6460 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6461 A typical URL might look like this:
6464 ssh://charlie@@guix.example.org:22
6467 As for @command{guix copy}, the usual OpenSSH client configuration files
6468 are honored (@pxref{Invoking guix copy}).
6471 Additional URI schemes may be supported in the future.
6473 @c XXX: Remove this note when the protocol incurs fewer round trips
6474 @c and when (guix derivations) no longer relies on file system access.
6476 The ability to connect to remote build daemons is considered
6477 experimental as of @value{VERSION}. Please get in touch with us to
6478 share any problems or suggestions you may have (@pxref{Contributing}).
6482 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6483 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6484 @var{reserve-space?} is true, instruct it to reserve a little bit of
6485 extra space on the file system so that the garbage collector can still
6486 operate should the disk become full. Return a server object.
6488 @var{file} defaults to @code{%default-socket-path}, which is the normal
6489 location given the options that were passed to @command{configure}.
6492 @deffn {Scheme Procedure} close-connection @var{server}
6493 Close the connection to @var{server}.
6496 @defvr {Scheme Variable} current-build-output-port
6497 This variable is bound to a SRFI-39 parameter, which refers to the port
6498 where build and error logs sent by the daemon should be written.
6501 Procedures that make RPCs all take a server object as their first
6504 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6505 @cindex invalid store items
6506 Return @code{#t} when @var{path} designates a valid store item and
6507 @code{#f} otherwise (an invalid item may exist on disk but still be
6508 invalid, for instance because it is the result of an aborted or failed
6511 A @code{&store-protocol-error} condition is raised if @var{path} is not
6512 prefixed by the store directory (@file{/gnu/store}).
6515 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6516 Add @var{text} under file @var{name} in the store, and return its store
6517 path. @var{references} is the list of store paths referred to by the
6518 resulting store path.
6521 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6523 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6524 file names, or derivation/output pairs, using the specified
6525 @var{mode}---@code{(build-mode normal)} by default.
6528 Note that the @code{(guix monads)} module provides a monad as well as
6529 monadic versions of the above procedures, with the goal of making it
6530 more convenient to work with code that accesses the store (@pxref{The
6534 @i{This section is currently incomplete.}
6537 @section Derivations
6540 Low-level build actions and the environment in which they are performed
6541 are represented by @dfn{derivations}. A derivation contains the
6542 following pieces of information:
6546 The outputs of the derivation---derivations produce at least one file or
6547 directory in the store, but may produce more.
6550 @cindex build-time dependencies
6551 @cindex dependencies, build-time
6552 The inputs of the derivations---i.e., its build-time dependencies---which may
6553 be other derivations or plain files in the store (patches, build scripts,
6557 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6560 The file name of a build script in the store, along with the arguments
6564 A list of environment variables to be defined.
6568 @cindex derivation path
6569 Derivations allow clients of the daemon to communicate build actions to
6570 the store. They exist in two forms: as an in-memory representation,
6571 both on the client- and daemon-side, and as files in the store whose
6572 name end in @code{.drv}---these files are referred to as @dfn{derivation
6573 paths}. Derivations paths can be passed to the @code{build-derivations}
6574 procedure to perform the build actions they prescribe (@pxref{The
6577 @cindex fixed-output derivations
6578 Operations such as file downloads and version-control checkouts for
6579 which the expected content hash is known in advance are modeled as
6580 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6581 of a fixed-output derivation are independent of its inputs---e.g., a
6582 source code download produces the same result regardless of the download
6583 method and tools being used.
6586 @cindex run-time dependencies
6587 @cindex dependencies, run-time
6588 The outputs of derivations---i.e., the build results---have a set of
6589 @dfn{references}, as reported by the @code{references} RPC or the
6590 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6591 are the set of run-time dependencies of the build results. References are a
6592 subset of the inputs of the derivation; this subset is automatically computed
6593 by the build daemon by scanning all the files in the outputs.
6595 The @code{(guix derivations)} module provides a representation of
6596 derivations as Scheme objects, along with procedures to create and
6597 otherwise manipulate derivations. The lowest-level primitive to create
6598 a derivation is the @code{derivation} procedure:
6600 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6601 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6602 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6603 [#:system (%current-system)] [#:references-graphs #f] @
6604 [#:allowed-references #f] [#:disallowed-references #f] @
6605 [#:leaked-env-vars #f] [#:local-build? #f] @
6606 [#:substitutable? #t] [#:properties '()]
6607 Build a derivation with the given arguments, and return the resulting
6608 @code{<derivation>} object.
6610 When @var{hash} and @var{hash-algo} are given, a
6611 @dfn{fixed-output derivation} is created---i.e., one whose result is
6612 known in advance, such as a file download. If, in addition,
6613 @var{recursive?} is true, then that fixed output may be an executable
6614 file or a directory and @var{hash} must be the hash of an archive
6615 containing this output.
6617 When @var{references-graphs} is true, it must be a list of file
6618 name/store path pairs. In that case, the reference graph of each store
6619 path is exported in the build environment in the corresponding file, in
6620 a simple text format.
6622 When @var{allowed-references} is true, it must be a list of store items
6623 or outputs that the derivation's output may refer to. Likewise,
6624 @var{disallowed-references}, if true, must be a list of things the
6625 outputs may @emph{not} refer to.
6627 When @var{leaked-env-vars} is true, it must be a list of strings
6628 denoting environment variables that are allowed to ``leak'' from the
6629 daemon's environment to the build environment. This is only applicable
6630 to fixed-output derivations---i.e., when @var{hash} is true. The main
6631 use is to allow variables such as @code{http_proxy} to be passed to
6632 derivations that download files.
6634 When @var{local-build?} is true, declare that the derivation is not a
6635 good candidate for offloading and should rather be built locally
6636 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6637 where the costs of data transfers would outweigh the benefits.
6639 When @var{substitutable?} is false, declare that substitutes of the
6640 derivation's output should not be used (@pxref{Substitutes}). This is
6641 useful, for instance, when building packages that capture details of the
6642 host CPU instruction set.
6644 @var{properties} must be an association list describing ``properties'' of the
6645 derivation. It is kept as-is, uninterpreted, in the derivation.
6649 Here's an example with a shell script as its builder, assuming
6650 @var{store} is an open connection to the daemon, and @var{bash} points
6651 to a Bash executable in the store:
6654 (use-modules (guix utils)
6658 (let ((builder ; add the Bash script to the store
6659 (add-text-to-store store "my-builder.sh"
6660 "echo hello world > $out\n" '())))
6661 (derivation store "foo"
6662 bash `("-e" ,builder)
6663 #:inputs `((,bash) (,builder))
6664 #:env-vars '(("HOME" . "/homeless"))))
6665 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6668 As can be guessed, this primitive is cumbersome to use directly. A
6669 better approach is to write build scripts in Scheme, of course! The
6670 best course of action for that is to write the build code as a
6671 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6672 information, @pxref{G-Expressions}.
6674 Once upon a time, @code{gexp->derivation} did not exist and constructing
6675 derivations with build code written in Scheme was achieved with
6676 @code{build-expression->derivation}, documented below. This procedure
6677 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6679 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6680 @var{name} @var{exp} @
6681 [#:system (%current-system)] [#:inputs '()] @
6682 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6683 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6684 [#:references-graphs #f] [#:allowed-references #f] @
6685 [#:disallowed-references #f] @
6686 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6687 Return a derivation that executes Scheme expression @var{exp} as a
6688 builder for derivation @var{name}. @var{inputs} must be a list of
6689 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6690 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6691 modules from the current search path to be copied in the store,
6692 compiled, and made available in the load path during the execution of
6693 @var{exp}---e.g., @code{((guix build utils) (guix build
6694 gnu-build-system))}.
6696 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6697 to a list of output/path pairs, and where @code{%build-inputs} is bound
6698 to a list of string/output-path pairs made from @var{inputs}.
6699 Optionally, @var{env-vars} is a list of string pairs specifying the name
6700 and value of environment variables visible to the builder. The builder
6701 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6702 @var{exp} returns @code{#f}, the build is considered to have failed.
6704 @var{exp} is built using @var{guile-for-build} (a derivation). When
6705 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6706 @code{%guile-for-build} fluid is used instead.
6708 See the @code{derivation} procedure for the meaning of
6709 @var{references-graphs}, @var{allowed-references},
6710 @var{disallowed-references}, @var{local-build?}, and
6711 @var{substitutable?}.
6715 Here's an example of a single-output derivation that creates a directory
6716 containing one file:
6719 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6720 (mkdir out) ; create /gnu/store/@dots{}-goo
6721 (call-with-output-file (string-append out "/test")
6723 (display '(hello guix) p))))))
6724 (build-expression->derivation store "goo" builder))
6726 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
6730 @node The Store Monad
6731 @section The Store Monad
6735 The procedures that operate on the store described in the previous
6736 sections all take an open connection to the build daemon as their first
6737 argument. Although the underlying model is functional, they either have
6738 side effects or depend on the current state of the store.
6740 The former is inconvenient: the connection to the build daemon has to be
6741 carried around in all those functions, making it impossible to compose
6742 functions that do not take that parameter with functions that do. The
6743 latter can be problematic: since store operations have side effects
6744 and/or depend on external state, they have to be properly sequenced.
6746 @cindex monadic values
6747 @cindex monadic functions
6748 This is where the @code{(guix monads)} module comes in. This module
6749 provides a framework for working with @dfn{monads}, and a particularly
6750 useful monad for our uses, the @dfn{store monad}. Monads are a
6751 construct that allows two things: associating ``context'' with values
6752 (in our case, the context is the store), and building sequences of
6753 computations (here computations include accesses to the store). Values
6754 in a monad---values that carry this additional context---are called
6755 @dfn{monadic values}; procedures that return such values are called
6756 @dfn{monadic procedures}.
6758 Consider this ``normal'' procedure:
6761 (define (sh-symlink store)
6762 ;; Return a derivation that symlinks the 'bash' executable.
6763 (let* ((drv (package-derivation store bash))
6764 (out (derivation->output-path drv))
6765 (sh (string-append out "/bin/bash")))
6766 (build-expression->derivation store "sh"
6767 `(symlink ,sh %output))))
6770 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
6771 as a monadic function:
6774 (define (sh-symlink)
6775 ;; Same, but return a monadic value.
6776 (mlet %store-monad ((drv (package->derivation bash)))
6777 (gexp->derivation "sh"
6778 #~(symlink (string-append #$drv "/bin/bash")
6782 There are several things to note in the second version: the @code{store}
6783 parameter is now implicit and is ``threaded'' in the calls to the
6784 @code{package->derivation} and @code{gexp->derivation} monadic
6785 procedures, and the monadic value returned by @code{package->derivation}
6786 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
6788 As it turns out, the call to @code{package->derivation} can even be
6789 omitted since it will take place implicitly, as we will see later
6790 (@pxref{G-Expressions}):
6793 (define (sh-symlink)
6794 (gexp->derivation "sh"
6795 #~(symlink (string-append #$bash "/bin/bash")
6800 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
6801 @c for the funny quote.
6802 Calling the monadic @code{sh-symlink} has no effect. As someone once
6803 said, ``you exit a monad like you exit a building on fire: by running''.
6804 So, to exit the monad and get the desired effect, one must use
6805 @code{run-with-store}:
6808 (run-with-store (open-connection) (sh-symlink))
6809 @result{} /gnu/store/...-sh-symlink
6812 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
6813 new ``meta-commands'' to make it easier to deal with monadic procedures:
6814 @code{run-in-store}, and @code{enter-store-monad}. The former is used
6815 to ``run'' a single monadic value through the store:
6818 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
6819 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6822 The latter enters a recursive REPL, where all the return values are
6823 automatically run through the store:
6826 scheme@@(guile-user)> ,enter-store-monad
6827 store-monad@@(guile-user) [1]> (package->derivation hello)
6828 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
6829 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
6830 $3 = "/gnu/store/@dots{}-foo"
6831 store-monad@@(guile-user) [1]> ,q
6832 scheme@@(guile-user)>
6836 Note that non-monadic values cannot be returned in the
6837 @code{store-monad} REPL.
6839 The main syntactic forms to deal with monads in general are provided by
6840 the @code{(guix monads)} module and are described below.
6842 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
6843 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
6847 @deffn {Scheme Syntax} return @var{val}
6848 Return a monadic value that encapsulates @var{val}.
6851 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
6852 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
6853 procedures @var{mproc}@dots{}@footnote{This operation is commonly
6854 referred to as ``bind'', but that name denotes an unrelated procedure in
6855 Guile. Thus we use this somewhat cryptic symbol inherited from the
6856 Haskell language.}. There can be one @var{mproc} or several of them, as
6861 (with-monad %state-monad
6863 (lambda (x) (return (+ 1 x)))
6864 (lambda (x) (return (* 2 x)))))
6868 @result{} some-state
6872 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
6874 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
6876 Bind the variables @var{var} to the monadic values @var{mval} in
6877 @var{body}, which is a sequence of expressions. As with the bind
6878 operator, this can be thought of as ``unpacking'' the raw, non-monadic
6879 value ``contained'' in @var{mval} and making @var{var} refer to that
6880 raw, non-monadic value within the scope of the @var{body}. The form
6881 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
6882 @var{val}, as per @code{let}. The binding operations occur in sequence
6883 from left to right. The last expression of @var{body} must be a monadic
6884 expression, and its result will become the result of the @code{mlet} or
6885 @code{mlet*} when run in the @var{monad}.
6887 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
6888 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
6891 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
6892 Bind @var{mexp} and the following monadic expressions in sequence,
6893 returning the result of the last expression. Every expression in the
6894 sequence must be a monadic expression.
6896 This is akin to @code{mlet}, except that the return values of the
6897 monadic expressions are ignored. In that sense, it is analogous to
6898 @code{begin}, but applied to monadic expressions.
6901 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
6902 When @var{condition} is true, evaluate the sequence of monadic
6903 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6904 @var{condition} is false, return @code{*unspecified*} in the current
6905 monad. Every expression in the sequence must be a monadic expression.
6908 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
6909 When @var{condition} is false, evaluate the sequence of monadic
6910 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
6911 @var{condition} is true, return @code{*unspecified*} in the current
6912 monad. Every expression in the sequence must be a monadic expression.
6916 The @code{(guix monads)} module provides the @dfn{state monad}, which
6917 allows an additional value---the state---to be @emph{threaded} through
6918 monadic procedure calls.
6920 @defvr {Scheme Variable} %state-monad
6921 The state monad. Procedures in the state monad can access and change
6922 the state that is threaded.
6924 Consider the example below. The @code{square} procedure returns a value
6925 in the state monad. It returns the square of its argument, but also
6926 increments the current state value:
6930 (mlet %state-monad ((count (current-state)))
6931 (mbegin %state-monad
6932 (set-current-state (+ 1 count))
6935 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
6940 When ``run'' through @var{%state-monad}, we obtain that additional state
6941 value, which is the number of @code{square} calls.
6944 @deffn {Monadic Procedure} current-state
6945 Return the current state as a monadic value.
6948 @deffn {Monadic Procedure} set-current-state @var{value}
6949 Set the current state to @var{value} and return the previous state as a
6953 @deffn {Monadic Procedure} state-push @var{value}
6954 Push @var{value} to the current state, which is assumed to be a list,
6955 and return the previous state as a monadic value.
6958 @deffn {Monadic Procedure} state-pop
6959 Pop a value from the current state and return it as a monadic value.
6960 The state is assumed to be a list.
6963 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
6964 Run monadic value @var{mval} starting with @var{state} as the initial
6965 state. Return two values: the resulting value, and the resulting state.
6968 The main interface to the store monad, provided by the @code{(guix
6969 store)} module, is as follows.
6971 @defvr {Scheme Variable} %store-monad
6972 The store monad---an alias for @var{%state-monad}.
6974 Values in the store monad encapsulate accesses to the store. When its
6975 effect is needed, a value of the store monad must be ``evaluated'' by
6976 passing it to the @code{run-with-store} procedure (see below.)
6979 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
6980 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
6981 open store connection.
6984 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
6985 Return as a monadic value the absolute file name in the store of the file
6986 containing @var{text}, a string. @var{references} is a list of store items that the
6987 resulting text file refers to; it defaults to the empty list.
6990 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
6991 Return as a monadic value the absolute file name in the store of the file
6992 containing @var{data}, a bytevector. @var{references} is a list of store
6993 items that the resulting binary file refers to; it defaults to the empty list.
6996 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
6997 [#:recursive? #t] [#:select? (const #t)]
6998 Return the name of @var{file} once interned in the store. Use
6999 @var{name} as its store name, or the basename of @var{file} if
7000 @var{name} is omitted.
7002 When @var{recursive?} is true, the contents of @var{file} are added
7003 recursively; if @var{file} designates a flat file and @var{recursive?}
7004 is true, its contents are added, and its permission bits are kept.
7006 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7007 @var{stat})} for each directory entry, where @var{file} is the entry's
7008 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7009 entries for which @var{select?} does not return true.
7011 The example below adds a file to the store, under two different names:
7014 (run-with-store (open-connection)
7015 (mlet %store-monad ((a (interned-file "README"))
7016 (b (interned-file "README" "LEGU-MIN")))
7017 (return (list a b))))
7019 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7024 The @code{(guix packages)} module exports the following package-related
7027 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7028 [#:system (%current-system)] [#:target #f] @
7031 value in the absolute file name of @var{file} within the @var{output}
7032 directory of @var{package}. When @var{file} is omitted, return the name
7033 of the @var{output} directory of @var{package}. When @var{target} is
7034 true, use it as a cross-compilation target triplet.
7037 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7038 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7039 @var{target} [@var{system}]
7040 Monadic version of @code{package-derivation} and
7041 @code{package-cross-derivation} (@pxref{Defining Packages}).
7046 @section G-Expressions
7048 @cindex G-expression
7049 @cindex build code quoting
7050 So we have ``derivations'', which represent a sequence of build actions
7051 to be performed to produce an item in the store (@pxref{Derivations}).
7052 These build actions are performed when asking the daemon to actually
7053 build the derivations; they are run by the daemon in a container
7054 (@pxref{Invoking guix-daemon}).
7056 @cindex strata of code
7057 It should come as no surprise that we like to write these build actions
7058 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7059 code@footnote{The term @dfn{stratum} in this context was coined by
7060 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7061 Kiselyov, who has written insightful
7062 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7063 on this topic}, refers to this kind of code generation as
7064 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7065 to the daemon, etc.---and the ``build code''---code that actually
7066 performs build actions, such as making directories, invoking
7067 @command{make}, etc.
7069 To describe a derivation and its build actions, one typically needs to
7070 embed build code inside host code. It boils down to manipulating build
7071 code as data, and the homoiconicity of Scheme---code has a direct
7072 representation as data---comes in handy for that. But we need more than
7073 the normal @code{quasiquote} mechanism in Scheme to construct build
7076 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7077 S-expressions adapted to build expressions. G-expressions, or
7078 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7079 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7080 @code{#$}, and @code{#$@@}), which are comparable to
7081 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7082 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7083 GNU Guile Reference Manual}). However, there are major differences:
7087 Gexps are meant to be written to a file and run or manipulated by other
7091 When a high-level object such as a package or derivation is unquoted
7092 inside a gexp, the result is as if its output file name had been
7096 Gexps carry information about the packages or derivations they refer to,
7097 and these dependencies are automatically added as inputs to the build
7098 processes that use them.
7101 @cindex lowering, of high-level objects in gexps
7102 This mechanism is not limited to package and derivation
7103 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7104 derivations or files in the store can be defined,
7105 such that these objects can also be inserted
7106 into gexps. For example, a useful type of high-level objects that can be
7107 inserted in a gexp is ``file-like objects'', which make it easy to
7108 add files to the store and to refer to them in
7109 derivations and such (see @code{local-file} and @code{plain-file}
7112 To illustrate the idea, here is an example of a gexp:
7119 (symlink (string-append #$coreutils "/bin/ls")
7123 This gexp can be passed to @code{gexp->derivation}; we obtain a
7124 derivation that builds a directory containing exactly one symlink to
7125 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7128 (gexp->derivation "the-thing" build-exp)
7131 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7132 substituted to the reference to the @var{coreutils} package in the
7133 actual build code, and @var{coreutils} is automatically made an input to
7134 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7135 output)}) is replaced by a string containing the directory name of the
7136 output of the derivation.
7138 @cindex cross compilation
7139 In a cross-compilation context, it is useful to distinguish between
7140 references to the @emph{native} build of a package---that can run on the
7141 host---versus references to cross builds of a package. To that end, the
7142 @code{#+} plays the same role as @code{#$}, but is a reference to a
7143 native package build:
7146 (gexp->derivation "vi"
7149 (system* (string-append #+coreutils "/bin/ln")
7151 (string-append #$emacs "/bin/emacs")
7152 (string-append #$output "/bin/vi")))
7153 #:target "mips64el-linux-gnu")
7157 In the example above, the native build of @var{coreutils} is used, so
7158 that @command{ln} can actually run on the host; but then the
7159 cross-compiled build of @var{emacs} is referenced.
7161 @cindex imported modules, for gexps
7162 @findex with-imported-modules
7163 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7164 able to use certain Guile modules from the ``host environment'' in the
7165 gexp, so those modules should be imported in the ``build environment''.
7166 The @code{with-imported-modules} form allows you to express that:
7169 (let ((build (with-imported-modules '((guix build utils))
7171 (use-modules (guix build utils))
7172 (mkdir-p (string-append #$output "/bin"))))))
7173 (gexp->derivation "empty-dir"
7176 (display "success!\n")
7181 In this example, the @code{(guix build utils)} module is automatically
7182 pulled into the isolated build environment of our gexp, such that
7183 @code{(use-modules (guix build utils))} works as expected.
7185 @cindex module closure
7186 @findex source-module-closure
7187 Usually you want the @emph{closure} of the module to be imported---i.e.,
7188 the module itself and all the modules it depends on---rather than just
7189 the module; failing to do that, attempts to use the module will fail
7190 because of missing dependent modules. The @code{source-module-closure}
7191 procedure computes the closure of a module by looking at its source file
7192 headers, which comes in handy in this case:
7195 (use-modules (guix modules)) ;for 'source-module-closure'
7197 (with-imported-modules (source-module-closure
7198 '((guix build utils)
7200 (gexp->derivation "something-with-vms"
7202 (use-modules (guix build utils)
7207 @cindex extensions, for gexps
7208 @findex with-extensions
7209 In the same vein, sometimes you want to import not just pure-Scheme
7210 modules, but also ``extensions'' such as Guile bindings to C libraries
7211 or other ``full-blown'' packages. Say you need the @code{guile-json}
7212 package available on the build side, here's how you would do it:
7215 (use-modules (gnu packages guile)) ;for 'guile-json'
7217 (with-extensions (list guile-json)
7218 (gexp->derivation "something-with-json"
7220 (use-modules (json))
7224 The syntactic form to construct gexps is summarized below.
7226 @deffn {Scheme Syntax} #~@var{exp}
7227 @deffnx {Scheme Syntax} (gexp @var{exp})
7228 Return a G-expression containing @var{exp}. @var{exp} may contain one
7229 or more of the following forms:
7233 @itemx (ungexp @var{obj})
7234 Introduce a reference to @var{obj}. @var{obj} may have one of the
7235 supported types, for example a package or a
7236 derivation, in which case the @code{ungexp} form is replaced by its
7237 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7239 If @var{obj} is a list, it is traversed and references to supported
7240 objects are substituted similarly.
7242 If @var{obj} is another gexp, its contents are inserted and its
7243 dependencies are added to those of the containing gexp.
7245 If @var{obj} is another kind of object, it is inserted as is.
7247 @item #$@var{obj}:@var{output}
7248 @itemx (ungexp @var{obj} @var{output})
7249 This is like the form above, but referring explicitly to the
7250 @var{output} of @var{obj}---this is useful when @var{obj} produces
7251 multiple outputs (@pxref{Packages with Multiple Outputs}).
7254 @itemx #+@var{obj}:output
7255 @itemx (ungexp-native @var{obj})
7256 @itemx (ungexp-native @var{obj} @var{output})
7257 Same as @code{ungexp}, but produces a reference to the @emph{native}
7258 build of @var{obj} when used in a cross compilation context.
7260 @item #$output[:@var{output}]
7261 @itemx (ungexp output [@var{output}])
7262 Insert a reference to derivation output @var{output}, or to the main
7263 output when @var{output} is omitted.
7265 This only makes sense for gexps passed to @code{gexp->derivation}.
7268 @itemx (ungexp-splicing @var{lst})
7269 Like the above, but splices the contents of @var{lst} inside the
7273 @itemx (ungexp-native-splicing @var{lst})
7274 Like the above, but refers to native builds of the objects listed in
7279 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7280 of the @code{gexp?} type (see below.)
7283 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7284 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7285 in their execution environment.
7287 Each item in @var{modules} can be the name of a module, such as
7288 @code{(guix build utils)}, or it can be a module name, followed by an
7289 arrow, followed by a file-like object:
7292 `((guix build utils)
7294 ((guix config) => ,(scheme-file "config.scm"
7295 #~(define-module @dots{}))))
7299 In the example above, the first two modules are taken from the search
7300 path, and the last one is created from the given file-like object.
7302 This form has @emph{lexical} scope: it has an effect on the gexps
7303 directly defined in @var{body}@dots{}, but not on those defined, say, in
7304 procedures called from @var{body}@dots{}.
7307 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7308 Mark the gexps defined in @var{body}@dots{} as requiring
7309 @var{extensions} in their build and execution environment.
7310 @var{extensions} is typically a list of package objects such as those
7311 defined in the @code{(gnu packages guile)} module.
7313 Concretely, the packages listed in @var{extensions} are added to the
7314 load path while compiling imported modules in @var{body}@dots{}; they
7315 are also added to the load path of the gexp returned by
7319 @deffn {Scheme Procedure} gexp? @var{obj}
7320 Return @code{#t} if @var{obj} is a G-expression.
7323 G-expressions are meant to be written to disk, either as code building
7324 some derivation, or as plain files in the store. The monadic procedures
7325 below allow you to do that (@pxref{The Store Monad}, for more
7326 information about monads.)
7328 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7329 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7330 [#:hash #f] [#:hash-algo #f] @
7331 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7332 [#:module-path @var{%load-path}] @
7333 [#:effective-version "2.2"] @
7334 [#:references-graphs #f] [#:allowed-references #f] @
7335 [#:disallowed-references #f] @
7336 [#:leaked-env-vars #f] @
7337 [#:script-name (string-append @var{name} "-builder")] @
7338 [#:deprecation-warnings #f] @
7339 [#:local-build? #f] [#:substitutable? #t] @
7340 [#:properties '()] [#:guile-for-build #f]
7341 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7342 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7343 stored in a file called @var{script-name}. When @var{target} is true,
7344 it is used as the cross-compilation target triplet for packages referred
7347 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7349 make @var{modules} available in the evaluation context of @var{exp};
7350 @var{modules} is a list of names of Guile modules searched in
7351 @var{module-path} to be copied in the store, compiled, and made available in
7352 the load path during the execution of @var{exp}---e.g., @code{((guix
7353 build utils) (guix build gnu-build-system))}.
7355 @var{effective-version} determines the string to use when adding extensions of
7356 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7358 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7361 When @var{references-graphs} is true, it must be a list of tuples of one of the
7365 (@var{file-name} @var{package})
7366 (@var{file-name} @var{package} @var{output})
7367 (@var{file-name} @var{derivation})
7368 (@var{file-name} @var{derivation} @var{output})
7369 (@var{file-name} @var{store-item})
7372 The right-hand-side of each element of @var{references-graphs} is automatically made
7373 an input of the build process of @var{exp}. In the build environment, each
7374 @var{file-name} contains the reference graph of the corresponding item, in a simple
7377 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7378 In the latter case, the list denotes store items that the result is allowed to
7379 refer to. Any reference to another store item will lead to a build error.
7380 Similarly for @var{disallowed-references}, which can list items that must not be
7381 referenced by the outputs.
7383 @var{deprecation-warnings} determines whether to show deprecation warnings while
7384 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7386 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7389 @cindex file-like objects
7390 The @code{local-file}, @code{plain-file}, @code{computed-file},
7391 @code{program-file}, and @code{scheme-file} procedures below return
7392 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7393 these objects lead to a file in the store. Consider this G-expression:
7396 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7397 #$(local-file "/tmp/my-nscd.conf"))
7400 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7401 to the store. Once expanded, for instance @i{via}
7402 @code{gexp->derivation}, the G-expression refers to that copy under
7403 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7404 does not have any effect on what the G-expression does.
7405 @code{plain-file} can be used similarly; it differs in that the file
7406 content is directly passed as a string.
7408 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7409 [#:recursive? #f] [#:select? (const #t)]
7410 Return an object representing local file @var{file} to add to the store; this
7411 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7412 up relative to the source file where this form appears. @var{file} will be added to
7413 the store under @var{name}--by default the base name of @var{file}.
7415 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7416 designates a flat file and @var{recursive?} is true, its contents are added, and its
7417 permission bits are kept.
7419 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7420 @var{stat})} for each directory entry, where @var{file} is the entry's
7421 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7422 entries for which @var{select?} does not return true.
7424 This is the declarative counterpart of the @code{interned-file} monadic
7425 procedure (@pxref{The Store Monad, @code{interned-file}}).
7428 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7429 Return an object representing a text file called @var{name} with the given
7430 @var{content} (a string or a bytevector) to be added to the store.
7432 This is the declarative counterpart of @code{text-file}.
7435 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7436 [#:options '(#:local-build? #t)]
7437 Return an object representing the store item @var{name}, a file or
7438 directory computed by @var{gexp}. @var{options}
7439 is a list of additional arguments to pass to @code{gexp->derivation}.
7441 This is the declarative counterpart of @code{gexp->derivation}.
7444 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7445 [#:guile (default-guile)] [#:module-path %load-path] @
7446 [#:system (%current-system)] [#:target #f]
7447 Return an executable script @var{name} that runs @var{exp} using
7448 @var{guile}, with @var{exp}'s imported modules in its search path.
7449 Look up @var{exp}'s modules in @var{module-path}.
7451 The example below builds a script that simply invokes the @command{ls}
7455 (use-modules (guix gexp) (gnu packages base))
7457 (gexp->script "list-files"
7458 #~(execl #$(file-append coreutils "/bin/ls")
7462 When ``running'' it through the store (@pxref{The Store Monad,
7463 @code{run-with-store}}), we obtain a derivation that produces an
7464 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7467 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7469 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7473 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7474 [#:guile #f] [#:module-path %load-path]
7475 Return an object representing the executable store item @var{name} that
7476 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7477 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7479 This is the declarative counterpart of @code{gexp->script}.
7482 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7483 [#:set-load-path? #t] [#:module-path %load-path] @
7485 [#:guile (default-guile)]
7486 Return a derivation that builds a file @var{name} containing @var{exp}.
7487 When @var{splice?} is true, @var{exp} is considered to be a list of
7488 expressions that will be spliced in the resulting file.
7490 When @var{set-load-path?} is true, emit code in the resulting file to
7491 set @code{%load-path} and @code{%load-compiled-path} to honor
7492 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7495 The resulting file holds references to all the dependencies of @var{exp}
7496 or a subset thereof.
7499 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7500 Return an object representing the Scheme file @var{name} that contains
7503 This is the declarative counterpart of @code{gexp->file}.
7506 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7507 Return as a monadic value a derivation that builds a text file
7508 containing all of @var{text}. @var{text} may list, in addition to
7509 strings, objects of any type that can be used in a gexp: packages,
7510 derivations, local file objects, etc. The resulting store file holds
7511 references to all these.
7513 This variant should be preferred over @code{text-file} anytime the file
7514 to create will reference items from the store. This is typically the
7515 case when building a configuration file that embeds store file names,
7519 (define (profile.sh)
7520 ;; Return the name of a shell script in the store that
7521 ;; initializes the 'PATH' environment variable.
7522 (text-file* "profile.sh"
7523 "export PATH=" coreutils "/bin:"
7524 grep "/bin:" sed "/bin\n"))
7527 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7528 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7529 preventing them from being garbage-collected during its lifetime.
7532 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7533 Return an object representing store file @var{name} containing
7534 @var{text}. @var{text} is a sequence of strings and file-like objects,
7538 (mixed-text-file "profile"
7539 "export PATH=" coreutils "/bin:" grep "/bin")
7542 This is the declarative counterpart of @code{text-file*}.
7545 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7546 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7547 Each item in @var{files} must be a two-element list where the first element is the
7548 file name to use in the new directory, and the second element is a gexp
7549 denoting the target file. Here's an example:
7553 `(("hosts" ,(plain-file "hosts"
7554 "127.0.0.1 localhost"))
7555 ("bashrc" ,(plain-file "bashrc"
7556 "alias ls='ls --color=auto'"))))
7559 This yields an @code{etc} directory containing these two files.
7562 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7563 Return a directory that is the union of @var{things}, where @var{things} is a list of
7564 file-like objects denoting directories. For example:
7567 (directory-union "guile+emacs" (list guile emacs))
7570 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7573 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7574 Return a file-like object that expands to the concatenation of @var{obj}
7575 and @var{suffix}, where @var{obj} is a lowerable object and each
7576 @var{suffix} is a string.
7578 As an example, consider this gexp:
7581 (gexp->script "run-uname"
7582 #~(system* #$(file-append coreutils
7586 The same effect could be achieved with:
7589 (gexp->script "run-uname"
7590 #~(system* (string-append #$coreutils
7594 There is one difference though: in the @code{file-append} case, the
7595 resulting script contains the absolute file name as a string, whereas in
7596 the second case, the resulting script contains a @code{(string-append
7597 @dots{})} expression to construct the file name @emph{at run time}.
7601 Of course, in addition to gexps embedded in ``host'' code, there are
7602 also modules containing build tools. To make it clear that they are
7603 meant to be used in the build stratum, these modules are kept in the
7604 @code{(guix build @dots{})} name space.
7606 @cindex lowering, of high-level objects in gexps
7607 Internally, high-level objects are @dfn{lowered}, using their compiler,
7608 to either derivations or store items. For instance, lowering a package
7609 yields a derivation, and lowering a @code{plain-file} yields a store
7610 item. This is achieved using the @code{lower-object} monadic procedure.
7612 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7614 Return as a value in @var{%store-monad} the derivation or store item
7615 corresponding to @var{obj} for @var{system}, cross-compiling for
7616 @var{target} if @var{target} is true. @var{obj} must be an object that
7617 has an associated gexp compiler, such as a @code{<package>}.
7620 @node Invoking guix repl
7621 @section Invoking @command{guix repl}
7623 @cindex REPL, read-eval-print loop
7624 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7625 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7626 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7627 command, @command{guix repl} guarantees that all the Guix modules and all its
7628 dependencies are available in the search path. You can use it this way:
7632 scheme@@(guile-user)> ,use (gnu packages base)
7633 scheme@@(guile-user)> coreutils
7634 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7638 In addition, @command{guix repl} implements a simple machine-readable REPL
7639 protocol for use by @code{(guix inferior)}, a facility to interact with
7640 @dfn{inferiors}, separate processes running a potentially different revision
7643 The available options are as follows:
7646 @item --type=@var{type}
7647 @itemx -t @var{type}
7648 Start a REPL of the given @var{TYPE}, which can be one of the following:
7652 This is default, and it spawns a standard full-featured Guile REPL.
7654 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7655 that the @code{(guix inferior)} module speaks.
7658 @item --listen=@var{endpoint}
7659 By default, @command{guix repl} reads from standard input and writes to
7660 standard output. When this option is passed, it will instead listen for
7661 connections on @var{endpoint}. Here are examples of valid options:
7664 @item --listen=tcp:37146
7665 Accept connections on localhost on port 37146.
7667 @item --listen=unix:/tmp/socket
7668 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7672 @c *********************************************************************
7676 This section describes Guix command-line utilities. Some of them are
7677 primarily targeted at developers and users who write new package
7678 definitions, while others are more generally useful. They complement
7679 the Scheme programming interface of Guix in a convenient way.
7682 * Invoking guix build:: Building packages from the command line.
7683 * Invoking guix edit:: Editing package definitions.
7684 * Invoking guix download:: Downloading a file and printing its hash.
7685 * Invoking guix hash:: Computing the cryptographic hash of a file.
7686 * Invoking guix import:: Importing package definitions.
7687 * Invoking guix refresh:: Updating package definitions.
7688 * Invoking guix lint:: Finding errors in package definitions.
7689 * Invoking guix size:: Profiling disk usage.
7690 * Invoking guix graph:: Visualizing the graph of packages.
7691 * Invoking guix publish:: Sharing substitutes.
7692 * Invoking guix challenge:: Challenging substitute servers.
7693 * Invoking guix copy:: Copying to and from a remote store.
7694 * Invoking guix container:: Process isolation.
7695 * Invoking guix weather:: Assessing substitute availability.
7696 * Invoking guix processes:: Listing client processes.
7699 @node Invoking guix build
7700 @section Invoking @command{guix build}
7702 @cindex package building
7703 @cindex @command{guix build}
7704 The @command{guix build} command builds packages or derivations and
7705 their dependencies, and prints the resulting store paths. Note that it
7706 does not modify the user's profile---this is the job of the
7707 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7708 it is mainly useful for distribution developers.
7710 The general syntax is:
7713 guix build @var{options} @var{package-or-derivation}@dots{}
7716 As an example, the following command builds the latest versions of Emacs
7717 and of Guile, displays their build logs, and finally displays the
7718 resulting directories:
7721 guix build emacs guile
7724 Similarly, the following command builds all the available packages:
7727 guix build --quiet --keep-going \
7728 `guix package -A | cut -f1,2 --output-delimiter=@@`
7731 @var{package-or-derivation} may be either the name of a package found in
7732 the software distribution such as @code{coreutils} or
7733 @code{coreutils@@8.20}, or a derivation such as
7734 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
7735 package with the corresponding name (and optionally version) is searched
7736 for among the GNU distribution modules (@pxref{Package Modules}).
7738 Alternatively, the @code{--expression} option may be used to specify a
7739 Scheme expression that evaluates to a package; this is useful when
7740 disambiguating among several same-named packages or package variants is
7743 There may be zero or more @var{options}. The available options are
7744 described in the subsections below.
7747 * Common Build Options:: Build options for most commands.
7748 * Package Transformation Options:: Creating variants of packages.
7749 * Additional Build Options:: Options specific to 'guix build'.
7750 * Debugging Build Failures:: Real life packaging experience.
7753 @node Common Build Options
7754 @subsection Common Build Options
7756 A number of options that control the build process are common to
7757 @command{guix build} and other commands that can spawn builds, such as
7758 @command{guix package} or @command{guix archive}. These are the
7763 @item --load-path=@var{directory}
7764 @itemx -L @var{directory}
7765 Add @var{directory} to the front of the package module search path
7766 (@pxref{Package Modules}).
7768 This allows users to define their own packages and make them visible to
7769 the command-line tools.
7773 Keep the build tree of failed builds. Thus, if a build fails, its build
7774 tree is kept under @file{/tmp}, in a directory whose name is shown at
7775 the end of the build log. This is useful when debugging build issues.
7776 @xref{Debugging Build Failures}, for tips and tricks on how to debug
7779 This option has no effect when connecting to a remote daemon with a
7780 @code{guix://} URI (@pxref{The Store, the @code{GUIX_DAEMON_SOCKET}
7785 Keep going when some of the derivations fail to build; return only once
7786 all the builds have either completed or failed.
7788 The default behavior is to stop as soon as one of the specified
7789 derivations has failed.
7793 Do not build the derivations.
7795 @anchor{fallback-option}
7797 When substituting a pre-built binary fails, fall back to building
7798 packages locally (@pxref{Substitution Failure}).
7800 @item --substitute-urls=@var{urls}
7801 @anchor{client-substitute-urls}
7802 Consider @var{urls} the whitespace-separated list of substitute source
7803 URLs, overriding the default list of URLs of @command{guix-daemon}
7804 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
7806 This means that substitutes may be downloaded from @var{urls}, provided
7807 they are signed by a key authorized by the system administrator
7808 (@pxref{Substitutes}).
7810 When @var{urls} is the empty string, substitutes are effectively
7813 @item --no-substitutes
7814 Do not use substitutes for build products. That is, always build things
7815 locally instead of allowing downloads of pre-built binaries
7816 (@pxref{Substitutes}).
7819 Do not ``graft'' packages. In practice, this means that package updates
7820 available as grafts are not applied. @xref{Security Updates}, for more
7821 information on grafts.
7823 @item --rounds=@var{n}
7824 Build each derivation @var{n} times in a row, and raise an error if
7825 consecutive build results are not bit-for-bit identical.
7827 This is a useful way to detect non-deterministic builds processes.
7828 Non-deterministic build processes are a problem because they make it
7829 practically impossible for users to @emph{verify} whether third-party
7830 binaries are genuine. @xref{Invoking guix challenge}, for more.
7832 Note that, currently, the differing build results are not kept around,
7833 so you will have to manually investigate in case of an error---e.g., by
7834 stashing one of the build results with @code{guix archive --export}
7835 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
7838 @item --no-build-hook
7839 Do not attempt to offload builds @i{via} the ``build hook'' of the daemon
7840 (@pxref{Daemon Offload Setup}). That is, always build things locally
7841 instead of offloading builds to remote machines.
7843 @item --max-silent-time=@var{seconds}
7844 When the build or substitution process remains silent for more than
7845 @var{seconds}, terminate it and report a build failure.
7847 By default, the daemon's setting is honored (@pxref{Invoking
7848 guix-daemon, @code{--max-silent-time}}).
7850 @item --timeout=@var{seconds}
7851 Likewise, when the build or substitution process lasts for more than
7852 @var{seconds}, terminate it and report a build failure.
7854 By default, the daemon's setting is honored (@pxref{Invoking
7855 guix-daemon, @code{--timeout}}).
7857 @c Note: This option is actually not part of %standard-build-options but
7858 @c most programs honor it.
7859 @cindex verbosity, of the command-line tools
7860 @cindex build logs, verbosity
7861 @item -v @var{level}
7862 @itemx --verbosity=@var{level}
7863 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
7864 output is produced, 1 is for quiet output, and 2 shows all the build log
7865 output on standard error.
7867 @item --cores=@var{n}
7869 Allow the use of up to @var{n} CPU cores for the build. The special
7870 value @code{0} means to use as many CPU cores as available.
7872 @item --max-jobs=@var{n}
7874 Allow at most @var{n} build jobs in parallel. @xref{Invoking
7875 guix-daemon, @code{--max-jobs}}, for details about this option and the
7876 equivalent @command{guix-daemon} option.
7878 @item --debug=@var{level}
7879 Produce debugging output coming from the build daemon. @var{level} must be an
7880 integer between 0 and 5; higher means more verbose output. Setting a level of
7881 4 or more may be helpful when debugging setup issues with the build daemon.
7885 Behind the scenes, @command{guix build} is essentially an interface to
7886 the @code{package-derivation} procedure of the @code{(guix packages)}
7887 module, and to the @code{build-derivations} procedure of the @code{(guix
7888 derivations)} module.
7890 In addition to options explicitly passed on the command line,
7891 @command{guix build} and other @command{guix} commands that support
7892 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
7894 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
7895 Users can define this variable to a list of command line options that
7896 will automatically be used by @command{guix build} and other
7897 @command{guix} commands that can perform builds, as in the example
7901 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
7904 These options are parsed independently, and the result is appended to
7905 the parsed command-line options.
7909 @node Package Transformation Options
7910 @subsection Package Transformation Options
7912 @cindex package variants
7913 Another set of command-line options supported by @command{guix build}
7914 and also @command{guix package} are @dfn{package transformation
7915 options}. These are options that make it possible to define @dfn{package
7916 variants}---for instance, packages built from different source code.
7917 This is a convenient way to create customized packages on the fly
7918 without having to type in the definitions of package variants
7919 (@pxref{Defining Packages}).
7923 @item --with-source=@var{source}
7924 @itemx --with-source=@var{package}=@var{source}
7925 @itemx --with-source=@var{package}@@@var{version}=@var{source}
7926 Use @var{source} as the source of @var{package}, and @var{version} as
7928 @var{source} must be a file name or a URL, as for @command{guix
7929 download} (@pxref{Invoking guix download}).
7931 When @var{package} is omitted,
7932 it is taken to be the package name specified on the
7933 command line that matches the base of @var{source}---e.g.,
7934 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
7935 package is @code{guile}.
7937 Likewise, when @var{version} is omitted, the version string is inferred from
7938 @var{source}; in the previous example, it is @code{2.0.10}.
7940 This option allows users to try out versions of packages other than the
7941 one provided by the distribution. The example below downloads
7942 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
7943 the @code{ed} package:
7946 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
7949 As a developer, @code{--with-source} makes it easy to test release
7953 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
7956 @dots{} or to build from a checkout in a pristine environment:
7959 $ git clone git://git.sv.gnu.org/guix.git
7960 $ guix build guix --with-source=guix@@1.0=./guix
7963 @item --with-input=@var{package}=@var{replacement}
7964 Replace dependency on @var{package} by a dependency on
7965 @var{replacement}. @var{package} must be a package name, and
7966 @var{replacement} must be a package specification such as @code{guile}
7967 or @code{guile@@1.8}.
7969 For instance, the following command builds Guix, but replaces its
7970 dependency on the current stable version of Guile with a dependency on
7971 the legacy version of Guile, @code{guile@@2.0}:
7974 guix build --with-input=guile=guile@@2.0 guix
7977 This is a recursive, deep replacement. So in this example, both
7978 @code{guix} and its dependency @code{guile-json} (which also depends on
7979 @code{guile}) get rebuilt against @code{guile@@2.0}.
7981 This is implemented using the @code{package-input-rewriting} Scheme
7982 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
7984 @item --with-graft=@var{package}=@var{replacement}
7985 This is similar to @code{--with-input} but with an important difference:
7986 instead of rebuilding the whole dependency chain, @var{replacement} is
7987 built and then @dfn{grafted} onto the binaries that were initially
7988 referring to @var{package}. @xref{Security Updates}, for more
7989 information on grafts.
7991 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
7992 and all its dependencies, replacing references to the version of GnuTLS
7993 they currently refer to:
7996 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
7999 This has the advantage of being much faster than rebuilding everything.
8000 But there is a caveat: it works if and only if @var{package} and
8001 @var{replacement} are strictly compatible---for example, if they provide
8002 a library, the application binary interface (ABI) of those libraries
8003 must be compatible. If @var{replacement} is somehow incompatible with
8004 @var{package}, then the resulting package may be unusable. Use with
8007 @item --with-git-url=@var{package}=@var{url}
8008 @cindex Git, using the latest commit
8009 @cindex latest commit, building
8010 Build @var{package} from the latest commit of the @code{master} branch of the
8011 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8014 For example, the following command builds the NumPy Python library against the
8015 latest commit of the master branch of Python itself:
8018 guix build python-numpy \
8019 --with-git-url=python=https://github.com/python/cpython
8022 This option can also be combined with @code{--with-branch} or
8023 @code{--with-commit} (see below).
8025 @cindex continuous integration
8026 Obviously, since it uses the latest commit of the given branch, the result of
8027 such a command varies over time. Nevertheless it is a convenient way to
8028 rebuild entire software stacks against the latest commit of one or more
8029 packages. This is particularly useful in the context of continuous
8032 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8033 consecutive accesses to the same repository. You may want to clean it up once
8034 in a while to save disk space.
8036 @item --with-branch=@var{package}=@var{branch}
8037 Build @var{package} from the latest commit of @var{branch}. If the
8038 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8039 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8040 repository URL is taken from that @code{source}. Otherwise you have to use
8041 @code{--with-git-url} to specify the URL of the Git repository.
8043 For instance, the following command builds @code{guile-sqlite3} from the
8044 latest commit of its @code{master} branch, and then builds @code{guix} (which
8045 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8046 specific @code{guile-sqlite3} build:
8049 guix build --with-branch=guile-sqlite3=master cuirass
8052 @item --with-commit=@var{package}=@var{commit}
8053 This is similar to @code{--with-branch}, except that it builds from
8054 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8055 Git commit SHA1 identifier or a tag.
8058 @node Additional Build Options
8059 @subsection Additional Build Options
8061 The command-line options presented below are specific to @command{guix
8068 Build quietly, without displaying the build log; this is equivalent to
8069 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8070 (or similar) and can always be retrieved using the @option{--log-file} option.
8072 @item --file=@var{file}
8073 @itemx -f @var{file}
8074 Build the package, derivation, or other file-like object that the code within
8075 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8077 As an example, @var{file} might contain a package definition like this
8078 (@pxref{Defining Packages}):
8081 @verbatiminclude package-hello.scm
8084 @item --expression=@var{expr}
8085 @itemx -e @var{expr}
8086 Build the package or derivation @var{expr} evaluates to.
8088 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8089 guile-1.8)}, which unambiguously designates this specific variant of
8090 version 1.8 of Guile.
8092 Alternatively, @var{expr} may be a G-expression, in which case it is used
8093 as a build program passed to @code{gexp->derivation}
8094 (@pxref{G-Expressions}).
8096 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8097 (@pxref{The Store Monad}). The procedure must return a derivation as a
8098 monadic value, which is then passed through @code{run-with-store}.
8102 Build the source derivations of the packages, rather than the packages
8105 For instance, @code{guix build -S gcc} returns something like
8106 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8109 The returned source tarball is the result of applying any patches and
8110 code snippets specified in the package @code{origin} (@pxref{Defining
8114 Fetch and return the source of @var{package-or-derivation} and all their
8115 dependencies, recursively. This is a handy way to obtain a local copy
8116 of all the source code needed to build @var{packages}, allowing you to
8117 eventually build them even without network access. It is an extension
8118 of the @code{--source} option and can accept one of the following
8119 optional argument values:
8123 This value causes the @code{--sources} option to behave in the same way
8124 as the @code{--source} option.
8127 Build the source derivations of all packages, including any source that
8128 might be listed as @code{inputs}. This is the default value.
8131 $ guix build --sources tzdata
8132 The following derivations will be built:
8133 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8134 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8138 Build the source derivations of all packages, as well of all transitive
8139 inputs to the packages. This can be used e.g.@: to
8140 prefetch package source for later offline building.
8143 $ guix build --sources=transitive tzdata
8144 The following derivations will be built:
8145 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8146 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8147 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8148 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8149 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8150 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8156 @item --system=@var{system}
8157 @itemx -s @var{system}
8158 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8159 the system type of the build host. The @command{guix build} command allows
8160 you to repeat this option several times, in which case it builds for all the
8161 specified systems; other commands ignore extraneous @option{-s} options.
8164 The @code{--system} flag is for @emph{native} compilation and must not
8165 be confused with cross-compilation. See @code{--target} below for
8166 information on cross-compilation.
8169 An example use of this is on Linux-based systems, which can emulate
8170 different personalities. For instance, passing
8171 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8172 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8173 to build packages in a complete 32-bit environment.
8176 Building for an @code{armhf-linux} system is unconditionally enabled on
8177 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8178 allow for this functionality, notably the ThunderX.
8181 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8182 is enabled (@pxref{Virtualization Services,
8183 @code{qemu-binfmt-service-type}}), you can build for any system for
8184 which a QEMU @code{binfmt_misc} handler is installed.
8186 Builds for a system other than that of the machine you are using can
8187 also be offloaded to a remote machine of the right architecture.
8188 @xref{Daemon Offload Setup}, for more information on offloading.
8190 @item --target=@var{triplet}
8191 @cindex cross-compilation
8192 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8193 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8194 configuration triplets,, autoconf, Autoconf}).
8196 @anchor{build-check}
8198 @cindex determinism, checking
8199 @cindex reproducibility, checking
8200 Rebuild @var{package-or-derivation}, which are already available in the
8201 store, and raise an error if the build results are not bit-for-bit
8204 This mechanism allows you to check whether previously installed
8205 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8206 of a package is deterministic. @xref{Invoking guix challenge}, for more
8207 background information and tools.
8209 When used in conjunction with @option{--keep-failed}, the differing
8210 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8211 This makes it easy to look for differences between the two results.
8214 @cindex repairing store items
8215 @cindex corruption, recovering from
8216 Attempt to repair the specified store items, if they are corrupt, by
8217 re-downloading or rebuilding them.
8219 This operation is not atomic and thus restricted to @code{root}.
8223 Return the derivation paths, not the output paths, of the given
8226 @item --root=@var{file}
8227 @itemx -r @var{file}
8228 @cindex GC roots, adding
8229 @cindex garbage collector roots, adding
8230 Make @var{file} a symlink to the result, and register it as a garbage
8233 Consequently, the results of this @command{guix build} invocation are
8234 protected from garbage collection until @var{file} is removed. When
8235 that option is omitted, build results are eligible for garbage
8236 collection as soon as the build completes. @xref{Invoking guix gc}, for
8240 @cindex build logs, access
8241 Return the build log file names or URLs for the given
8242 @var{package-or-derivation}, or raise an error if build logs are
8245 This works regardless of how packages or derivations are specified. For
8246 instance, the following invocations are equivalent:
8249 guix build --log-file `guix build -d guile`
8250 guix build --log-file `guix build guile`
8251 guix build --log-file guile
8252 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8255 If a log is unavailable locally, and unless @code{--no-substitutes} is
8256 passed, the command looks for a corresponding log on one of the
8257 substitute servers (as specified with @code{--substitute-urls}.)
8259 So for instance, imagine you want to see the build log of GDB on MIPS,
8260 but you are actually on an @code{x86_64} machine:
8263 $ guix build --log-file gdb -s mips64el-linux
8264 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8267 You can freely access a huge library of build logs!
8270 @node Debugging Build Failures
8271 @subsection Debugging Build Failures
8273 @cindex build failures, debugging
8274 When defining a new package (@pxref{Defining Packages}), you will
8275 probably find yourself spending some time debugging and tweaking the
8276 build until it succeeds. To do that, you need to operate the build
8277 commands yourself in an environment as close as possible to the one the
8280 To that end, the first thing to do is to use the @option{--keep-failed}
8281 or @option{-K} option of @command{guix build}, which will keep the
8282 failed build tree in @file{/tmp} or whatever directory you specified as
8283 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8285 From there on, you can @command{cd} to the failed build tree and source
8286 the @file{environment-variables} file, which contains all the
8287 environment variable definitions that were in place when the build
8288 failed. So let's say you're debugging a build failure in package
8289 @code{foo}; a typical session would look like this:
8293 @dots{} @i{build fails}
8294 $ cd /tmp/guix-build-foo.drv-0
8295 $ source ./environment-variables
8299 Now, you can invoke commands as if you were the daemon (almost) and
8300 troubleshoot your build process.
8302 Sometimes it happens that, for example, a package's tests pass when you
8303 run them manually but they fail when the daemon runs them. This can
8304 happen because the daemon runs builds in containers where, unlike in our
8305 environment above, network access is missing, @file{/bin/sh} does not
8306 exist, etc. (@pxref{Build Environment Setup}).
8308 In such cases, you may need to run inspect the build process from within
8309 a container similar to the one the build daemon creates:
8314 $ cd /tmp/guix-build-foo.drv-0
8315 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8316 [env]# source ./environment-variables
8320 Here, @command{guix environment -C} creates a container and spawns a new
8321 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8322 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8323 the container, which would may find handy while debugging. The
8324 @option{--no-grafts} option makes sure we get the exact same
8325 environment, with ungrafted packages (@pxref{Security Updates}, for more
8328 To get closer to a container like that used by the build daemon, we can
8329 remove @file{/bin/sh}:
8335 (Don't worry, this is harmless: this is all happening in the throw-away
8336 container created by @command{guix environment}.)
8338 The @command{strace} command is probably not in the search path, but we
8342 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8345 In this way, not only you will have reproduced the environment variables
8346 the daemon uses, you will also be running the build process in a container
8347 similar to the one the daemon uses.
8350 @node Invoking guix edit
8351 @section Invoking @command{guix edit}
8353 @cindex @command{guix edit}
8354 @cindex package definition, editing
8355 So many packages, so many source files! The @command{guix edit} command
8356 facilitates the life of users and packagers by pointing their editor at
8357 the source file containing the definition of the specified packages.
8361 guix edit gcc@@4.9 vim
8365 launches the program specified in the @code{VISUAL} or in the
8366 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8369 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8370 have created your own packages on @code{GUIX_PACKAGE_PATH}
8371 (@pxref{Package Modules}), you will be able to edit the package
8372 recipes. In other cases, you will be able to examine the read-only recipes
8373 for packages currently in the store.
8376 @node Invoking guix download
8377 @section Invoking @command{guix download}
8379 @cindex @command{guix download}
8380 @cindex downloading package sources
8381 When writing a package definition, developers typically need to download
8382 a source tarball, compute its SHA256 hash, and write that
8383 hash in the package definition (@pxref{Defining Packages}). The
8384 @command{guix download} tool helps with this task: it downloads a file
8385 from the given URI, adds it to the store, and prints both its file name
8386 in the store and its SHA256 hash.
8388 The fact that the downloaded file is added to the store saves bandwidth:
8389 when the developer eventually tries to build the newly defined package
8390 with @command{guix build}, the source tarball will not have to be
8391 downloaded again because it is already in the store. It is also a
8392 convenient way to temporarily stash files, which may be deleted
8393 eventually (@pxref{Invoking guix gc}).
8395 The @command{guix download} command supports the same URIs as used in
8396 package definitions. In particular, it supports @code{mirror://} URIs.
8397 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8398 Guile bindings for GnuTLS are available in the user's environment; when
8399 they are not available, an error is raised. @xref{Guile Preparations,
8400 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8401 GnuTLS-Guile}, for more information.
8403 @command{guix download} verifies HTTPS server certificates by loading
8404 the certificates of X.509 authorities from the directory pointed to by
8405 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8406 Certificates}), unless @option{--no-check-certificate} is used.
8408 The following options are available:
8411 @item --format=@var{fmt}
8413 Write the hash in the format specified by @var{fmt}. For more
8414 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8416 @item --no-check-certificate
8417 Do not validate the X.509 certificates of HTTPS servers.
8419 When using this option, you have @emph{absolutely no guarantee} that you
8420 are communicating with the authentic server responsible for the given
8421 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8423 @item --output=@var{file}
8424 @itemx -o @var{file}
8425 Save the downloaded file to @var{file} instead of adding it to the
8429 @node Invoking guix hash
8430 @section Invoking @command{guix hash}
8432 @cindex @command{guix hash}
8433 The @command{guix hash} command computes the SHA256 hash of a file.
8434 It is primarily a convenience tool for anyone contributing to the
8435 distribution: it computes the cryptographic hash of a file, which can be
8436 used in the definition of a package (@pxref{Defining Packages}).
8438 The general syntax is:
8441 guix hash @var{option} @var{file}
8444 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8445 hash of data read from standard input. @command{guix hash} has the
8450 @item --format=@var{fmt}
8452 Write the hash in the format specified by @var{fmt}.
8454 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8455 (@code{hex} and @code{hexadecimal} can be used as well).
8457 If the @option{--format} option is not specified, @command{guix hash}
8458 will output the hash in @code{nix-base32}. This representation is used
8459 in the definitions of packages.
8463 Compute the hash on @var{file} recursively.
8465 In this case, the hash is computed on an archive containing @var{file},
8466 including its children if it is a directory. Some of the metadata of
8467 @var{file} is part of the archive; for instance, when @var{file} is a
8468 regular file, the hash is different depending on whether @var{file} is
8469 executable or not. Metadata such as time stamps has no impact on the
8470 hash (@pxref{Invoking guix archive}).
8471 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8476 When combined with @option{--recursive}, exclude version control system
8477 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8480 As an example, here is how you would compute the hash of a Git checkout,
8481 which is useful when using the @code{git-fetch} method (@pxref{origin
8485 $ git clone http://example.org/foo.git
8491 @node Invoking guix import
8492 @section Invoking @command{guix import}
8494 @cindex importing packages
8495 @cindex package import
8496 @cindex package conversion
8497 @cindex Invoking @command{guix import}
8498 The @command{guix import} command is useful for people who would like to
8499 add a package to the distribution with as little work as
8500 possible---a legitimate demand. The command knows of a few
8501 repositories from which it can ``import'' package metadata. The result
8502 is a package definition, or a template thereof, in the format we know
8503 (@pxref{Defining Packages}).
8505 The general syntax is:
8508 guix import @var{importer} @var{options}@dots{}
8511 @var{importer} specifies the source from which to import package
8512 metadata, and @var{options} specifies a package identifier and other
8513 options specific to @var{importer}. Currently, the available
8518 Import metadata for the given GNU package. This provides a template
8519 for the latest version of that GNU package, including the hash of its
8520 source tarball, and its canonical synopsis and description.
8522 Additional information such as the package dependencies and its
8523 license needs to be figured out manually.
8525 For example, the following command returns a package definition for
8529 guix import gnu hello
8532 Specific command-line options are:
8535 @item --key-download=@var{policy}
8536 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8537 keys when verifying the package signature. @xref{Invoking guix
8538 refresh, @code{--key-download}}.
8543 Import metadata from the @uref{https://pypi.python.org/, Python Package
8544 Index}. Information is taken from the JSON-formatted description
8545 available at @code{pypi.python.org} and usually includes all the relevant
8546 information, including package dependencies. For maximum efficiency, it
8547 is recommended to install the @command{unzip} utility, so that the
8548 importer can unzip Python wheels and gather data from them.
8550 The command below imports metadata for the @code{itsdangerous} Python
8554 guix import pypi itsdangerous
8560 Traverse the dependency graph of the given upstream package recursively
8561 and generate package expressions for all those packages that are not yet
8567 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8568 is taken from the JSON-formatted description available at
8569 @code{rubygems.org} and includes most relevant information, including
8570 runtime dependencies. There are some caveats, however. The metadata
8571 doesn't distinguish between synopses and descriptions, so the same string
8572 is used for both fields. Additionally, the details of non-Ruby
8573 dependencies required to build native extensions is unavailable and left
8574 as an exercise to the packager.
8576 The command below imports metadata for the @code{rails} Ruby package:
8579 guix import gem rails
8585 Traverse the dependency graph of the given upstream package recursively
8586 and generate package expressions for all those packages that are not yet
8592 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8593 Information is taken from the JSON-formatted metadata provided through
8594 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8595 relevant information, such as module dependencies. License information
8596 should be checked closely. If Perl is available in the store, then the
8597 @code{corelist} utility will be used to filter core modules out of the
8598 list of dependencies.
8600 The command command below imports metadata for the @code{Acme::Boolean}
8604 guix import cpan Acme::Boolean
8609 @cindex Bioconductor
8610 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8611 central repository for the @uref{https://r-project.org, GNU@tie{}R
8612 statistical and graphical environment}.
8614 Information is extracted from the @code{DESCRIPTION} file of the package.
8616 The command command below imports metadata for the @code{Cairo}
8620 guix import cran Cairo
8623 When @code{--recursive} is added, the importer will traverse the
8624 dependency graph of the given upstream package recursively and generate
8625 package expressions for all those packages that are not yet in Guix.
8627 When @code{--archive=bioconductor} is added, metadata is imported from
8628 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8629 packages for for the analysis and comprehension of high-throughput
8630 genomic data in bioinformatics.
8632 Information is extracted from the @code{DESCRIPTION} file of a package
8633 published on the web interface of the Bioconductor SVN repository.
8635 The command below imports metadata for the @code{GenomicRanges}
8639 guix import cran --archive=bioconductor GenomicRanges
8645 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8646 comprehensive TeX archive network for TeX packages that are part of the
8647 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8649 Information about the package is obtained through the XML API provided
8650 by CTAN, while the source code is downloaded from the SVN repository of
8651 the Tex Live project. This is done because the CTAN does not keep
8654 The command command below imports metadata for the @code{fontspec}
8658 guix import texlive fontspec
8661 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8662 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8663 tree in the TeX Live SVN repository, but from the specified sibling
8664 directory under the same root.
8666 The command below imports metadata for the @code{ifxetex} package from
8667 CTAN while fetching the sources from the directory
8668 @file{texmf/source/generic}:
8671 guix import texlive --archive=generic ifxetex
8675 @cindex JSON, import
8676 Import package metadata from a local JSON file. Consider the following
8677 example package definition in JSON format:
8683 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8684 "build-system": "gnu",
8685 "home-page": "https://www.gnu.org/software/hello/",
8686 "synopsis": "Hello, GNU world: An example GNU package",
8687 "description": "GNU Hello prints a greeting.",
8688 "license": "GPL-3.0+",
8689 "native-inputs": ["gettext"]
8693 The field names are the same as for the @code{<package>} record
8694 (@xref{Defining Packages}). References to other packages are provided
8695 as JSON lists of quoted package specification strings such as
8696 @code{guile} or @code{guile@@2.0}.
8698 The importer also supports a more explicit source definition using the
8699 common fields for @code{<origin>} records:
8705 "method": "url-fetch",
8706 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
8708 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
8715 The command below reads metadata from the JSON file @code{hello.json}
8716 and outputs a package expression:
8719 guix import json hello.json
8723 Import metadata from a local copy of the source of the
8724 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
8725 relies on the @command{nix-instantiate} command of
8726 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
8727 typically written in a mixture of Nix-language and Bash code. This
8728 command only imports the high-level package structure that is written in
8729 the Nix language. It normally includes all the basic fields of a
8732 When importing a GNU package, the synopsis and descriptions are replaced
8733 by their canonical upstream variant.
8735 Usually, you will first need to do:
8738 export NIX_REMOTE=daemon
8742 so that @command{nix-instantiate} does not try to open the Nix database.
8744 As an example, the command below imports the package definition of
8745 LibreOffice (more precisely, it imports the definition of the package
8746 bound to the @code{libreoffice} top-level attribute):
8749 guix import nix ~/path/to/nixpkgs libreoffice
8754 Import metadata from the Haskell community's central package archive
8755 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
8756 Cabal files and includes all the relevant information, including package
8759 Specific command-line options are:
8764 Read a Cabal file from standard input.
8765 @item --no-test-dependencies
8767 Do not include dependencies required only by the test suites.
8768 @item --cabal-environment=@var{alist}
8769 @itemx -e @var{alist}
8770 @var{alist} is a Scheme alist defining the environment in which the
8771 Cabal conditionals are evaluated. The accepted keys are: @code{os},
8772 @code{arch}, @code{impl} and a string representing the name of a flag.
8773 The value associated with a flag has to be either the symbol
8774 @code{true} or @code{false}. The value associated with other keys
8775 has to conform to the Cabal file format definition. The default value
8776 associated with the keys @code{os}, @code{arch} and @code{impl} is
8777 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
8780 Traverse the dependency graph of the given upstream package recursively
8781 and generate package expressions for all those packages that are not yet
8785 The command below imports metadata for the latest version of the
8786 @code{HTTP} Haskell package without including test dependencies and
8787 specifying the value of the flag @samp{network-uri} as @code{false}:
8790 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
8793 A specific package version may optionally be specified by following the
8794 package name by an at-sign and a version number as in the following example:
8797 guix import hackage mtl@@2.1.3.1
8802 The @code{stackage} importer is a wrapper around the @code{hackage} one.
8803 It takes a package name, looks up the package version included in a
8804 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
8805 release and uses the @code{hackage} importer to retrieve its metadata.
8806 Note that it is up to you to select an LTS release compatible with the
8807 GHC compiler used by Guix.
8809 Specific command-line options are:
8812 @item --no-test-dependencies
8814 Do not include dependencies required only by the test suites.
8815 @item --lts-version=@var{version}
8816 @itemx -l @var{version}
8817 @var{version} is the desired LTS release version. If omitted the latest
8821 Traverse the dependency graph of the given upstream package recursively
8822 and generate package expressions for all those packages that are not yet
8826 The command below imports metadata for the @code{HTTP} Haskell package
8827 included in the LTS Stackage release version 7.18:
8830 guix import stackage --lts-version=7.18 HTTP
8835 Import metadata from an Emacs Lisp Package Archive (ELPA) package
8836 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8838 Specific command-line options are:
8841 @item --archive=@var{repo}
8842 @itemx -a @var{repo}
8843 @var{repo} identifies the archive repository from which to retrieve the
8844 information. Currently the supported repositories and their identifiers
8848 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
8849 identifier. This is the default.
8851 Packages from @code{elpa.gnu.org} are signed with one of the keys
8852 contained in the GnuPG keyring at
8853 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
8854 @code{emacs} package (@pxref{Package Installation, ELPA package
8855 signatures,, emacs, The GNU Emacs Manual}).
8858 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
8859 @code{melpa-stable} identifier.
8862 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
8868 Traverse the dependency graph of the given upstream package recursively
8869 and generate package expressions for all those packages that are not yet
8875 Import metadata from the crates.io Rust package repository
8876 @uref{https://crates.io, crates.io}.
8881 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
8882 repository used by the OCaml community.
8885 The structure of the @command{guix import} code is modular. It would be
8886 useful to have more importers for other package formats, and your help
8887 is welcome here (@pxref{Contributing}).
8889 @node Invoking guix refresh
8890 @section Invoking @command{guix refresh}
8892 @cindex @command {guix refresh}
8893 The primary audience of the @command{guix refresh} command is developers
8894 of the GNU software distribution. By default, it reports any packages
8895 provided by the distribution that are outdated compared to the latest
8896 upstream version, like this:
8900 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
8901 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
8904 Alternately, one can specify packages to consider, in which case a
8905 warning is emitted for packages that lack an updater:
8908 $ guix refresh coreutils guile guile-ssh
8909 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
8910 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
8913 @command{guix refresh} browses the upstream repository of each package and determines
8914 the highest version number of the releases therein. The command
8915 knows how to update specific types of packages: GNU packages, ELPA
8916 packages, etc.---see the documentation for @option{--type} below. There
8917 are many packages, though, for which it lacks a method to determine
8918 whether a new upstream release is available. However, the mechanism is
8919 extensible, so feel free to get in touch with us to add a new method!
8924 Consider the packages specified, and all the packages upon which they depend.
8927 $ guix refresh --recursive coreutils
8928 gnu/packages/acl.scm:35:2: warning: no updater for acl
8929 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
8930 gnu/packages/xml.scm:68:2: warning: no updater for expat
8931 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
8937 Sometimes the upstream name differs from the package name used in Guix,
8938 and @command{guix refresh} needs a little help. Most updaters honor the
8939 @code{upstream-name} property in package definitions, which can be used
8943 (define-public network-manager
8945 (name "network-manager")
8947 (properties '((upstream-name . "NetworkManager")))))
8950 When passed @code{--update}, it modifies distribution source files to
8951 update the version numbers and source tarball hashes of those package
8952 recipes (@pxref{Defining Packages}). This is achieved by downloading
8953 each package's latest source tarball and its associated OpenPGP
8954 signature, authenticating the downloaded tarball against its signature
8955 using @command{gpg}, and finally computing its hash. When the public
8956 key used to sign the tarball is missing from the user's keyring, an
8957 attempt is made to automatically retrieve it from a public key server;
8958 when this is successful, the key is added to the user's keyring; otherwise,
8959 @command{guix refresh} reports an error.
8961 The following options are supported:
8965 @item --expression=@var{expr}
8966 @itemx -e @var{expr}
8967 Consider the package @var{expr} evaluates to.
8969 This is useful to precisely refer to a package, as in this example:
8972 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
8975 This command lists the dependents of the ``final'' libc (essentially all
8980 Update distribution source files (package recipes) in place. This is
8981 usually run from a checkout of the Guix source tree (@pxref{Running
8982 Guix Before It Is Installed}):
8985 $ ./pre-inst-env guix refresh -s non-core -u
8988 @xref{Defining Packages}, for more information on package definitions.
8990 @item --select=[@var{subset}]
8991 @itemx -s @var{subset}
8992 Select all the packages in @var{subset}, one of @code{core} or
8995 The @code{core} subset refers to all the packages at the core of the
8996 distribution---i.e., packages that are used to build ``everything
8997 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
8998 changing one of these packages in the distribution entails a rebuild of
8999 all the others. Thus, such updates are an inconvenience to users in
9000 terms of build time or bandwidth used to achieve the upgrade.
9002 The @code{non-core} subset refers to the remaining packages. It is
9003 typically useful in cases where an update of the core packages would be
9006 @item --manifest=@var{file}
9007 @itemx -m @var{file}
9008 Select all the packages from the manifest in @var{file}. This is useful to
9009 check if any packages of the user manifest can be updated.
9011 @item --type=@var{updater}
9012 @itemx -t @var{updater}
9013 Select only packages handled by @var{updater} (may be a comma-separated
9014 list of updaters). Currently, @var{updater} may be one of:
9018 the updater for GNU packages;
9020 the updater for GNOME packages;
9022 the updater for KDE packages;
9024 the updater for X.org packages;
9026 the updater for packages hosted on kernel.org;
9028 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9030 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9032 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9034 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9036 the updater for @uref{https://pypi.python.org, PyPI} packages.
9038 the updater for @uref{https://rubygems.org, RubyGems} packages.
9040 the updater for @uref{https://github.com, GitHub} packages.
9042 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9044 the updater for @uref{https://www.stackage.org, Stackage} packages.
9046 the updater for @uref{https://crates.io, Crates} packages.
9048 the updater for @uref{https://launchpad.net, Launchpad} packages.
9051 For instance, the following command only checks for updates of Emacs
9052 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9055 $ guix refresh --type=elpa,cran
9056 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9057 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9062 In addition, @command{guix refresh} can be passed one or more package
9063 names, as in this example:
9066 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9070 The command above specifically updates the @code{emacs} and
9071 @code{idutils} packages. The @code{--select} option would have no
9072 effect in this case.
9074 When considering whether to upgrade a package, it is sometimes
9075 convenient to know which packages would be affected by the upgrade and
9076 should be checked for compatibility. For this the following option may
9077 be used when passing @command{guix refresh} one or more package names:
9081 @item --list-updaters
9083 List available updaters and exit (see @option{--type} above.)
9085 For each updater, display the fraction of packages it covers; at the
9086 end, display the fraction of packages covered by all these updaters.
9088 @item --list-dependent
9090 List top-level dependent packages that would need to be rebuilt as a
9091 result of upgrading one or more packages.
9093 @xref{Invoking guix graph, the @code{reverse-package} type of
9094 @command{guix graph}}, for information on how to visualize the list of
9095 dependents of a package.
9099 Be aware that the @code{--list-dependent} option only
9100 @emph{approximates} the rebuilds that would be required as a result of
9101 an upgrade. More rebuilds might be required under some circumstances.
9104 $ guix refresh --list-dependent flex
9105 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9106 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9109 The command above lists a set of packages that could be built to check
9110 for compatibility with an upgraded @code{flex} package.
9114 @item --list-transitive
9115 List all the packages which one or more packages depend upon.
9118 $ guix refresh --list-transitive flex
9119 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9120 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{}
9125 The command above lists a set of packages which, when changed, would cause
9126 @code{flex} to be rebuilt.
9128 The following options can be used to customize GnuPG operation:
9132 @item --gpg=@var{command}
9133 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9134 for in @code{$PATH}.
9136 @item --keyring=@var{file}
9137 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9138 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9139 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9140 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9141 information on a tool to manipulate keybox files).
9143 When this option is omitted, @command{guix refresh} uses
9144 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9145 signing keys. OpenPGP signatures are checked against keys from this keyring;
9146 missing keys are downloaded to this keyring as well (see
9147 @option{--key-download} below.)
9149 You can export keys from your default GPG keyring into a keybox file using
9150 commands like this one:
9153 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9156 Likewise, you can fetch keys to a specific keybox file like this:
9159 gpg --no-default-keyring --keyring mykeyring.kbx \
9160 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9163 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9164 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9166 @item --key-download=@var{policy}
9167 Handle missing OpenPGP keys according to @var{policy}, which may be one
9172 Always download missing OpenPGP keys from the key server, and add them
9173 to the user's GnuPG keyring.
9176 Never try to download missing OpenPGP keys. Instead just bail out.
9179 When a package signed with an unknown OpenPGP key is encountered, ask
9180 the user whether to download it or not. This is the default behavior.
9183 @item --key-server=@var{host}
9184 Use @var{host} as the OpenPGP key server when importing a public key.
9188 The @code{github} updater uses the
9189 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9190 releases. When used repeatedly e.g.@: when refreshing all packages,
9191 GitHub will eventually refuse to answer any further API requests. By
9192 default 60 API requests per hour are allowed, and a full refresh on all
9193 GitHub packages in Guix requires more than this. Authentication with
9194 GitHub through the use of an API token alleviates these limits. To use
9195 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9196 token procured from @uref{https://github.com/settings/tokens} or
9200 @node Invoking guix lint
9201 @section Invoking @command{guix lint}
9203 @cindex @command{guix lint}
9204 @cindex package, checking for errors
9205 The @command{guix lint} command is meant to help package developers avoid
9206 common errors and use a consistent style. It runs a number of checks on
9207 a given set of packages in order to find common mistakes in their
9208 definitions. Available @dfn{checkers} include (see
9209 @code{--list-checkers} for a complete list):
9214 Validate certain typographical and stylistic rules about package
9215 descriptions and synopses.
9217 @item inputs-should-be-native
9218 Identify inputs that should most likely be native inputs.
9224 @itemx source-file-name
9225 Probe @code{home-page} and @code{source} URLs and report those that are
9226 invalid. Suggest a @code{mirror://} URL when applicable. If the
9227 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9228 URL. Check that the source file name is meaningful, e.g.@: is not just a
9229 version number or ``git-checkout'', without a declared @code{file-name}
9230 (@pxref{origin Reference}).
9232 @item source-unstable-tarball
9233 Parse the @code{source} URL to determine if a tarball from GitHub is
9234 autogenerated or if it is a release tarball. Unfortunately GitHub's
9235 autogenerated tarballs are sometimes regenerated.
9238 @cindex security vulnerabilities
9239 @cindex CVE, Common Vulnerabilities and Exposures
9240 Report known vulnerabilities found in the Common Vulnerabilities and
9241 Exposures (CVE) databases of the current and past year
9242 @uref{https://nvd.nist.gov/download.cfm#CVE_FEED, published by the US
9245 To view information about a particular vulnerability, visit pages such as:
9249 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9251 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9255 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9256 @code{CVE-2015-7554}.
9258 Package developers can specify in package recipes the
9259 @uref{https://nvd.nist.gov/cpe.cfm,Common Platform Enumeration (CPE)}
9260 name and version of the package when they differ from the name or version
9261 that Guix uses, as in this example:
9267 ;; CPE calls this package "grub2".
9268 (properties '((cpe-name . "grub2")
9269 (cpe-version . "2.3")))
9272 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9273 Some entries in the CVE database do not specify which version of a
9274 package they apply to, and would thus ``stick around'' forever. Package
9275 developers who found CVE alerts and verified they can be ignored can
9276 declare them as in this example:
9282 ;; These CVEs no longer apply and can be safely ignored.
9283 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9286 "CVE-2011-5244")))))
9290 Warn about obvious source code formatting issues: trailing white space,
9291 use of tabulations, etc.
9294 The general syntax is:
9297 guix lint @var{options} @var{package}@dots{}
9300 If no package is given on the command line, then all packages are checked.
9301 The @var{options} may be zero or more of the following:
9304 @item --list-checkers
9306 List and describe all the available checkers that will be run on packages
9311 Only enable the checkers specified in a comma-separated list using the
9312 names returned by @code{--list-checkers}.
9316 @node Invoking guix size
9317 @section Invoking @command{guix size}
9320 @cindex package size
9322 @cindex @command{guix size}
9323 The @command{guix size} command helps package developers profile the
9324 disk usage of packages. It is easy to overlook the impact of an
9325 additional dependency added to a package, or the impact of using a
9326 single output for a package that could easily be split (@pxref{Packages
9327 with Multiple Outputs}). Such are the typical issues that
9328 @command{guix size} can highlight.
9330 The command can be passed one or more package specifications
9331 such as @code{gcc@@4.8}
9332 or @code{guile:debug}, or a file name in the store. Consider this
9336 $ guix size coreutils
9337 store item total self
9338 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9339 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9340 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9341 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9342 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9343 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9344 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9345 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9350 The store items listed here constitute the @dfn{transitive closure} of
9351 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9352 would be returned by:
9355 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9358 Here the output shows three columns next to store items. The first column,
9359 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9360 the store item---that is, its own size plus the size of all its
9361 dependencies. The next column, labeled ``self'', shows the size of the
9362 item itself. The last column shows the ratio of the size of the item
9363 itself to the space occupied by all the items listed here.
9365 In this example, we see that the closure of Coreutils weighs in at
9366 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9367 libraries. (That libc and GCC's libraries represent a large fraction of
9368 the closure is not a problem @i{per se} because they are always available
9369 on the system anyway.)
9371 When the package(s) passed to @command{guix size} are available in the
9372 store@footnote{More precisely, @command{guix size} looks for the
9373 @emph{ungrafted} variant of the given package(s), as returned by
9374 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9375 for information on grafts.}, @command{guix size} queries the daemon to determine its
9376 dependencies, and measures its size in the store, similar to @command{du
9377 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9380 When the given packages are @emph{not} in the store, @command{guix size}
9381 reports information based on the available substitutes
9382 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9383 store items that are not even on disk, only available remotely.
9385 You can also specify several package names:
9388 $ guix size coreutils grep sed bash
9389 store item total self
9390 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9391 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9392 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9393 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9399 In this example we see that the combination of the four packages takes
9400 102.3@tie{}MiB in total, which is much less than the sum of each closure
9401 since they have a lot of dependencies in common.
9403 The available options are:
9407 @item --substitute-urls=@var{urls}
9408 Use substitute information from @var{urls}.
9409 @xref{client-substitute-urls, the same option for @code{guix build}}.
9411 @item --sort=@var{key}
9412 Sort lines according to @var{key}, one of the following options:
9416 the size of each item (the default);
9418 the total size of the item's closure.
9421 @item --map-file=@var{file}
9422 Write a graphical map of disk usage in PNG format to @var{file}.
9424 For the example above, the map looks like this:
9426 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9427 produced by @command{guix size}}
9429 This option requires that
9430 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9431 installed and visible in Guile's module search path. When that is not
9432 the case, @command{guix size} fails as it tries to load it.
9434 @item --system=@var{system}
9435 @itemx -s @var{system}
9436 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9440 @node Invoking guix graph
9441 @section Invoking @command{guix graph}
9444 @cindex @command{guix graph}
9445 @cindex package dependencies
9446 Packages and their dependencies form a @dfn{graph}, specifically a
9447 directed acyclic graph (DAG). It can quickly become difficult to have a
9448 mental model of the package DAG, so the @command{guix graph} command
9449 provides a visual representation of the DAG. By default,
9450 @command{guix graph} emits a DAG representation in the input format of
9451 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9452 directly to the @command{dot} command of Graphviz. It can also emit an
9453 HTML page with embedded JavaScript code to display a ``chord diagram''
9454 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9455 emit Cypher queries to construct a graph in a graph database supporting
9456 the @uref{https://www.opencypher.org/, openCypher} query language.
9457 The general syntax is:
9460 guix graph @var{options} @var{package}@dots{}
9463 For example, the following command generates a PDF file representing the
9464 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9468 guix graph coreutils | dot -Tpdf > dag.pdf
9471 The output looks like this:
9473 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9475 Nice little graph, no?
9477 But there is more than one graph! The one above is concise: it is the
9478 graph of package objects, omitting implicit inputs such as GCC, libc,
9479 grep, etc. It is often useful to have such a concise graph, but
9480 sometimes one may want to see more details. @command{guix graph} supports
9481 several types of graphs, allowing you to choose the level of detail:
9485 This is the default type used in the example above. It shows the DAG of
9486 package objects, excluding implicit dependencies. It is concise, but
9487 filters out many details.
9489 @item reverse-package
9490 This shows the @emph{reverse} DAG of packages. For example:
9493 guix graph --type=reverse-package ocaml
9496 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9497 you are also interested in cases where OCaml is an implicit dependency, see
9498 @code{reverse-bag} below.)
9500 Note that for core packages this can yield huge graphs. If all you want
9501 is to know the number of packages that depend on a given package, use
9502 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9503 @option{--list-dependent}}).
9506 This is the package DAG, @emph{including} implicit inputs.
9508 For instance, the following command:
9511 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9514 ...@: yields this bigger graph:
9516 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9518 At the bottom of the graph, we see all the implicit inputs of
9519 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9521 Now, note that the dependencies of these implicit inputs---that is, the
9522 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9523 here, for conciseness.
9526 Similar to @code{bag-emerged}, but this time including all the bootstrap
9529 @item bag-with-origins
9530 Similar to @code{bag}, but also showing origins and their dependencies.
9533 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9534 it also takes implicit dependencies into account. For example:
9537 guix graph -t reverse-bag dune
9541 ...@: yields the graph of all packages that depend on Dune, directly or
9542 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9543 @i{via} @code{dune-build-system}, this shows a large number of packages,
9544 whereas @code{reverse-package} would show very few if any.
9547 This is the most detailed representation: It shows the DAG of
9548 derivations (@pxref{Derivations}) and plain store items. Compared to
9549 the above representation, many additional nodes are visible, including
9550 build scripts, patches, Guile modules, etc.
9552 For this type of graph, it is also possible to pass a @file{.drv} file
9553 name instead of a package name, as in:
9556 guix graph -t derivation `guix system build -d my-config.scm`
9560 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9561 For example, the following command shows the graph for the package
9562 module that defines the @code{guile} package:
9565 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9569 All the types above correspond to @emph{build-time dependencies}. The
9570 following graph type represents the @emph{run-time dependencies}:
9574 This is the graph of @dfn{references} of a package output, as returned
9575 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9577 If the given package output is not available in the store, @command{guix
9578 graph} attempts to obtain dependency information from substitutes.
9580 Here you can also pass a store file name instead of a package name. For
9581 example, the command below produces the reference graph of your profile
9582 (which can be big!):
9585 guix graph -t references `readlink -f ~/.guix-profile`
9589 This is the graph of the @dfn{referrers} of a store item, as returned by
9590 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9592 This relies exclusively on local information from your store. For
9593 instance, let us suppose that the current Inkscape is available in 10
9594 profiles on your machine; @command{guix graph -t referrers inkscape}
9595 will show a graph rooted at Inkscape and with those 10 profiles linked
9598 It can help determine what is preventing a store item from being garbage
9603 The available options are the following:
9606 @item --type=@var{type}
9607 @itemx -t @var{type}
9608 Produce a graph output of @var{type}, where @var{type} must be one of
9609 the values listed above.
9612 List the supported graph types.
9614 @item --backend=@var{backend}
9615 @itemx -b @var{backend}
9616 Produce a graph using the selected @var{backend}.
9618 @item --list-backends
9619 List the supported graph backends.
9621 Currently, the available backends are Graphviz and d3.js.
9623 @item --expression=@var{expr}
9624 @itemx -e @var{expr}
9625 Consider the package @var{expr} evaluates to.
9627 This is useful to precisely refer to a package, as in this example:
9630 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9633 @item --system=@var{system}
9634 @itemx -s @var{system}
9635 Display the graph for @var{system}---e.g., @code{i686-linux}.
9637 The package dependency graph is largely architecture-independent, but there
9638 are some architecture-dependent bits that this option allows you to visualize.
9643 @node Invoking guix publish
9644 @section Invoking @command{guix publish}
9646 @cindex @command{guix publish}
9647 The purpose of @command{guix publish} is to enable users to easily share
9648 their store with others, who can then use it as a substitute server
9649 (@pxref{Substitutes}).
9651 When @command{guix publish} runs, it spawns an HTTP server which allows
9652 anyone with network access to obtain substitutes from it. This means
9653 that any machine running Guix can also act as if it were a build farm,
9654 since the HTTP interface is compatible with Cuirass, the software behind
9655 the @code{@value{SUBSTITUTE-SERVER}} build farm.
9657 For security, each substitute is signed, allowing recipients to check
9658 their authenticity and integrity (@pxref{Substitutes}). Because
9659 @command{guix publish} uses the signing key of the system, which is only
9660 readable by the system administrator, it must be started as root; the
9661 @code{--user} option makes it drop root privileges early on.
9663 The signing key pair must be generated before @command{guix publish} is
9664 launched, using @command{guix archive --generate-key} (@pxref{Invoking
9667 The general syntax is:
9670 guix publish @var{options}@dots{}
9673 Running @command{guix publish} without any additional arguments will
9674 spawn an HTTP server on port 8080:
9680 Once a publishing server has been authorized (@pxref{Invoking guix
9681 archive}), the daemon may download substitutes from it:
9684 guix-daemon --substitute-urls=http://example.org:8080
9687 By default, @command{guix publish} compresses archives on the fly as it
9688 serves them. This ``on-the-fly'' mode is convenient in that it requires
9689 no setup and is immediately available. However, when serving lots of
9690 clients, we recommend using the @option{--cache} option, which enables
9691 caching of the archives before they are sent to clients---see below for
9692 details. The @command{guix weather} command provides a handy way to
9693 check what a server provides (@pxref{Invoking guix weather}).
9695 As a bonus, @command{guix publish} also serves as a content-addressed
9696 mirror for source files referenced in @code{origin} records
9697 (@pxref{origin Reference}). For instance, assuming @command{guix
9698 publish} is running on @code{example.org}, the following URL returns the
9699 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
9700 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
9703 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
9706 Obviously, these URLs only work for files that are in the store; in
9707 other cases, they return 404 (``Not Found'').
9709 @cindex build logs, publication
9710 Build logs are available from @code{/log} URLs like:
9713 http://example.org/log/gwspk@dots{}-guile-2.2.3
9717 When @command{guix-daemon} is configured to save compressed build logs,
9718 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
9719 URLs return the compressed log as-is, with an appropriate
9720 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
9721 running @command{guix-daemon} with @code{--log-compression=gzip} since
9722 Web browsers can automatically decompress it, which is not the case with
9725 The following options are available:
9728 @item --port=@var{port}
9729 @itemx -p @var{port}
9730 Listen for HTTP requests on @var{port}.
9732 @item --listen=@var{host}
9733 Listen on the network interface for @var{host}. The default is to
9734 accept connections from any interface.
9736 @item --user=@var{user}
9737 @itemx -u @var{user}
9738 Change privileges to @var{user} as soon as possible---i.e., once the
9739 server socket is open and the signing key has been read.
9741 @item --compression[=@var{method}[:@var{level}]]
9742 @itemx -C [@var{method}[:@var{level}]]
9743 Compress data using the given @var{method} and @var{level}. @var{method} is
9744 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
9747 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
9748 to different compression levels: 1 is the fastest, and 9 is the best
9749 (CPU-intensive). The default is 3.
9751 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
9752 increase in CPU usage; see
9753 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
9756 Unless @option{--cache} is used, compression occurs on the fly and
9757 the compressed streams are not
9758 cached. Thus, to reduce load on the machine that runs @command{guix
9759 publish}, it may be a good idea to choose a low compression level, to
9760 run @command{guix publish} behind a caching proxy, or to use
9761 @option{--cache}. Using @option{--cache} has the advantage that it
9762 allows @command{guix publish} to add @code{Content-Length} HTTP header
9765 This option can be repeated, in which case every substitute gets compressed
9766 using all the selected methods, and all of them are advertised. This is
9767 useful when users may not support all the compression methods: they can select
9768 the one they support.
9770 @item --cache=@var{directory}
9771 @itemx -c @var{directory}
9772 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
9773 and only serve archives that are in cache.
9775 When this option is omitted, archives and meta-data are created
9776 on-the-fly. This can reduce the available bandwidth, especially when
9777 compression is enabled, since this may become CPU-bound. Another
9778 drawback of the default mode is that the length of archives is not known
9779 in advance, so @command{guix publish} does not add a
9780 @code{Content-Length} HTTP header to its responses, which in turn
9781 prevents clients from knowing the amount of data being downloaded.
9783 Conversely, when @option{--cache} is used, the first request for a store
9784 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
9785 background process to @dfn{bake} the archive---computing its
9786 @code{.narinfo} and compressing the archive, if needed. Once the
9787 archive is cached in @var{directory}, subsequent requests succeed and
9788 are served directly from the cache, which guarantees that clients get
9789 the best possible bandwidth.
9791 The ``baking'' process is performed by worker threads. By default, one
9792 thread per CPU core is created, but this can be customized. See
9793 @option{--workers} below.
9795 When @option{--ttl} is used, cached entries are automatically deleted
9796 when they have expired.
9798 @item --workers=@var{N}
9799 When @option{--cache} is used, request the allocation of @var{N} worker
9800 threads to ``bake'' archives.
9802 @item --ttl=@var{ttl}
9803 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
9804 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
9805 days, @code{1m} means 1 month, and so on.
9807 This allows the user's Guix to keep substitute information in cache for
9808 @var{ttl}. However, note that @code{guix publish} does not itself
9809 guarantee that the store items it provides will indeed remain available
9810 for as long as @var{ttl}.
9812 Additionally, when @option{--cache} is used, cached entries that have
9813 not been accessed for @var{ttl} and that no longer have a corresponding
9814 item in the store, may be deleted.
9816 @item --nar-path=@var{path}
9817 Use @var{path} as the prefix for the URLs of ``nar'' files
9818 (@pxref{Invoking guix archive, normalized archives}).
9820 By default, nars are served at a URL such as
9821 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
9822 change the @code{/nar} part to @var{path}.
9824 @item --public-key=@var{file}
9825 @itemx --private-key=@var{file}
9826 Use the specific @var{file}s as the public/private key pair used to sign
9827 the store items being published.
9829 The files must correspond to the same key pair (the private key is used
9830 for signing and the public key is merely advertised in the signature
9831 metadata). They must contain keys in the canonical s-expression format
9832 as produced by @command{guix archive --generate-key} (@pxref{Invoking
9833 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
9834 @file{/etc/guix/signing-key.sec} are used.
9836 @item --repl[=@var{port}]
9837 @itemx -r [@var{port}]
9838 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
9839 Reference Manual}) on @var{port} (37146 by default). This is used
9840 primarily for debugging a running @command{guix publish} server.
9843 Enabling @command{guix publish} on Guix System is a one-liner: just
9844 instantiate a @code{guix-publish-service-type} service in the @code{services} field
9845 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
9846 @code{guix-publish-service-type}}).
9848 If you are instead running Guix on a ``foreign distro'', follow these
9853 If your host distro uses the systemd init system:
9856 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
9857 /etc/systemd/system/
9858 # systemctl start guix-publish && systemctl enable guix-publish
9862 If your host distro uses the Upstart init system:
9865 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
9866 # start guix-publish
9870 Otherwise, proceed similarly with your distro's init system.
9873 @node Invoking guix challenge
9874 @section Invoking @command{guix challenge}
9876 @cindex reproducible builds
9877 @cindex verifiable builds
9878 @cindex @command{guix challenge}
9880 Do the binaries provided by this server really correspond to the source
9881 code it claims to build? Is a package build process deterministic?
9882 These are the questions the @command{guix challenge} command attempts to
9885 The former is obviously an important question: Before using a substitute
9886 server (@pxref{Substitutes}), one had better @emph{verify} that it
9887 provides the right binaries, and thus @emph{challenge} it. The latter
9888 is what enables the former: If package builds are deterministic, then
9889 independent builds of the package should yield the exact same result,
9890 bit for bit; if a server provides a binary different from the one
9891 obtained locally, it may be either corrupt or malicious.
9893 We know that the hash that shows up in @file{/gnu/store} file names is
9894 the hash of all the inputs of the process that built the file or
9895 directory---compilers, libraries, build scripts,
9896 etc. (@pxref{Introduction}). Assuming deterministic build processes,
9897 one store file name should map to exactly one build output.
9898 @command{guix challenge} checks whether there is, indeed, a single
9899 mapping by comparing the build outputs of several independent builds of
9900 any given store item.
9902 The command output looks like this:
9905 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
9906 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
9907 updating list of substitutes from 'https://guix.example.org'... 100.0%
9908 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
9909 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9910 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
9911 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
9912 /gnu/store/@dots{}-git-2.5.0 contents differ:
9913 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
9914 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
9915 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
9916 /gnu/store/@dots{}-pius-2.1.1 contents differ:
9917 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9918 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
9919 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
9923 6,406 store items were analyzed:
9924 - 4,749 (74.1%) were identical
9925 - 525 (8.2%) differed
9926 - 1,132 (17.7%) were inconclusive
9930 In this example, @command{guix challenge} first scans the store to
9931 determine the set of locally-built derivations---as opposed to store
9932 items that were downloaded from a substitute server---and then queries
9933 all the substitute servers. It then reports those store items for which
9934 the servers obtained a result different from the local build.
9936 @cindex non-determinism, in package builds
9937 As an example, @code{guix.example.org} always gets a different answer.
9938 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
9939 case of Git. This might indicate that the build process of Git is
9940 non-deterministic, meaning that its output varies as a function of
9941 various things that Guix does not fully control, in spite of building
9942 packages in isolated environments (@pxref{Features}). Most common
9943 sources of non-determinism include the addition of timestamps in build
9944 results, the inclusion of random numbers, and directory listings sorted
9945 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
9948 To find out what is wrong with this Git binary, we can do something along
9949 these lines (@pxref{Invoking guix archive}):
9952 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
9953 | guix archive -x /tmp/git
9954 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
9957 This command shows the difference between the files resulting from the
9958 local build, and the files resulting from the build on
9959 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
9960 diffutils, Comparing and Merging Files}). The @command{diff} command
9961 works great for text files. When binary files differ, a better option
9962 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
9963 visualize differences for all kinds of files.
9965 Once you have done that work, you can tell whether the differences are due
9966 to a non-deterministic build process or to a malicious server. We try
9967 hard to remove sources of non-determinism in packages to make it easier
9968 to verify substitutes, but of course, this is a process that
9969 involves not just Guix, but a large part of the free software community.
9970 In the meantime, @command{guix challenge} is one tool to help address
9973 If you are writing packages for Guix, you are encouraged to check
9974 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
9975 same build result as you did with:
9978 $ guix challenge @var{package}
9982 where @var{package} is a package specification such as
9983 @code{guile@@2.0} or @code{glibc:debug}.
9985 The general syntax is:
9988 guix challenge @var{options} [@var{packages}@dots{}]
9991 When a difference is found between the hash of a locally-built item and
9992 that of a server-provided substitute, or among substitutes provided by
9993 different servers, the command displays it as in the example above and
9994 its exit code is 2 (other non-zero exit codes denote other kinds of
9997 The one option that matters is:
10001 @item --substitute-urls=@var{urls}
10002 Consider @var{urls} the whitespace-separated list of substitute source
10003 URLs to compare to.
10007 Show details about matches (identical contents) in addition to
10008 information about mismatches.
10012 @node Invoking guix copy
10013 @section Invoking @command{guix copy}
10015 @cindex copy, of store items, over SSH
10016 @cindex SSH, copy of store items
10017 @cindex sharing store items across machines
10018 @cindex transferring store items across machines
10019 The @command{guix copy} command copies items from the store of one
10020 machine to that of another machine over a secure shell (SSH)
10021 connection@footnote{This command is available only when Guile-SSH was
10022 found. @xref{Requirements}, for details.}. For example, the following
10023 command copies the @code{coreutils} package, the user's profile, and all
10024 their dependencies over to @var{host}, logged in as @var{user}:
10027 guix copy --to=@var{user}@@@var{host} \
10028 coreutils `readlink -f ~/.guix-profile`
10031 If some of the items to be copied are already present on @var{host},
10032 they are not actually sent.
10034 The command below retrieves @code{libreoffice} and @code{gimp} from
10035 @var{host}, assuming they are available there:
10038 guix copy --from=@var{host} libreoffice gimp
10041 The SSH connection is established using the Guile-SSH client, which is
10042 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10043 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10045 The key used to sign items that are sent must be accepted by the remote
10046 machine. Likewise, the key used by the remote machine to sign items you
10047 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10048 own daemon. @xref{Invoking guix archive}, for more information about
10049 store item authentication.
10051 The general syntax is:
10054 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10057 You must always specify one of the following options:
10060 @item --to=@var{spec}
10061 @itemx --from=@var{spec}
10062 Specify the host to send to or receive from. @var{spec} must be an SSH
10063 spec such as @code{example.org}, @code{charlie@@example.org}, or
10064 @code{charlie@@example.org:2222}.
10067 The @var{items} can be either package names, such as @code{gimp}, or
10068 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10070 When specifying the name of a package to send, it is first built if
10071 needed, unless @option{--dry-run} was specified. Common build options
10072 are supported (@pxref{Common Build Options}).
10075 @node Invoking guix container
10076 @section Invoking @command{guix container}
10078 @cindex @command{guix container}
10080 As of version @value{VERSION}, this tool is experimental. The interface
10081 is subject to radical change in the future.
10084 The purpose of @command{guix container} is to manipulate processes
10085 running within an isolated environment, commonly known as a
10086 ``container'', typically created by the @command{guix environment}
10087 (@pxref{Invoking guix environment}) and @command{guix system container}
10088 (@pxref{Invoking guix system}) commands.
10090 The general syntax is:
10093 guix container @var{action} @var{options}@dots{}
10096 @var{action} specifies the operation to perform with a container, and
10097 @var{options} specifies the context-specific arguments for the action.
10099 The following actions are available:
10103 Execute a command within the context of a running container.
10108 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10111 @var{pid} specifies the process ID of the running container.
10112 @var{program} specifies an executable file name within the root file
10113 system of the container. @var{arguments} are the additional options that
10114 will be passed to @var{program}.
10116 The following command launches an interactive login shell inside a
10117 Guix system container, started by @command{guix system container}, and whose
10118 process ID is 9001:
10121 guix container exec 9001 /run/current-system/profile/bin/bash --login
10124 Note that the @var{pid} cannot be the parent process of a container. It
10125 must be PID 1 of the container or one of its child processes.
10129 @node Invoking guix weather
10130 @section Invoking @command{guix weather}
10132 Occasionally you're grumpy because substitutes are lacking and you end
10133 up building packages by yourself (@pxref{Substitutes}). The
10134 @command{guix weather} command reports on substitute availability on the
10135 specified servers so you can have an idea of whether you'll be grumpy
10136 today. It can sometimes be useful info as a user, but it is primarily
10137 useful to people running @command{guix publish} (@pxref{Invoking guix
10140 @cindex statistics, for substitutes
10141 @cindex availability of substitutes
10142 @cindex substitute availability
10143 @cindex weather, substitute availability
10144 Here's a sample run:
10147 $ guix weather --substitute-urls=https://guix.example.org
10148 computing 5,872 package derivations for x86_64-linux...
10149 looking for 6,128 store items on https://guix.example.org..
10150 updating list of substitutes from 'https://guix.example.org'... 100.0%
10151 https://guix.example.org
10152 43.4% substitutes available (2,658 out of 6,128)
10153 7,032.5 MiB of nars (compressed)
10154 19,824.2 MiB on disk (uncompressed)
10155 0.030 seconds per request (182.9 seconds in total)
10156 33.5 requests per second
10158 9.8% (342 out of 3,470) of the missing items are queued
10160 x86_64-linux: 518 (59.7%)
10161 i686-linux: 221 (25.5%)
10162 aarch64-linux: 128 (14.8%)
10163 build rate: 23.41 builds per hour
10164 x86_64-linux: 11.16 builds per hour
10165 i686-linux: 6.03 builds per hour
10166 aarch64-linux: 6.41 builds per hour
10169 @cindex continuous integration, statistics
10170 As you can see, it reports the fraction of all the packages for which
10171 substitutes are available on the server---regardless of whether
10172 substitutes are enabled, and regardless of whether this server's signing
10173 key is authorized. It also reports the size of the compressed archives
10174 (``nars'') provided by the server, the size the corresponding store
10175 items occupy in the store (assuming deduplication is turned off), and
10176 the server's throughput. The second part gives continuous integration
10177 (CI) statistics, if the server supports it. In addition, using the
10178 @option{--coverage} option, @command{guix weather} can list ``important''
10179 package substitutes missing on the server (see below).
10181 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10182 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10183 challenge}, it ignores signatures on those substitutes, which is
10184 innocuous since the command only gathers statistics and cannot install
10187 The general syntax is:
10190 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10193 When @var{packages} is omitted, @command{guix weather} checks the availability
10194 of substitutes for @emph{all} the packages, or for those specified with
10195 @option{--manifest}; otherwise it only considers the specified packages. It
10196 is also possible to query specific system types with @option{--system}. The
10197 available options are listed below.
10200 @item --substitute-urls=@var{urls}
10201 @var{urls} is the space-separated list of substitute server URLs to
10202 query. When this option is omitted, the default set of substitute
10203 servers is queried.
10205 @item --system=@var{system}
10206 @itemx -s @var{system}
10207 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10208 option can be repeated, in which case @command{guix weather} will query
10209 substitutes for several system types.
10211 @item --manifest=@var{file}
10212 Instead of querying substitutes for all the packages, only ask for those
10213 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10214 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10217 @item --coverage[=@var{count}]
10218 @itemx -c [@var{count}]
10219 Report on substitute coverage for packages: list packages with at least
10220 @var{count} dependents (zero by default) for which substitutes are
10221 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10222 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10223 @var{b} usually lacks substitutes as well. The result looks like this:
10226 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10227 computing 8,983 package derivations for x86_64-linux...
10228 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10229 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10230 @value{SUBSTITUTE-URL}
10231 64.7% substitutes available (6,047 out of 9,343)
10233 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10234 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10235 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10236 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10240 What this example shows is that @code{kcoreaddons} and presumably the 58
10241 packages that depend on it have no substitutes at @code{ci.guix.info};
10242 likewise for @code{qgpgme} and the 46 packages that depend on it.
10244 If you are a Guix developer, or if you are taking care of this build farm,
10245 you'll probably want to have a closer look at these packages: they may simply
10249 @node Invoking guix processes
10250 @section Invoking @command{guix processes}
10252 The @command{guix processes} command can be useful to developers and system
10253 administrators, especially on multi-user machines and on build farms: it lists
10254 the current sessions (connections to the daemon), as well as information about
10255 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10256 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10257 listed.}. Here's an example of the information it returns:
10260 $ sudo guix processes
10263 ClientCommand: guix environment --ad-hoc python
10267 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10271 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10272 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10273 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10274 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10275 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10276 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10277 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10280 In this example we see that @command{guix-daemon} has three clients:
10281 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10282 integration tool; their process identifier (PID) is given by the
10283 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10284 @command{guix-daemon} sub-process of this particular session.
10286 The @code{LockHeld} fields show which store items are currently locked by this
10287 session, which corresponds to store items being built or substituted (the
10288 @code{LockHeld} field is not displayed when @command{guix processes} is not
10289 running as root.) Last, by looking at the @code{ChildProcess} field, we
10290 understand that these three builds are being offloaded (@pxref{Daemon Offload
10293 The output is in Recutils format so we can use the handy @command{recsel}
10294 command to select sessions of interest (@pxref{Selection Expressions,,,
10295 recutils, GNU recutils manual}). As an example, the command shows the command
10296 line and PID of the client that triggered the build of a Perl package:
10299 $ sudo guix processes | \
10300 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10302 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10306 @node System Configuration
10307 @chapter System Configuration
10309 @cindex system configuration
10310 Guix System supports a consistent whole-system configuration
10311 mechanism. By that we mean that all aspects of the global system
10312 configuration---such as the available system services, timezone and
10313 locale settings, user accounts---are declared in a single place. Such
10314 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10316 One of the advantages of putting all the system configuration under the
10317 control of Guix is that it supports transactional system upgrades, and
10318 makes it possible to roll back to a previous system instantiation,
10319 should something go wrong with the new one (@pxref{Features}). Another
10320 advantage is that it makes it easy to replicate the exact same configuration
10321 across different machines, or at different points in time, without
10322 having to resort to additional administration tools layered on top of
10323 the own tools of the system.
10324 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10326 This section describes this mechanism. First we focus on the system
10327 administrator's viewpoint---explaining how the system is configured and
10328 instantiated. Then we show how this mechanism can be extended, for
10329 instance to support new system services.
10332 * Using the Configuration System:: Customizing your GNU system.
10333 * operating-system Reference:: Detail of operating-system declarations.
10334 * File Systems:: Configuring file system mounts.
10335 * Mapped Devices:: Block device extra processing.
10336 * User Accounts:: Specifying user accounts.
10337 * Keyboard Layout:: How the system interprets key strokes.
10338 * Locales:: Language and cultural convention settings.
10339 * Services:: Specifying system services.
10340 * Setuid Programs:: Programs running with root privileges.
10341 * X.509 Certificates:: Authenticating HTTPS servers.
10342 * Name Service Switch:: Configuring libc's name service switch.
10343 * Initial RAM Disk:: Linux-Libre bootstrapping.
10344 * Bootloader Configuration:: Configuring the boot loader.
10345 * Invoking guix system:: Instantiating a system configuration.
10346 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10347 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10348 * Defining Services:: Adding new service definitions.
10351 @node Using the Configuration System
10352 @section Using the Configuration System
10354 The operating system is configured by providing an
10355 @code{operating-system} declaration in a file that can then be passed to
10356 the @command{guix system} command (@pxref{Invoking guix system}). A
10357 simple setup, with the default system services, the default Linux-Libre
10358 kernel, initial RAM disk, and boot loader looks like this:
10360 @findex operating-system
10362 @include os-config-bare-bones.texi
10365 This example should be self-describing. Some of the fields defined
10366 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10367 Others, such as @code{packages} and @code{services}, can be omitted, in
10368 which case they get a default value.
10370 Below we discuss the effect of some of the most important fields
10371 (@pxref{operating-system Reference}, for details about all the available
10372 fields), and how to @dfn{instantiate} the operating system using
10373 @command{guix system}.
10375 @unnumberedsubsec Bootloader
10377 @cindex legacy boot, on Intel machines
10378 @cindex BIOS boot, on Intel machines
10381 The @code{bootloader} field describes the method that will be used to boot
10382 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10383 mode, as in the example above. However, more recent machines rely instead on
10384 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10385 the @code{bootloader} field should contain something along these lines:
10388 (bootloader-configuration
10389 (bootloader grub-efi-bootloader)
10390 (target "/boot/efi"))
10393 @xref{Bootloader Configuration}, for more information on the available
10394 configuration options.
10396 @unnumberedsubsec Globally-Visible Packages
10398 @vindex %base-packages
10399 The @code{packages} field lists packages that will be globally visible
10400 on the system, for all user accounts---i.e., in every user's @code{PATH}
10401 environment variable---in addition to the per-user profiles
10402 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10403 provides all the tools one would expect for basic user and administrator
10404 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10405 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10406 etc. The example above adds GNU@tie{}Screen to those,
10407 taken from the @code{(gnu packages screen)}
10408 module (@pxref{Package Modules}). The
10409 @code{(list package output)} syntax can be used to add a specific output
10413 (use-modules (gnu packages))
10414 (use-modules (gnu packages dns))
10418 (packages (cons (list bind "utils")
10422 @findex specification->package
10423 Referring to packages by variable name, like @code{bind} above, has
10424 the advantage of being unambiguous; it also allows typos and such to be
10425 diagnosed right away as ``unbound variables''. The downside is that one
10426 needs to know which module defines which package, and to augment the
10427 @code{use-package-modules} line accordingly. To avoid that, one can use
10428 the @code{specification->package} procedure of the @code{(gnu packages)}
10429 module, which returns the best package for a given name or name and
10433 (use-modules (gnu packages))
10437 (packages (append (map specification->package
10438 '("tcpdump" "htop" "gnupg@@2.0"))
10442 @unnumberedsubsec System Services
10445 @vindex %base-services
10446 The @code{services} field lists @dfn{system services} to be made
10447 available when the system starts (@pxref{Services}).
10448 The @code{operating-system} declaration above specifies that, in
10449 addition to the basic services, we want the OpenSSH secure shell
10450 daemon listening on port 2222 (@pxref{Networking Services,
10451 @code{openssh-service-type}}). Under the hood,
10452 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10453 right command-line options, possibly with supporting configuration files
10454 generated as needed (@pxref{Defining Services}).
10456 @cindex customization, of services
10457 @findex modify-services
10458 Occasionally, instead of using the base services as is, you will want to
10459 customize them. To do this, use @code{modify-services} (@pxref{Service
10460 Reference, @code{modify-services}}) to modify the list.
10462 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10463 (the console log-in) in the @code{%base-services} list (@pxref{Base
10464 Services, @code{%base-services}}). To do that, you can write the
10465 following in your operating system declaration:
10468 (define %my-services
10469 ;; My very own list of services.
10470 (modify-services %base-services
10471 (guix-service-type config =>
10472 (guix-configuration
10474 (use-substitutes? #f)
10475 (extra-options '("--gc-keep-derivations"))))
10476 (mingetty-service-type config =>
10477 (mingetty-configuration
10478 (inherit config)))))
10482 (services %my-services))
10485 This changes the configuration---i.e., the service parameters---of the
10486 @code{guix-service-type} instance, and that of all the
10487 @code{mingetty-service-type} instances in the @code{%base-services} list.
10488 Observe how this is accomplished: first, we arrange for the original
10489 configuration to be bound to the identifier @code{config} in the
10490 @var{body}, and then we write the @var{body} so that it evaluates to the
10491 desired configuration. In particular, notice how we use @code{inherit}
10492 to create a new configuration which has the same values as the old
10493 configuration, but with a few modifications.
10495 @cindex encrypted disk
10496 The configuration for a typical ``desktop'' usage, with an encrypted
10497 root partition, the X11 display
10498 server, GNOME and Xfce (users can choose which of these desktop
10499 environments to use at the log-in screen by pressing @kbd{F1}), network
10500 management, power management, and more, would look like this:
10503 @include os-config-desktop.texi
10506 A graphical system with a choice of lightweight window managers
10507 instead of full-blown desktop environments would look like this:
10510 @include os-config-lightweight-desktop.texi
10513 This example refers to the @file{/boot/efi} file system by its UUID,
10514 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10515 as returned by the @command{blkid} command.
10517 @xref{Desktop Services}, for the exact list of services provided by
10518 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10519 information about the @code{nss-certs} package that is used here.
10521 Again, @code{%desktop-services} is just a list of service objects. If
10522 you want to remove services from there, you can do so using the
10523 procedures for list filtering (@pxref{SRFI-1 Filtering and
10524 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10525 following expression returns a list that contains all the services in
10526 @code{%desktop-services} minus the Avahi service:
10529 (remove (lambda (service)
10530 (eq? (service-kind service) avahi-service-type))
10534 @unnumberedsubsec Instantiating the System
10536 Assuming the @code{operating-system} declaration
10537 is stored in the @file{my-system-config.scm}
10538 file, the @command{guix system reconfigure my-system-config.scm} command
10539 instantiates that configuration, and makes it the default GRUB boot
10540 entry (@pxref{Invoking guix system}).
10542 The normal way to change the system configuration is by updating this
10543 file and re-running @command{guix system reconfigure}. One should never
10544 have to touch files in @file{/etc} or to run commands that modify the
10545 system state such as @command{useradd} or @command{grub-install}. In
10546 fact, you must avoid that since that would not only void your warranty
10547 but also prevent you from rolling back to previous versions of your
10548 system, should you ever need to.
10550 @cindex roll-back, of the operating system
10551 Speaking of roll-back, each time you run @command{guix system
10552 reconfigure}, a new @dfn{generation} of the system is created---without
10553 modifying or deleting previous generations. Old system generations get
10554 an entry in the bootloader boot menu, allowing you to boot them in case
10555 something went wrong with the latest generation. Reassuring, no? The
10556 @command{guix system list-generations} command lists the system
10557 generations available on disk. It is also possible to roll back the
10558 system via the commands @command{guix system roll-back} and
10559 @command{guix system switch-generation}.
10561 Although the @command{guix system reconfigure} command will not modify
10562 previous generations, you must take care when the current generation is not
10563 the latest (e.g., after invoking @command{guix system roll-back}), since
10564 the operation might overwrite a later generation (@pxref{Invoking guix
10567 @unnumberedsubsec The Programming Interface
10569 At the Scheme level, the bulk of an @code{operating-system} declaration
10570 is instantiated with the following monadic procedure (@pxref{The Store
10573 @deffn {Monadic Procedure} operating-system-derivation os
10574 Return a derivation that builds @var{os}, an @code{operating-system}
10575 object (@pxref{Derivations}).
10577 The output of the derivation is a single directory that refers to all
10578 the packages, configuration files, and other supporting files needed to
10579 instantiate @var{os}.
10582 This procedure is provided by the @code{(gnu system)} module. Along
10583 with @code{(gnu services)} (@pxref{Services}), this module contains the
10584 guts of Guix System. Make sure to visit it!
10587 @node operating-system Reference
10588 @section @code{operating-system} Reference
10590 This section summarizes all the options available in
10591 @code{operating-system} declarations (@pxref{Using the Configuration
10594 @deftp {Data Type} operating-system
10595 This is the data type representing an operating system configuration.
10596 By that, we mean all the global system configuration, not per-user
10597 configuration (@pxref{Using the Configuration System}).
10600 @item @code{kernel} (default: @var{linux-libre})
10601 The package object of the operating system kernel to use@footnote{Currently
10602 only the Linux-libre kernel is supported. In the future, it will be
10603 possible to use the GNU@tie{}Hurd.}.
10605 @item @code{kernel-arguments} (default: @code{'("quiet")})
10606 List of strings or gexps representing additional arguments to pass on
10607 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10609 @item @code{bootloader}
10610 The system bootloader configuration object. @xref{Bootloader Configuration}.
10613 This is the label (a string) as it appears in the bootloader's menu entry.
10614 The default label includes the kernel name and version.
10616 @item @code{keyboard-layout} (default: @code{#f})
10617 This field specifies the keyboard layout to use in the console. It can be
10618 either @code{#f}, in which case the default keyboard layout is used (usually
10619 US English), or a @code{<keyboard-layout>} record.
10621 This keyboard layout is in effect as soon as the kernel has booted. For
10622 instance, it is the keyboard layout in effect when you type a passphrase if
10623 your root file system is on a @code{luks-device-mapping} mapped device
10624 (@pxref{Mapped Devices}).
10627 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10628 that used by the graphical display server. @xref{Bootloader Configuration},
10629 for information on how to specify the bootloader's keyboard layout. @xref{X
10630 Window}, for information on how to specify the keyboard layout used by the X
10634 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10636 @cindex initial RAM disk
10637 The list of Linux kernel modules that need to be available in the
10638 initial RAM disk. @xref{Initial RAM Disk}.
10640 @item @code{initrd} (default: @code{base-initrd})
10641 A procedure that returns an initial RAM disk for the Linux
10642 kernel. This field is provided to support low-level customization and
10643 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10645 @item @code{firmware} (default: @code{%base-firmware})
10647 List of firmware packages loadable by the operating system kernel.
10649 The default includes firmware needed for Atheros- and Broadcom-based
10650 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
10651 respectively). @xref{Hardware Considerations}, for more info on
10652 supported hardware.
10654 @item @code{host-name}
10657 @item @code{hosts-file}
10659 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
10660 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
10661 Reference Manual}). The default is a file with entries for
10662 @code{localhost} and @var{host-name}.
10664 @item @code{mapped-devices} (default: @code{'()})
10665 A list of mapped devices. @xref{Mapped Devices}.
10667 @item @code{file-systems}
10668 A list of file systems. @xref{File Systems}.
10670 @item @code{swap-devices} (default: @code{'()})
10671 @cindex swap devices
10672 A list of strings identifying devices or files to be used for ``swap
10673 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
10674 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
10675 It is possible to specify a swap file in a file system on a mapped
10676 device, provided that the necessary device mapping and file system are
10677 also specified. @xref{Mapped Devices} and @ref{File Systems}.
10679 @item @code{users} (default: @code{%base-user-accounts})
10680 @itemx @code{groups} (default: @code{%base-groups})
10681 List of user accounts and groups. @xref{User Accounts}.
10683 If the @code{users} list lacks a user account with UID@tie{}0, a
10684 ``root'' account with UID@tie{}0 is automatically added.
10686 @item @code{skeletons} (default: @code{(default-skeletons)})
10687 A list target file name/file-like object tuples (@pxref{G-Expressions,
10688 file-like objects}). These are the skeleton files that will be added to
10689 the home directory of newly-created user accounts.
10691 For instance, a valid value may look like this:
10694 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
10695 (".guile" ,(plain-file "guile"
10696 "(use-modules (ice-9 readline))
10697 (activate-readline)")))
10700 @item @code{issue} (default: @code{%default-issue})
10701 A string denoting the contents of the @file{/etc/issue} file, which is
10702 displayed when users log in on a text console.
10704 @item @code{packages} (default: @code{%base-packages})
10705 The set of packages installed in the global profile, which is accessible
10706 at @file{/run/current-system/profile}.
10708 The default set includes core utilities and it is good practice to
10709 install non-core utilities in user profiles (@pxref{Invoking guix
10712 @item @code{timezone}
10713 A timezone identifying string---e.g., @code{"Europe/Paris"}.
10715 You can run the @command{tzselect} command to find out which timezone
10716 string corresponds to your region. Choosing an invalid timezone name
10717 causes @command{guix system} to fail.
10719 @item @code{locale} (default: @code{"en_US.utf8"})
10720 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
10721 Library Reference Manual}). @xref{Locales}, for more information.
10723 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
10724 The list of locale definitions to be compiled and that may be used at
10725 run time. @xref{Locales}.
10727 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
10728 The list of GNU@tie{}libc packages whose locale data and tools are used
10729 to build the locale definitions. @xref{Locales}, for compatibility
10730 considerations that justify this option.
10732 @item @code{name-service-switch} (default: @code{%default-nss})
10733 Configuration of the libc name service switch (NSS)---a
10734 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
10737 @item @code{services} (default: @code{%base-services})
10738 A list of service objects denoting system services. @xref{Services}.
10740 @cindex essential services
10741 @item @code{essential-services} (default: ...)
10742 The list of ``essential services''---i.e., things like instances of
10743 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
10744 Reference}), which are derived from the operating system definition itself.
10745 As a user you should @emph{never} need to touch this field.
10747 @item @code{pam-services} (default: @code{(base-pam-services)})
10749 @cindex pluggable authentication modules
10750 Linux @dfn{pluggable authentication module} (PAM) services.
10751 @c FIXME: Add xref to PAM services section.
10753 @item @code{setuid-programs} (default: @var{%setuid-programs})
10754 List of string-valued G-expressions denoting setuid programs.
10755 @xref{Setuid Programs}.
10757 @item @code{sudoers-file} (default: @var{%sudoers-specification})
10758 @cindex sudoers file
10759 The contents of the @file{/etc/sudoers} file as a file-like object
10760 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
10762 This file specifies which users can use the @command{sudo} command, what
10763 they are allowed to do, and what privileges they may gain. The default
10764 is that only @code{root} and members of the @code{wheel} group may use
10769 @deffn {Scheme Syntax} this-operating-system
10770 When used in the @emph{lexical scope} of an operating system field definition,
10771 this identifier resolves to the operating system being defined.
10773 The example below shows how to refer to the operating system being defined in
10774 the definition of the @code{label} field:
10777 (use-modules (gnu) (guix))
10781 (label (package-full-name
10782 (operating-system-kernel this-operating-system))))
10785 It is an error to refer to @code{this-operating-system} outside an operating
10792 @section File Systems
10794 The list of file systems to be mounted is specified in the
10795 @code{file-systems} field of the operating system declaration
10796 (@pxref{Using the Configuration System}). Each file system is declared
10797 using the @code{file-system} form, like this:
10801 (mount-point "/home")
10802 (device "/dev/sda3")
10806 As usual, some of the fields are mandatory---those shown in the example
10807 above---while others can be omitted. These are described below.
10809 @deftp {Data Type} file-system
10810 Objects of this type represent file systems to be mounted. They
10811 contain the following members:
10815 This is a string specifying the type of the file system---e.g.,
10818 @item @code{mount-point}
10819 This designates the place where the file system is to be mounted.
10821 @item @code{device}
10822 This names the ``source'' of the file system. It can be one of three
10823 things: a file system label, a file system UUID, or the name of a
10824 @file{/dev} node. Labels and UUIDs offer a way to refer to file
10825 systems without having to hard-code their actual device
10826 name@footnote{Note that, while it is tempting to use
10827 @file{/dev/disk/by-uuid} and similar device names to achieve the same
10828 result, this is not recommended: These special device nodes are created
10829 by the udev daemon and may be unavailable at the time the device is
10832 @findex file-system-label
10833 File system labels are created using the @code{file-system-label}
10834 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
10835 plain strings. Here's an example of a file system referred to by its
10836 label, as shown by the @command{e2label} command:
10840 (mount-point "/home")
10842 (device (file-system-label "my-home")))
10846 UUIDs are converted from their string representation (as shown by the
10847 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
10848 @code{uuid} form expects 16-byte UUIDs as defined in
10849 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
10850 form of UUID used by the ext2 family of file systems and others, but it
10851 is different from ``UUIDs'' found in FAT file systems, for instance.},
10856 (mount-point "/home")
10858 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
10861 When the source of a file system is a mapped device (@pxref{Mapped
10862 Devices}), its @code{device} field @emph{must} refer to the mapped
10863 device name---e.g., @file{"/dev/mapper/root-partition"}.
10864 This is required so that
10865 the system knows that mounting the file system depends on having the
10866 corresponding device mapping established.
10868 @item @code{flags} (default: @code{'()})
10869 This is a list of symbols denoting mount flags. Recognized flags
10870 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
10871 access to special files), @code{no-suid} (ignore setuid and setgid
10872 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
10873 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
10874 Library Reference Manual}, for more information on these flags.
10876 @item @code{options} (default: @code{#f})
10877 This is either @code{#f}, or a string denoting mount options passed to the
10878 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
10879 Reference Manual}, for details and run @command{man 8 mount} for options for
10880 various file systems.
10882 @item @code{mount?} (default: @code{#t})
10883 This value indicates whether to automatically mount the file system when
10884 the system is brought up. When set to @code{#f}, the file system gets
10885 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
10886 is not automatically mounted.
10888 @item @code{needed-for-boot?} (default: @code{#f})
10889 This Boolean value indicates whether the file system is needed when
10890 booting. If that is true, then the file system is mounted when the
10891 initial RAM disk (initrd) is loaded. This is always the case, for
10892 instance, for the root file system.
10894 @item @code{check?} (default: @code{#t})
10895 This Boolean indicates whether the file system needs to be checked for
10896 errors before being mounted.
10898 @item @code{create-mount-point?} (default: @code{#f})
10899 When true, the mount point is created if it does not exist yet.
10901 @item @code{dependencies} (default: @code{'()})
10902 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
10903 representing file systems that must be mounted or mapped devices that
10904 must be opened before (and unmounted or closed after) this one.
10906 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
10907 a dependency of @file{/sys/fs/cgroup/cpu} and
10908 @file{/sys/fs/cgroup/memory}.
10910 Another example is a file system that depends on a mapped device, for
10911 example for an encrypted partition (@pxref{Mapped Devices}).
10915 The @code{(gnu system file-systems)} exports the following useful
10918 @defvr {Scheme Variable} %base-file-systems
10919 These are essential file systems that are required on normal systems,
10920 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
10921 below.) Operating system declarations should always contain at least
10925 @defvr {Scheme Variable} %pseudo-terminal-file-system
10926 This is the file system to be mounted as @file{/dev/pts}. It supports
10927 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
10928 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
10929 Manual}). Pseudo-terminals are used by terminal emulators such as
10933 @defvr {Scheme Variable} %shared-memory-file-system
10934 This file system is mounted as @file{/dev/shm} and is used to support
10935 memory sharing across processes (@pxref{Memory-mapped I/O,
10936 @code{shm_open},, libc, The GNU C Library Reference Manual}).
10939 @defvr {Scheme Variable} %immutable-store
10940 This file system performs a read-only ``bind mount'' of
10941 @file{/gnu/store}, making it read-only for all the users including
10942 @code{root}. This prevents against accidental modification by software
10943 running as @code{root} or by system administrators.
10945 The daemon itself is still able to write to the store: it remounts it
10946 read-write in its own ``name space.''
10949 @defvr {Scheme Variable} %binary-format-file-system
10950 The @code{binfmt_misc} file system, which allows handling of arbitrary
10951 executable file types to be delegated to user space. This requires the
10952 @code{binfmt.ko} kernel module to be loaded.
10955 @defvr {Scheme Variable} %fuse-control-file-system
10956 The @code{fusectl} file system, which allows unprivileged users to mount
10957 and unmount user-space FUSE file systems. This requires the
10958 @code{fuse.ko} kernel module to be loaded.
10961 @node Mapped Devices
10962 @section Mapped Devices
10964 @cindex device mapping
10965 @cindex mapped devices
10966 The Linux kernel has a notion of @dfn{device mapping}: a block device,
10967 such as a hard disk partition, can be @dfn{mapped} into another device,
10968 usually in @code{/dev/mapper/},
10969 with additional processing over the data that flows through
10970 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
10971 concept of a ``mapped device'' and that of a file system: both boil down
10972 to @emph{translating} input/output operations made on a file to
10973 operations on its backing store. Thus, the Hurd implements mapped
10974 devices, like file systems, using the generic @dfn{translator} mechanism
10975 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
10976 typical example is encryption device mapping: all writes to the mapped
10977 device are encrypted, and all reads are deciphered, transparently.
10978 Guix extends this notion by considering any device or set of devices that
10979 are @dfn{transformed} in some way to create a new device; for instance,
10980 RAID devices are obtained by @dfn{assembling} several other devices, such
10981 as hard disks or partitions, into a new one that behaves as one partition.
10982 Other examples, not yet implemented, are LVM logical volumes.
10984 Mapped devices are declared using the @code{mapped-device} form,
10985 defined as follows; for examples, see below.
10987 @deftp {Data Type} mapped-device
10988 Objects of this type represent device mappings that will be made when
10989 the system boots up.
10993 This is either a string specifying the name of the block device to be mapped,
10994 such as @code{"/dev/sda3"}, or a list of such strings when several devices
10995 need to be assembled for creating a new one.
10998 This string specifies the name of the resulting mapped device. For
10999 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11000 specifying @code{"my-partition"} leads to the creation of
11001 the @code{"/dev/mapper/my-partition"} device.
11002 For RAID devices of type @code{raid-device-mapping}, the full device name
11003 such as @code{"/dev/md0"} needs to be given.
11006 This must be a @code{mapped-device-kind} object, which specifies how
11007 @var{source} is mapped to @var{target}.
11011 @defvr {Scheme Variable} luks-device-mapping
11012 This defines LUKS block device encryption using the @command{cryptsetup}
11013 command from the package with the same name. It relies on the
11014 @code{dm-crypt} Linux kernel module.
11017 @defvr {Scheme Variable} raid-device-mapping
11018 This defines a RAID device, which is assembled using the @code{mdadm}
11019 command from the package with the same name. It requires a Linux kernel
11020 module for the appropriate RAID level to be loaded, such as @code{raid456}
11021 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11024 @cindex disk encryption
11026 The following example specifies a mapping from @file{/dev/sda3} to
11027 @file{/dev/mapper/home} using LUKS---the
11028 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11029 standard mechanism for disk encryption.
11030 The @file{/dev/mapper/home}
11031 device can then be used as the @code{device} of a @code{file-system}
11032 declaration (@pxref{File Systems}).
11036 (source "/dev/sda3")
11038 (type luks-device-mapping))
11041 Alternatively, to become independent of device numbering, one may obtain
11042 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11046 cryptsetup luksUUID /dev/sda3
11049 and use it as follows:
11053 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11055 (type luks-device-mapping))
11058 @cindex swap encryption
11059 It is also desirable to encrypt swap space, since swap space may contain
11060 sensitive data. One way to accomplish that is to use a swap file in a
11061 file system on a device mapped via LUKS encryption. In this way, the
11062 swap file is encrypted because the entire device is encrypted.
11063 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11065 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11066 may be declared as follows:
11070 (source (list "/dev/sda1" "/dev/sdb1"))
11071 (target "/dev/md0")
11072 (type raid-device-mapping))
11075 The @file{/dev/md0} device can then be used as the @code{device} of a
11076 @code{file-system} declaration (@pxref{File Systems}).
11077 Note that the RAID level need not be given; it is chosen during the
11078 initial creation and formatting of the RAID device and is determined
11079 automatically later.
11082 @node User Accounts
11083 @section User Accounts
11087 @cindex user accounts
11088 User accounts and groups are entirely managed through the
11089 @code{operating-system} declaration. They are specified with the
11090 @code{user-account} and @code{user-group} forms:
11096 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11097 "audio" ;sound card
11098 "video" ;video devices such as webcams
11099 "cdrom")) ;the good ol' CD-ROM
11100 (comment "Bob's sister")
11101 (home-directory "/home/alice"))
11104 When booting or upon completion of @command{guix system reconfigure},
11105 the system ensures that only the user accounts and groups specified in
11106 the @code{operating-system} declaration exist, and with the specified
11107 properties. Thus, account or group creations or modifications made by
11108 directly invoking commands such as @command{useradd} are lost upon
11109 reconfiguration or reboot. This ensures that the system remains exactly
11112 @deftp {Data Type} user-account
11113 Objects of this type represent user accounts. The following members may
11118 The name of the user account.
11122 This is the name (a string) or identifier (a number) of the user group
11123 this account belongs to.
11125 @item @code{supplementary-groups} (default: @code{'()})
11126 Optionally, this can be defined as a list of group names that this
11127 account belongs to.
11129 @item @code{uid} (default: @code{#f})
11130 This is the user ID for this account (a number), or @code{#f}. In the
11131 latter case, a number is automatically chosen by the system when the
11132 account is created.
11134 @item @code{comment} (default: @code{""})
11135 A comment about the account, such as the account owner's full name.
11137 @item @code{home-directory}
11138 This is the name of the home directory for the account.
11140 @item @code{create-home-directory?} (default: @code{#t})
11141 Indicates whether the home directory of this account should be created
11142 if it does not exist yet.
11144 @item @code{shell} (default: Bash)
11145 This is a G-expression denoting the file name of a program to be used as
11146 the shell (@pxref{G-Expressions}).
11148 @item @code{system?} (default: @code{#f})
11149 This Boolean value indicates whether the account is a ``system''
11150 account. System accounts are sometimes treated specially; for instance,
11151 graphical login managers do not list them.
11153 @anchor{user-account-password}
11154 @cindex password, for user accounts
11155 @item @code{password} (default: @code{#f})
11156 You would normally leave this field to @code{#f}, initialize user
11157 passwords as @code{root} with the @command{passwd} command, and then let
11158 users change it with @command{passwd}. Passwords set with
11159 @command{passwd} are of course preserved across reboot and
11162 If you @emph{do} want to set an initial password for an account, then
11163 this field must contain the encrypted password, as a string. You can use the
11164 @code{crypt} procedure for this purpose:
11171 ;; Specify a SHA-512-hashed initial password.
11172 (password (crypt "InitialPassword!" "$6$abc")))
11176 The hash of this initial password will be available in a file in
11177 @file{/gnu/store}, readable by all the users, so this method must be used with
11181 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11182 more information on password encryption, and @ref{Encryption,,, guile, GNU
11183 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11189 User group declarations are even simpler:
11192 (user-group (name "students"))
11195 @deftp {Data Type} user-group
11196 This type is for, well, user groups. There are just a few fields:
11200 The name of the group.
11202 @item @code{id} (default: @code{#f})
11203 The group identifier (a number). If @code{#f}, a new number is
11204 automatically allocated when the group is created.
11206 @item @code{system?} (default: @code{#f})
11207 This Boolean value indicates whether the group is a ``system'' group.
11208 System groups have low numerical IDs.
11210 @item @code{password} (default: @code{#f})
11211 What, user groups can have a password? Well, apparently yes. Unless
11212 @code{#f}, this field specifies the password of the group.
11217 For convenience, a variable lists all the basic user groups one may
11220 @defvr {Scheme Variable} %base-groups
11221 This is the list of basic user groups that users and/or packages expect
11222 to be present on the system. This includes groups such as ``root'',
11223 ``wheel'', and ``users'', as well as groups used to control access to
11224 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11227 @defvr {Scheme Variable} %base-user-accounts
11228 This is the list of basic system accounts that programs may expect to
11229 find on a GNU/Linux system, such as the ``nobody'' account.
11231 Note that the ``root'' account is not included here. It is a
11232 special-case and is automatically added whether or not it is specified.
11235 @node Keyboard Layout
11236 @section Keyboard Layout
11238 @cindex keyboard layout
11240 To specify what each key of your keyboard does, you need to tell the operating
11241 system what @dfn{keyboard layout} you want to use. The default, when nothing
11242 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11243 However, German speakers will usually prefer the German QWERTZ layout, French
11244 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11245 or bépo, and they might even want to further customize the effect of some of
11246 the keys. This section explains how to get that done.
11248 @cindex keyboard layout, definition
11249 There are three components that will want to know about your keyboard layout:
11253 The @emph{bootloader} may want to know what keyboard layout you want to use
11254 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11255 you want, for instance, to make sure that you can type the passphrase of your
11256 encrypted root partition using the right layout.
11259 The @emph{operating system kernel}, Linux, will need that so that the console
11260 is properly configured (@pxref{operating-system Reference,
11261 @code{keyboard-layout}}).
11264 The @emph{graphical display server}, usually Xorg, also has its own idea of
11265 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11268 Guix allows you to configure all three separately but, fortunately, it allows
11269 you to share the same keyboard layout for all three components.
11271 @cindex XKB, keyboard layouts
11272 Keyboard layouts are represented by records created by the
11273 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11274 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11275 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11276 optional variant name, an optional keyboard model name, and a possibly empty
11277 list of additional options. In most cases the layout name is all you care
11278 about. Here are a few example:
11281 ;; The German QWERTZ layout. Here we assume a standard
11282 ;; "pc105" keyboard model.
11283 (keyboard-layout "de")
11285 ;; The bépo variant of the French layout.
11286 (keyboard-layout "fr" "bepo")
11288 ;; The Catalan layout.
11289 (keyboard-layout "es" "cat")
11291 ;; The Latin American Spanish layout. In addition, the
11292 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11293 ;; and the "Menu" key is used as a "Compose" key to enter
11294 ;; accented letters.
11295 (keyboard-layout "latam"
11296 #:options '("ctrl:nocaps" "compose:menu"))
11298 ;; The Russian layout for a ThinkPad keyboard.
11299 (keyboard-layout "ru" #:model "thinkpad")
11301 ;; The "US international" layout, which is the US layout plus
11302 ;; dead keys to enter accented characters. This is for an
11303 ;; Apple MacBook keyboard.
11304 (keyboard-layout "us" "intl" #:model "macbook78")
11307 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11308 for a complete list of supported layouts, variants, and models.
11310 @cindex keyboard layout, configuration
11311 Let's say you want your system to use the Turkish keyboard layout throughout
11312 your system---bootloader, console, and Xorg. Here's what your system
11313 configuration would look like:
11315 @findex set-xorg-configuration
11317 ;; Using the Turkish layout for the bootloader, the console,
11322 (keyboard-layout (keyboard-layout "tr")) ;for the console
11323 (bootloader (bootloader-configuration
11324 (bootloader grub-efi-bootloader)
11325 (target "/boot/efi")
11326 (keyboard-layout keyboard-layout))) ;for GRUB
11327 (services (cons (set-xorg-configuration
11328 (xorg-configuration ;for Xorg
11329 (keyboard-layout keyboard-layout)))
11330 %desktop-services)))
11333 In the example above, for GRUB and for Xorg, we just refer to the
11334 @code{keyboard-layout} field defined above, but we could just as well refer to
11335 a different layout. The @code{set-xorg-configuration} procedure communicates
11336 the desired Xorg configuration to the graphical log-in manager, by default
11339 We've discussed how to specify the @emph{default} keyboard layout of your
11340 system when it starts, but you can also adjust it at run time:
11344 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11345 where you can select one or more keyboard layouts.
11348 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11349 allows you to change the current layout. For example, this is how you would
11350 change the layout to US Dvorak:
11353 setxkbmap us dvorak
11357 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11358 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11359 keyboard layout categorization described above. The command below loads the
11360 French bépo layout:
11371 A @dfn{locale} defines cultural conventions for a particular language
11372 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11373 Reference Manual}). Each locale has a name that typically has the form
11374 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11375 @code{fr_LU.utf8} designates the locale for the French language, with
11376 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11378 @cindex locale definition
11379 Usually, you will want to specify the default locale for the machine
11380 using the @code{locale} field of the @code{operating-system} declaration
11381 (@pxref{operating-system Reference, @code{locale}}).
11383 The selected locale is automatically added to the @dfn{locale
11384 definitions} known to the system if needed, with its codeset inferred
11385 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11386 @code{UTF-8} codeset. Additional locale definitions can be specified in
11387 the @code{locale-definitions} slot of @code{operating-system}---this is
11388 useful, for instance, if the codeset could not be inferred from the
11389 locale name. The default set of locale definitions includes some widely
11390 used locales, but not all the available locales, in order to save space.
11392 For instance, to add the North Frisian locale for Germany, the value of
11396 (cons (locale-definition
11397 (name "fy_DE.utf8") (source "fy_DE"))
11398 %default-locale-definitions)
11401 Likewise, to save space, one might want @code{locale-definitions} to
11402 list only the locales that are actually used, as in:
11405 (list (locale-definition
11406 (name "ja_JP.eucjp") (source "ja_JP")
11407 (charset "EUC-JP")))
11411 The compiled locale definitions are available at
11412 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11413 version, which is the default location where the GNU@tie{}libc provided
11414 by Guix looks for locale data. This can be overridden using the
11415 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11416 @code{LOCPATH} and locale packages}).
11418 The @code{locale-definition} form is provided by the @code{(gnu system
11419 locale)} module. Details are given below.
11421 @deftp {Data Type} locale-definition
11422 This is the data type of a locale definition.
11427 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11428 Reference Manual}, for more information on locale names.
11430 @item @code{source}
11431 The name of the source for that locale. This is typically the
11432 @code{@var{language}_@var{territory}} part of the locale name.
11434 @item @code{charset} (default: @code{"UTF-8"})
11435 The ``character set'' or ``code set'' for that locale,
11436 @uref{https://www.iana.org/assignments/character-sets, as defined by
11442 @defvr {Scheme Variable} %default-locale-definitions
11443 A list of commonly used UTF-8 locales, used as the default
11444 value of the @code{locale-definitions} field of @code{operating-system}
11447 @cindex locale name
11448 @cindex normalized codeset in locale names
11449 These locale definitions use the @dfn{normalized codeset} for the part
11450 that follows the dot in the name (@pxref{Using gettextized software,
11451 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11452 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11453 @code{uk_UA.UTF-8}.
11456 @subsection Locale Data Compatibility Considerations
11458 @cindex incompatibility, of locale data
11459 @code{operating-system} declarations provide a @code{locale-libcs} field
11460 to specify the GNU@tie{}libc packages that are used to compile locale
11461 declarations (@pxref{operating-system Reference}). ``Why would I
11462 care?'', you may ask. Well, it turns out that the binary format of
11463 locale data is occasionally incompatible from one libc version to
11466 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11467 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11468 For instance, a program linked against libc version 2.21 is unable to
11469 read locale data produced with libc 2.22; worse, that program
11470 @emph{aborts} instead of simply ignoring the incompatible locale
11471 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11472 the incompatible locale data, which is already an improvement.}.
11473 Similarly, a program linked against libc 2.22 can read most, but not
11474 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11475 data is incompatible); thus calls to @code{setlocale} may fail, but
11476 programs will not abort.
11478 The ``problem'' with Guix is that users have a lot of freedom: They can
11479 choose whether and when to upgrade software in their profiles, and might
11480 be using a libc version different from the one the system administrator
11481 used to build the system-wide locale data.
11483 Fortunately, unprivileged users can also install their own locale data
11484 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11485 @code{GUIX_LOCPATH} and locale packages}).
11487 Still, it is best if the system-wide locale data at
11488 @file{/run/current-system/locale} is built for all the libc versions
11489 actually in use on the system, so that all the programs can access
11490 it---this is especially crucial on a multi-user system. To do that, the
11491 administrator can specify several libc packages in the
11492 @code{locale-libcs} field of @code{operating-system}:
11495 (use-package-modules base)
11499 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11502 This example would lead to a system containing locale definitions for
11503 both libc 2.21 and the current version of libc in
11504 @file{/run/current-system/locale}.
11510 @cindex system services
11511 An important part of preparing an @code{operating-system} declaration is
11512 listing @dfn{system services} and their configuration (@pxref{Using the
11513 Configuration System}). System services are typically daemons launched
11514 when the system boots, or other actions needed at that time---e.g.,
11515 configuring network access.
11517 Guix has a broad definition of ``service'' (@pxref{Service
11518 Composition}), but many services are managed by the GNU@tie{}Shepherd
11519 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11520 command allows you to list the available services, show their status,
11521 start and stop them, or do other specific operations (@pxref{Jump
11522 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11528 The above command, run as @code{root}, lists the currently defined
11529 services. The @command{herd doc} command shows a synopsis of the given
11530 service and its associated actions:
11534 Run libc's name service cache daemon (nscd).
11536 # herd doc nscd action invalidate
11537 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11540 The @command{start}, @command{stop}, and @command{restart} sub-commands
11541 have the effect you would expect. For instance, the commands below stop
11542 the nscd service and restart the Xorg display server:
11546 Service nscd has been stopped.
11547 # herd restart xorg-server
11548 Service xorg-server has been stopped.
11549 Service xorg-server has been started.
11552 The following sections document the available services, starting with
11553 the core services, that may be used in an @code{operating-system}
11557 * Base Services:: Essential system services.
11558 * Scheduled Job Execution:: The mcron service.
11559 * Log Rotation:: The rottlog service.
11560 * Networking Services:: Network setup, SSH daemon, etc.
11561 * X Window:: Graphical display.
11562 * Printing Services:: Local and remote printer support.
11563 * Desktop Services:: D-Bus and desktop services.
11564 * Sound Services:: ALSA and Pulseaudio services.
11565 * Database Services:: SQL databases, key-value stores, etc.
11566 * Mail Services:: IMAP, POP3, SMTP, and all that.
11567 * Messaging Services:: Messaging services.
11568 * Telephony Services:: Telephony services.
11569 * Monitoring Services:: Monitoring services.
11570 * Kerberos Services:: Kerberos services.
11571 * LDAP Services:: LDAP services.
11572 * Web Services:: Web servers.
11573 * Certificate Services:: TLS certificates via Let's Encrypt.
11574 * DNS Services:: DNS daemons.
11575 * VPN Services:: VPN daemons.
11576 * Network File System:: NFS related services.
11577 * Continuous Integration:: The Cuirass service.
11578 * Power Management Services:: Extending battery life.
11579 * Audio Services:: The MPD.
11580 * Virtualization Services:: Virtualization services.
11581 * Version Control Services:: Providing remote access to Git repositories.
11582 * Game Services:: Game servers.
11583 * Miscellaneous Services:: Other services.
11586 @node Base Services
11587 @subsection Base Services
11589 The @code{(gnu services base)} module provides definitions for the basic
11590 services that one expects from the system. The services exported by
11591 this module are listed below.
11593 @defvr {Scheme Variable} %base-services
11594 This variable contains a list of basic services (@pxref{Service Types
11595 and Services}, for more information on service objects) one would
11596 expect from the system: a login service (mingetty) on each tty, syslogd,
11597 the libc name service cache daemon (nscd), the udev device manager, and
11600 This is the default value of the @code{services} field of
11601 @code{operating-system} declarations. Usually, when customizing a
11602 system, you will want to append services to @code{%base-services}, like
11606 (append (list (service avahi-service-type)
11607 (service openssh-service-type))
11612 @defvr {Scheme Variable} special-files-service-type
11613 This is the service that sets up ``special files'' such as
11614 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11616 The value associated with @code{special-files-service-type} services
11617 must be a list of tuples where the first element is the ``special file''
11618 and the second element is its target. By default it is:
11620 @cindex @file{/bin/sh}
11621 @cindex @file{sh}, in @file{/bin}
11623 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh")))
11626 @cindex @file{/usr/bin/env}
11627 @cindex @file{env}, in @file{/usr/bin}
11628 If you want to add, say, @code{/usr/bin/env} to your system, you can
11632 `(("/bin/sh" ,(file-append @var{bash} "/bin/sh"))
11633 ("/usr/bin/env" ,(file-append @var{coreutils} "/bin/env")))
11636 Since this is part of @code{%base-services}, you can use
11637 @code{modify-services} to customize the set of special files
11638 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11639 to add a special file is @i{via} the @code{extra-special-file} procedure
11643 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11644 Use @var{target} as the ``special file'' @var{file}.
11646 For example, adding the following lines to the @code{services} field of
11647 your operating system declaration leads to a @file{/usr/bin/env}
11651 (extra-special-file "/usr/bin/env"
11652 (file-append coreutils "/bin/env"))
11656 @deffn {Scheme Procedure} host-name-service @var{name}
11657 Return a service that sets the host name to @var{name}.
11660 @deffn {Scheme Procedure} login-service @var{config}
11661 Return a service to run login according to @var{config}, a
11662 @code{<login-configuration>} object, which specifies the message of the day,
11663 among other things.
11666 @deftp {Data Type} login-configuration
11667 This is the data type representing the configuration of login.
11672 @cindex message of the day
11673 A file-like object containing the ``message of the day''.
11675 @item @code{allow-empty-passwords?} (default: @code{#t})
11676 Allow empty passwords by default so that first-time users can log in when
11677 the 'root' account has just been created.
11682 @deffn {Scheme Procedure} mingetty-service @var{config}
11683 Return a service to run mingetty according to @var{config}, a
11684 @code{<mingetty-configuration>} object, which specifies the tty to run, among
11688 @deftp {Data Type} mingetty-configuration
11689 This is the data type representing the configuration of Mingetty, which
11690 provides the default implementation of virtual console log-in.
11695 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
11697 @item @code{auto-login} (default: @code{#f})
11698 When true, this field must be a string denoting the user name under
11699 which the system automatically logs in. When it is @code{#f}, a
11700 user name and password must be entered to log in.
11702 @item @code{login-program} (default: @code{#f})
11703 This must be either @code{#f}, in which case the default log-in program
11704 is used (@command{login} from the Shadow tool suite), or a gexp denoting
11705 the name of the log-in program.
11707 @item @code{login-pause?} (default: @code{#f})
11708 When set to @code{#t} in conjunction with @var{auto-login}, the user
11709 will have to press a key before the log-in shell is launched.
11711 @item @code{mingetty} (default: @var{mingetty})
11712 The Mingetty package to use.
11717 @deffn {Scheme Procedure} agetty-service @var{config}
11718 Return a service to run agetty according to @var{config}, an
11719 @code{<agetty-configuration>} object, which specifies the tty to run,
11720 among other things.
11723 @deftp {Data Type} agetty-configuration
11724 This is the data type representing the configuration of agetty, which
11725 implements virtual and serial console log-in. See the @code{agetty(8)}
11726 man page for more information.
11731 The name of the console this agetty runs on, as a string---e.g.,
11732 @code{"ttyS0"}. This argument is optional, it will default to
11733 a reasonable default serial port used by the kernel Linux.
11735 For this, if there is a value for an option @code{agetty.tty} in the kernel
11736 command line, agetty will extract the device name of the serial port
11737 from it and use that.
11739 If not and if there is a value for an option @code{console} with a tty in
11740 the Linux command line, agetty will extract the device name of the
11741 serial port from it and use that.
11743 In both cases, agetty will leave the other serial device settings
11744 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
11747 @item @code{baud-rate} (default: @code{#f})
11748 A string containing a comma-separated list of one or more baud rates, in
11751 @item @code{term} (default: @code{#f})
11752 A string containing the value used for the @code{TERM} environment
11755 @item @code{eight-bits?} (default: @code{#f})
11756 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
11759 @item @code{auto-login} (default: @code{#f})
11760 When passed a login name, as a string, the specified user will be logged
11761 in automatically without prompting for their login name or password.
11763 @item @code{no-reset?} (default: @code{#f})
11764 When @code{#t}, don't reset terminal cflags (control modes).
11766 @item @code{host} (default: @code{#f})
11767 This accepts a string containing the "login_host", which will be written
11768 into the @file{/var/run/utmpx} file.
11770 @item @code{remote?} (default: @code{#f})
11771 When set to @code{#t} in conjunction with @var{host}, this will add an
11772 @code{-r} fakehost option to the command line of the login program
11773 specified in @var{login-program}.
11775 @item @code{flow-control?} (default: @code{#f})
11776 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
11778 @item @code{no-issue?} (default: @code{#f})
11779 When set to @code{#t}, the contents of the @file{/etc/issue} file will
11780 not be displayed before presenting the login prompt.
11782 @item @code{init-string} (default: @code{#f})
11783 This accepts a string that will be sent to the tty or modem before
11784 sending anything else. It can be used to initialize a modem.
11786 @item @code{no-clear?} (default: @code{#f})
11787 When set to @code{#t}, agetty will not clear the screen before showing
11790 @item @code{login-program} (default: (file-append shadow "/bin/login"))
11791 This must be either a gexp denoting the name of a log-in program, or
11792 unset, in which case the default value is the @command{login} from the
11795 @item @code{local-line} (default: @code{#f})
11796 Control the CLOCAL line flag. This accepts one of three symbols as
11797 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
11798 the default value chosen by agetty is @code{'auto}.
11800 @item @code{extract-baud?} (default: @code{#f})
11801 When set to @code{#t}, instruct agetty to try to extract the baud rate
11802 from the status messages produced by certain types of modems.
11804 @item @code{skip-login?} (default: @code{#f})
11805 When set to @code{#t}, do not prompt the user for a login name. This
11806 can be used with @var{login-program} field to use non-standard login
11809 @item @code{no-newline?} (default: @code{#f})
11810 When set to @code{#t}, do not print a newline before printing the
11811 @file{/etc/issue} file.
11813 @c Is this dangerous only when used with login-program, or always?
11814 @item @code{login-options} (default: @code{#f})
11815 This option accepts a string containing options that are passed to the
11816 login program. When used with the @var{login-program}, be aware that a
11817 malicious user could try to enter a login name containing embedded
11818 options that could be parsed by the login program.
11820 @item @code{login-pause} (default: @code{#f})
11821 When set to @code{#t}, wait for any key before showing the login prompt.
11822 This can be used in conjunction with @var{auto-login} to save memory by
11823 lazily spawning shells.
11825 @item @code{chroot} (default: @code{#f})
11826 Change root to the specified directory. This option accepts a directory
11829 @item @code{hangup?} (default: @code{#f})
11830 Use the Linux system call @code{vhangup} to do a virtual hangup of the
11831 specified terminal.
11833 @item @code{keep-baud?} (default: @code{#f})
11834 When set to @code{#t}, try to keep the existing baud rate. The baud
11835 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
11838 @item @code{timeout} (default: @code{#f})
11839 When set to an integer value, terminate if no user name could be read
11840 within @var{timeout} seconds.
11842 @item @code{detect-case?} (default: @code{#f})
11843 When set to @code{#t}, turn on support for detecting an uppercase-only
11844 terminal. This setting will detect a login name containing only
11845 uppercase letters as indicating an uppercase-only terminal and turn on
11846 some upper-to-lower case conversions. Note that this will not support
11847 Unicode characters.
11849 @item @code{wait-cr?} (default: @code{#f})
11850 When set to @code{#t}, wait for the user or modem to send a
11851 carriage-return or linefeed character before displaying
11852 @file{/etc/issue} or login prompt. This is typically used with the
11853 @var{init-string} option.
11855 @item @code{no-hints?} (default: @code{#f})
11856 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
11859 @item @code{no-hostname?} (default: @code{#f})
11860 By default, the hostname is printed. When this option is set to
11861 @code{#t}, no hostname will be shown at all.
11863 @item @code{long-hostname?} (default: @code{#f})
11864 By default, the hostname is only printed until the first dot. When this
11865 option is set to @code{#t}, the fully qualified hostname by
11866 @code{gethostname} or @code{getaddrinfo} is shown.
11868 @item @code{erase-characters} (default: @code{#f})
11869 This option accepts a string of additional characters that should be
11870 interpreted as backspace when the user types their login name.
11872 @item @code{kill-characters} (default: @code{#f})
11873 This option accepts a string that should be interpreted to mean "ignore
11874 all previous characters" (also called a "kill" character) when the user
11875 types their login name.
11877 @item @code{chdir} (default: @code{#f})
11878 This option accepts, as a string, a directory path that will be changed
11881 @item @code{delay} (default: @code{#f})
11882 This options accepts, as an integer, the number of seconds to sleep
11883 before opening the tty and displaying the login prompt.
11885 @item @code{nice} (default: @code{#f})
11886 This option accepts, as an integer, the nice value with which to run the
11887 @command{login} program.
11889 @item @code{extra-options} (default: @code{'()})
11890 This option provides an "escape hatch" for the user to provide arbitrary
11891 command-line arguments to @command{agetty} as a list of strings.
11896 @deffn {Scheme Procedure} kmscon-service-type @var{config}
11897 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
11898 according to @var{config}, a @code{<kmscon-configuration>} object, which
11899 specifies the tty to run, among other things.
11902 @deftp {Data Type} kmscon-configuration
11903 This is the data type representing the configuration of Kmscon, which
11904 implements virtual console log-in.
11908 @item @code{virtual-terminal}
11909 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
11911 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
11912 A gexp denoting the name of the log-in program. The default log-in program is
11913 @command{login} from the Shadow tool suite.
11915 @item @code{login-arguments} (default: @code{'("-p")})
11916 A list of arguments to pass to @command{login}.
11918 @item @code{auto-login} (default: @code{#f})
11919 When passed a login name, as a string, the specified user will be logged
11920 in automatically without prompting for their login name or password.
11922 @item @code{hardware-acceleration?} (default: #f)
11923 Whether to use hardware acceleration.
11925 @item @code{kmscon} (default: @var{kmscon})
11926 The Kmscon package to use.
11931 @cindex name service cache daemon
11933 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
11934 [#:name-services '()]
11935 Return a service that runs the libc name service cache daemon (nscd) with the
11936 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
11937 Service Switch}, for an example.
11939 For convenience, the Shepherd service for nscd provides the following actions:
11943 @cindex cache invalidation, nscd
11944 @cindex nscd, cache invalidation
11945 This invalidate the given cache. For instance, running:
11948 herd invalidate nscd hosts
11952 invalidates the host name lookup cache of nscd.
11955 Running @command{herd statistics nscd} displays information about nscd usage
11961 @defvr {Scheme Variable} %nscd-default-configuration
11962 This is the default @code{<nscd-configuration>} value (see below) used
11963 by @code{nscd-service}. It uses the caches defined by
11964 @var{%nscd-default-caches}; see below.
11967 @deftp {Data Type} nscd-configuration
11968 This is the data type representing the name service cache daemon (nscd)
11973 @item @code{name-services} (default: @code{'()})
11974 List of packages denoting @dfn{name services} that must be visible to
11975 the nscd---e.g., @code{(list @var{nss-mdns})}.
11977 @item @code{glibc} (default: @var{glibc})
11978 Package object denoting the GNU C Library providing the @command{nscd}
11981 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
11982 Name of the nscd log file. This is where debugging output goes when
11983 @code{debug-level} is strictly positive.
11985 @item @code{debug-level} (default: @code{0})
11986 Integer denoting the debugging levels. Higher numbers mean that more
11987 debugging output is logged.
11989 @item @code{caches} (default: @var{%nscd-default-caches})
11990 List of @code{<nscd-cache>} objects denoting things to be cached; see
11996 @deftp {Data Type} nscd-cache
11997 Data type representing a cache database of nscd and its parameters.
12001 @item @code{database}
12002 This is a symbol representing the name of the database to be cached.
12003 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12004 @code{services}, which designate the corresponding NSS database
12005 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12007 @item @code{positive-time-to-live}
12008 @itemx @code{negative-time-to-live} (default: @code{20})
12009 A number representing the number of seconds during which a positive or
12010 negative lookup result remains in cache.
12012 @item @code{check-files?} (default: @code{#t})
12013 Whether to check for updates of the files corresponding to
12016 For instance, when @var{database} is @code{hosts}, setting this flag
12017 instructs nscd to check for updates in @file{/etc/hosts} and to take
12020 @item @code{persistent?} (default: @code{#t})
12021 Whether the cache should be stored persistently on disk.
12023 @item @code{shared?} (default: @code{#t})
12024 Whether the cache should be shared among users.
12026 @item @code{max-database-size} (default: 32@tie{}MiB)
12027 Maximum size in bytes of the database cache.
12029 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12030 @c settings, so leave them out.
12035 @defvr {Scheme Variable} %nscd-default-caches
12036 List of @code{<nscd-cache>} objects used by default by
12037 @code{nscd-configuration} (see above).
12039 It enables persistent and aggressive caching of service and host name
12040 lookups. The latter provides better host name lookup performance,
12041 resilience in the face of unreliable name servers, and also better
12042 privacy---often the result of host name lookups is in local cache, so
12043 external name servers do not even need to be queried.
12046 @anchor{syslog-configuration-type}
12049 @deftp {Data Type} syslog-configuration
12050 This data type represents the configuration of the syslog daemon.
12053 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12054 The syslog daemon to use.
12056 @item @code{config-file} (default: @code{%default-syslog.conf})
12057 The syslog configuration file to use.
12062 @anchor{syslog-service}
12064 @deffn {Scheme Procedure} syslog-service @var{config}
12065 Return a service that runs a syslog daemon according to @var{config}.
12067 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12068 information on the configuration file syntax.
12071 @defvr {Scheme Variable} guix-service-type
12072 This is the type of the service that runs the build daemon,
12073 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12074 @code{guix-configuration} record as described below.
12077 @anchor{guix-configuration-type}
12078 @deftp {Data Type} guix-configuration
12079 This data type represents the configuration of the Guix build daemon.
12080 @xref{Invoking guix-daemon}, for more information.
12083 @item @code{guix} (default: @var{guix})
12084 The Guix package to use.
12086 @item @code{build-group} (default: @code{"guixbuild"})
12087 Name of the group for build user accounts.
12089 @item @code{build-accounts} (default: @code{10})
12090 Number of build user accounts to create.
12092 @item @code{authorize-key?} (default: @code{#t})
12093 @cindex substitutes, authorization thereof
12094 Whether to authorize the substitute keys listed in
12095 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12096 (@pxref{Substitutes}).
12098 @vindex %default-authorized-guix-keys
12099 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12100 The list of authorized key files for archive imports, as a list of
12101 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12102 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12104 @item @code{use-substitutes?} (default: @code{#t})
12105 Whether to use substitutes.
12107 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12108 The list of URLs where to look for substitutes by default.
12110 @item @code{max-silent-time} (default: @code{0})
12111 @itemx @code{timeout} (default: @code{0})
12112 The number of seconds of silence and the number of seconds of activity,
12113 respectively, after which a build process times out. A value of zero
12114 disables the timeout.
12116 @item @code{log-compression} (default: @code{'bzip2})
12117 The type of compression used for build logs---one of @code{gzip},
12118 @code{bzip2}, or @code{none}.
12120 @item @code{extra-options} (default: @code{'()})
12121 List of extra command-line options for @command{guix-daemon}.
12123 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12124 File where @command{guix-daemon}'s standard output and standard error
12127 @item @code{http-proxy} (default: @code{#f})
12128 The HTTP proxy used for downloading fixed-output derivations and
12131 @item @code{tmpdir} (default: @code{#f})
12132 A directory path where the @command{guix-daemon} will perform builds.
12137 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12138 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12139 udev rules can be provided as a list of files through the @var{rules}
12140 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12141 @code{(gnu services base)} simplify the creation of such rule files.
12144 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12145 Return a udev-rule file named @var{file-name} containing the rules
12146 defined by the @var{contents} literal.
12148 In the following example, a rule for a USB device is defined to be
12149 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12150 upon detecting a USB device with a given product identifier.
12153 (define %example-udev-rule
12155 "90-usb-thing.rules"
12156 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12157 "ATTR@{product@}==\"Example\", "
12158 "RUN+=\"/path/to/script\"")))
12161 The @command{herd rules udev} command, as root, returns the name of the
12162 directory containing all the active udev rules.
12165 Here we show how the default @var{udev-service} can be extended with it.
12171 (modify-services %desktop-services
12172 (udev-service-type config =>
12173 (udev-configuration (inherit config)
12174 (rules (append (udev-configuration-rules config)
12175 (list %example-udev-rule))))))))
12178 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12179 Return a udev file named @var{file-name} containing the rules defined
12180 within @var{file}, a file-like object.
12182 The following example showcases how we can use an existing rule file.
12185 (use-modules (guix download) ;for url-fetch
12186 (guix packages) ;for origin
12189 (define %android-udev-rules
12191 "51-android-udev.rules"
12192 (let ((version "20170910"))
12195 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12196 "android-udev-rules/" version "/51-android.rules"))
12198 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12202 Additionally, Guix package definitions can be included in @var{rules} in
12203 order to extend the udev rules with the definitions found under their
12204 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12205 @var{file->udev-rule} example, we could have used the
12206 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12207 packages android)} module.
12209 The following example shows how to use the @var{android-udev-rules}
12210 package so that the Android tool @command{adb} can detect devices
12211 without root privileges. It also details how to create the
12212 @code{adbusers} group, which is required for the proper functioning of
12213 the rules defined within the @var{android-udev-rules} package. To
12214 create such a group, we must define it both as part of the
12215 @var{supplementary-groups} of our @var{user-account} declaration, as
12216 well as in the @var{groups} field of the @var{operating-system} record.
12219 (use-modules (gnu packages android) ;for android-udev-rules
12220 (gnu system shadow) ;for user-group
12225 (users (cons (user-acount
12227 (supplementary-groups
12228 '("adbusers" ;for adb
12229 "wheel" "netdev" "audio" "video"))
12232 (groups (cons (user-group (system? #t) (name "adbusers"))
12238 (modify-services %desktop-services
12241 (udev-configuration (inherit config)
12242 (rules (cons android-udev-rules
12243 (udev-configuration-rules config))))))))
12246 @defvr {Scheme Variable} urandom-seed-service-type
12247 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12248 when rebooting. It also tries to seed @file{/dev/urandom} from
12249 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12253 @defvr {Scheme Variable} %random-seed-file
12254 This is the name of the file where some random bytes are saved by
12255 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12256 It defaults to @file{/var/lib/random-seed}.
12261 @defvr {Scheme Variable} gpm-service-type
12262 This is the type of the service that runs GPM, the @dfn{general-purpose
12263 mouse daemon}, which provides mouse support to the Linux console. GPM
12264 allows users to use the mouse in the console, notably to select, copy,
12267 The value for services of this type must be a @code{gpm-configuration}
12268 (see below). This service is not part of @code{%base-services}.
12271 @deftp {Data Type} gpm-configuration
12272 Data type representing the configuration of GPM.
12275 @item @code{options} (default: @code{%default-gpm-options})
12276 Command-line options passed to @command{gpm}. The default set of
12277 options instruct @command{gpm} to listen to mouse events on
12278 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12281 @item @code{gpm} (default: @code{gpm})
12282 The GPM package to use.
12287 @anchor{guix-publish-service-type}
12288 @deffn {Scheme Variable} guix-publish-service-type
12289 This is the service type for @command{guix publish} (@pxref{Invoking
12290 guix publish}). Its value must be a @code{guix-publish-configuration}
12291 object, as described below.
12293 This assumes that @file{/etc/guix} already contains a signing key pair as
12294 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12295 archive}). If that is not the case, the service will fail to start.
12298 @deftp {Data Type} guix-publish-configuration
12299 Data type representing the configuration of the @code{guix publish}
12303 @item @code{guix} (default: @code{guix})
12304 The Guix package to use.
12306 @item @code{port} (default: @code{80})
12307 The TCP port to listen for connections.
12309 @item @code{host} (default: @code{"localhost"})
12310 The host (and thus, network interface) to listen to. Use
12311 @code{"0.0.0.0"} to listen on all the network interfaces.
12313 @item @code{compression} (default: @code{'(("gzip" 3))})
12314 This is a list of compression method/level tuple used when compressing
12315 substitutes. For example, to compress all substitutes with @emph{both} lzip
12316 at level 7 and gzip at level 9, write:
12319 '(("lzip" 7) ("gzip" 9))
12322 Level 9 achieves the best compression ratio at the expense of increased CPU
12323 usage, whereas level 1 achieves fast compression.
12325 An empty list disables compression altogether.
12327 @item @code{nar-path} (default: @code{"nar"})
12328 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12329 publish, @code{--nar-path}}, for details.
12331 @item @code{cache} (default: @code{#f})
12332 When it is @code{#f}, disable caching and instead generate archives on
12333 demand. Otherwise, this should be the name of a directory---e.g.,
12334 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12335 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12336 @option{--cache}}, for more information on the tradeoffs involved.
12338 @item @code{workers} (default: @code{#f})
12339 When it is an integer, this is the number of worker threads used for
12340 caching; when @code{#f}, the number of processors is used.
12341 @xref{Invoking guix publish, @option{--workers}}, for more information.
12343 @item @code{ttl} (default: @code{#f})
12344 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12345 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12346 for more information.
12350 @anchor{rngd-service}
12351 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12352 [#:device "/dev/hwrng"]
12353 Return a service that runs the @command{rngd} program from @var{rng-tools}
12354 to add @var{device} to the kernel's entropy pool. The service will fail if
12355 @var{device} does not exist.
12358 @anchor{pam-limits-service}
12359 @cindex session limits
12364 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12366 Return a service that installs a configuration file for the
12367 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12368 @code{pam_limits} module}. The procedure optionally takes a list of
12369 @code{pam-limits-entry} values, which can be used to specify
12370 @code{ulimit} limits and nice priority limits to user sessions.
12372 The following limits definition sets two hard and soft limits for all
12373 login sessions of users in the @code{realtime} group:
12376 (pam-limits-service
12378 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12379 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12382 The first entry increases the maximum realtime priority for
12383 non-privileged processes; the second entry lifts any restriction of the
12384 maximum address space that can be locked in memory. These settings are
12385 commonly used for real-time audio systems.
12388 @node Scheduled Job Execution
12389 @subsection Scheduled Job Execution
12393 @cindex scheduling jobs
12394 The @code{(gnu services mcron)} module provides an interface to
12395 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12396 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12397 Unix @command{cron} daemon; the main difference is that it is
12398 implemented in Guile Scheme, which provides a lot of flexibility when
12399 specifying the scheduling of jobs and their actions.
12401 The example below defines an operating system that runs the
12402 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12403 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12404 well as the @command{mkid} command on behalf of an unprivileged user
12405 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12406 gexps to introduce job definitions that are passed to mcron
12407 (@pxref{G-Expressions}).
12410 (use-modules (guix) (gnu) (gnu services mcron))
12411 (use-package-modules base idutils)
12413 (define updatedb-job
12414 ;; Run 'updatedb' at 3AM every day. Here we write the
12415 ;; job's action as a Scheme procedure.
12416 #~(job '(next-hour '(3))
12418 (execl (string-append #$findutils "/bin/updatedb")
12420 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12422 (define garbage-collector-job
12423 ;; Collect garbage 5 minutes after midnight every day.
12424 ;; The job's action is a shell command.
12425 #~(job "5 0 * * *" ;Vixie cron syntax
12428 (define idutils-job
12429 ;; Update the index database as user "charlie" at 12:15PM
12430 ;; and 19:15PM. This runs from the user's home directory.
12431 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12432 (string-append #$idutils "/bin/mkid src")
12437 (services (cons (service mcron-service-type
12438 (mcron-configuration
12439 (jobs (list garbage-collector-job
12445 For more complex jobs defined in Scheme where you need control over the top
12446 level, for instance to introduce a @code{use-modules} form, you can move your
12447 code to a separate program using the @code{program-file} procedure of the
12448 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
12452 (define %battery-alert-job
12453 ;; Beep when the battery percentage falls below %MIN-LEVEL.
12455 '(next-minute (range 0 60 1))
12457 "battery-alert.scm"
12458 (with-imported-modules (source-module-closure
12459 '((guix build utils)))
12461 (define %min-level 20)
12462 (use-modules (guix build utils)
12465 (ice-9 textual-ports)
12467 (setenv "LC_ALL" "C") ;ensure English output
12468 (and-let* ((input-pipe (open-pipe*
12470 #$(file-append acpi "/bin/acpi")))
12471 (output (get-string-all input-pipe))
12472 (m (string-match "Discharging, ([0-9]+)%" output))
12473 (level (string->number (match:substring m 1)))
12474 ((< level %min-level)))
12475 (format #t "warning: Battery level is low (~a%)~%" level)
12476 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
12479 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12480 for more information on mcron job specifications. Below is the
12481 reference of the mcron service.
12483 On a running system, you can use the @code{schedule} action of the service to
12484 visualize the mcron jobs that will be executed next:
12487 # herd schedule mcron
12491 The example above lists the next five tasks that will be executed, but you can
12492 also specify the number of tasks to display:
12495 # herd schedule mcron 10
12498 @defvr {Scheme Variable} mcron-service-type
12499 This is the type of the @code{mcron} service, whose value is an
12500 @code{mcron-configuration} object.
12502 This service type can be the target of a service extension that provides
12503 it additional job specifications (@pxref{Service Composition}). In
12504 other words, it is possible to define services that provide additional
12508 @deftp {Data Type} mcron-configuration
12509 Data type representing the configuration of mcron.
12512 @item @code{mcron} (default: @var{mcron})
12513 The mcron package to use.
12516 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12517 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12518 specifications,, mcron, GNU@tie{}mcron}).
12524 @subsection Log Rotation
12527 @cindex log rotation
12529 Log files such as those found in @file{/var/log} tend to grow endlessly,
12530 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12531 their contents in separate files, possibly compressed. The @code{(gnu
12532 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12533 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12535 The example below defines an operating system that provides log rotation
12536 with the default settings, for commonly encountered log files.
12539 (use-modules (guix) (gnu))
12540 (use-service-modules admin mcron)
12541 (use-package-modules base idutils)
12545 (services (cons (service rottlog-service-type)
12549 @defvr {Scheme Variable} rottlog-service-type
12550 This is the type of the Rottlog service, whose value is a
12551 @code{rottlog-configuration} object.
12553 Other services can extend this one with new @code{log-rotation} objects
12554 (see below), thereby augmenting the set of files to be rotated.
12556 This service type can define mcron jobs (@pxref{Scheduled Job
12557 Execution}) to run the rottlog service.
12560 @deftp {Data Type} rottlog-configuration
12561 Data type representing the configuration of rottlog.
12564 @item @code{rottlog} (default: @code{rottlog})
12565 The Rottlog package to use.
12567 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12568 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12569 rottlog, GNU Rot[t]log Manual}).
12571 @item @code{rotations} (default: @code{%default-rotations})
12572 A list of @code{log-rotation} objects as defined below.
12575 This is a list of gexps where each gexp corresponds to an mcron job
12576 specification (@pxref{Scheduled Job Execution}).
12580 @deftp {Data Type} log-rotation
12581 Data type representing the rotation of a group of log files.
12583 Taking an example from the Rottlog manual (@pxref{Period Related File
12584 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12590 (files '("/var/log/apache/*"))
12591 (options '("storedir apache-archives"
12597 The list of fields is as follows:
12600 @item @code{frequency} (default: @code{'weekly})
12601 The log rotation frequency, a symbol.
12604 The list of files or file glob patterns to rotate.
12606 @item @code{options} (default: @code{'()})
12607 The list of rottlog options for this rotation (@pxref{Configuration
12608 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12610 @item @code{post-rotate} (default: @code{#f})
12611 Either @code{#f} or a gexp to execute once the rotation has completed.
12615 @defvr {Scheme Variable} %default-rotations
12616 Specifies weekly rotation of @var{%rotated-files} and
12617 a couple of other files.
12620 @defvr {Scheme Variable} %rotated-files
12621 The list of syslog-controlled files to be rotated. By default it is:
12622 @code{'("/var/log/messages" "/var/log/secure")}.
12625 @node Networking Services
12626 @subsection Networking Services
12628 The @code{(gnu services networking)} module provides services to configure
12629 the network interface.
12631 @cindex DHCP, networking service
12632 @defvr {Scheme Variable} dhcp-client-service-type
12633 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12634 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12635 is the DHCP client package to use, @code{isc-dhcp} by default.
12638 @deffn {Scheme Procedure} dhcpd-service-type
12639 This type defines a service that runs a DHCP daemon. To create a
12640 service of this type, you must supply a @code{<dhcpd-configuration>}.
12644 (service dhcpd-service-type
12645 (dhcpd-configuration
12646 (config-file (local-file "my-dhcpd.conf"))
12647 (interfaces '("enp0s25"))))
12651 @deftp {Data Type} dhcpd-configuration
12653 @item @code{package} (default: @code{isc-dhcp})
12654 The package that provides the DHCP daemon. This package is expected to
12655 provide the daemon at @file{sbin/dhcpd} relative to its output
12656 directory. The default package is the
12657 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
12658 @item @code{config-file} (default: @code{#f})
12659 The configuration file to use. This is required. It will be passed to
12660 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
12661 object (@pxref{G-Expressions, file-like objects}). See @code{man
12662 dhcpd.conf} for details on the configuration file syntax.
12663 @item @code{version} (default: @code{"4"})
12664 The DHCP version to use. The ISC DHCP server supports the values ``4'',
12665 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
12666 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
12668 @item @code{run-directory} (default: @code{"/run/dhcpd"})
12669 The run directory to use. At service activation time, this directory
12670 will be created if it does not exist.
12671 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
12672 The PID file to use. This corresponds to the @code{-pf} option of
12673 @code{dhcpd}. See @code{man dhcpd} for details.
12674 @item @code{interfaces} (default: @code{'()})
12675 The names of the network interfaces on which dhcpd should listen for
12676 broadcasts. If this list is not empty, then its elements (which must be
12677 strings) will be appended to the @code{dhcpd} invocation when starting
12678 the daemon. It may not be necessary to explicitly specify any
12679 interfaces here; see @code{man dhcpd} for details.
12683 @defvr {Scheme Variable} static-networking-service-type
12684 This is the type for statically-configured network interfaces.
12685 @c TODO Document <static-networking> data structures.
12688 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
12689 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
12690 [#:requirement @code{'(udev)}]
12691 Return a service that starts @var{interface} with address @var{ip}. If
12692 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
12693 it must be a string specifying the default network gateway. @var{requirement}
12694 can be used to declare a dependency on another service before configuring the
12697 This procedure can be called several times, one for each network
12698 interface of interest. Behind the scenes what it does is extend
12699 @code{static-networking-service-type} with additional network interfaces
12705 (static-networking-service "eno1" "192.168.1.82"
12706 #:gateway "192.168.1.2"
12707 #:name-servers '("192.168.1.2"))
12714 @cindex network management
12715 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
12716 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
12717 management daemon that aims to simplify wired and wireless networking.
12719 This service adds the @var{wicd} package to the global profile, providing
12720 several commands to interact with the daemon and configure networking:
12721 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
12722 and @command{wicd-curses} user interfaces.
12725 @cindex ModemManager
12727 @defvr {Scheme Variable} modem-manager-service-type
12728 This is the service type for the
12729 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
12730 service. The value for this service type is a
12731 @code{modem-manager-configuration} record.
12733 This service is part of @code{%desktop-services} (@pxref{Desktop
12737 @deftp {Data Type} modem-manager-configuration
12738 Data type representing the configuration of ModemManager.
12741 @item @code{modem-manager} (default: @code{modem-manager})
12742 The ModemManager package to use.
12747 @cindex USB_ModeSwitch
12748 @cindex Modeswitching
12750 @defvr {Scheme Variable} usb-modeswitch-service-type
12751 This is the service type for the
12752 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
12753 value for this service type is a @code{usb-modeswitch-configuration} record.
12755 When plugged in, some USB modems (and other USB devices) initially present
12756 themselves as a read-only storage medium and not as a modem. They need to be
12757 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
12758 installs udev rules to automatically modeswitch these devices when they are
12761 This service is part of @code{%desktop-services} (@pxref{Desktop
12765 @deftp {Data Type} usb-modeswitch-configuration
12766 Data type representing the configuration of USB_ModeSwitch.
12769 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
12770 The USB_ModeSwitch package providing the binaries for modeswitching.
12772 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
12773 The package providing the device data and udev rules file used by
12776 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
12777 Which config file to use for the USB_ModeSwitch dispatcher. By default the
12778 config file shipped with USB_ModeSwitch is used which disables logging to
12779 @file{/var/log} among other default settings. If set to @code{#f}, no config
12785 @cindex NetworkManager
12787 @defvr {Scheme Variable} network-manager-service-type
12788 This is the service type for the
12789 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
12790 service. The value for this service type is a
12791 @code{network-manager-configuration} record.
12793 This service is part of @code{%desktop-services} (@pxref{Desktop
12797 @deftp {Data Type} network-manager-configuration
12798 Data type representing the configuration of NetworkManager.
12801 @item @code{network-manager} (default: @code{network-manager})
12802 The NetworkManager package to use.
12804 @item @code{dns} (default: @code{"default"})
12805 Processing mode for DNS, which affects how NetworkManager uses the
12806 @code{resolv.conf} configuration file.
12810 NetworkManager will update @code{resolv.conf} to reflect the nameservers
12811 provided by currently active connections.
12814 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
12815 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
12816 then update @code{resolv.conf} to point to the local nameserver.
12818 With this setting, you can share your network connection. For example when
12819 you want to share your network connection to another laptop @i{via} an
12820 Ethernet cable, you can open @command{nm-connection-editor} and configure the
12821 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
12822 and reestablish the connection (or reboot).
12824 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
12825 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
12826 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
12827 browser on your host system, or connect to the VM @i{via} SSH
12828 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
12829 host-to-guest connection, run this command once:
12832 nmcli connection add type tun \
12833 connection.interface-name tap0 \
12834 tun.mode tap tun.owner $(id -u) \
12835 ipv4.method shared \
12836 ipv4.addresses 172.28.112.1/24
12839 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
12840 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
12841 @command{qemu-system-...}.
12844 NetworkManager will not modify @code{resolv.conf}.
12847 @item @code{vpn-plugins} (default: @code{'()})
12848 This is the list of available plugins for virtual private networks
12849 (VPNs). An example of this is the @code{network-manager-openvpn}
12850 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
12856 @deffn {Scheme Variable} connman-service-type
12857 This is the service type to run @url{https://01.org/connman,Connman},
12858 a network connection manager.
12860 Its value must be an
12861 @code{connman-configuration} record as in this example:
12864 (service connman-service-type
12865 (connman-configuration
12866 (disable-vpn? #t)))
12869 See below for details about @code{connman-configuration}.
12872 @deftp {Data Type} connman-configuration
12873 Data Type representing the configuration of connman.
12876 @item @code{connman} (default: @var{connman})
12877 The connman package to use.
12879 @item @code{disable-vpn?} (default: @code{#f})
12880 When true, disable connman's vpn plugin.
12884 @cindex WPA Supplicant
12885 @defvr {Scheme Variable} wpa-supplicant-service-type
12886 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
12887 supplicant}, an authentication daemon required to authenticate against
12888 encrypted WiFi or ethernet networks.
12891 @deftp {Data Type} wpa-supplicant-configuration
12892 Data type representing the configuration of WPA Supplicant.
12894 It takes the following parameters:
12897 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
12898 The WPA Supplicant package to use.
12900 @item @code{dbus?} (default: @code{#t})
12901 Whether to listen for requests on D-Bus.
12903 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
12904 Where to store the PID file.
12906 @item @code{interface} (default: @code{#f})
12907 If this is set, it must specify the name of a network interface that
12908 WPA supplicant will control.
12910 @item @code{config-file} (default: @code{#f})
12911 Optional configuration file to use.
12913 @item @code{extra-options} (default: @code{'()})
12914 List of additional command-line arguments to pass to the daemon.
12919 @defvr {Scheme Variable} iptables-service-type
12920 This is the service type to set up an iptables configuration. iptables is a
12921 packet filtering framework supported by the Linux kernel. This service
12922 supports configuring iptables for both IPv4 and IPv6. A simple example
12923 configuration rejecting all incoming connections except those to the ssh port
12927 (service iptables-service-type
12928 (iptables-configuration
12929 (ipv4-rules (plain-file "iptables.rules" "*filter
12933 -A INPUT -p tcp --dport 22 -j ACCEPT
12934 -A INPUT -j REJECT --reject-with icmp-port-unreachable
12937 (ipv6-rules (plain-file "ip6tables.rules" "*filter
12941 -A INPUT -p tcp --dport 22 -j ACCEPT
12942 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
12948 @deftp {Data Type} iptables-configuration
12949 The data type representing the configuration of iptables.
12952 @item @code{iptables} (default: @code{iptables})
12953 The iptables package that provides @code{iptables-restore} and
12954 @code{ip6tables-restore}.
12955 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
12956 The iptables rules to use. It will be passed to @code{iptables-restore}.
12957 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12959 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
12960 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
12961 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
12966 @cindex NTP (Network Time Protocol), service
12967 @cindex real time clock
12968 @defvr {Scheme Variable} ntp-service-type
12969 This is the type of the service running the @uref{http://www.ntp.org,
12970 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
12971 system clock synchronized with that of the specified NTP servers.
12973 The value of this service is an @code{ntpd-configuration} object, as described
12977 @deftp {Data Type} ntp-configuration
12978 This is the data type for the NTP service configuration.
12981 @item @code{servers} (default: @code{%ntp-servers})
12982 This is the list of servers (host names) with which @command{ntpd} will be
12985 @item @code{allow-large-adjustment?} (default: @code{#f})
12986 This determines whether @command{ntpd} is allowed to make an initial
12987 adjustment of more than 1,000 seconds.
12989 @item @code{ntp} (default: @code{ntp})
12990 The NTP package to use.
12994 @defvr {Scheme Variable} %ntp-servers
12995 List of host names used as the default NTP servers. These are servers of the
12996 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13000 @deffn {Scheme Procedure} openntpd-service-type
13001 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13002 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13003 clock synchronized with that of the given servers.
13007 openntpd-service-type
13008 (openntpd-configuration
13009 (listen-on '("127.0.0.1" "::1"))
13010 (sensor '("udcf0 correction 70000"))
13011 (constraint-from '("www.gnu.org"))
13012 (constraints-from '("https://www.google.com/"))
13013 (allow-large-adjustment? #t)))
13018 @deftp {Data Type} openntpd-configuration
13020 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13021 The openntpd executable to use.
13022 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13023 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13024 @item @code{query-from} (default: @code{'()})
13025 A list of local IP address the ntpd daemon should use for outgoing queries.
13026 @item @code{sensor} (default: @code{'()})
13027 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13028 will listen to each sensor that actually exists and ignore non-existent ones.
13029 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13031 @item @code{server} (default: @var{%ntp-servers})
13032 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13033 @item @code{servers} (default: @code{'()})
13034 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13035 @item @code{constraint-from} (default: @code{'()})
13036 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13037 This time information is not used for precision but acts as an authenticated
13038 constraint, thereby reducing the impact of unauthenticated NTP
13039 man-in-the-middle attacks.
13040 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13042 @item @code{constraints-from} (default: @code{'()})
13043 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13044 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13045 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13046 @item @code{allow-large-adjustment?} (default: @code{#f})
13047 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13053 @deffn {Scheme variable} inetd-service-type
13054 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13055 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13056 connections on internet sockets, and lazily starts the specified server
13057 program when a connection is made on one of these sockets.
13059 The value of this service is an @code{inetd-configuration} object. The
13060 following example configures the @command{inetd} daemon to provide the
13061 built-in @command{echo} service, as well as an smtp service which
13062 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13063 gateway @code{hostname}:
13068 (inetd-configuration
13072 (socket-type 'stream)
13079 (socket-type 'stream)
13083 (program (file-append openssh "/bin/ssh"))
13085 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13086 "-W" "smtp-server:25" "user@@hostname")))))
13089 See below for more details about @code{inetd-configuration}.
13092 @deftp {Data Type} inetd-configuration
13093 Data type representing the configuration of @command{inetd}.
13096 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13097 The @command{inetd} executable to use.
13099 @item @code{entries} (default: @code{'()})
13100 A list of @command{inetd} service entries. Each entry should be created
13101 by the @code{inetd-entry} constructor.
13105 @deftp {Data Type} inetd-entry
13106 Data type representing an entry in the @command{inetd} configuration.
13107 Each entry corresponds to a socket where @command{inetd} will listen for
13111 @item @code{node} (default: @code{#f})
13112 Optional string, a comma-separated list of local addresses
13113 @command{inetd} should use when listening for this service.
13114 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13115 description of all options.
13117 A string, the name must correspond to an entry in @code{/etc/services}.
13118 @item @code{socket-type}
13119 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13121 @item @code{protocol}
13122 A string, must correspond to an entry in @code{/etc/protocols}.
13123 @item @code{wait?} (default: @code{#t})
13124 Whether @command{inetd} should wait for the server to exit before
13125 listening to new service requests.
13127 A string containing the user (and, optionally, group) name of the user
13128 as whom the server should run. The group name can be specified in a
13129 suffix, separated by a colon or period, i.e.@: @code{"user"},
13130 @code{"user:group"} or @code{"user.group"}.
13131 @item @code{program} (default: @code{"internal"})
13132 The server program which will serve the requests, or @code{"internal"}
13133 if @command{inetd} should use a built-in service.
13134 @item @code{arguments} (default: @code{'()})
13135 A list strings or file-like objects, which are the server program's
13136 arguments, starting with the zeroth argument, i.e.@: the name of the
13137 program itself. For @command{inetd}'s internal services, this entry
13138 must be @code{'()} or @code{'("internal")}.
13141 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13142 detailed discussion of each configuration field.
13146 @defvr {Scheme Variable} tor-service-type
13147 This is the type for a service that runs the @uref{https://torproject.org,
13148 Tor} anonymous networking daemon. The service is configured using a
13149 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13150 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13154 @deftp {Data Type} tor-configuration
13156 @item @code{tor} (default: @code{tor})
13157 The package that provides the Tor daemon. This package is expected to provide
13158 the daemon at @file{bin/tor} relative to its output directory. The default
13159 package is the @uref{https://www.torproject.org, Tor Project's}
13162 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13163 The configuration file to use. It will be appended to a default configuration
13164 file, and the final configuration file will be passed to @code{tor} via its
13165 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13166 file-like objects}). See @code{man tor} for details on the configuration file
13169 @item @code{hidden-services} (default: @code{'()})
13170 The list of @code{<hidden-service>} records to use. For any hidden service
13171 you include in this list, appropriate configuration to enable the hidden
13172 service will be automatically added to the default configuration file. You
13173 may conveniently create @code{<hidden-service>} records using the
13174 @code{tor-hidden-service} procedure described below.
13176 @item @code{socks-socket-type} (default: @code{'tcp})
13177 The default socket type that Tor should use for its SOCKS socket. This must
13178 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13179 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13180 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13181 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13184 If you want to customize the SOCKS socket in more detail, leave
13185 @code{socks-socket-type} at its default value of @code{'tcp} and use
13186 @code{config-file} to override the default by providing your own
13187 @code{SocksPort} option.
13191 @cindex hidden service
13192 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13193 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13194 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13197 '((22 "127.0.0.1:22")
13198 (80 "127.0.0.1:8080"))
13201 In this example, port 22 of the hidden service is mapped to local port 22, and
13202 port 80 is mapped to local port 8080.
13204 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13205 the @file{hostname} file contains the @code{.onion} host name for the hidden
13208 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13209 project's documentation} for more information.
13212 The @code{(gnu services rsync)} module provides the following services:
13214 You might want an rsync daemon if you have files that you want available
13215 so anyone (or just yourself) can download existing files or upload new
13218 @deffn {Scheme Variable} rsync-service-type
13219 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13220 The value for this service type is a
13221 @command{rsync-configuration} record as in this example:
13224 (service rsync-service-type)
13227 See below for details about @code{rsync-configuration}.
13230 @deftp {Data Type} rsync-configuration
13231 Data type representing the configuration for @code{rsync-service}.
13234 @item @code{package} (default: @var{rsync})
13235 @code{rsync} package to use.
13237 @item @code{port-number} (default: @code{873})
13238 TCP port on which @command{rsync} listens for incoming connections. If port
13239 is less than @code{1024} @command{rsync} needs to be started as the
13240 @code{root} user and group.
13242 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13243 Name of the file where @command{rsync} writes its PID.
13245 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13246 Name of the file where @command{rsync} writes its lock file.
13248 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13249 Name of the file where @command{rsync} writes its log file.
13251 @item @code{use-chroot?} (default: @var{#t})
13252 Whether to use chroot for @command{rsync} shared directory.
13254 @item @code{share-path} (default: @file{/srv/rsync})
13255 Location of the @command{rsync} shared directory.
13257 @item @code{share-comment} (default: @code{"Rsync share"})
13258 Comment of the @command{rsync} shared directory.
13260 @item @code{read-only?} (default: @var{#f})
13261 Read-write permissions to shared directory.
13263 @item @code{timeout} (default: @code{300})
13264 I/O timeout in seconds.
13266 @item @code{user} (default: @var{"root"})
13267 Owner of the @code{rsync} process.
13269 @item @code{group} (default: @var{"root"})
13270 Group of the @code{rsync} process.
13272 @item @code{uid} (default: @var{"rsyncd"})
13273 User name or user ID that file transfers to and from that module should take
13274 place as when the daemon was run as @code{root}.
13276 @item @code{gid} (default: @var{"rsyncd"})
13277 Group name or group ID that will be used when accessing the module.
13282 Furthermore, @code{(gnu services ssh)} provides the following services.
13286 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13287 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13288 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13289 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13290 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13291 [#:public-key-authentication? #t] [#:initialize? #t]
13292 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13293 @var{host-key} must designate a file containing the host key, and readable
13296 When @var{daemonic?} is true, @command{lshd} will detach from the
13297 controlling terminal and log its output to syslogd, unless one sets
13298 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13299 depend on existence of syslogd service. When @var{pid-file?} is true,
13300 @command{lshd} writes its PID to the file called @var{pid-file}.
13302 When @var{initialize?} is true, automatically create the seed and host key
13303 upon service activation if they do not exist yet. This may take long and
13304 require interaction.
13306 When @var{initialize?} is false, it is up to the user to initialize the
13307 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13308 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13309 basics,,, lsh, LSH Manual}).
13311 When @var{interfaces} is empty, lshd listens for connections on all the
13312 network interfaces; otherwise, @var{interfaces} must be a list of host names
13315 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13316 passwords, and @var{root-login?} specifies whether to accept log-ins as
13319 The other options should be self-descriptive.
13324 @deffn {Scheme Variable} openssh-service-type
13325 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13326 shell daemon, @command{sshd}. Its value must be an
13327 @code{openssh-configuration} record as in this example:
13330 (service openssh-service-type
13331 (openssh-configuration
13332 (x11-forwarding? #t)
13333 (permit-root-login 'without-password)
13335 `(("alice" ,(local-file "alice.pub"))
13336 ("bob" ,(local-file "bob.pub"))))))
13339 See below for details about @code{openssh-configuration}.
13341 This service can be extended with extra authorized keys, as in this
13345 (service-extension openssh-service-type
13346 (const `(("charlie"
13347 ,(local-file "charlie.pub")))))
13351 @deftp {Data Type} openssh-configuration
13352 This is the configuration record for OpenSSH's @command{sshd}.
13355 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13356 Name of the file where @command{sshd} writes its PID.
13358 @item @code{port-number} (default: @code{22})
13359 TCP port on which @command{sshd} listens for incoming connections.
13361 @item @code{permit-root-login} (default: @code{#f})
13362 This field determines whether and when to allow logins as root. If
13363 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13364 If it's the symbol @code{'without-password}, then root logins are
13365 permitted but not with password-based authentication.
13367 @item @code{allow-empty-passwords?} (default: @code{#f})
13368 When true, users with empty passwords may log in. When false, they may
13371 @item @code{password-authentication?} (default: @code{#t})
13372 When true, users may log in with their password. When false, they have
13373 other authentication methods.
13375 @item @code{public-key-authentication?} (default: @code{#t})
13376 When true, users may log in using public key authentication. When
13377 false, users have to use other authentication method.
13379 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13380 This is used only by protocol version 2.
13382 @item @code{x11-forwarding?} (default: @code{#f})
13383 When true, forwarding of X11 graphical client connections is
13384 enabled---in other words, @command{ssh} options @option{-X} and
13385 @option{-Y} will work.
13387 @item @code{allow-agent-forwarding?} (default: @code{#t})
13388 Whether to allow agent forwarding.
13390 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13391 Whether to allow TCP forwarding.
13393 @item @code{gateway-ports?} (default: @code{#f})
13394 Whether to allow gateway ports.
13396 @item @code{challenge-response-authentication?} (default: @code{#f})
13397 Specifies whether challenge response authentication is allowed (e.g.@: via
13400 @item @code{use-pam?} (default: @code{#t})
13401 Enables the Pluggable Authentication Module interface. If set to
13402 @code{#t}, this will enable PAM authentication using
13403 @code{challenge-response-authentication?} and
13404 @code{password-authentication?}, in addition to PAM account and session
13405 module processing for all authentication types.
13407 Because PAM challenge response authentication usually serves an
13408 equivalent role to password authentication, you should disable either
13409 @code{challenge-response-authentication?} or
13410 @code{password-authentication?}.
13412 @item @code{print-last-log?} (default: @code{#t})
13413 Specifies whether @command{sshd} should print the date and time of the
13414 last user login when a user logs in interactively.
13416 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13417 Configures external subsystems (e.g.@: file transfer daemon).
13419 This is a list of two-element lists, each of which containing the
13420 subsystem name and a command (with optional arguments) to execute upon
13423 The command @command{internal-sftp} implements an in-process SFTP
13424 server. Alternately, one can specify the @command{sftp-server} command:
13426 (service openssh-service-type
13427 (openssh-configuration
13429 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13432 @item @code{accepted-environment} (default: @code{'()})
13433 List of strings describing which environment variables may be exported.
13435 Each string gets on its own line. See the @code{AcceptEnv} option in
13436 @code{man sshd_config}.
13438 This example allows ssh-clients to export the @code{COLORTERM} variable.
13439 It is set by terminal emulators, which support colors. You can use it in
13440 your shell's ressource file to enable colors for the prompt and commands
13441 if this variable is set.
13444 (service openssh-service-type
13445 (openssh-configuration
13446 (accepted-environment '("COLORTERM"))))
13449 @item @code{authorized-keys} (default: @code{'()})
13450 @cindex authorized keys, SSH
13451 @cindex SSH authorized keys
13452 This is the list of authorized keys. Each element of the list is a user
13453 name followed by one or more file-like objects that represent SSH public
13457 (openssh-configuration
13459 `(("rekado" ,(local-file "rekado.pub"))
13460 ("chris" ,(local-file "chris.pub"))
13461 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13465 registers the specified public keys for user accounts @code{rekado},
13466 @code{chris}, and @code{root}.
13468 Additional authorized keys can be specified @i{via}
13469 @code{service-extension}.
13471 Note that this does @emph{not} interfere with the use of
13472 @file{~/.ssh/authorized_keys}.
13474 @item @code{log-level} (default: @code{'info})
13475 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13476 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13477 page for @file{sshd_config} for the full list of level names.
13479 @item @code{extra-content} (default: @code{""})
13480 This field can be used to append arbitrary text to the configuration file. It
13481 is especially useful for elaborate configurations that cannot be expressed
13482 otherwise. This configuration, for example, would generally disable root
13483 logins, but permit them from one specific IP address:
13486 (openssh-configuration
13488 Match Address 192.168.0.1
13489 PermitRootLogin yes"))
13495 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13496 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13497 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13500 For example, to specify a Dropbear service listening on port 1234, add
13501 this call to the operating system's @code{services} field:
13504 (dropbear-service (dropbear-configuration
13505 (port-number 1234)))
13509 @deftp {Data Type} dropbear-configuration
13510 This data type represents the configuration of a Dropbear SSH daemon.
13513 @item @code{dropbear} (default: @var{dropbear})
13514 The Dropbear package to use.
13516 @item @code{port-number} (default: 22)
13517 The TCP port where the daemon waits for incoming connections.
13519 @item @code{syslog-output?} (default: @code{#t})
13520 Whether to enable syslog output.
13522 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13523 File name of the daemon's PID file.
13525 @item @code{root-login?} (default: @code{#f})
13526 Whether to allow @code{root} logins.
13528 @item @code{allow-empty-passwords?} (default: @code{#f})
13529 Whether to allow empty passwords.
13531 @item @code{password-authentication?} (default: @code{#t})
13532 Whether to enable password-based authentication.
13536 @defvr {Scheme Variable} %facebook-host-aliases
13537 This variable contains a string for use in @file{/etc/hosts}
13538 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13539 line contains a entry that maps a known server name of the Facebook
13540 on-line service---e.g., @code{www.facebook.com}---to the local
13541 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13543 This variable is typically used in the @code{hosts-file} field of an
13544 @code{operating-system} declaration (@pxref{operating-system Reference,
13545 @file{/etc/hosts}}):
13548 (use-modules (gnu) (guix))
13551 (host-name "mymachine")
13554 ;; Create a /etc/hosts file with aliases for "localhost"
13555 ;; and "mymachine", as well as for Facebook servers.
13556 (plain-file "hosts"
13557 (string-append (local-host-aliases host-name)
13558 %facebook-host-aliases))))
13561 This mechanism can prevent programs running locally, such as Web
13562 browsers, from accessing Facebook.
13565 The @code{(gnu services avahi)} provides the following definition.
13567 @defvr {Scheme Variable} avahi-service-type
13568 This is the service that runs @command{avahi-daemon}, a system-wide
13569 mDNS/DNS-SD responder that allows for service discovery and
13570 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13571 Its value must be a @code{zero-configuration} record---see below.
13573 This service extends the name service cache daemon (nscd) so that it can
13574 resolve @code{.local} host names using
13575 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13576 Service Switch}, for information on host name resolution.
13578 Additionally, add the @var{avahi} package to the system profile so that
13579 commands such as @command{avahi-browse} are directly usable.
13582 @deftp {Data Type} avahi-configuration
13583 Data type representation the configuration for Avahi.
13587 @item @code{host-name} (default: @code{#f})
13588 If different from @code{#f}, use that as the host name to
13589 publish for this machine; otherwise, use the machine's actual host name.
13591 @item @code{publish?} (default: @code{#t})
13592 When true, allow host names and services to be published (broadcast) over the
13595 @item @code{publish-workstation?} (default: @code{#t})
13596 When true, @command{avahi-daemon} publishes the machine's host name and IP
13597 address via mDNS on the local network. To view the host names published on
13598 your local network, you can run:
13601 avahi-browse _workstation._tcp
13604 @item @code{wide-area?} (default: @code{#f})
13605 When true, DNS-SD over unicast DNS is enabled.
13607 @item @code{ipv4?} (default: @code{#t})
13608 @itemx @code{ipv6?} (default: @code{#t})
13609 These fields determine whether to use IPv4/IPv6 sockets.
13611 @item @code{domains-to-browse} (default: @code{'()})
13612 This is a list of domains to browse.
13616 @deffn {Scheme Variable} openvswitch-service-type
13617 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
13618 service, whose value should be an @code{openvswitch-configuration}
13622 @deftp {Data Type} openvswitch-configuration
13623 Data type representing the configuration of Open vSwitch, a multilayer
13624 virtual switch which is designed to enable massive network automation
13625 through programmatic extension.
13628 @item @code{package} (default: @var{openvswitch})
13629 Package object of the Open vSwitch.
13635 @subsection X Window
13638 @cindex X Window System
13639 @cindex login manager
13640 Support for the X Window graphical display system---specifically
13641 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
13642 there is no @code{xorg-service} procedure. Instead, the X server is
13643 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
13646 @cindex GNOME, login manager
13647 GDM of course allows users to log in into window managers and desktop
13648 environments other than GNOME; for those using GNOME, GDM is required for
13649 features such as automatic screen locking.
13651 @cindex window manager
13652 To use X11, you must install at least one @dfn{window manager}---for
13653 example the @code{windowmaker} or @code{openbox} packages---preferably
13654 by adding it to the @code{packages} field of your operating system
13655 definition (@pxref{operating-system Reference, system-wide packages}).
13657 @defvr {Scheme Variable} gdm-service-type
13658 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
13659 Desktop Manager} (GDM), a program that manages graphical display servers and
13660 handles graphical user logins. Its value must be a @code{gdm-configuration}
13663 @cindex session types (X11)
13664 @cindex X11 session types
13665 GDM looks for @dfn{session types} described by the @file{.desktop} files in
13666 @file{/run/current-system/profile/share/xsessions} and allows users to choose
13667 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
13668 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
13669 set of packages automatically makes them available at the log-in screen.
13671 In addition, @file{~/.xsession} files are honored. When available,
13672 @file{~/.xsession} must be an executable that starts a window manager
13673 and/or other X clients.
13676 @deftp {Data Type} gdm-configuration
13678 @item @code{auto-login?} (default: @code{#f})
13679 @itemx @code{default-user} (default: @code{#f})
13680 When @code{auto-login?} is false, GDM presents a log-in screen.
13682 When @code{auto-login?} is true, GDM logs in directly as
13683 @code{default-user}.
13685 @item @code{gnome-shell-assets} (default: ...)
13686 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
13688 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
13689 Configuration of the Xorg graphical server.
13691 @item @code{xsession} (default: @code{(xinitrc)})
13692 Script to run before starting a X session.
13694 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
13695 File name of the @code{dbus-daemon} executable.
13697 @item @code{gdm} (default: @code{gdm})
13698 The GDM package to use.
13702 @defvr {Scheme Variable} slim-service-type
13703 This is the type for the SLiM graphical login manager for X11.
13705 Like GDM, SLiM looks for session types described by @file{.desktop} files and
13706 allows users to choose a session from the log-in screen using @kbd{F1}. It
13707 also honors @file{~/.xsession} files.
13709 Unlike GDM, SLiM does not spawn the user session on a different VT after
13710 logging in, which means that you can only start one graphical session. If you
13711 want to be able to run multiple graphical sessions at the same time you have
13712 to add multiple SLiM services to your system services. The following example
13713 shows how to replace the default GDM service with two SLiM services on tty7
13717 (use-modules (gnu services)
13718 (gnu services desktop)
13719 (gnu services xorg)
13720 (srfi srfi-1)) ;for 'remove'
13724 (services (cons* (service slim-service-type (slim-configuration
13727 (service slim-service-type (slim-configuration
13730 (remove (lambda (service)
13731 (eq? (service-kind service) gdm-service-type))
13732 %desktop-services))))
13737 @deftp {Data Type} slim-configuration
13738 Data type representing the configuration of @code{slim-service-type}.
13741 @item @code{allow-empty-passwords?} (default: @code{#t})
13742 Whether to allow logins with empty passwords.
13744 @item @code{auto-login?} (default: @code{#f})
13745 @itemx @code{default-user} (default: @code{""})
13746 When @code{auto-login?} is false, SLiM presents a log-in screen.
13748 When @code{auto-login?} is true, SLiM logs in directly as
13749 @code{default-user}.
13751 @item @code{theme} (default: @code{%default-slim-theme})
13752 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
13753 The graphical theme to use and its name.
13755 @item @code{auto-login-session} (default: @code{#f})
13756 If true, this must be the name of the executable to start as the default
13757 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
13759 If false, a session described by one of the available @file{.desktop}
13760 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
13764 You must install at least one window manager in the system profile or in
13765 your user profile. Failing to do that, if @code{auto-login-session} is
13766 false, you will be unable to log in.
13769 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13770 Configuration of the Xorg graphical server.
13772 @item @code{display} (default @code{":0"})
13773 The display on which to start the Xorg graphical server.
13775 @item @code{vt} (default @code{"vt7"})
13776 The VT on which to start the Xorg graphical server.
13778 @item @code{xauth} (default: @code{xauth})
13779 The XAuth package to use.
13781 @item @code{shepherd} (default: @code{shepherd})
13782 The Shepherd package used when invoking @command{halt} and
13785 @item @code{sessreg} (default: @code{sessreg})
13786 The sessreg package used in order to register the session.
13788 @item @code{slim} (default: @code{slim})
13789 The SLiM package to use.
13793 @defvr {Scheme Variable} %default-theme
13794 @defvrx {Scheme Variable} %default-theme-name
13795 The default SLiM theme and its name.
13799 @deftp {Data Type} sddm-configuration
13800 This is the data type representing the sddm service configuration.
13803 @item @code{display-server} (default: "x11")
13804 Select display server to use for the greeter. Valid values are "x11"
13807 @item @code{numlock} (default: "on")
13808 Valid values are "on", "off" or "none".
13810 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
13811 Command to run when halting.
13813 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
13814 Command to run when rebooting.
13816 @item @code{theme} (default "maldives")
13817 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
13819 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
13820 Directory to look for themes.
13822 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
13823 Directory to look for faces.
13825 @item @code{default-path} (default "/run/current-system/profile/bin")
13826 Default PATH to use.
13828 @item @code{minimum-uid} (default: 1000)
13829 Minimum UID displayed in SDDM and allowed for log-in.
13831 @item @code{maximum-uid} (default: 2000)
13832 Maximum UID to display in SDDM.
13834 @item @code{remember-last-user?} (default #t)
13835 Remember last user.
13837 @item @code{remember-last-session?} (default #t)
13838 Remember last session.
13840 @item @code{hide-users} (default "")
13841 Usernames to hide from SDDM greeter.
13843 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
13844 Users with shells listed will be hidden from the SDDM greeter.
13846 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
13847 Script to run before starting a wayland session.
13849 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
13850 Directory to look for desktop files starting wayland sessions.
13852 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
13853 Configuration of the Xorg graphical server.
13855 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
13858 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
13861 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
13862 Script to run after starting xorg-server.
13864 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
13865 Script to run before stopping xorg-server.
13867 @item @code{xsession-command} (default: @code{xinitrc})
13868 Script to run before starting a X session.
13870 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
13871 Directory to look for desktop files starting X sessions.
13873 @item @code{minimum-vt} (default: 7)
13876 @item @code{auto-login-user} (default "")
13877 User to use for auto-login.
13879 @item @code{auto-login-session} (default "")
13880 Desktop file to use for auto-login.
13882 @item @code{relogin?} (default #f)
13883 Relogin after logout.
13888 @cindex login manager
13890 @deffn {Scheme Procedure} sddm-service config
13891 Return a service that spawns the SDDM graphical login manager for config of
13892 type @code{<sddm-configuration>}.
13895 (sddm-service (sddm-configuration
13896 (auto-login-user "Alice")
13897 (auto-login-session "xfce.desktop")))
13901 @cindex Xorg, configuration
13902 @deftp {Data Type} xorg-configuration
13903 This data type represents the configuration of the Xorg graphical display
13904 server. Note that there is not Xorg service; instead, the X server is started
13905 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
13906 of these display managers aggregates an @code{xorg-configuration} record.
13909 @item @code{modules} (default: @code{%default-xorg-modules})
13910 This is a list of @dfn{module packages} loaded by the Xorg
13911 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
13913 @item @code{fonts} (default: @code{%default-xorg-fonts})
13914 This is a list of font directories to add to the server's @dfn{font path}.
13916 @item @code{drivers} (default: @code{'()})
13917 This must be either the empty list, in which case Xorg chooses a graphics
13918 driver automatically, or a list of driver names that will be tried in this
13919 order---e.g., @code{("modesetting" "vesa")}.
13921 @item @code{resolutions} (default: @code{'()})
13922 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
13923 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
13926 @cindex keyboard layout, for Xorg
13927 @cindex keymap, for Xorg
13928 @item @code{keyboard-layout} (default: @code{#f})
13929 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
13930 English (``qwerty'') for a 105-key PC keyboard.
13932 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
13933 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
13934 information on how to specify the keyboard layout.
13936 @item @code{extra-config} (default: @code{'()})
13937 This is a list of strings or objects appended to the configuration file. It
13938 is used to pass extra text to be added verbatim to the configuration file.
13940 @item @code{server} (default: @code{xorg-server})
13941 This is the package providing the Xorg server.
13943 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
13944 This is the list of command-line arguments to pass to the X server. The
13945 default is @code{-nolisten tcp}.
13949 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
13950 [@var{login-manager-service-type}]
13951 Tell the log-in manager (of type @var{login-manager-service-type}) to use
13952 @var{config}, an @code{<xorg-configuration>} record.
13954 Since the Xorg configuration is embedded in the log-in manager's
13955 configuration---e.g., @code{gdm-configuration}---this procedure provides a
13956 shorthand to set the Xorg configuration.
13959 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
13960 Return a @code{startx} script in which the modules, fonts, etc. specified
13961 in @var{config}, are available. The result should be used in place of
13964 Usually the X server is started by a login manager.
13968 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
13969 Add @var{package}, a package for a screen locker or screen saver whose
13970 command is @var{program}, to the set of setuid programs and add a PAM entry
13971 for it. For example:
13974 (screen-locker-service xlockmore "xlock")
13977 makes the good ol' XlockMore usable.
13981 @node Printing Services
13982 @subsection Printing Services
13984 @cindex printer support with CUPS
13985 The @code{(gnu services cups)} module provides a Guix service definition
13986 for the CUPS printing service. To add printer support to a Guix
13987 system, add a @code{cups-service} to the operating system definition:
13989 @deffn {Scheme Variable} cups-service-type
13990 The service type for the CUPS print server. Its value should be a valid
13991 CUPS configuration (see below). To use the default settings, simply
13994 (service cups-service-type)
13998 The CUPS configuration controls the basic things about your CUPS
13999 installation: what interfaces it listens on, what to do if a print job
14000 fails, how much logging to do, and so on. To actually add a printer,
14001 you have to visit the @url{http://localhost:631} URL, or use a tool such
14002 as GNOME's printer configuration services. By default, configuring a
14003 CUPS service will generate a self-signed certificate if needed, for
14004 secure connections to the print server.
14006 Suppose you want to enable the Web interface of CUPS and also add
14007 support for Epson printers @i{via} the @code{escpr} package and for HP
14008 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14009 like this (you need to use the @code{(gnu packages cups)} module):
14012 (service cups-service-type
14013 (cups-configuration
14014 (web-interface? #t)
14016 (list cups-filters escpr hplip-minimal))))
14019 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14020 package then it is suggested that you install the @code{hplip} package,
14021 either in your OS configuration file or as your user.
14023 The available configuration parameters follow. Each parameter
14024 definition is preceded by its type; for example, @samp{string-list foo}
14025 indicates that the @code{foo} parameter should be specified as a list of
14026 strings. There is also a way to specify the configuration as a string,
14027 if you have an old @code{cupsd.conf} file that you want to port over
14028 from some other system; see the end for more details.
14030 @c The following documentation was initially generated by
14031 @c (generate-documentation) in (gnu services cups). Manually maintained
14032 @c documentation is better, so we shouldn't hesitate to edit below as
14033 @c needed. However if the change you want to make to this documentation
14034 @c can be done in an automated way, it's probably easier to change
14035 @c (generate-documentation) than to make it below and have to deal with
14036 @c the churn as CUPS updates.
14039 Available @code{cups-configuration} fields are:
14041 @deftypevr {@code{cups-configuration} parameter} package cups
14045 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14046 Drivers and other extensions to the CUPS package.
14049 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14050 Configuration of where to write logs, what directories to use for print
14051 spools, and related privileged configuration parameters.
14053 Available @code{files-configuration} fields are:
14055 @deftypevr {@code{files-configuration} parameter} log-location access-log
14056 Defines the access log filename. Specifying a blank filename disables
14057 access log generation. The value @code{stderr} causes log entries to be
14058 sent to the standard error file when the scheduler is running in the
14059 foreground, or to the system log daemon when run in the background. The
14060 value @code{syslog} causes log entries to be sent to the system log
14061 daemon. The server name may be included in filenames using the string
14062 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14064 Defaults to @samp{"/var/log/cups/access_log"}.
14067 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14068 Where CUPS should cache data.
14070 Defaults to @samp{"/var/cache/cups"}.
14073 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14074 Specifies the permissions for all configuration files that the scheduler
14077 Note that the permissions for the printers.conf file are currently
14078 masked to only allow access from the scheduler user (typically root).
14079 This is done because printer device URIs sometimes contain sensitive
14080 authentication information that should not be generally known on the
14081 system. There is no way to disable this security feature.
14083 Defaults to @samp{"0640"}.
14086 @deftypevr {@code{files-configuration} parameter} log-location error-log
14087 Defines the error log filename. Specifying a blank filename disables
14088 error log generation. The value @code{stderr} causes log entries to be
14089 sent to the standard error file when the scheduler is running in the
14090 foreground, or to the system log daemon when run in the background. The
14091 value @code{syslog} causes log entries to be sent to the system log
14092 daemon. The server name may be included in filenames using the string
14093 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14095 Defaults to @samp{"/var/log/cups/error_log"}.
14098 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14099 Specifies which errors are fatal, causing the scheduler to exit. The
14104 No errors are fatal.
14107 All of the errors below are fatal.
14110 Browsing initialization errors are fatal, for example failed connections
14111 to the DNS-SD daemon.
14114 Configuration file syntax errors are fatal.
14117 Listen or Port errors are fatal, except for IPv6 failures on the
14118 loopback or @code{any} addresses.
14121 Log file creation or write errors are fatal.
14124 Bad startup file permissions are fatal, for example shared TLS
14125 certificate and key files with world-read permissions.
14128 Defaults to @samp{"all -browse"}.
14131 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14132 Specifies whether the file pseudo-device can be used for new printer
14133 queues. The URI @uref{file:///dev/null} is always allowed.
14135 Defaults to @samp{#f}.
14138 @deftypevr {@code{files-configuration} parameter} string group
14139 Specifies the group name or ID that will be used when executing external
14142 Defaults to @samp{"lp"}.
14145 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14146 Specifies the permissions for all log files that the scheduler writes.
14148 Defaults to @samp{"0644"}.
14151 @deftypevr {@code{files-configuration} parameter} log-location page-log
14152 Defines the page log filename. Specifying a blank filename disables
14153 page log generation. The value @code{stderr} causes log entries to be
14154 sent to the standard error file when the scheduler is running in the
14155 foreground, or to the system log daemon when run in the background. The
14156 value @code{syslog} causes log entries to be sent to the system log
14157 daemon. The server name may be included in filenames using the string
14158 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14160 Defaults to @samp{"/var/log/cups/page_log"}.
14163 @deftypevr {@code{files-configuration} parameter} string remote-root
14164 Specifies the username that is associated with unauthenticated accesses
14165 by clients claiming to be the root user. The default is @code{remroot}.
14167 Defaults to @samp{"remroot"}.
14170 @deftypevr {@code{files-configuration} parameter} file-name request-root
14171 Specifies the directory that contains print jobs and other HTTP request
14174 Defaults to @samp{"/var/spool/cups"}.
14177 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14178 Specifies the level of security sandboxing that is applied to print
14179 filters, backends, and other child processes of the scheduler; either
14180 @code{relaxed} or @code{strict}. This directive is currently only
14181 used/supported on macOS.
14183 Defaults to @samp{strict}.
14186 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14187 Specifies the location of TLS certificates and private keys. CUPS will
14188 look for public and private keys in this directory: a @code{.crt} files
14189 for PEM-encoded certificates and corresponding @code{.key} files for
14190 PEM-encoded private keys.
14192 Defaults to @samp{"/etc/cups/ssl"}.
14195 @deftypevr {@code{files-configuration} parameter} file-name server-root
14196 Specifies the directory containing the server configuration files.
14198 Defaults to @samp{"/etc/cups"}.
14201 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14202 Specifies whether the scheduler calls fsync(2) after writing
14203 configuration or state files.
14205 Defaults to @samp{#f}.
14208 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14209 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14212 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14213 Specifies the directory where temporary files are stored.
14215 Defaults to @samp{"/var/spool/cups/tmp"}.
14218 @deftypevr {@code{files-configuration} parameter} string user
14219 Specifies the user name or ID that is used when running external
14222 Defaults to @samp{"lp"}.
14226 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14227 Specifies the logging level for the AccessLog file. The @code{config}
14228 level logs when printers and classes are added, deleted, or modified and
14229 when configuration files are accessed or updated. The @code{actions}
14230 level logs when print jobs are submitted, held, released, modified, or
14231 canceled, and any of the conditions for @code{config}. The @code{all}
14232 level logs all requests.
14234 Defaults to @samp{actions}.
14237 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14238 Specifies whether to purge job history data automatically when it is no
14239 longer required for quotas.
14241 Defaults to @samp{#f}.
14244 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14245 Specifies which protocols to use for local printer sharing.
14247 Defaults to @samp{dnssd}.
14250 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14251 Specifies whether the CUPS web interface is advertised.
14253 Defaults to @samp{#f}.
14256 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14257 Specifies whether shared printers are advertised.
14259 Defaults to @samp{#f}.
14262 @deftypevr {@code{cups-configuration} parameter} string classification
14263 Specifies the security classification of the server. Any valid banner
14264 name can be used, including "classified", "confidential", "secret",
14265 "topsecret", and "unclassified", or the banner can be omitted to disable
14266 secure printing functions.
14268 Defaults to @samp{""}.
14271 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14272 Specifies whether users may override the classification (cover page) of
14273 individual print jobs using the @code{job-sheets} option.
14275 Defaults to @samp{#f}.
14278 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14279 Specifies the default type of authentication to use.
14281 Defaults to @samp{Basic}.
14284 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14285 Specifies whether encryption will be used for authenticated requests.
14287 Defaults to @samp{Required}.
14290 @deftypevr {@code{cups-configuration} parameter} string default-language
14291 Specifies the default language to use for text and web content.
14293 Defaults to @samp{"en"}.
14296 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14297 Specifies the default paper size for new print queues. @samp{"Auto"}
14298 uses a locale-specific default, while @samp{"None"} specifies there is
14299 no default paper size. Specific size names are typically
14300 @samp{"Letter"} or @samp{"A4"}.
14302 Defaults to @samp{"Auto"}.
14305 @deftypevr {@code{cups-configuration} parameter} string default-policy
14306 Specifies the default access policy to use.
14308 Defaults to @samp{"default"}.
14311 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14312 Specifies whether local printers are shared by default.
14314 Defaults to @samp{#t}.
14317 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14318 Specifies the delay for updating of configuration and state files, in
14319 seconds. A value of 0 causes the update to happen as soon as possible,
14320 typically within a few milliseconds.
14322 Defaults to @samp{30}.
14325 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14326 Specifies what to do when an error occurs. Possible values are
14327 @code{abort-job}, which will discard the failed print job;
14328 @code{retry-job}, which will retry the job at a later time;
14329 @code{retry-this-job}, which retries the failed job immediately; and
14330 @code{stop-printer}, which stops the printer.
14332 Defaults to @samp{stop-printer}.
14335 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14336 Specifies the maximum cost of filters that are run concurrently, which
14337 can be used to minimize disk, memory, and CPU resource problems. A
14338 limit of 0 disables filter limiting. An average print to a
14339 non-PostScript printer needs a filter limit of about 200. A PostScript
14340 printer needs about half that (100). Setting the limit below these
14341 thresholds will effectively limit the scheduler to printing a single job
14344 Defaults to @samp{0}.
14347 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14348 Specifies the scheduling priority of filters that are run to print a
14349 job. The nice value ranges from 0, the highest priority, to 19, the
14352 Defaults to @samp{0}.
14355 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14356 Specifies whether to do reverse lookups on connecting clients. The
14357 @code{double} setting causes @code{cupsd} to verify that the hostname
14358 resolved from the address matches one of the addresses returned for that
14359 hostname. Double lookups also prevent clients with unregistered
14360 addresses from connecting to your server. Only set this option to
14361 @code{#t} or @code{double} if absolutely required.
14363 Defaults to @samp{#f}.
14366 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14367 Specifies the number of seconds to wait before killing the filters and
14368 backend associated with a canceled or held job.
14370 Defaults to @samp{30}.
14373 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14374 Specifies the interval between retries of jobs in seconds. This is
14375 typically used for fax queues but can also be used with normal print
14376 queues whose error policy is @code{retry-job} or
14377 @code{retry-current-job}.
14379 Defaults to @samp{30}.
14382 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14383 Specifies the number of retries that are done for jobs. This is
14384 typically used for fax queues but can also be used with normal print
14385 queues whose error policy is @code{retry-job} or
14386 @code{retry-current-job}.
14388 Defaults to @samp{5}.
14391 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14392 Specifies whether to support HTTP keep-alive connections.
14394 Defaults to @samp{#t}.
14397 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14398 Specifies how long an idle client connection remains open, in seconds.
14400 Defaults to @samp{30}.
14403 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14404 Specifies the maximum size of print files, IPP requests, and HTML form
14405 data. A limit of 0 disables the limit check.
14407 Defaults to @samp{0}.
14410 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14411 Listens on the specified interfaces for connections. Valid values are
14412 of the form @var{address}:@var{port}, where @var{address} is either an
14413 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14414 indicate all addresses. Values can also be file names of local UNIX
14415 domain sockets. The Listen directive is similar to the Port directive
14416 but allows you to restrict access to specific interfaces or networks.
14419 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14420 Specifies the number of pending connections that will be allowed. This
14421 normally only affects very busy servers that have reached the MaxClients
14422 limit, but can also be triggered by large numbers of simultaneous
14423 connections. When the limit is reached, the operating system will
14424 refuse additional connections until the scheduler can accept the pending
14427 Defaults to @samp{128}.
14430 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14431 Specifies a set of additional access controls.
14433 Available @code{location-access-controls} fields are:
14435 @deftypevr {@code{location-access-controls} parameter} file-name path
14436 Specifies the URI path to which the access control applies.
14439 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14440 Access controls for all access to this path, in the same format as the
14441 @code{access-controls} of @code{operation-access-control}.
14443 Defaults to @samp{()}.
14446 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14447 Access controls for method-specific access to this path.
14449 Defaults to @samp{()}.
14451 Available @code{method-access-controls} fields are:
14453 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14454 If @code{#t}, apply access controls to all methods except the listed
14455 methods. Otherwise apply to only the listed methods.
14457 Defaults to @samp{#f}.
14460 @deftypevr {@code{method-access-controls} parameter} method-list methods
14461 Methods to which this access control applies.
14463 Defaults to @samp{()}.
14466 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14467 Access control directives, as a list of strings. Each string should be
14468 one directive, such as "Order allow,deny".
14470 Defaults to @samp{()}.
14475 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14476 Specifies the number of debugging messages that are retained for logging
14477 if an error occurs in a print job. Debug messages are logged regardless
14478 of the LogLevel setting.
14480 Defaults to @samp{100}.
14483 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14484 Specifies the level of logging for the ErrorLog file. The value
14485 @code{none} stops all logging while @code{debug2} logs everything.
14487 Defaults to @samp{info}.
14490 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14491 Specifies the format of the date and time in the log files. The value
14492 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14494 Defaults to @samp{standard}.
14497 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
14498 Specifies the maximum number of simultaneous clients that are allowed by
14501 Defaults to @samp{100}.
14504 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
14505 Specifies the maximum number of simultaneous clients that are allowed
14506 from a single address.
14508 Defaults to @samp{100}.
14511 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
14512 Specifies the maximum number of copies that a user can print of each
14515 Defaults to @samp{9999}.
14518 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
14519 Specifies the maximum time a job may remain in the @code{indefinite}
14520 hold state before it is canceled. A value of 0 disables cancellation of
14523 Defaults to @samp{0}.
14526 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
14527 Specifies the maximum number of simultaneous jobs that are allowed. Set
14528 to 0 to allow an unlimited number of jobs.
14530 Defaults to @samp{500}.
14533 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
14534 Specifies the maximum number of simultaneous jobs that are allowed per
14535 printer. A value of 0 allows up to MaxJobs jobs per printer.
14537 Defaults to @samp{0}.
14540 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
14541 Specifies the maximum number of simultaneous jobs that are allowed per
14542 user. A value of 0 allows up to MaxJobs jobs per user.
14544 Defaults to @samp{0}.
14547 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
14548 Specifies the maximum time a job may take to print before it is
14549 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
14551 Defaults to @samp{10800}.
14554 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
14555 Specifies the maximum size of the log files before they are rotated, in
14556 bytes. The value 0 disables log rotation.
14558 Defaults to @samp{1048576}.
14561 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
14562 Specifies the maximum amount of time to allow between files in a
14563 multiple file print job, in seconds.
14565 Defaults to @samp{300}.
14568 @deftypevr {@code{cups-configuration} parameter} string page-log-format
14569 Specifies the format of PageLog lines. Sequences beginning with percent
14570 (@samp{%}) characters are replaced with the corresponding information,
14571 while all other characters are copied literally. The following percent
14572 sequences are recognized:
14576 insert a single percent character
14579 insert the value of the specified IPP attribute
14582 insert the number of copies for the current page
14585 insert the current page number
14588 insert the current date and time in common log format
14594 insert the printer name
14597 insert the username
14600 A value of the empty string disables page logging. The string @code{%p
14601 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
14602 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
14605 Defaults to @samp{""}.
14608 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
14609 Passes the specified environment variable(s) to child processes; a list
14612 Defaults to @samp{()}.
14615 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
14616 Specifies named access control policies.
14618 Available @code{policy-configuration} fields are:
14620 @deftypevr {@code{policy-configuration} parameter} string name
14621 Name of the policy.
14624 @deftypevr {@code{policy-configuration} parameter} string job-private-access
14625 Specifies an access list for a job's private values. @code{@@ACL} maps
14626 to the printer's requesting-user-name-allowed or
14627 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14628 owner. @code{@@SYSTEM} maps to the groups listed for the
14629 @code{system-group} field of the @code{files-config} configuration,
14630 which is reified into the @code{cups-files.conf(5)} file. Other
14631 possible elements of the access list include specific user names, and
14632 @code{@@@var{group}} to indicate members of a specific group. The
14633 access list may also be simply @code{all} or @code{default}.
14635 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14638 @deftypevr {@code{policy-configuration} parameter} string job-private-values
14639 Specifies the list of job values to make private, or @code{all},
14640 @code{default}, or @code{none}.
14642 Defaults to @samp{"job-name job-originating-host-name
14643 job-originating-user-name phone"}.
14646 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
14647 Specifies an access list for a subscription's private values.
14648 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
14649 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
14650 owner. @code{@@SYSTEM} maps to the groups listed for the
14651 @code{system-group} field of the @code{files-config} configuration,
14652 which is reified into the @code{cups-files.conf(5)} file. Other
14653 possible elements of the access list include specific user names, and
14654 @code{@@@var{group}} to indicate members of a specific group. The
14655 access list may also be simply @code{all} or @code{default}.
14657 Defaults to @samp{"@@OWNER @@SYSTEM"}.
14660 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
14661 Specifies the list of job values to make private, or @code{all},
14662 @code{default}, or @code{none}.
14664 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
14665 notify-subscriber-user-name notify-user-data"}.
14668 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
14669 Access control by IPP operation.
14671 Defaults to @samp{()}.
14675 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
14676 Specifies whether job files (documents) are preserved after a job is
14677 printed. If a numeric value is specified, job files are preserved for
14678 the indicated number of seconds after printing. Otherwise a boolean
14679 value applies indefinitely.
14681 Defaults to @samp{86400}.
14684 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
14685 Specifies whether the job history is preserved after a job is printed.
14686 If a numeric value is specified, the job history is preserved for the
14687 indicated number of seconds after printing. If @code{#t}, the job
14688 history is preserved until the MaxJobs limit is reached.
14690 Defaults to @samp{#t}.
14693 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
14694 Specifies the amount of time to wait for job completion before
14695 restarting the scheduler.
14697 Defaults to @samp{30}.
14700 @deftypevr {@code{cups-configuration} parameter} string rip-cache
14701 Specifies the maximum amount of memory to use when converting documents
14702 into bitmaps for a printer.
14704 Defaults to @samp{"128m"}.
14707 @deftypevr {@code{cups-configuration} parameter} string server-admin
14708 Specifies the email address of the server administrator.
14710 Defaults to @samp{"root@@localhost.localdomain"}.
14713 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
14714 The ServerAlias directive is used for HTTP Host header validation when
14715 clients connect to the scheduler from external interfaces. Using the
14716 special name @code{*} can expose your system to known browser-based DNS
14717 rebinding attacks, even when accessing sites through a firewall. If the
14718 auto-discovery of alternate names does not work, we recommend listing
14719 each alternate name with a ServerAlias directive instead of using
14722 Defaults to @samp{*}.
14725 @deftypevr {@code{cups-configuration} parameter} string server-name
14726 Specifies the fully-qualified host name of the server.
14728 Defaults to @samp{"localhost"}.
14731 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
14732 Specifies what information is included in the Server header of HTTP
14733 responses. @code{None} disables the Server header. @code{ProductOnly}
14734 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
14735 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
14736 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
14737 the output of the @code{uname} command. @code{Full} reports @code{CUPS
14738 2.0.0 (@var{uname}) IPP/2.0}.
14740 Defaults to @samp{Minimal}.
14743 @deftypevr {@code{cups-configuration} parameter} string set-env
14744 Set the specified environment variable to be passed to child processes.
14746 Defaults to @samp{"variable value"}.
14749 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
14750 Listens on the specified interfaces for encrypted connections. Valid
14751 values are of the form @var{address}:@var{port}, where @var{address} is
14752 either an IPv6 address enclosed in brackets, an IPv4 address, or
14753 @code{*} to indicate all addresses.
14755 Defaults to @samp{()}.
14758 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
14759 Sets encryption options. By default, CUPS only supports encryption
14760 using TLS v1.0 or higher using known secure cipher suites. The
14761 @code{AllowRC4} option enables the 128-bit RC4 cipher suites, which are
14762 required for some older clients that do not implement newer ones. The
14763 @code{AllowSSL3} option enables SSL v3.0, which is required for some
14764 older clients that do not support TLS v1.0.
14766 Defaults to @samp{()}.
14769 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
14770 Specifies whether the scheduler requires clients to strictly adhere to
14771 the IPP specifications.
14773 Defaults to @samp{#f}.
14776 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
14777 Specifies the HTTP request timeout, in seconds.
14779 Defaults to @samp{300}.
14783 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
14784 Specifies whether the web interface is enabled.
14786 Defaults to @samp{#f}.
14789 At this point you're probably thinking ``oh dear, Guix manual, I like
14790 you but you can stop already with the configuration options''. Indeed.
14791 However, one more point: it could be that you have an existing
14792 @code{cupsd.conf} that you want to use. In that case, you can pass an
14793 @code{opaque-cups-configuration} as the configuration of a
14794 @code{cups-service-type}.
14796 Available @code{opaque-cups-configuration} fields are:
14798 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
14802 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
14803 The contents of the @code{cupsd.conf}, as a string.
14806 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
14807 The contents of the @code{cups-files.conf} file, as a string.
14810 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
14811 strings of the same name, you could instantiate a CUPS service like
14815 (service cups-service-type
14816 (opaque-cups-configuration
14817 (cupsd.conf cupsd.conf)
14818 (cups-files.conf cups-files.conf)))
14822 @node Desktop Services
14823 @subsection Desktop Services
14825 The @code{(gnu services desktop)} module provides services that are
14826 usually useful in the context of a ``desktop'' setup---that is, on a
14827 machine running a graphical display server, possibly with graphical user
14828 interfaces, etc. It also defines services that provide specific desktop
14829 environments like GNOME, Xfce or MATE.
14831 To simplify things, the module defines a variable containing the set of
14832 services that users typically expect on a machine with a graphical
14833 environment and networking:
14835 @defvr {Scheme Variable} %desktop-services
14836 This is a list of services that builds upon @code{%base-services} and
14837 adds or adjusts services for a typical ``desktop'' setup.
14839 In particular, it adds a graphical login manager (@pxref{X Window,
14840 @code{gdm-service-type}}), screen lockers, a network management tool
14841 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
14842 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
14843 energy and color management services, the @code{elogind} login and seat
14844 manager, the Polkit privilege service, the GeoClue location service, the
14845 AccountsService daemon that allows authorized users change system passwords,
14846 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
14847 name service switch service configured to be able to use @code{nss-mdns}
14848 (@pxref{Name Service Switch, mDNS}).
14851 The @code{%desktop-services} variable can be used as the @code{services}
14852 field of an @code{operating-system} declaration (@pxref{operating-system
14853 Reference, @code{services}}).
14855 Additionally, the @code{gnome-desktop-service-type},
14856 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
14857 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
14858 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
14859 services like the backlight adjustment helpers and the power management
14860 utilities are added to the system, extending @code{polkit} and @code{dbus}
14861 appropriately, allowing GNOME to operate with elevated privileges on a
14862 limited number of special-purpose system interfaces. Additionally,
14863 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
14864 metapackage to the system profile. Likewise, adding the Xfce service
14865 not only adds the @code{xfce} metapackage to the system profile, but it
14866 also gives the Thunar file manager the ability to open a ``root-mode''
14867 file management window, if the user authenticates using the
14868 administrator's password via the standard polkit graphical interface.
14869 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
14870 appropriately, allowing MATE to operate with elevated privileges on a
14871 limited number of special-purpose system interfaces. Additionally,
14872 adding a service of type @code{mate-desktop-service-type} adds the MATE
14873 metapackage to the system profile. ``Adding Enlightenment'' means that
14874 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
14875 are set as setuid, allowing Enlightenment's screen locker and other
14876 functionality to work as expetected.
14878 The desktop environments in Guix use the Xorg display server by
14879 default. If you'd like to use the newer display server protocol
14880 called Wayland, you need to use the @code{sddm-service} instead of
14881 GDM as the graphical login manager. You should then
14882 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
14883 also try starting GNOME on Wayland manually from a TTY with the
14884 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
14885 gnome-session``. Currently only GNOME has support for Wayland.
14887 @defvr {Scheme Variable} gnome-desktop-service-type
14888 This is the type of the service that adds the @uref{https://www.gnome.org,
14889 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
14890 object (see below.)
14892 This service adds the @code{gnome} package to the system profile, and extends
14893 polkit with the actions from @code{gnome-settings-daemon}.
14896 @deftp {Data Type} gnome-desktop-configuration
14897 Configuration record for the GNOME desktop environment.
14900 @item @code{gnome} (default: @code{gnome})
14901 The GNOME package to use.
14905 @defvr {Scheme Variable} xfce-desktop-service-type
14906 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
14907 desktop environment. Its value is an @code{xfce-desktop-configuration} object
14910 This service adds the @code{xfce} package to the system profile, and
14911 extends polkit with the ability for @code{thunar} to manipulate the file
14912 system as root from within a user session, after the user has authenticated
14913 with the administrator's password.
14916 @deftp {Data Type} xfce-desktop-configuration
14917 Configuration record for the Xfce desktop environment.
14920 @item @code{xfce} (default: @code{xfce})
14921 The Xfce package to use.
14925 @deffn {Scheme Variable} mate-desktop-service-type
14926 This is the type of the service that runs the @uref{https://mate-desktop.org/,
14927 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
14928 object (see below.)
14930 This service adds the @code{mate} package to the system
14931 profile, and extends polkit with the actions from
14932 @code{mate-settings-daemon}.
14935 @deftp {Data Type} mate-desktop-configuration
14936 Configuration record for the MATE desktop environment.
14939 @item @code{mate} (default: @code{mate})
14940 The MATE package to use.
14944 @deffn {Scheme Variable} enlightenment-desktop-service-type
14945 Return a service that adds the @code{enlightenment} package to the system
14946 profile, and extends dbus with actions from @code{efl}.
14949 @deftp {Data Type} enlightenment-desktop-service-configuration
14951 @item @code{enlightenment} (default: @code{enlightenment})
14952 The enlightenment package to use.
14956 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
14957 the default @code{%desktop-services} variable doesn't include any of
14958 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
14959 @code{%desktop-services} in the @code{services} field of your
14960 @code{operating-system}:
14963 (use-modules (gnu))
14964 (use-service-modules desktop)
14967 ;; cons* adds items to the list given as its last argument.
14968 (services (cons* (service gnome-desktop-service-type)
14969 (service xfce-desktop-service)
14970 %desktop-services))
14974 These desktop environments will then be available as options in the
14975 graphical login window.
14977 The actual service definitions included in @code{%desktop-services} and
14978 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
14979 are described below.
14981 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
14982 Return a service that runs the ``system bus'', using @var{dbus}, with
14983 support for @var{services}.
14985 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
14986 facility. Its system bus is used to allow system services to communicate
14987 and to be notified of system-wide events.
14989 @var{services} must be a list of packages that provide an
14990 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
14991 and policy files. For example, to allow avahi-daemon to use the system bus,
14992 @var{services} must be equal to @code{(list avahi)}.
14995 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
14996 Return a service that runs the @code{elogind} login and
14997 seat management daemon. @uref{https://github.com/elogind/elogind,
14998 Elogind} exposes a D-Bus interface that can be used to know which users
14999 are logged in, know what kind of sessions they have open, suspend the
15000 system, inhibit system suspend, reboot the system, and other tasks.
15002 Elogind handles most system-level power events for a computer, for
15003 example suspending the system when a lid is closed, or shutting it down
15004 when the power button is pressed.
15006 The @var{config} keyword argument specifies the configuration for
15007 elogind, and should be the result of an @code{(elogind-configuration
15008 (@var{parameter} @var{value})...)} invocation. Available parameters and
15009 their default values are:
15012 @item kill-user-processes?
15014 @item kill-only-users
15016 @item kill-exclude-users
15018 @item inhibit-delay-max-seconds
15020 @item handle-power-key
15022 @item handle-suspend-key
15024 @item handle-hibernate-key
15026 @item handle-lid-switch
15028 @item handle-lid-switch-docked
15030 @item power-key-ignore-inhibited?
15032 @item suspend-key-ignore-inhibited?
15034 @item hibernate-key-ignore-inhibited?
15036 @item lid-switch-ignore-inhibited?
15038 @item holdoff-timeout-seconds
15042 @item idle-action-seconds
15044 @item runtime-directory-size-percent
15046 @item runtime-directory-size
15050 @item suspend-state
15051 @code{("mem" "standby" "freeze")}
15054 @item hibernate-state
15056 @item hibernate-mode
15057 @code{("platform" "shutdown")}
15058 @item hybrid-sleep-state
15060 @item hybrid-sleep-mode
15061 @code{("suspend" "platform" "shutdown")}
15065 @deffn {Scheme Procedure} accountsservice-service @
15066 [#:accountsservice @var{accountsservice}]
15067 Return a service that runs AccountsService, a system service that can
15068 list available accounts, change their passwords, and so on.
15069 AccountsService integrates with PolicyKit to enable unprivileged users
15070 to acquire the capability to modify their system configuration.
15071 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15072 accountsservice web site} for more information.
15074 The @var{accountsservice} keyword argument is the @code{accountsservice}
15075 package to expose as a service.
15078 @deffn {Scheme Procedure} polkit-service @
15079 [#:polkit @var{polkit}]
15080 Return a service that runs the
15081 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15082 management service}, which allows system administrators to grant access to
15083 privileged operations in a structured way. By querying the Polkit service, a
15084 privileged system component can know when it should grant additional
15085 capabilities to ordinary users. For example, an ordinary user can be granted
15086 the capability to suspend the system if the user is logged in locally.
15089 @defvr {Scheme Variable} upower-service-type
15090 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15091 system-wide monitor for power consumption and battery levels, with the given
15092 configuration settings.
15094 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15095 notably used by GNOME.
15098 @deftp {Data Type} upower-configuration
15099 Data type representation the configuration for UPower.
15103 @item @code{upower} (default: @var{upower})
15104 Package to use for @code{upower}.
15106 @item @code{watts-up-pro?} (default: @code{#f})
15107 Enable the Watts Up Pro device.
15109 @item @code{poll-batteries?} (default: @code{#t})
15110 Enable polling the kernel for battery level changes.
15112 @item @code{ignore-lid?} (default: @code{#f})
15113 Ignore the lid state, this can be useful if it's incorrect on a device.
15115 @item @code{use-percentage-for-policy?} (default: @code{#f})
15116 Whether battery percentage based policy should be used. The default is to use
15117 the time left, change to @code{#t} to use the percentage.
15119 @item @code{percentage-low} (default: @code{10})
15120 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15121 at which the battery is considered low.
15123 @item @code{percentage-critical} (default: @code{3})
15124 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15125 at which the battery is considered critical.
15127 @item @code{percentage-action} (default: @code{2})
15128 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15129 at which action will be taken.
15131 @item @code{time-low} (default: @code{1200})
15132 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15133 seconds at which the battery is considered low.
15135 @item @code{time-critical} (default: @code{300})
15136 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15137 seconds at which the battery is considered critical.
15139 @item @code{time-action} (default: @code{120})
15140 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15141 seconds at which action will be taken.
15143 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15144 The action taken when @code{percentage-action} or @code{time-action} is
15145 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15147 Possible values are:
15157 @code{'hybrid-sleep}.
15163 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15164 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15165 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15166 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15167 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15170 @deffn {Scheme Procedure} colord-service [#:colord @var{colord}]
15171 Return a service that runs @command{colord}, a system service with a D-Bus
15172 interface to manage the color profiles of input and output devices such as
15173 screens and scanners. It is notably used by the GNOME Color Manager graphical
15174 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15175 site} for more information.
15178 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15179 Return a configuration allowing an application to access GeoClue
15180 location data. @var{name} is the Desktop ID of the application, without
15181 the @code{.desktop} part. If @var{allowed?} is true, the application
15182 will have access to location information by default. The boolean
15183 @var{system?} value indicates whether an application is a system component
15184 or not. Finally @var{users} is a list of UIDs of all users for which
15185 this application is allowed location info access. An empty users list
15186 means that all users are allowed.
15189 @defvr {Scheme Variable} %standard-geoclue-applications
15190 The standard list of well-known GeoClue application configurations,
15191 granting authority to the GNOME date-and-time utility to ask for the
15192 current location in order to set the time zone, and allowing the
15193 IceCat and Epiphany web browsers to request location information.
15194 IceCat and Epiphany both query the user before allowing a web page to
15195 know the user's location.
15198 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15199 [#:whitelist '()] @
15200 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15201 [#:submit-data? #f]
15202 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15203 [#:submission-nick "geoclue"] @
15204 [#:applications %standard-geoclue-applications]
15205 Return a service that runs the GeoClue location service. This service
15206 provides a D-Bus interface to allow applications to request access to a
15207 user's physical location, and optionally to add information to online
15208 location databases. See
15209 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15210 web site} for more information.
15213 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15214 [@w{#:auto-enable? #f}]
15215 Return a service that runs the @command{bluetoothd} daemon, which
15216 manages all the Bluetooth devices and provides a number of D-Bus
15217 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15218 powered automatically at boot, which can be useful when using a
15219 bluetooth keyboard or mouse.
15221 Users need to be in the @code{lp} group to access the D-Bus service.
15224 @node Sound Services
15225 @subsection Sound Services
15227 @cindex sound support
15229 @cindex PulseAudio, sound support
15231 The @code{(gnu services sound)} module provides a service to configure the
15232 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15233 preferred ALSA output driver.
15235 @deffn {Scheme Variable} alsa-service-type
15236 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15237 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15238 configuration file. The value for this type is a @command{alsa-configuration}
15239 record as in this example:
15242 (service alsa-service-type)
15245 See below for details about @code{alsa-configuration}.
15248 @deftp {Data Type} alsa-configuration
15249 Data type representing the configuration for @code{alsa-service}.
15252 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15253 @code{alsa-plugins} package to use.
15255 @item @code{pulseaudio?} (default: @var{#t})
15256 Whether ALSA applications should transparently be made to use the
15257 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15259 Using PulseAudio allows you to run several sound-producing applications
15260 at the same time and to individual control them @i{via}
15261 @command{pavucontrol}, among other things.
15263 @item @code{extra-options} (default: @var{""})
15264 String to append to the @file{/etc/asound.conf} file.
15269 Individual users who want to override the system configuration of ALSA can do
15270 it with the @file{~/.asoundrc} file:
15273 # In guix, we have to specify the absolute path for plugins.
15275 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15278 # Routing ALSA to jack:
15279 # <http://jackaudio.org/faq/routing_alsa.html>.
15283 0 system:playback_1
15284 1 system:playback_2
15301 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15305 @node Database Services
15306 @subsection Database Services
15310 The @code{(gnu services databases)} module provides the following services.
15312 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15313 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15314 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15315 Return a service that runs @var{postgresql}, the PostgreSQL database
15318 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15319 creates a database cluster with @var{locale} as the default
15320 locale, stored in @var{data-directory}. It then listens on @var{port}.
15322 @cindex postgresql extension-packages
15323 Additional extensions are loaded from packages listed in
15324 @var{extension-packages}. Extensions are available at runtime. For instance,
15325 to create a geographic database using the @code{postgis} extension, a user can
15326 configure the postgresql-service as in this example:
15330 (use-package-modules databases geo)
15334 ;; postgresql is required to run `psql' but postgis is not required for
15335 ;; proper operation.
15336 (packages (cons* postgresql %base-packages))
15339 (postgresql-service #:extension-packages (list postgis))
15343 Then the extension becomes visible and you can initialise an empty geographic
15344 database in this way:
15348 > create database postgistest;
15349 > \connect postgistest;
15350 > create extension postgis;
15351 > create extension postgis_topology;
15354 There is no need to add this field for contrib extensions such as hstore or
15355 dblink as they are already loadable by postgresql. This field is only
15356 required to add extensions provided by other packages.
15359 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15360 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15363 The optional @var{config} argument specifies the configuration for
15364 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15367 @deftp {Data Type} mysql-configuration
15368 Data type representing the configuration of @var{mysql-service}.
15371 @item @code{mysql} (default: @var{mariadb})
15372 Package object of the MySQL database server, can be either @var{mariadb}
15375 For MySQL, a temporary root password will be displayed at activation time.
15376 For MariaDB, the root password is empty.
15378 @item @code{port} (default: @code{3306})
15379 TCP port on which the database server listens for incoming connections.
15383 @defvr {Scheme Variable} memcached-service-type
15384 This is the service type for the @uref{https://memcached.org/,
15385 Memcached} service, which provides a distributed in memory cache. The
15386 value for the service type is a @code{memcached-configuration} object.
15390 (service memcached-service-type)
15393 @deftp {Data Type} memcached-configuration
15394 Data type representing the configuration of memcached.
15397 @item @code{memcached} (default: @code{memcached})
15398 The Memcached package to use.
15400 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15401 Network interfaces on which to listen.
15403 @item @code{tcp-port} (default: @code{11211})
15404 Port on which to accept connections on,
15406 @item @code{udp-port} (default: @code{11211})
15407 Port on which to accept UDP connections on, a value of 0 will disable
15408 listening on a UDP socket.
15410 @item @code{additional-options} (default: @code{'()})
15411 Additional command line options to pass to @code{memcached}.
15415 @defvr {Scheme Variable} mongodb-service-type
15416 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15417 The value for the service type is a @code{mongodb-configuration} object.
15421 (service mongodb-service-type)
15424 @deftp {Data Type} mongodb-configuration
15425 Data type representing the configuration of mongodb.
15428 @item @code{mongodb} (default: @code{mongodb})
15429 The MongoDB package to use.
15431 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15432 The configuration file for MongoDB.
15434 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15435 This value is used to create the directory, so that it exists and is
15436 owned by the mongodb user. It should match the data-directory which
15437 MongoDB is configured to use through the configuration file.
15441 @defvr {Scheme Variable} redis-service-type
15442 This is the service type for the @uref{https://redis.io/, Redis}
15443 key/value store, whose value is a @code{redis-configuration} object.
15446 @deftp {Data Type} redis-configuration
15447 Data type representing the configuration of redis.
15450 @item @code{redis} (default: @code{redis})
15451 The Redis package to use.
15453 @item @code{bind} (default: @code{"127.0.0.1"})
15454 Network interface on which to listen.
15456 @item @code{port} (default: @code{6379})
15457 Port on which to accept connections on, a value of 0 will disable
15458 listening on a TCP socket.
15460 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15461 Directory in which to store the database and related files.
15465 @node Mail Services
15466 @subsection Mail Services
15470 The @code{(gnu services mail)} module provides Guix service definitions
15471 for email services: IMAP, POP3, and LMTP servers, as well as mail
15472 transport agents (MTAs). Lots of acronyms! These services are detailed
15473 in the subsections below.
15475 @subsubheading Dovecot Service
15477 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15478 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15481 By default, Dovecot does not need much configuration; the default
15482 configuration object created by @code{(dovecot-configuration)} will
15483 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15484 certificate will be generated for TLS-protected connections, though
15485 Dovecot will also listen on cleartext ports by default. There are a
15486 number of options, though, which mail administrators might need to change,
15487 and as is the case with other services, Guix allows the system
15488 administrator to specify these parameters via a uniform Scheme interface.
15490 For example, to specify that mail is located at @code{maildir~/.mail},
15491 one would instantiate the Dovecot service like this:
15494 (dovecot-service #:config
15495 (dovecot-configuration
15496 (mail-location "maildir:~/.mail")))
15499 The available configuration parameters follow. Each parameter
15500 definition is preceded by its type; for example, @samp{string-list foo}
15501 indicates that the @code{foo} parameter should be specified as a list of
15502 strings. There is also a way to specify the configuration as a string,
15503 if you have an old @code{dovecot.conf} file that you want to port over
15504 from some other system; see the end for more details.
15506 @c The following documentation was initially generated by
15507 @c (generate-documentation) in (gnu services mail). Manually maintained
15508 @c documentation is better, so we shouldn't hesitate to edit below as
15509 @c needed. However if the change you want to make to this documentation
15510 @c can be done in an automated way, it's probably easier to change
15511 @c (generate-documentation) than to make it below and have to deal with
15512 @c the churn as dovecot updates.
15514 Available @code{dovecot-configuration} fields are:
15516 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
15517 The dovecot package.
15520 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
15521 A list of IPs or hosts where to listen for connections. @samp{*}
15522 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
15523 interfaces. If you want to specify non-default ports or anything more
15524 complex, customize the address and port fields of the
15525 @samp{inet-listener} of the specific services you are interested in.
15528 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
15529 List of protocols we want to serve. Available protocols include
15530 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
15532 Available @code{protocol-configuration} fields are:
15534 @deftypevr {@code{protocol-configuration} parameter} string name
15535 The name of the protocol.
15538 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
15539 UNIX socket path to the master authentication server to find users.
15540 This is used by imap (for shared users) and lda.
15541 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
15544 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
15545 Space separated list of plugins to load.
15548 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
15549 Maximum number of IMAP connections allowed for a user from each IP
15550 address. NOTE: The username is compared case-sensitively.
15551 Defaults to @samp{10}.
15556 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
15557 List of services to enable. Available services include @samp{imap},
15558 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
15561 Available @code{service-configuration} fields are:
15563 @deftypevr {@code{service-configuration} parameter} string kind
15564 The service kind. Valid values include @code{director},
15565 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
15566 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
15567 @code{tcpwrap}, @code{quota-warning}, or anything else.
15570 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
15571 Listeners for the service. A listener is either a
15572 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
15573 an @code{inet-listener-configuration}.
15574 Defaults to @samp{()}.
15576 Available @code{unix-listener-configuration} fields are:
15578 @deftypevr {@code{unix-listener-configuration} parameter} string path
15579 Path to the file, relative to @code{base-dir} field. This is also used as
15583 @deftypevr {@code{unix-listener-configuration} parameter} string mode
15584 The access mode for the socket.
15585 Defaults to @samp{"0600"}.
15588 @deftypevr {@code{unix-listener-configuration} parameter} string user
15589 The user to own the socket.
15590 Defaults to @samp{""}.
15593 @deftypevr {@code{unix-listener-configuration} parameter} string group
15594 The group to own the socket.
15595 Defaults to @samp{""}.
15599 Available @code{fifo-listener-configuration} fields are:
15601 @deftypevr {@code{fifo-listener-configuration} parameter} string path
15602 Path to the file, relative to @code{base-dir} field. This is also used as
15606 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
15607 The access mode for the socket.
15608 Defaults to @samp{"0600"}.
15611 @deftypevr {@code{fifo-listener-configuration} parameter} string user
15612 The user to own the socket.
15613 Defaults to @samp{""}.
15616 @deftypevr {@code{fifo-listener-configuration} parameter} string group
15617 The group to own the socket.
15618 Defaults to @samp{""}.
15622 Available @code{inet-listener-configuration} fields are:
15624 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
15625 The protocol to listen for.
15628 @deftypevr {@code{inet-listener-configuration} parameter} string address
15629 The address on which to listen, or empty for all addresses.
15630 Defaults to @samp{""}.
15633 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
15634 The port on which to listen.
15637 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
15638 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
15640 Defaults to @samp{#t}.
15645 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
15646 Maximum number of simultaneous client connections per process. Once
15647 this number of connections is received, the next incoming connection
15648 will prompt Dovecot to spawn another process. If set to 0,
15649 @code{default-client-limit} is used instead.
15651 Defaults to @samp{0}.
15655 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
15656 Number of connections to handle before starting a new process.
15657 Typically the only useful values are 0 (unlimited) or 1. 1 is more
15658 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
15659 Defaults to @samp{1}.
15663 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
15664 Maximum number of processes that can exist for this service. If set to
15665 0, @code{default-process-limit} is used instead.
15667 Defaults to @samp{0}.
15671 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
15672 Number of processes to always keep waiting for more connections.
15673 Defaults to @samp{0}.
15676 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
15677 If you set @samp{service-count 0}, you probably need to grow
15679 Defaults to @samp{256000000}.
15684 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
15685 Dict configuration, as created by the @code{dict-configuration}
15688 Available @code{dict-configuration} fields are:
15690 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
15691 A list of key-value pairs that this dict should hold.
15692 Defaults to @samp{()}.
15697 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
15698 A list of passdb configurations, each one created by the
15699 @code{passdb-configuration} constructor.
15701 Available @code{passdb-configuration} fields are:
15703 @deftypevr {@code{passdb-configuration} parameter} string driver
15704 The driver that the passdb should use. Valid values include
15705 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
15707 Defaults to @samp{"pam"}.
15710 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
15711 Space separated list of arguments to the passdb driver.
15712 Defaults to @samp{""}.
15717 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
15718 List of userdb configurations, each one created by the
15719 @code{userdb-configuration} constructor.
15721 Available @code{userdb-configuration} fields are:
15723 @deftypevr {@code{userdb-configuration} parameter} string driver
15724 The driver that the userdb should use. Valid values include
15725 @samp{passwd} and @samp{static}.
15726 Defaults to @samp{"passwd"}.
15729 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
15730 Space separated list of arguments to the userdb driver.
15731 Defaults to @samp{""}.
15734 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
15735 Override fields from passwd.
15736 Defaults to @samp{()}.
15741 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
15742 Plug-in configuration, created by the @code{plugin-configuration}
15746 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
15747 List of namespaces. Each item in the list is created by the
15748 @code{namespace-configuration} constructor.
15750 Available @code{namespace-configuration} fields are:
15752 @deftypevr {@code{namespace-configuration} parameter} string name
15753 Name for this namespace.
15756 @deftypevr {@code{namespace-configuration} parameter} string type
15757 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
15758 Defaults to @samp{"private"}.
15761 @deftypevr {@code{namespace-configuration} parameter} string separator
15762 Hierarchy separator to use. You should use the same separator for
15763 all namespaces or some clients get confused. @samp{/} is usually a good
15764 one. The default however depends on the underlying mail storage
15766 Defaults to @samp{""}.
15769 @deftypevr {@code{namespace-configuration} parameter} string prefix
15770 Prefix required to access this namespace. This needs to be
15771 different for all namespaces. For example @samp{Public/}.
15772 Defaults to @samp{""}.
15775 @deftypevr {@code{namespace-configuration} parameter} string location
15776 Physical location of the mailbox. This is in the same format as
15777 mail_location, which is also the default for it.
15778 Defaults to @samp{""}.
15781 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
15782 There can be only one INBOX, and this setting defines which
15784 Defaults to @samp{#f}.
15787 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
15788 If namespace is hidden, it's not advertised to clients via NAMESPACE
15789 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
15790 useful when converting from another server with different namespaces
15791 which you want to deprecate but still keep working. For example you can
15792 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
15794 Defaults to @samp{#f}.
15797 @deftypevr {@code{namespace-configuration} parameter} boolean list?
15798 Show the mailboxes under this namespace with the LIST command. This
15799 makes the namespace visible for clients that do not support the NAMESPACE
15800 extension. The special @code{children} value lists child mailboxes, but
15801 hides the namespace prefix.
15802 Defaults to @samp{#t}.
15805 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
15806 Namespace handles its own subscriptions. If set to @code{#f}, the
15807 parent namespace handles them. The empty prefix should always have this
15809 Defaults to @samp{#t}.
15812 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
15813 List of predefined mailboxes in this namespace.
15814 Defaults to @samp{()}.
15816 Available @code{mailbox-configuration} fields are:
15818 @deftypevr {@code{mailbox-configuration} parameter} string name
15819 Name for this mailbox.
15822 @deftypevr {@code{mailbox-configuration} parameter} string auto
15823 @samp{create} will automatically create this mailbox.
15824 @samp{subscribe} will both create and subscribe to the mailbox.
15825 Defaults to @samp{"no"}.
15828 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
15829 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
15830 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
15831 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
15832 Defaults to @samp{()}.
15839 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
15840 Base directory where to store runtime data.
15841 Defaults to @samp{"/var/run/dovecot/"}.
15844 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
15845 Greeting message for clients.
15846 Defaults to @samp{"Dovecot ready."}.
15849 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
15850 List of trusted network ranges. Connections from these IPs are
15851 allowed to override their IP addresses and ports (for logging and for
15852 authentication checks). @samp{disable-plaintext-auth} is also ignored
15853 for these networks. Typically you would specify your IMAP proxy servers
15855 Defaults to @samp{()}.
15858 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
15859 List of login access check sockets (e.g.@: tcpwrap).
15860 Defaults to @samp{()}.
15863 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
15864 Show more verbose process titles (in ps). Currently shows user name
15865 and IP address. Useful for seeing who is actually using the IMAP
15866 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
15868 Defaults to @samp{#f}.
15871 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
15872 Should all processes be killed when Dovecot master process shuts down.
15873 Setting this to @code{#f} means that Dovecot can be upgraded without
15874 forcing existing client connections to close (although that could also
15875 be a problem if the upgrade is e.g.@: due to a security fix).
15876 Defaults to @samp{#t}.
15879 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
15880 If non-zero, run mail commands via this many connections to doveadm
15881 server, instead of running them directly in the same process.
15882 Defaults to @samp{0}.
15885 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
15886 UNIX socket or host:port used for connecting to doveadm server.
15887 Defaults to @samp{"doveadm-server"}.
15890 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
15891 List of environment variables that are preserved on Dovecot startup
15892 and passed down to all of its child processes. You can also give
15893 key=value pairs to always set specific settings.
15896 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
15897 Disable LOGIN command and all other plaintext authentications unless
15898 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
15899 matches the local IP (i.e.@: you're connecting from the same computer),
15900 the connection is considered secure and plaintext authentication is
15901 allowed. See also ssl=required setting.
15902 Defaults to @samp{#t}.
15905 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
15906 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
15907 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
15908 for caching to be used.
15909 Defaults to @samp{0}.
15912 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
15913 Time to live for cached data. After TTL expires the cached record
15914 is no longer used, *except* if the main database lookup returns internal
15915 failure. We also try to handle password changes automatically: If
15916 user's previous authentication was successful, but this one wasn't, the
15917 cache isn't used. For now this works only with plaintext
15919 Defaults to @samp{"1 hour"}.
15922 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
15923 TTL for negative hits (user not found, password mismatch).
15924 0 disables caching them completely.
15925 Defaults to @samp{"1 hour"}.
15928 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
15929 List of realms for SASL authentication mechanisms that need them.
15930 You can leave it empty if you don't want to support multiple realms.
15931 Many clients simply use the first one listed here, so keep the default
15933 Defaults to @samp{()}.
15936 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
15937 Default realm/domain to use if none was specified. This is used for
15938 both SASL realms and appending @@domain to username in plaintext
15940 Defaults to @samp{""}.
15943 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
15944 List of allowed characters in username. If the user-given username
15945 contains a character not listed in here, the login automatically fails.
15946 This is just an extra check to make sure user can't exploit any
15947 potential quote escaping vulnerabilities with SQL/LDAP databases. If
15948 you want to allow all characters, set this value to empty.
15949 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
15952 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
15953 Username character translations before it's looked up from
15954 databases. The value contains series of from -> to characters. For
15955 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
15956 translated to @samp{@@}.
15957 Defaults to @samp{""}.
15960 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
15961 Username formatting before it's looked up from databases. You can
15962 use the standard variables here, e.g.@: %Lu would lowercase the username,
15963 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
15964 change the @samp{@@} into @samp{-AT-}. This translation is done after
15965 @samp{auth-username-translation} changes.
15966 Defaults to @samp{"%Lu"}.
15969 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
15970 If you want to allow master users to log in by specifying the master
15971 username within the normal username string (i.e.@: not using SASL
15972 mechanism's support for it), you can specify the separator character
15973 here. The format is then <username><separator><master username>.
15974 UW-IMAP uses @samp{*} as the separator, so that could be a good
15976 Defaults to @samp{""}.
15979 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
15980 Username to use for users logging in with ANONYMOUS SASL
15982 Defaults to @samp{"anonymous"}.
15985 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
15986 Maximum number of dovecot-auth worker processes. They're used to
15987 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
15988 They're automatically created and destroyed as needed.
15989 Defaults to @samp{30}.
15992 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
15993 Host name to use in GSSAPI principal names. The default is to use
15994 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
15995 allow all keytab entries.
15996 Defaults to @samp{""}.
15999 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16000 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16001 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16002 need to change the auth service to run as root to be able to read this
16004 Defaults to @samp{""}.
16007 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16008 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16009 and @samp{ntlm-auth} helper.
16010 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16011 Defaults to @samp{#f}.
16014 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16015 Path for Samba's @samp{ntlm-auth} helper binary.
16016 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16019 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16020 Time to delay before replying to failed authentications.
16021 Defaults to @samp{"2 secs"}.
16024 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16025 Require a valid SSL client certificate or the authentication
16027 Defaults to @samp{#f}.
16030 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16031 Take the username from client's SSL certificate, using
16032 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16034 Defaults to @samp{#f}.
16037 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16038 List of wanted authentication mechanisms. Supported mechanisms are:
16039 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16040 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16041 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16042 @samp{disable-plaintext-auth} setting.
16045 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16046 List of IPs or hostnames to all director servers, including ourself.
16047 Ports can be specified as ip:port. The default port is the same as what
16048 director service's @samp{inet-listener} is using.
16049 Defaults to @samp{()}.
16052 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16053 List of IPs or hostnames to all backend mail servers. Ranges are
16054 allowed too, like 10.0.0.10-10.0.0.30.
16055 Defaults to @samp{()}.
16058 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16059 How long to redirect users to a specific server after it no longer
16060 has any connections.
16061 Defaults to @samp{"15 min"}.
16064 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16065 How the username is translated before being hashed. Useful values
16066 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16067 are shared within domain.
16068 Defaults to @samp{"%Lu"}.
16071 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16072 Log file to use for error messages. @samp{syslog} logs to syslog,
16073 @samp{/dev/stderr} logs to stderr.
16074 Defaults to @samp{"syslog"}.
16077 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16078 Log file to use for informational messages. Defaults to
16080 Defaults to @samp{""}.
16083 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16084 Log file to use for debug messages. Defaults to
16085 @samp{info-log-path}.
16086 Defaults to @samp{""}.
16089 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16090 Syslog facility to use if you're logging to syslog. Usually if you
16091 don't want to use @samp{mail}, you'll use local0..local7. Also other
16092 standard facilities are supported.
16093 Defaults to @samp{"mail"}.
16096 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16097 Log unsuccessful authentication attempts and the reasons why they
16099 Defaults to @samp{#f}.
16102 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16103 In case of password mismatches, log the attempted password. Valid
16104 values are no, plain and sha1. sha1 can be useful for detecting brute
16105 force password attempts vs. user simply trying the same password over
16106 and over again. You can also truncate the value to n chars by appending
16107 ":n" (e.g.@: sha1:6).
16108 Defaults to @samp{"no"}.
16111 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16112 Even more verbose logging for debugging purposes. Shows for example
16114 Defaults to @samp{#f}.
16117 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16118 In case of password mismatches, log the passwords and used scheme so
16119 the problem can be debugged. Enabling this also enables
16121 Defaults to @samp{#f}.
16124 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16125 Enable mail process debugging. This can help you figure out why
16126 Dovecot isn't finding your mails.
16127 Defaults to @samp{#f}.
16130 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16131 Show protocol level SSL errors.
16132 Defaults to @samp{#f}.
16135 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16136 Prefix for each line written to log file. % codes are in
16137 strftime(3) format.
16138 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16141 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16142 List of elements we want to log. The elements which have a
16143 non-empty variable value are joined together to form a comma-separated
16147 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16148 Login log format. %s contains @samp{login-log-format-elements}
16149 string, %$ contains the data we want to log.
16150 Defaults to @samp{"%$: %s"}.
16153 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16154 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16155 of possible variables you can use.
16156 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16159 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16160 Format to use for logging mail deliveries. You can use variables:
16163 Delivery status message (e.g.@: @samp{saved to INBOX})
16175 Defaults to @samp{"msgid=%m: %$"}.
16178 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16179 Location for users' mailboxes. The default is empty, which means
16180 that Dovecot tries to find the mailboxes automatically. This won't work
16181 if the user doesn't yet have any mail, so you should explicitly tell
16182 Dovecot the full location.
16184 If you're using mbox, giving a path to the INBOX
16185 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16186 where the other mailboxes are kept. This is called the "root mail
16187 directory", and it must be the first path given in the
16188 @samp{mail-location} setting.
16190 There are a few special variables you can use, eg.:
16196 user part in user@@domain, same as %u if there's no domain
16198 domain part in user@@domain, empty if there's no domain
16203 See doc/wiki/Variables.txt for full list. Some examples:
16205 @item maildir:~/Maildir
16206 @item mbox:~/mail:INBOX=/var/mail/%u
16207 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16209 Defaults to @samp{""}.
16212 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16213 System user and group used to access mails. If you use multiple,
16214 userdb can override these by returning uid or gid fields. You can use
16215 either numbers or names. <doc/wiki/UserIds.txt>.
16216 Defaults to @samp{""}.
16219 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16221 Defaults to @samp{""}.
16224 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16225 Group to enable temporarily for privileged operations. Currently
16226 this is used only with INBOX when either its initial creation or
16227 dotlocking fails. Typically this is set to "mail" to give access to
16229 Defaults to @samp{""}.
16232 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16233 Grant access to these supplementary groups for mail processes.
16234 Typically these are used to set up access to shared mailboxes. Note
16235 that it may be dangerous to set these if users can create
16236 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16237 could allow a user to delete others' mailboxes, or ln -s
16238 /secret/shared/box ~/mail/mybox would allow reading it).
16239 Defaults to @samp{""}.
16242 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16243 Allow full file system access to clients. There's no access checks
16244 other than what the operating system does for the active UID/GID. It
16245 works with both maildir and mboxes, allowing you to prefix mailboxes
16246 names with e.g.@: /path/ or ~user/.
16247 Defaults to @samp{#f}.
16250 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16251 Don't use mmap() at all. This is required if you store indexes to
16252 shared file systems (NFS or clustered file system).
16253 Defaults to @samp{#f}.
16256 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16257 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16258 supports @samp{O_EXCL} since version 3, so this should be safe to use
16259 nowadays by default.
16260 Defaults to @samp{#t}.
16263 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16264 When to use fsync() or fdatasync() calls:
16267 Whenever necessary to avoid losing important data
16269 Useful with e.g.@: NFS when write()s are delayed
16271 Never use it (best performance, but crashes can lose data).
16273 Defaults to @samp{"optimized"}.
16276 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16277 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16278 NFS caches whenever needed. If you're using only a single mail server
16280 Defaults to @samp{#f}.
16283 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16284 Mail index files also exist in NFS. Setting this to yes requires
16285 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16286 Defaults to @samp{#f}.
16289 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16290 Locking method for index files. Alternatives are fcntl, flock and
16291 dotlock. Dotlocking uses some tricks which may create more disk I/O
16292 than other locking methods. NFS users: flock doesn't work, remember to
16293 change @samp{mmap-disable}.
16294 Defaults to @samp{"fcntl"}.
16297 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16298 Directory in which LDA/LMTP temporarily stores incoming mails >128
16300 Defaults to @samp{"/tmp"}.
16303 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16304 Valid UID range for users. This is mostly to make sure that users can't
16305 log in as daemons or other system users. Note that denying root logins is
16306 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16308 Defaults to @samp{500}.
16311 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16313 Defaults to @samp{0}.
16316 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16317 Valid GID range for users. Users having non-valid GID as primary group ID
16318 aren't allowed to log in. If user belongs to supplementary groups with
16319 non-valid GIDs, those groups are not set.
16320 Defaults to @samp{1}.
16323 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16325 Defaults to @samp{0}.
16328 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16329 Maximum allowed length for mail keyword name. It's only forced when
16330 trying to create new keywords.
16331 Defaults to @samp{50}.
16334 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16335 List of directories under which chrooting is allowed for mail
16336 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16337 too). This setting doesn't affect @samp{login-chroot}
16338 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16339 "/./" in home dirs are ignored. WARNING: Never add directories here
16340 which local users can modify, that may lead to root exploit. Usually
16341 this should be done only if you don't allow shell access for users.
16342 <doc/wiki/Chrooting.txt>.
16343 Defaults to @samp{()}.
16346 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16347 Default chroot directory for mail processes. This can be overridden
16348 for specific users in user database by giving /./ in user's home
16349 directory (e.g.@: /home/./user chroots into /home). Note that usually
16350 there is no real need to do chrooting, Dovecot doesn't allow users to
16351 access files outside their mail directory anyway. If your home
16352 directories are prefixed with the chroot directory, append "/."@: to
16353 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16354 Defaults to @samp{""}.
16357 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16358 UNIX socket path to master authentication server to find users.
16359 This is used by imap (for shared users) and lda.
16360 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16363 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16364 Directory where to look up mail plugins.
16365 Defaults to @samp{"/usr/lib/dovecot"}.
16368 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16369 List of plugins to load for all services. Plugins specific to IMAP,
16370 LDA, etc.@: are added to this list in their own .conf files.
16371 Defaults to @samp{()}.
16374 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16375 The minimum number of mails in a mailbox before updates are done to
16376 cache file. This allows optimizing Dovecot's behavior to do less disk
16377 writes at the cost of more disk reads.
16378 Defaults to @samp{0}.
16381 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16382 When IDLE command is running, mailbox is checked once in a while to
16383 see if there are any new mails or other changes. This setting defines
16384 the minimum time to wait between those checks. Dovecot can also use
16385 dnotify, inotify and kqueue to find out immediately when changes
16387 Defaults to @samp{"30 secs"}.
16390 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16391 Save mails with CR+LF instead of plain LF. This makes sending those
16392 mails take less CPU, especially with sendfile() syscall with Linux and
16393 FreeBSD. But it also creates a bit more disk I/O which may just make it
16394 slower. Also note that if other software reads the mboxes/maildirs,
16395 they may handle the extra CRs wrong and cause problems.
16396 Defaults to @samp{#f}.
16399 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16400 By default LIST command returns all entries in maildir beginning
16401 with a dot. Enabling this option makes Dovecot return only entries
16402 which are directories. This is done by stat()ing each entry, so it
16403 causes more disk I/O.
16404 (For systems setting struct @samp{dirent->d_type} this check is free
16405 and it's done always regardless of this setting).
16406 Defaults to @samp{#f}.
16409 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16410 When copying a message, do it with hard links whenever possible.
16411 This makes the performance much better, and it's unlikely to have any
16413 Defaults to @samp{#t}.
16416 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16417 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16418 directory only when its mtime changes unexpectedly or when we can't find
16419 the mail otherwise.
16420 Defaults to @samp{#f}.
16423 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16424 Which locking methods to use for locking mbox. There are four
16429 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16430 solution. If you want to use /var/mail/ like directory, the users will
16431 need write access to that directory.
16433 Same as dotlock, but if it fails because of permissions or because there
16434 isn't enough disk space, just skip it.
16436 Use this if possible. Works with NFS too if lockd is used.
16438 May not exist in all systems. Doesn't work with NFS.
16440 May not exist in all systems. Doesn't work with NFS.
16443 You can use multiple locking methods; if you do the order they're declared
16444 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16445 locking methods as well. Some operating systems don't allow using some of
16446 them simultaneously.
16449 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16453 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16454 Maximum time to wait for lock (all of them) before aborting.
16455 Defaults to @samp{"5 mins"}.
16458 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16459 If dotlock exists but the mailbox isn't modified in any way,
16460 override the lock file after this much time.
16461 Defaults to @samp{"2 mins"}.
16464 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16465 When mbox changes unexpectedly we have to fully read it to find out
16466 what changed. If the mbox is large this can take a long time. Since
16467 the change is usually just a newly appended mail, it'd be faster to
16468 simply read the new mails. If this setting is enabled, Dovecot does
16469 this but still safely fallbacks to re-reading the whole mbox file
16470 whenever something in mbox isn't how it's expected to be. The only real
16471 downside to this setting is that if some other MUA changes message
16472 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16473 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16474 Defaults to @samp{#t}.
16477 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16478 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16479 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16480 @samp{mbox-dirty-syncs} is ignored.
16481 Defaults to @samp{#f}.
16484 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16485 Delay writing mbox headers until doing a full write sync (EXPUNGE
16486 and CHECK commands and when closing the mailbox). This is especially
16487 useful for POP3 where clients often delete all mails. The downside is
16488 that our changes aren't immediately visible to other MUAs.
16489 Defaults to @samp{#t}.
16492 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16493 If mbox size is smaller than this (e.g.@: 100k), don't write index
16494 files. If an index file already exists it's still read, just not
16496 Defaults to @samp{0}.
16499 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
16500 Maximum dbox file size until it's rotated.
16501 Defaults to @samp{10000000}.
16504 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
16505 Maximum dbox file age until it's rotated. Typically in days. Day
16506 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
16508 Defaults to @samp{"1d"}.
16511 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
16512 When creating new mdbox files, immediately preallocate their size to
16513 @samp{mdbox-rotate-size}. This setting currently works only in Linux
16514 with some file systems (ext4, xfs).
16515 Defaults to @samp{#f}.
16518 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
16519 sdbox and mdbox support saving mail attachments to external files,
16520 which also allows single instance storage for them. Other backends
16521 don't support this for now.
16523 WARNING: This feature hasn't been tested much yet. Use at your own risk.
16525 Directory root where to store mail attachments. Disabled, if empty.
16526 Defaults to @samp{""}.
16529 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
16530 Attachments smaller than this aren't saved externally. It's also
16531 possible to write a plugin to disable saving specific attachments
16533 Defaults to @samp{128000}.
16536 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
16537 File system backend to use for saving attachments:
16540 No SiS done by Dovecot (but this might help FS's own deduplication)
16542 SiS with immediate byte-by-byte comparison during saving
16543 @item sis-queue posix
16544 SiS with delayed comparison and deduplication.
16546 Defaults to @samp{"sis posix"}.
16549 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
16550 Hash format to use in attachment filenames. You can add any text and
16551 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
16552 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
16553 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
16554 Defaults to @samp{"%@{sha1@}"}.
16557 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
16559 Defaults to @samp{100}.
16562 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
16564 Defaults to @samp{1000}.
16567 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
16568 Default VSZ (virtual memory size) limit for service processes.
16569 This is mainly intended to catch and kill processes that leak memory
16570 before they eat up everything.
16571 Defaults to @samp{256000000}.
16574 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
16575 Login user is internally used by login processes. This is the most
16576 untrusted user in Dovecot system. It shouldn't have access to anything
16578 Defaults to @samp{"dovenull"}.
16581 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
16582 Internal user is used by unprivileged processes. It should be
16583 separate from login user, so that login processes can't disturb other
16585 Defaults to @samp{"dovecot"}.
16588 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
16589 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
16590 Defaults to @samp{"required"}.
16593 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
16594 PEM encoded X.509 SSL/TLS certificate (public key).
16595 Defaults to @samp{"</etc/dovecot/default.pem"}.
16598 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
16599 PEM encoded SSL/TLS private key. The key is opened before
16600 dropping root privileges, so keep the key file unreadable by anyone but
16602 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
16605 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
16606 If key file is password protected, give the password here.
16607 Alternatively give it when starting dovecot with -p parameter. Since
16608 this file is often world-readable, you may want to place this setting
16609 instead to a different.
16610 Defaults to @samp{""}.
16613 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
16614 PEM encoded trusted certificate authority. Set this only if you
16615 intend to use @samp{ssl-verify-client-cert? #t}. The file should
16616 contain the CA certificate(s) followed by the matching
16617 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
16618 Defaults to @samp{""}.
16621 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
16622 Require that CRL check succeeds for client certificates.
16623 Defaults to @samp{#t}.
16626 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
16627 Request client to send a certificate. If you also want to require
16628 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
16629 Defaults to @samp{#f}.
16632 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
16633 Which field from certificate to use for username. commonName and
16634 x500UniqueIdentifier are the usual choices. You'll also need to set
16635 @samp{auth-ssl-username-from-cert? #t}.
16636 Defaults to @samp{"commonName"}.
16639 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
16640 Minimum SSL protocol version to accept.
16641 Defaults to @samp{"TLSv1"}.
16644 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
16645 SSL ciphers to use.
16646 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
16649 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
16650 SSL crypto device to use, for valid values run "openssl engine".
16651 Defaults to @samp{""}.
16654 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
16655 Address to use when sending rejection mails.
16656 %d expands to recipient domain.
16657 Defaults to @samp{"postmaster@@%d"}.
16660 @deftypevr {@code{dovecot-configuration} parameter} string hostname
16661 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
16662 and in LMTP replies. Default is the system's real hostname@@domain.
16663 Defaults to @samp{""}.
16666 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
16667 If user is over quota, return with temporary failure instead of
16669 Defaults to @samp{#f}.
16672 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
16673 Binary to use for sending mails.
16674 Defaults to @samp{"/usr/sbin/sendmail"}.
16677 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
16678 If non-empty, send mails via this SMTP host[:port] instead of
16680 Defaults to @samp{""}.
16683 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
16684 Subject: header to use for rejection mails. You can use the same
16685 variables as for @samp{rejection-reason} below.
16686 Defaults to @samp{"Rejected: %s"}.
16689 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
16690 Human readable error message for rejection mails. You can use
16703 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
16706 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
16707 Delimiter character between local-part and detail in email
16709 Defaults to @samp{"+"}.
16712 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
16713 Header where the original recipient address (SMTP's RCPT TO:
16714 address) is taken from if not available elsewhere. With dovecot-lda -a
16715 parameter overrides this. A commonly used header for this is
16717 Defaults to @samp{""}.
16720 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
16721 Should saving a mail to a nonexistent mailbox automatically create
16723 Defaults to @samp{#f}.
16726 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
16727 Should automatically created mailboxes be also automatically
16729 Defaults to @samp{#f}.
16732 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
16733 Maximum IMAP command line length. Some clients generate very long
16734 command lines with huge mailboxes, so you may need to raise this if you
16735 get "Too long argument" or "IMAP command line too large" errors
16737 Defaults to @samp{64000}.
16740 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
16741 IMAP logout format string:
16744 total number of bytes read from client
16746 total number of bytes sent to client.
16748 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
16749 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@}"}.
16752 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
16753 Override the IMAP CAPABILITY response. If the value begins with '+',
16754 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
16755 Defaults to @samp{""}.
16758 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
16759 How long to wait between "OK Still here" notifications when client
16761 Defaults to @samp{"2 mins"}.
16764 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
16765 ID field names and values to send to clients. Using * as the value
16766 makes Dovecot use the default value. The following fields have default
16767 values currently: name, version, os, os-version, support-url,
16769 Defaults to @samp{""}.
16772 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
16773 ID fields sent by client to log. * means everything.
16774 Defaults to @samp{""}.
16777 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
16778 Workarounds for various client bugs:
16781 @item delay-newmail
16782 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
16783 CHECK commands. Some clients ignore them otherwise, for example OSX
16784 Mail (<v2.1). Outlook Express breaks more badly though, without this it
16785 may show user "Message no longer in server" errors. Note that OE6
16786 still breaks even with this workaround if synchronization is set to
16789 @item tb-extra-mailbox-sep
16790 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
16791 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
16792 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
16794 @item tb-lsub-flags
16795 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
16796 This makes Thunderbird realize they aren't selectable and show them
16797 greyed out, instead of only later giving "not selectable" popup error.
16799 Defaults to @samp{()}.
16802 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
16803 Host allowed in URLAUTH URLs sent by client. "*" allows all.
16804 Defaults to @samp{""}.
16808 Whew! Lots of configuration options. The nice thing about it though is
16809 that Guix has a complete interface to Dovecot's configuration
16810 language. This allows not only a nice way to declare configurations,
16811 but also offers reflective capabilities as well: users can write code to
16812 inspect and transform configurations from within Scheme.
16814 However, it could be that you just want to get a @code{dovecot.conf} up
16815 and running. In that case, you can pass an
16816 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
16817 @code{dovecot-service}. As its name indicates, an opaque configuration
16818 does not have easy reflective capabilities.
16820 Available @code{opaque-dovecot-configuration} fields are:
16822 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
16823 The dovecot package.
16826 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
16827 The contents of the @code{dovecot.conf}, as a string.
16830 For example, if your @code{dovecot.conf} is just the empty string, you
16831 could instantiate a dovecot service like this:
16834 (dovecot-service #:config
16835 (opaque-dovecot-configuration
16839 @subsubheading OpenSMTPD Service
16841 @deffn {Scheme Variable} opensmtpd-service-type
16842 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
16843 service, whose value should be an @code{opensmtpd-configuration} object
16844 as in this example:
16847 (service opensmtpd-service-type
16848 (opensmtpd-configuration
16849 (config-file (local-file "./my-smtpd.conf"))))
16853 @deftp {Data Type} opensmtpd-configuration
16854 Data type representing the configuration of opensmtpd.
16857 @item @code{package} (default: @var{opensmtpd})
16858 Package object of the OpenSMTPD SMTP server.
16860 @item @code{config-file} (default: @code{%default-opensmtpd-file})
16861 File-like object of the OpenSMTPD configuration file to use. By default
16862 it listens on the loopback network interface, and allows for mail from
16863 users and daemons on the local machine, as well as permitting email to
16864 remote servers. Run @command{man smtpd.conf} for more information.
16869 @subsubheading Exim Service
16871 @cindex mail transfer agent (MTA)
16872 @cindex MTA (mail transfer agent)
16875 @deffn {Scheme Variable} exim-service-type
16876 This is the type of the @uref{https://exim.org, Exim} mail transfer
16877 agent (MTA), whose value should be an @code{exim-configuration} object
16878 as in this example:
16881 (service exim-service-type
16882 (exim-configuration
16883 (config-file (local-file "./my-exim.conf"))))
16887 In order to use an @code{exim-service-type} service you must also have a
16888 @code{mail-aliases-service-type} service present in your
16889 @code{operating-system} (even if it has no aliases).
16891 @deftp {Data Type} exim-configuration
16892 Data type representing the configuration of exim.
16895 @item @code{package} (default: @var{exim})
16896 Package object of the Exim server.
16898 @item @code{config-file} (default: @code{#f})
16899 File-like object of the Exim configuration file to use. If its value is
16900 @code{#f} then use the default configuration file from the package
16901 provided in @code{package}. The resulting configuration file is loaded
16902 after setting the @code{exim_user} and @code{exim_group} configuration
16908 @subsubheading Getmail service
16913 @deffn {Scheme Variable} getmail-service-type
16914 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
16915 mail retriever, whose value should be an @code{getmail-configuration}.
16918 Available @code{getmail-configuration} fields are:
16920 @deftypevr {@code{getmail-configuration} parameter} symbol name
16921 A symbol to identify the getmail service.
16923 Defaults to @samp{"unset"}.
16927 @deftypevr {@code{getmail-configuration} parameter} package package
16928 The getmail package to use.
16932 @deftypevr {@code{getmail-configuration} parameter} string user
16933 The user to run getmail as.
16935 Defaults to @samp{"getmail"}.
16939 @deftypevr {@code{getmail-configuration} parameter} string group
16940 The group to run getmail as.
16942 Defaults to @samp{"getmail"}.
16946 @deftypevr {@code{getmail-configuration} parameter} string directory
16947 The getmail directory to use.
16949 Defaults to @samp{"/var/lib/getmail/default"}.
16953 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
16954 The getmail configuration file to use.
16956 Available @code{getmail-configuration-file} fields are:
16958 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
16959 What mail account to retrieve mail from, and how to access that account.
16961 Available @code{getmail-retriever-configuration} fields are:
16963 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
16964 The type of mail retriever to use. Valid values include @samp{passwd}
16967 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
16971 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
16972 Space separated list of arguments to the userdb driver.
16974 Defaults to @samp{unset}.
16978 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
16979 Space separated list of arguments to the userdb driver.
16981 Defaults to @samp{unset}.
16985 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
16986 Space separated list of arguments to the userdb driver.
16988 Defaults to @samp{#f}.
16992 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
16993 Override fields from passwd.
16995 Defaults to @samp{""}.
16999 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17000 Override fields from passwd.
17002 Defaults to @samp{()}.
17006 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17007 PEM-formatted key file to use for the TLS negotiation
17009 Defaults to @samp{""}.
17013 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17014 PEM-formatted certificate file to use for the TLS negotiation
17016 Defaults to @samp{""}.
17020 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17021 CA certificates to use
17023 Defaults to @samp{""}.
17027 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17028 Extra retriever parameters
17030 Defaults to @samp{()}.
17036 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17037 What to do with retrieved messages.
17039 Available @code{getmail-destination-configuration} fields are:
17041 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17042 The type of mail destination. Valid values include @samp{Maildir},
17043 @samp{Mboxrd} and @samp{MDA_external}.
17045 Defaults to @samp{unset}.
17049 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17050 The path option for the mail destination. The behaviour depends on the
17053 Defaults to @samp{""}.
17057 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17058 Extra destination parameters
17060 Defaults to @samp{()}.
17066 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17069 Available @code{getmail-options-configuration} fields are:
17071 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17072 If set to @samp{0}, getmail will only print warnings and errors. A
17073 value of @samp{1} means that messages will be printed about retrieving
17074 and deleting messages. If set to @samp{2}, getmail will print messages
17075 about each of it's actions.
17077 Defaults to @samp{1}.
17081 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17082 If true, getmail will retrieve all available messages. Otherwise it
17083 will only retrieve messages it hasn't seen previously.
17085 Defaults to @samp{#t}.
17089 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17090 If set to true, messages will be deleted from the server after
17091 retrieving and successfully delivering them. Otherwise, messages will
17092 be left on the server.
17094 Defaults to @samp{#f}.
17098 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17099 Getmail will delete messages this number of days after seeing them, if
17100 they have not been delivered. This means messages will be left on the
17101 server this number of days after delivering them. A value of @samp{0}
17102 disabled this feature.
17104 Defaults to @samp{0}.
17108 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17109 Delete messages larger than this of bytes after retrieving them, even if
17110 the delete and delete-after options are disabled. A value of @samp{0}
17111 disables this feature.
17113 Defaults to @samp{0}.
17117 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17118 Retrieve messages totalling up to this number of bytes before closing
17119 the session with the server. A value of @samp{0} disables this feature.
17121 Defaults to @samp{0}.
17125 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17126 Don't retrieve messages larger than this number of bytes. A value of
17127 @samp{0} disables this feature.
17129 Defaults to @samp{0}.
17133 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17134 If true, getmail will add a Delivered-To header to messages.
17136 Defaults to @samp{#t}.
17140 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17141 If set, getmail adds a Received header to the messages.
17143 Defaults to @samp{#t}.
17147 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17148 Getmail will record a log of its actions to the named file. A value of
17149 @samp{""} disables this feature.
17151 Defaults to @samp{""}.
17155 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17156 If true, getmail will record a log of its actions using the system
17159 Defaults to @samp{#t}.
17163 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17164 If true, getmail will log information about messages not retrieved and
17165 the reason for not retrieving them, as well as starting and ending
17168 Defaults to @samp{#t}.
17172 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17173 Extra options to include.
17175 Defaults to @samp{()}.
17183 @deftypevr {@code{getmail-configuration} parameter} list idle
17184 A list of mailboxes that getmail should wait on the server for new mail
17185 notifications. This depends on the server supporting the IDLE
17188 Defaults to @samp{()}.
17192 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17193 Environment variables to set for getmail.
17195 Defaults to @samp{()}.
17199 @subsubheading Mail Aliases Service
17201 @cindex email aliases
17202 @cindex aliases, for email addresses
17204 @deffn {Scheme Variable} mail-aliases-service-type
17205 This is the type of the service which provides @code{/etc/aliases},
17206 specifying how to deliver mail to users on this system.
17209 (service mail-aliases-service-type
17210 '(("postmaster" "bob")
17211 ("bob" "bob@@example.com" "bob@@example2.com")))
17215 The configuration for a @code{mail-aliases-service-type} service is an
17216 association list denoting how to deliver mail that comes to this
17217 system. Each entry is of the form @code{(alias addresses ...)}, with
17218 @code{alias} specifying the local alias and @code{addresses} specifying
17219 where to deliver this user's mail.
17221 The aliases aren't required to exist as users on the local system. In
17222 the above example, there doesn't need to be a @code{postmaster} entry in
17223 the @code{operating-system}'s @code{user-accounts} in order to deliver
17224 the @code{postmaster} mail to @code{bob} (which subsequently would
17225 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17227 @subsubheading GNU Mailutils IMAP4 Daemon
17228 @cindex GNU Mailutils IMAP4 Daemon
17230 @deffn {Scheme Variable} imap4d-service-type
17231 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17232 mailutils, GNU Mailutils Manual}), whose value should be an
17233 @code{imap4d-configuration} object as in this example:
17236 (service imap4d-service-type
17237 (imap4d-configuration
17238 (config-file (local-file "imap4d.conf"))))
17242 @deftp {Data Type} imap4d-configuration
17243 Data type representing the configuration of @command{imap4d}.
17246 @item @code{package} (default: @code{mailutils})
17247 The package that provides @command{imap4d}.
17249 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17250 File-like object of the configuration file to use, by default it will listen
17251 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17252 Mailutils Manual}, for details.
17257 @node Messaging Services
17258 @subsection Messaging Services
17263 The @code{(gnu services messaging)} module provides Guix service
17264 definitions for messaging services: currently only Prosody is supported.
17266 @subsubheading Prosody Service
17268 @deffn {Scheme Variable} prosody-service-type
17269 This is the type for the @uref{https://prosody.im, Prosody XMPP
17270 communication server}. Its value must be a @code{prosody-configuration}
17271 record as in this example:
17274 (service prosody-service-type
17275 (prosody-configuration
17276 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17279 (int-component-configuration
17280 (hostname "conference.example.net")
17282 (mod-muc (mod-muc-configuration)))))
17285 (virtualhost-configuration
17286 (domain "example.net"))))))
17289 See below for details about @code{prosody-configuration}.
17293 By default, Prosody does not need much configuration. Only one
17294 @code{virtualhosts} field is needed: it specifies the domain you wish
17297 You can perform various sanity checks on the generated configuration
17298 with the @code{prosodyctl check} command.
17300 Prosodyctl will also help you to import certificates from the
17301 @code{letsencrypt} directory so that the @code{prosody} user can access
17302 them. See @url{https://prosody.im/doc/letsencrypt}.
17305 prosodyctl --root cert import /etc/letsencrypt/live
17308 The available configuration parameters follow. Each parameter
17309 definition is preceded by its type; for example, @samp{string-list foo}
17310 indicates that the @code{foo} parameter should be specified as a list of
17311 strings. Types starting with @code{maybe-} denote parameters that won't
17312 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
17314 There is also a way to specify the configuration as a string, if you
17315 have an old @code{prosody.cfg.lua} file that you want to port over from
17316 some other system; see the end for more details.
17318 The @code{file-object} type designates either a file-like object
17319 (@pxref{G-Expressions, file-like objects}) or a file name.
17321 @c The following documentation was initially generated by
17322 @c (generate-documentation) in (gnu services messaging). Manually maintained
17323 @c documentation is better, so we shouldn't hesitate to edit below as
17324 @c needed. However if the change you want to make to this documentation
17325 @c can be done in an automated way, it's probably easier to change
17326 @c (generate-documentation) than to make it below and have to deal with
17327 @c the churn as Prosody updates.
17329 Available @code{prosody-configuration} fields are:
17331 @deftypevr {@code{prosody-configuration} parameter} package prosody
17332 The Prosody package.
17335 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
17336 Location of the Prosody data storage directory. See
17337 @url{https://prosody.im/doc/configure}.
17338 Defaults to @samp{"/var/lib/prosody"}.
17341 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
17342 Additional plugin directories. They are searched in all the specified
17343 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
17344 Defaults to @samp{()}.
17347 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
17348 Every virtual host and component needs a certificate so that clients and
17349 servers can securely verify its identity. Prosody will automatically load
17350 certificates/keys from the directory specified here.
17351 Defaults to @samp{"/etc/prosody/certs"}.
17354 @deftypevr {@code{prosody-configuration} parameter} string-list admins
17355 This is a list of accounts that are admins for the server. Note that you
17356 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
17357 @url{https://prosody.im/doc/creating_accounts}.
17358 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
17359 Defaults to @samp{()}.
17362 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
17363 Enable use of libevent for better performance under high load. See
17364 @url{https://prosody.im/doc/libevent}.
17365 Defaults to @samp{#f}.
17368 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
17369 This is the list of modules Prosody will load on startup. It looks for
17370 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
17371 Documentation on modules can be found at:
17372 @url{https://prosody.im/doc/modules}.
17373 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
17376 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
17377 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
17378 should you want to disable them then add them to this list.
17379 Defaults to @samp{()}.
17382 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
17383 Path to a text file where the shared groups are defined. If this path is
17384 empty then @samp{mod_groups} does nothing. See
17385 @url{https://prosody.im/doc/modules/mod_groups}.
17386 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
17389 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
17390 Disable account creation by default, for security. See
17391 @url{https://prosody.im/doc/creating_accounts}.
17392 Defaults to @samp{#f}.
17395 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
17396 These are the SSL/TLS-related settings. Most of them are disabled so to
17397 use Prosody's defaults. If you do not completely understand these options, do
17398 not add them to your config, it is easy to lower the security of your server
17399 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
17401 Available @code{ssl-configuration} fields are:
17403 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
17404 This determines what handshake to use.
17407 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
17408 Path to your private key file.
17411 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
17412 Path to your certificate file.
17415 @deftypevr {@code{ssl-configuration} parameter} file-object capath
17416 Path to directory containing root certificates that you wish Prosody to
17417 trust when verifying the certificates of remote servers.
17418 Defaults to @samp{"/etc/ssl/certs"}.
17421 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
17422 Path to a file containing root certificates that you wish Prosody to trust.
17423 Similar to @code{capath} but with all certificates concatenated together.
17426 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
17427 A list of verification options (these mostly map to OpenSSL's
17428 @code{set_verify()} flags).
17431 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
17432 A list of general options relating to SSL/TLS. These map to OpenSSL's
17433 @code{set_options()}. For a full list of options available in LuaSec, see the
17437 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
17438 How long a chain of certificate authorities to check when looking for a
17439 trusted root certificate.
17442 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
17443 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
17444 clients, and in what order.
17447 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
17448 A path to a file containing parameters for Diffie-Hellman key exchange. You
17449 can create such a file with:
17450 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
17453 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
17454 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
17455 @samp{"secp384r1"}.
17458 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
17459 A list of "extra" verification options.
17462 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
17463 Password for encrypted private keys.
17468 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
17469 Whether to force all client-to-server connections to be encrypted or not.
17470 See @url{https://prosody.im/doc/modules/mod_tls}.
17471 Defaults to @samp{#f}.
17474 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
17475 Set of mechanisms that will never be offered. See
17476 @url{https://prosody.im/doc/modules/mod_saslauth}.
17477 Defaults to @samp{("DIGEST-MD5")}.
17480 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
17481 Whether to force all server-to-server connections to be encrypted or not.
17482 See @url{https://prosody.im/doc/modules/mod_tls}.
17483 Defaults to @samp{#f}.
17486 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
17487 Whether to require encryption and certificate authentication. This
17488 provides ideal security, but requires servers you communicate with to support
17489 encryption AND present valid, trusted certificates. See
17490 @url{https://prosody.im/doc/s2s#security}.
17491 Defaults to @samp{#f}.
17494 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
17495 Many servers don't support encryption or have invalid or self-signed
17496 certificates. You can list domains here that will not be required to
17497 authenticate using certificates. They will be authenticated using DNS. See
17498 @url{https://prosody.im/doc/s2s#security}.
17499 Defaults to @samp{()}.
17502 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
17503 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
17504 valid certificates for some domains by specifying a list here. See
17505 @url{https://prosody.im/doc/s2s#security}.
17506 Defaults to @samp{()}.
17509 @deftypevr {@code{prosody-configuration} parameter} string authentication
17510 Select the authentication backend to use. The default provider stores
17511 passwords in plaintext and uses Prosody's configured data storage to store the
17512 authentication data. If you do not trust your server please see
17513 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
17514 about using the hashed backend. See also
17515 @url{https://prosody.im/doc/authentication}
17516 Defaults to @samp{"internal_plain"}.
17519 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
17520 Set logging options. Advanced logging configuration is not yet supported
17521 by the Prosody service. See @url{https://prosody.im/doc/logging}.
17522 Defaults to @samp{"*syslog"}.
17525 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
17526 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
17527 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
17530 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
17531 Maximum allowed size of the HTTP body (in bytes).
17534 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
17535 Some modules expose their own URL in various ways. This URL is built
17536 from the protocol, host and port used. If Prosody sits behind a proxy, the
17537 public URL will be @code{http-external-url} instead. See
17538 @url{https://prosody.im/doc/http#external_url}.
17541 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
17542 A host in Prosody is a domain on which user accounts can be created. For
17543 example if you want your users to have addresses like
17544 @samp{"john.smith@@example.com"} then you need to add a host
17545 @samp{"example.com"}. All options in this list will apply only to this host.
17547 Note: the name "virtual" host is used in configuration to avoid confusion with
17548 the actual physical host that Prosody is installed on. A single Prosody
17549 instance can serve many domains, each one defined as a VirtualHost entry in
17550 Prosody's configuration. Conversely a server that hosts a single domain would
17551 have just one VirtualHost entry.
17553 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
17555 Available @code{virtualhost-configuration} fields are:
17557 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:
17558 @deftypevr {@code{virtualhost-configuration} parameter} string domain
17559 Domain you wish Prosody to serve.
17564 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
17565 Components are extra services on a server which are available to clients,
17566 usually on a subdomain of the main server (such as
17567 @samp{"mycomponent.example.com"}). Example components might be chatroom
17568 servers, user directories, or gateways to other protocols.
17570 Internal components are implemented with Prosody-specific plugins. To add an
17571 internal component, you simply fill the hostname field, and the plugin you wish
17572 to use for the component.
17574 See @url{https://prosody.im/doc/components}.
17575 Defaults to @samp{()}.
17577 Available @code{int-component-configuration} fields are:
17579 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:
17580 @deftypevr {@code{int-component-configuration} parameter} string hostname
17581 Hostname of the component.
17584 @deftypevr {@code{int-component-configuration} parameter} string plugin
17585 Plugin you wish to use for the component.
17588 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
17589 Multi-user chat (MUC) is Prosody's module for allowing you to create
17590 hosted chatrooms/conferences for XMPP users.
17592 General information on setting up and using multi-user chatrooms can be found
17593 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
17594 which you should read if you are new to XMPP chatrooms.
17596 See also @url{https://prosody.im/doc/modules/mod_muc}.
17598 Available @code{mod-muc-configuration} fields are:
17600 @deftypevr {@code{mod-muc-configuration} parameter} string name
17601 The name to return in service discovery responses.
17602 Defaults to @samp{"Prosody Chatrooms"}.
17605 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
17606 If @samp{#t}, this will only allow admins to create new chatrooms.
17607 Otherwise anyone can create a room. The value @samp{"local"} restricts room
17608 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
17609 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
17610 restricts to service administrators only.
17611 Defaults to @samp{#f}.
17614 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
17615 Maximum number of history messages that will be sent to the member that has
17616 just joined the room.
17617 Defaults to @samp{20}.
17624 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
17625 External components use XEP-0114, which most standalone components
17626 support. To add an external component, you simply fill the hostname field. See
17627 @url{https://prosody.im/doc/components}.
17628 Defaults to @samp{()}.
17630 Available @code{ext-component-configuration} fields are:
17632 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:
17633 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
17634 Password which the component will use to log in.
17637 @deftypevr {@code{ext-component-configuration} parameter} string hostname
17638 Hostname of the component.
17643 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
17644 Port(s) Prosody listens on for component connections.
17645 Defaults to @samp{(5347)}.
17648 @deftypevr {@code{prosody-configuration} parameter} string component-interface
17649 Interface Prosody listens on for component connections.
17650 Defaults to @samp{"127.0.0.1"}.
17653 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
17654 Raw content that will be added to the configuration file.
17657 It could be that you just want to get a @code{prosody.cfg.lua}
17658 up and running. In that case, you can pass an
17659 @code{opaque-prosody-configuration} record as the value of
17660 @code{prosody-service-type}. As its name indicates, an opaque configuration
17661 does not have easy reflective capabilities.
17662 Available @code{opaque-prosody-configuration} fields are:
17664 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
17665 The prosody package.
17668 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
17669 The contents of the @code{prosody.cfg.lua} to use.
17672 For example, if your @code{prosody.cfg.lua} is just the empty
17673 string, you could instantiate a prosody service like this:
17676 (service prosody-service-type
17677 (opaque-prosody-configuration
17678 (prosody.cfg.lua "")))
17681 @c end of Prosody auto-generated documentation
17683 @subsubheading BitlBee Service
17685 @cindex IRC (Internet Relay Chat)
17686 @cindex IRC gateway
17687 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
17688 interface to a variety of messaging protocols such as XMPP.
17690 @defvr {Scheme Variable} bitlbee-service-type
17691 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
17692 gateway daemon. Its value is a @code{bitlbee-configuration} (see
17695 To have BitlBee listen on port 6667 on localhost, add this line to your
17699 (service bitlbee-service-type)
17703 @deftp {Data Type} bitlbee-configuration
17704 This is the configuration for BitlBee, with the following fields:
17707 @item @code{interface} (default: @code{"127.0.0.1"})
17708 @itemx @code{port} (default: @code{6667})
17709 Listen on the network interface corresponding to the IP address
17710 specified in @var{interface}, on @var{port}.
17712 When @var{interface} is @code{127.0.0.1}, only local clients can
17713 connect; when it is @code{0.0.0.0}, connections can come from any
17714 networking interface.
17716 @item @code{package} (default: @code{bitlbee})
17717 The BitlBee package to use.
17719 @item @code{plugins} (default: @code{'()})
17720 List of plugin packages to use---e.g., @code{bitlbee-discord}.
17722 @item @code{extra-settings} (default: @code{""})
17723 Configuration snippet added as-is to the BitlBee configuration file.
17727 @subsubheading Quassel Service
17729 @cindex IRC (Internet Relay Chat)
17730 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
17731 meaning that one or more clients can attach to and detach from the
17734 @defvr {Scheme Variable} quassel-service-type
17735 This is the service type for the @url{https://quassel-irc.org/,Quassel}
17736 IRC backend daemon. Its value is a @code{quassel-configuration}
17740 @deftp {Data Type} quassel-configuration
17741 This is the configuration for Quassel, with the following fields:
17744 @item @code{quassel} (default: @code{quassel})
17745 The Quassel package to use.
17747 @item @code{interface} (default: @code{"::,0.0.0.0"})
17748 @item @code{port} (default: @code{4242})
17749 Listen on the network interface(s) corresponding to the IPv4 or IPv6
17750 interfaces specified in the comma delimited @var{interface}, on
17753 @item @code{loglevel} (default: @code{"Info"})
17754 The level of logging desired. Accepted values are Debug, Info, Warning
17759 @node Telephony Services
17760 @subsection Telephony Services
17762 @cindex Murmur (VoIP server)
17763 @cindex VoIP server
17764 This section describes how to set up and run a Murmur server. Murmur is
17765 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
17768 @deftp {Data Type} murmur-configuration
17769 The service type for the Murmur server. An example configuration can
17773 (service murmur-service-type
17774 (murmur-configuration
17776 "Welcome to this Mumble server running on Guix!")
17777 (cert-required? #t) ;disallow text password logins
17778 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
17779 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
17782 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
17783 password with the command that is printed during the activation phase.
17785 It is recommended to register a normal Mumble user account
17786 and grant it admin or moderator rights.
17787 You can use the @code{mumble} client to
17788 login as new normal user, register yourself, and log out.
17789 For the next step login with the name @code{SuperUser} use
17790 the @code{SuperUser} password that you set previously,
17791 and grant your newly registered mumble user administrator or moderator
17792 rights and create some channels.
17794 Available @code{murmur-configuration} fields are:
17797 @item @code{package} (default: @code{mumble})
17798 Package that contains @code{bin/murmurd}.
17800 @item @code{user} (default: @code{"murmur"})
17801 User who will run the Murmur server.
17803 @item @code{group} (default: @code{"murmur"})
17804 Group of the user who will run the murmur server.
17806 @item @code{port} (default: @code{64738})
17807 Port on which the server will listen.
17809 @item @code{welcome-text} (default: @code{""})
17810 Welcome text sent to clients when they connect.
17812 @item @code{server-password} (default: @code{""})
17813 Password the clients have to enter in order to connect.
17815 @item @code{max-users} (default: @code{100})
17816 Maximum of users that can be connected to the server at once.
17818 @item @code{max-user-bandwidth} (default: @code{#f})
17819 Maximum voice traffic a user can send per second.
17821 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
17822 File name of the sqlite database.
17823 The service's user will become the owner of the directory.
17825 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
17826 File name of the log file.
17827 The service's user will become the owner of the directory.
17829 @item @code{autoban-attempts} (default: @code{10})
17830 Maximum number of logins a user can make in @code{autoban-timeframe}
17831 without getting auto banned for @code{autoban-time}.
17833 @item @code{autoban-timeframe} (default: @code{120})
17834 Timeframe for autoban in seconds.
17836 @item @code{autoban-time} (default: @code{300})
17837 Amount of time in seconds for which a client gets banned
17838 when violating the autoban limits.
17840 @item @code{opus-threshold} (default: @code{100})
17841 Percentage of clients that need to support opus
17842 before switching over to opus audio codec.
17844 @item @code{channel-nesting-limit} (default: @code{10})
17845 How deep channels can be nested at maximum.
17847 @item @code{channelname-regex} (default: @code{#f})
17848 A string in form of a Qt regular expression that channel names must conform to.
17850 @item @code{username-regex} (default: @code{#f})
17851 A string in form of a Qt regular expression that user names must conform to.
17853 @item @code{text-message-length} (default: @code{5000})
17854 Maximum size in bytes that a user can send in one text chat message.
17856 @item @code{image-message-length} (default: @code{(* 128 1024)})
17857 Maximum size in bytes that a user can send in one image message.
17859 @item @code{cert-required?} (default: @code{#f})
17860 If it is set to @code{#t} clients that use weak password authentication
17861 will not be accepted. Users must have completed the certificate wizard to join.
17863 @item @code{remember-channel?} (default: @code{#f})
17864 Should murmur remember the last channel each user was in when they disconnected
17865 and put them into the remembered channel when they rejoin.
17867 @item @code{allow-html?} (default: @code{#f})
17868 Should html be allowed in text messages, user comments, and channel descriptions.
17870 @item @code{allow-ping?} (default: @code{#f})
17871 Setting to true exposes the current user count, the maximum user count, and
17872 the server's maximum bandwidth per client to unauthenticated users. In the
17873 Mumble client, this information is shown in the Connect dialog.
17875 Disabling this setting will prevent public listing of the server.
17877 @item @code{bonjour?} (default: @code{#f})
17878 Should the server advertise itself in the local network through the bonjour protocol.
17880 @item @code{send-version?} (default: @code{#f})
17881 Should the murmur server version be exposed in ping requests.
17883 @item @code{log-days} (default: @code{31})
17884 Murmur also stores logs in the database, which are accessible via RPC.
17885 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
17886 or -1 to disable logging to the database.
17888 @item @code{obfuscate-ips?} (default: @code{#t})
17889 Should logged ips be obfuscated to protect the privacy of users.
17891 @item @code{ssl-cert} (default: @code{#f})
17892 File name of the SSL/TLS certificate used for encrypted connections.
17895 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
17897 @item @code{ssl-key} (default: @code{#f})
17898 Filepath to the ssl private key used for encrypted connections.
17900 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
17903 @item @code{ssl-dh-params} (default: @code{#f})
17904 File name of a PEM-encoded file with Diffie-Hellman parameters
17905 for the SSL/TLS encryption. Alternatively you set it to
17906 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
17907 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
17909 @item @code{ssl-ciphers} (default: @code{#f})
17910 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
17913 This option is specified using
17914 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
17915 OpenSSL cipher list notation}.
17917 It is recommended that you try your cipher string using 'openssl ciphers <string>'
17918 before setting it here, to get a feel for which cipher suites you will get.
17919 After setting this option, it is recommend that you inspect your Murmur log
17920 to ensure that Murmur is using the cipher suites that you expected it to.
17922 Note: Changing this option may impact the backwards compatibility of your
17923 Murmur server, and can remove the ability for older Mumble clients to be able
17926 @item @code{public-registration} (default: @code{#f})
17927 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
17929 You can optionally register your server in the public server list that the
17930 @code{mumble} client shows on startup.
17931 You cannot register your server if you have set a @code{server-password},
17932 or set @code{allow-ping} to @code{#f}.
17934 It might take a few hours until it shows up in the public list.
17936 @item @code{file} (default: @code{#f})
17937 Optional alternative override for this configuration.
17941 @deftp {Data Type} murmur-public-registration-configuration
17942 Configuration for public registration of a murmur service.
17946 This is a display name for your server. Not to be confused with the hostname.
17948 @item @code{password}
17949 A password to identify your registration.
17950 Subsequent updates will need the same password. Don't lose your password.
17953 This should be a @code{http://} or @code{https://} link to your web
17956 @item @code{hostname} (default: @code{#f})
17957 By default your server will be listed by its IP address.
17958 If it is set your server will be linked by this host name instead.
17964 @node Monitoring Services
17965 @subsection Monitoring Services
17967 @subsubheading Tailon Service
17969 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
17970 viewing and searching log files.
17972 The following example will configure the service with default values.
17973 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
17976 (service tailon-service-type)
17979 The following example customises more of the Tailon configuration,
17980 adding @command{sed} to the list of allowed commands.
17983 (service tailon-service-type
17984 (tailon-configuration
17986 (tailon-configuration-file
17987 (allowed-commands '("tail" "grep" "awk" "sed"))))))
17991 @deftp {Data Type} tailon-configuration
17992 Data type representing the configuration of Tailon.
17993 This type has the following parameters:
17996 @item @code{config-file} (default: @code{(tailon-configuration-file)})
17997 The configuration file to use for Tailon. This can be set to a
17998 @dfn{tailon-configuration-file} record value, or any gexp
17999 (@pxref{G-Expressions}).
18001 For example, to instead use a local file, the @code{local-file} function
18005 (service tailon-service-type
18006 (tailon-configuration
18007 (config-file (local-file "./my-tailon.conf"))))
18010 @item @code{package} (default: @code{tailon})
18011 The tailon package to use.
18016 @deftp {Data Type} tailon-configuration-file
18017 Data type representing the configuration options for Tailon.
18018 This type has the following parameters:
18021 @item @code{files} (default: @code{(list "/var/log")})
18022 List of files to display. The list can include strings for a single file
18023 or directory, or a list, where the first item is the name of a
18024 subsection, and the remaining items are the files or directories in that
18027 @item @code{bind} (default: @code{"localhost:8080"})
18028 Address and port to which Tailon should bind on.
18030 @item @code{relative-root} (default: @code{#f})
18031 URL path to use for Tailon, set to @code{#f} to not use a path.
18033 @item @code{allow-transfers?} (default: @code{#t})
18034 Allow downloading the log files in the web interface.
18036 @item @code{follow-names?} (default: @code{#t})
18037 Allow tailing of not-yet existent files.
18039 @item @code{tail-lines} (default: @code{200})
18040 Number of lines to read initially from each file.
18042 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18043 Commands to allow running. By default, @code{sed} is disabled.
18045 @item @code{debug?} (default: @code{#f})
18046 Set @code{debug?} to @code{#t} to show debug messages.
18048 @item @code{wrap-lines} (default: @code{#t})
18049 Initial line wrapping state in the web interface. Set to @code{#t} to
18050 initially wrap lines (the default), or to @code{#f} to initially not
18053 @item @code{http-auth} (default: @code{#f})
18054 HTTP authentication type to use. Set to @code{#f} to disable
18055 authentication (the default). Supported values are @code{"digest"} or
18058 @item @code{users} (default: @code{#f})
18059 If HTTP authentication is enabled (see @code{http-auth}), access will be
18060 restricted to the credentials provided here. To configure users, use a
18061 list of pairs, where the first element of the pair is the username, and
18062 the 2nd element of the pair is the password.
18065 (tailon-configuration-file
18066 (http-auth "basic")
18067 (users '(("user1" . "password1")
18068 ("user2" . "password2"))))
18075 @subsubheading Darkstat Service
18077 Darkstat is a packet sniffer that captures network traffic, calculates
18078 statistics about usage, and serves reports over HTTP.
18080 @defvar {Scheme Variable} darkstat-service-type
18081 This is the service type for the
18082 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18083 service, its value must be a @code{darkstat-configuration} record as in
18087 (service darkstat-service-type
18088 (darkstat-configuration
18089 (interface "eno1")))
18093 @deftp {Data Type} darkstat-configuration
18094 Data type representing the configuration of @command{darkstat}.
18097 @item @code{package} (default: @code{darkstat})
18098 The darkstat package to use.
18100 @item @code{interface}
18101 Capture traffic on the specified network interface.
18103 @item @code{port} (default: @code{"667"})
18104 Bind the web interface to the specified port.
18106 @item @code{bind-address} (default: @code{"127.0.0.1"})
18107 Bind the web interface to the specified address.
18109 @item @code{base} (default: @code{"/"})
18110 Specify the path of the base URL. This can be useful if
18111 @command{darkstat} is accessed via a reverse proxy.
18116 @subsubheading Prometheus Node Exporter Service
18118 @cindex prometheus-node-exporter
18119 The Prometheus ``node exporter'' makes hardware and operating system statistics
18120 provided by the Linux kernel available for the Prometheus monitoring system.
18121 This service should be deployed on all physical nodes and virtual machines,
18122 where monitoring these statistics is desirable.
18124 @defvar {Scheme variable} prometheus-node-exporter-service-type
18125 This is the service type for the
18126 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18127 service, its value must be a @code{prometheus-node-exporter-configuration}
18128 record as in this example:
18131 (service prometheus-node-exporter-service-type
18132 (prometheus-node-exporter-configuration
18133 (web-listen-address ":9100")))
18137 @deftp {Data Type} prometheus-node-exporter-configuration
18138 Data type representing the configuration of @command{node_exporter}.
18141 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18142 The prometheus-node-exporter package to use.
18144 @item @code{web-listen-address} (default: @code{":9100"})
18145 Bind the web interface to the specified address.
18150 @subsubheading Zabbix server
18151 @cindex zabbix zabbix-server
18152 Zabbix provides monitoring metrics, among others network utilization, CPU load
18153 and disk space consumption:
18156 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18157 @item Auto-discovery of servers and network devices and interfaces.
18158 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18159 @item Distributed monitoring with centralized web administration.
18160 @item Native high performance agents.
18161 @item SLA, and ITIL KPI metrics on reporting.
18162 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18163 @item Remote command execution through Zabbix proxies.
18166 @c %start of fragment
18168 Available @code{zabbix-server-configuration} fields are:
18170 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18171 The zabbix-server package.
18175 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18176 User who will run the Zabbix server.
18178 Defaults to @samp{"zabbix"}.
18182 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18183 Group who will run the Zabbix server.
18185 Defaults to @samp{"zabbix"}.
18189 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18190 Database host name.
18192 Defaults to @samp{"127.0.0.1"}.
18196 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18199 Defaults to @samp{"zabbix"}.
18203 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18206 Defaults to @samp{"zabbix"}.
18210 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18211 Database password. Please, use @code{include-files} with
18212 @code{DBPassword=SECRET} inside a specified file instead.
18214 Defaults to @samp{""}.
18218 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18221 Defaults to @samp{5432}.
18225 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18226 Specifies where log messages are written to:
18230 @code{system} - syslog.
18233 @code{file} - file specified with @code{log-file} parameter.
18236 @code{console} - standard output.
18240 Defaults to @samp{""}.
18244 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18245 Log file name for @code{log-type} @code{file} parameter.
18247 Defaults to @samp{"/var/log/zabbix/server.log"}.
18251 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18254 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18258 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18259 The location of certificate authority (CA) files for SSL server
18260 certificate verification.
18262 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18266 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18267 Location of SSL client certificates.
18269 Defaults to @samp{"/etc/ssl/certs"}.
18273 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18274 Extra options will be appended to Zabbix server configuration file.
18276 Defaults to @samp{""}.
18280 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18281 You may include individual files or all files in a directory in the
18282 configuration file.
18284 Defaults to @samp{()}.
18288 @c %end of fragment
18290 @subsubheading Zabbix agent
18291 @cindex zabbix zabbix-agent
18293 Zabbix agent gathers information for Zabbix server.
18295 @c %start of fragment
18297 Available @code{zabbix-agent-configuration} fields are:
18299 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
18300 The zabbix-agent package.
18304 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
18305 User who will run the Zabbix agent.
18307 Defaults to @samp{"zabbix"}.
18311 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
18312 Group who will run the Zabbix agent.
18314 Defaults to @samp{"zabbix"}.
18318 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
18319 Unique, case sensitive hostname which is required for active checks and
18320 must match hostname as configured on the server.
18322 Defaults to @samp{"Zabbix server"}.
18326 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
18327 Specifies where log messages are written to:
18331 @code{system} - syslog.
18334 @code{file} - file specified with @code{log-file} parameter.
18337 @code{console} - standard output.
18341 Defaults to @samp{""}.
18345 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
18346 Log file name for @code{log-type} @code{file} parameter.
18348 Defaults to @samp{"/var/log/zabbix/agent.log"}.
18352 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
18355 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
18359 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
18360 List of IP addresses, optionally in CIDR notation, or hostnames of
18361 Zabbix servers and Zabbix proxies. Incoming connections will be
18362 accepted only from the hosts listed here.
18364 Defaults to @samp{("127.0.0.1")}.
18368 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
18369 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
18370 proxies for active checks. If port is not specified, default port is
18371 used. If this parameter is not specified, active checks are disabled.
18373 Defaults to @samp{("127.0.0.1")}.
18377 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
18378 Extra options will be appended to Zabbix server configuration file.
18380 Defaults to @samp{""}.
18384 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
18385 You may include individual files or all files in a directory in the
18386 configuration file.
18388 Defaults to @samp{()}.
18392 @c %end of fragment
18394 @subsubheading Zabbix front-end
18395 @cindex zabbix zabbix-front-end
18397 This service provides a WEB interface to Zabbix server.
18399 @c %start of fragment
18401 Available @code{zabbix-front-end-configuration} fields are:
18403 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
18404 NGINX configuration.
18408 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
18409 Database host name.
18411 Defaults to @samp{"localhost"}.
18415 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
18418 Defaults to @samp{5432}.
18422 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
18425 Defaults to @samp{"zabbix"}.
18429 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
18432 Defaults to @samp{"zabbix"}.
18436 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
18437 Database password. Please, use @code{db-secret-file} instead.
18439 Defaults to @samp{""}.
18443 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
18444 Secret file which will be appended to @file{zabbix.conf.php} file. This
18445 file contains credentials for use by Zabbix front-end. You are expected
18446 to create it manually.
18448 Defaults to @samp{""}.
18452 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
18453 Zabbix server hostname.
18455 Defaults to @samp{"localhost"}.
18459 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
18460 Zabbix server port.
18462 Defaults to @samp{10051}.
18467 @c %end of fragment
18469 @node Kerberos Services
18470 @subsection Kerberos Services
18473 The @code{(gnu services kerberos)} module provides services relating to
18474 the authentication protocol @dfn{Kerberos}.
18476 @subsubheading Krb5 Service
18478 Programs using a Kerberos client library normally
18479 expect a configuration file in @file{/etc/krb5.conf}.
18480 This service generates such a file from a definition provided in the
18481 operating system declaration.
18482 It does not cause any daemon to be started.
18484 No ``keytab'' files are provided by this service---you must explicitly create them.
18485 This service is known to work with the MIT client library, @code{mit-krb5}.
18486 Other implementations have not been tested.
18488 @defvr {Scheme Variable} krb5-service-type
18489 A service type for Kerberos 5 clients.
18493 Here is an example of its use:
18495 (service krb5-service-type
18496 (krb5-configuration
18497 (default-realm "EXAMPLE.COM")
18498 (allow-weak-crypto? #t)
18501 (name "EXAMPLE.COM")
18502 (admin-server "groucho.example.com")
18503 (kdc "karl.example.com"))
18506 (admin-server "kerb-admin.argrx.edu")
18507 (kdc "keys.argrx.edu"))))))
18511 This example provides a Kerberos@tie{}5 client configuration which:
18513 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
18514 of which have distinct administration servers and key distribution centers;
18515 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
18516 specified by clients;
18517 @item Accepts services which only support encryption types known to be weak.
18520 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
18521 Only the most commonly used ones are described here.
18522 For a full list, and more detailed explanation of each, see the MIT
18523 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
18527 @deftp {Data Type} krb5-realm
18528 @cindex realm, kerberos
18531 This field is a string identifying the name of the realm.
18532 A common convention is to use the fully qualified DNS name of your organization,
18533 converted to upper case.
18535 @item @code{admin-server}
18536 This field is a string identifying the host where the administration server is
18540 This field is a string identifying the key distribution center
18545 @deftp {Data Type} krb5-configuration
18548 @item @code{allow-weak-crypto?} (default: @code{#f})
18549 If this flag is @code{#t} then services which only offer encryption algorithms
18550 known to be weak will be accepted.
18552 @item @code{default-realm} (default: @code{#f})
18553 This field should be a string identifying the default Kerberos
18554 realm for the client.
18555 You should set this field to the name of your Kerberos realm.
18556 If this value is @code{#f}
18557 then a realm must be specified with every Kerberos principal when invoking programs
18558 such as @command{kinit}.
18560 @item @code{realms}
18561 This should be a non-empty list of @code{krb5-realm} objects, which clients may
18563 Normally, one of them will have a @code{name} field matching the @code{default-realm}
18569 @subsubheading PAM krb5 Service
18572 The @code{pam-krb5} service allows for login authentication and password
18573 management via Kerberos.
18574 You will need this service if you want PAM enabled applications to authenticate
18575 users using Kerberos.
18577 @defvr {Scheme Variable} pam-krb5-service-type
18578 A service type for the Kerberos 5 PAM module.
18581 @deftp {Data Type} pam-krb5-configuration
18582 Data type representing the configuration of the Kerberos 5 PAM module.
18583 This type has the following parameters:
18585 @item @code{pam-krb5} (default: @code{pam-krb5})
18586 The pam-krb5 package to use.
18588 @item @code{minimum-uid} (default: @code{1000})
18589 The smallest user ID for which Kerberos authentications should be attempted.
18590 Local accounts with lower values will silently fail to authenticate.
18595 @node LDAP Services
18596 @subsection LDAP Services
18598 @cindex nslcd, LDAP service
18600 The @code{(gnu services authentication)} module provides the
18601 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
18602 server. In addition to configuring the service itself, you may want to add
18603 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
18604 Switch} for detailed information.
18606 Here is a simple operating system declaration with a default configuration of
18607 the @code{nslcd-service-type} and a Name Service Switch configuration that
18608 consults the @code{ldap} name service last:
18611 (use-service-modules authentication)
18612 (use-modules (gnu system nss))
18618 (service nslcd-service-type)
18619 (service dhcp-client-service-type)
18621 (name-service-switch
18622 (let ((services (list (name-service (name "db"))
18623 (name-service (name "files"))
18624 (name-service (name "ldap")))))
18625 (name-service-switch
18626 (inherit %mdns-host-lookup-nss)
18627 (password services)
18630 (netgroup services)
18631 (gshadow services)))))
18634 @c %start of generated documentation for nslcd-configuration
18636 Available @code{nslcd-configuration} fields are:
18638 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
18639 The @code{nss-pam-ldapd} package to use.
18643 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
18644 The number of threads to start that can handle requests and perform LDAP
18645 queries. Each thread opens a separate connection to the LDAP server.
18646 The default is to start 5 threads.
18648 Defaults to @samp{disabled}.
18652 @deftypevr {@code{nslcd-configuration} parameter} string uid
18653 This specifies the user id with which the daemon should be run.
18655 Defaults to @samp{"nslcd"}.
18659 @deftypevr {@code{nslcd-configuration} parameter} string gid
18660 This specifies the group id with which the daemon should be run.
18662 Defaults to @samp{"nslcd"}.
18666 @deftypevr {@code{nslcd-configuration} parameter} log-option log
18667 This option controls the way logging is done via a list containing
18668 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
18669 or "syslog", or an absolute file name. The LEVEL argument is optional
18670 and specifies the log level. The log level may be one of the following
18671 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
18672 messages with the specified log level or higher are logged.
18674 Defaults to @samp{("/var/log/nslcd" info)}.
18678 @deftypevr {@code{nslcd-configuration} parameter} list uri
18679 The list of LDAP server URIs. Normally, only the first server will be
18680 used with the following servers as fall-back.
18682 Defaults to @samp{("ldap://localhost:389/")}.
18686 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
18687 The version of the LDAP protocol to use. The default is to use the
18688 maximum version supported by the LDAP library.
18690 Defaults to @samp{disabled}.
18694 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
18695 Specifies the distinguished name with which to bind to the directory
18696 server for lookups. The default is to bind anonymously.
18698 Defaults to @samp{disabled}.
18702 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
18703 Specifies the credentials with which to bind. This option is only
18704 applicable when used with binddn.
18706 Defaults to @samp{disabled}.
18710 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
18711 Specifies the distinguished name to use when the root user tries to
18712 modify a user's password using the PAM module.
18714 Defaults to @samp{disabled}.
18718 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
18719 Specifies the credentials with which to bind if the root user tries to
18720 change a user's password. This option is only applicable when used with
18723 Defaults to @samp{disabled}.
18727 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
18728 Specifies the SASL mechanism to be used when performing SASL
18731 Defaults to @samp{disabled}.
18735 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
18736 Specifies the SASL realm to be used when performing SASL authentication.
18738 Defaults to @samp{disabled}.
18742 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
18743 Specifies the authentication identity to be used when performing SASL
18746 Defaults to @samp{disabled}.
18750 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
18751 Specifies the authorization identity to be used when performing SASL
18754 Defaults to @samp{disabled}.
18758 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
18759 Determines whether the LDAP server host name should be canonicalised. If
18760 this is enabled the LDAP library will do a reverse host name lookup. By
18761 default, it is left up to the LDAP library whether this check is
18764 Defaults to @samp{disabled}.
18768 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
18769 Set the name for the GSS-API Kerberos credentials cache.
18771 Defaults to @samp{disabled}.
18775 @deftypevr {@code{nslcd-configuration} parameter} string base
18776 The directory search base.
18778 Defaults to @samp{"dc=example,dc=com"}.
18782 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
18783 Specifies the search scope (subtree, onelevel, base or children). The
18784 default scope is subtree; base scope is almost never useful for name
18785 service lookups; children scope is not supported on all servers.
18787 Defaults to @samp{(subtree)}.
18791 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
18792 Specifies the policy for dereferencing aliases. The default policy is
18793 to never dereference aliases.
18795 Defaults to @samp{disabled}.
18799 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
18800 Specifies whether automatic referral chasing should be enabled. The
18801 default behaviour is to chase referrals.
18803 Defaults to @samp{disabled}.
18807 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
18808 This option allows for custom attributes to be looked up instead of the
18809 default RFC 2307 attributes. It is a list of maps, each consisting of
18810 the name of a map, the RFC 2307 attribute to match and the query
18811 expression for the attribute as it is available in the directory.
18813 Defaults to @samp{()}.
18817 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
18818 A list of filters consisting of the name of a map to which the filter
18819 applies and an LDAP search filter expression.
18821 Defaults to @samp{()}.
18825 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
18826 Specifies the time limit in seconds to use when connecting to the
18827 directory server. The default value is 10 seconds.
18829 Defaults to @samp{disabled}.
18833 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
18834 Specifies the time limit (in seconds) to wait for a response from the
18835 LDAP server. A value of zero, which is the default, is to wait
18836 indefinitely for searches to be completed.
18838 Defaults to @samp{disabled}.
18842 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
18843 Specifies the period if inactivity (in seconds) after which the con‐
18844 nection to the LDAP server will be closed. The default is not to time
18847 Defaults to @samp{disabled}.
18851 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
18852 Specifies the number of seconds to sleep when connecting to all LDAP
18853 servers fails. By default one second is waited between the first
18854 failure and the first retry.
18856 Defaults to @samp{disabled}.
18860 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
18861 Specifies the time after which the LDAP server is considered to be
18862 permanently unavailable. Once this time is reached retries will be done
18863 only once per this time period. The default value is 10 seconds.
18865 Defaults to @samp{disabled}.
18869 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
18870 Specifies whether to use SSL/TLS or not (the default is not to). If
18871 'start-tls is specified then StartTLS is used rather than raw LDAP over
18874 Defaults to @samp{disabled}.
18878 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
18879 Specifies what checks to perform on a server-supplied certificate. The
18880 meaning of the values is described in the ldap.conf(5) manual page.
18882 Defaults to @samp{disabled}.
18886 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
18887 Specifies the directory containing X.509 certificates for peer authen‐
18888 tication. This parameter is ignored when using GnuTLS.
18890 Defaults to @samp{disabled}.
18894 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
18895 Specifies the path to the X.509 certificate for peer authentication.
18897 Defaults to @samp{disabled}.
18901 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
18902 Specifies the path to an entropy source. This parameter is ignored when
18905 Defaults to @samp{disabled}.
18909 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
18910 Specifies the ciphers to use for TLS as a string.
18912 Defaults to @samp{disabled}.
18916 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
18917 Specifies the path to the file containing the local certificate for
18918 client TLS authentication.
18920 Defaults to @samp{disabled}.
18924 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
18925 Specifies the path to the file containing the private key for client TLS
18928 Defaults to @samp{disabled}.
18932 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
18933 Set this to a number greater than 0 to request paged results from the
18934 LDAP server in accordance with RFC2696. The default (0) is to not
18935 request paged results.
18937 Defaults to @samp{disabled}.
18941 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
18942 This option prevents group membership lookups through LDAP for the
18943 specified users. Alternatively, the value 'all-local may be used. With
18944 that value nslcd builds a full list of non-LDAP users on startup.
18946 Defaults to @samp{disabled}.
18950 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
18951 This option ensures that LDAP users with a numeric user id lower than
18952 the specified value are ignored.
18954 Defaults to @samp{disabled}.
18958 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
18959 This option specifies an offset that is added to all LDAP numeric user
18960 ids. This can be used to avoid user id collisions with local users.
18962 Defaults to @samp{disabled}.
18966 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
18967 This option specifies an offset that is added to all LDAP numeric group
18968 ids. This can be used to avoid user id collisions with local groups.
18970 Defaults to @samp{disabled}.
18974 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
18975 If this option is set, the member attribute of a group may point to
18976 another group. Members of nested groups are also returned in the higher
18977 level group and parent groups are returned when finding groups for a
18978 specific user. The default is not to perform extra searches for nested
18981 Defaults to @samp{disabled}.
18985 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
18986 If this option is set, the group member list is not retrieved when
18987 looking up groups. Lookups for finding which groups a user belongs to
18988 will remain functional so the user will likely still get the correct
18989 groups assigned on login.
18991 Defaults to @samp{disabled}.
18995 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
18996 If this option is set, functions which cause all user/group entries to
18997 be loaded from the directory will not succeed in doing so. This can
18998 dramatically reduce LDAP server load in situations where there are a
18999 great number of users and/or groups. This option is not recommended for
19000 most configurations.
19002 Defaults to @samp{disabled}.
19006 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19007 This option can be used to specify how user and group names are verified
19008 within the system. This pattern is used to check all user and group
19009 names that are requested and returned from LDAP.
19011 Defaults to @samp{disabled}.
19015 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19016 This specifies whether or not to perform searches using case-insensitive
19017 matching. Enabling this could open up the system to authorization
19018 bypass vulnerabilities and introduce nscd cache poisoning
19019 vulnerabilities which allow denial of service.
19021 Defaults to @samp{disabled}.
19025 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19026 This option specifies whether password policy controls are requested and
19027 handled from the LDAP server when performing user authentication.
19029 Defaults to @samp{disabled}.
19033 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19034 By default nslcd performs an LDAP search with the user's credentials
19035 after BIND (authentication) to ensure that the BIND operation was
19036 successful. The default search is a simple check to see if the user's
19037 DN exists. A search filter can be specified that will be used instead.
19038 It should return at least one entry.
19040 Defaults to @samp{disabled}.
19044 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19045 This option allows flexible fine tuning of the authorisation check that
19046 should be performed. The search filter specified is executed and if any
19047 entries match, access is granted, otherwise access is denied.
19049 Defaults to @samp{disabled}.
19053 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19054 If this option is set password modification using pam_ldap will be
19055 denied and the specified message will be presented to the user instead.
19056 The message can be used to direct the user to an alternative means of
19057 changing their password.
19059 Defaults to @samp{disabled}.
19063 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19064 List of pam service names for which LDAP authentication should suffice.
19066 Defaults to @samp{()}.
19070 @c %end of generated documentation for nslcd-configuration
19074 @subsection Web Services
19079 The @code{(gnu services web)} module provides the Apache HTTP Server,
19080 the nginx web server, and also a fastcgi wrapper daemon.
19082 @subsubheading Apache HTTP Server
19084 @deffn {Scheme Variable} httpd-service-type
19085 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19086 (@dfn{httpd}). The value for this service type is a
19087 @code{httpd-configuration} record.
19089 A simple example configuration is given below.
19092 (service httpd-service-type
19093 (httpd-configuration
19096 (server-name "www.example.com")
19097 (document-root "/srv/http/www.example.com")))))
19100 Other services can also extend the @code{httpd-service-type} to add to
19104 (simple-service 'my-extra-server httpd-service-type
19108 (list (string-append
19109 "ServerName "www.example.com
19110 DocumentRoot \"/srv/http/www.example.com\"")))))
19114 The details for the @code{httpd-configuration}, @code{httpd-module},
19115 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19118 @deffn {Data Type} httpd-configuration
19119 This data type represents the configuration for the httpd service.
19122 @item @code{package} (default: @code{httpd})
19123 The httpd package to use.
19125 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19126 The pid file used by the shepherd-service.
19128 @item @code{config} (default: @code{(httpd-config-file)})
19129 The configuration file to use with the httpd service. The default value
19130 is a @code{httpd-config-file} record, but this can also be a different
19131 G-expression that generates a file, for example a @code{plain-file}. A
19132 file outside of the store can also be specified through a string.
19137 @deffn {Data Type} httpd-module
19138 This data type represents a module for the httpd service.
19142 The name of the module.
19145 The file for the module. This can be relative to the httpd package being
19146 used, the absolute location of a file, or a G-expression for a file
19147 within the store, for example @code{(file-append mod-wsgi
19148 "/modules/mod_wsgi.so")}.
19153 @defvr {Scheme Variable} %default-httpd-modules
19154 A default list of @code{httpd-module} objects.
19157 @deffn {Data Type} httpd-config-file
19158 This data type represents a configuration file for the httpd service.
19161 @item @code{modules} (default: @code{%default-httpd-modules})
19162 The modules to load. Additional modules can be added here, or loaded by
19163 additional configuration.
19165 For example, in order to handle requests for PHP files, you can use Apache’s
19166 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19169 (service httpd-service-type
19170 (httpd-configuration
19175 (name "proxy_module")
19176 (file "modules/mod_proxy.so"))
19178 (name "proxy_fcgi_module")
19179 (file "modules/mod_proxy_fcgi.so"))
19180 %default-httpd-modules))
19181 (extra-config (list "\
19182 <FilesMatch \\.php$>
19183 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19184 </FilesMatch>"))))))
19185 (service php-fpm-service-type
19186 (php-fpm-configuration
19187 (socket "/var/run/php-fpm.sock")
19188 (socket-group "httpd")))
19191 @item @code{server-root} (default: @code{httpd})
19192 The @code{ServerRoot} in the configuration file, defaults to the httpd
19193 package. Directives including @code{Include} and @code{LoadModule} are
19194 taken as relative to the server root.
19196 @item @code{server-name} (default: @code{#f})
19197 The @code{ServerName} in the configuration file, used to specify the
19198 request scheme, hostname and port that the server uses to identify
19201 This doesn't need to be set in the server config, and can be specifyed
19202 in virtual hosts. The default is @code{#f} to not specify a
19205 @item @code{document-root} (default: @code{"/srv/http"})
19206 The @code{DocumentRoot} from which files will be served.
19208 @item @code{listen} (default: @code{'("80")})
19209 The list of values for the @code{Listen} directives in the config
19210 file. The value should be a list of strings, when each string can
19211 specify the port number to listen on, and optionally the IP address and
19214 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19215 The @code{PidFile} to use. This should match the @code{pid-file} set in
19216 the @code{httpd-configuration} so that the Shepherd service is
19217 configured correctly.
19219 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19220 The @code{ErrorLog} to which the server will log errors.
19222 @item @code{user} (default: @code{"httpd"})
19223 The @code{User} which the server will answer requests as.
19225 @item @code{group} (default: @code{"httpd"})
19226 The @code{Group} which the server will answer requests as.
19228 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19229 A flat list of strings and G-expressions which will be added to the end
19230 of the configuration file.
19232 Any values which the service is extended with will be appended to this
19238 @deffn {Data Type} httpd-virtualhost
19239 This data type represents a virtualhost configuration block for the httpd service.
19241 These should be added to the extra-config for the httpd-service.
19244 (simple-service 'my-extra-server httpd-service-type
19248 (list (string-append
19249 "ServerName "www.example.com
19250 DocumentRoot \"/srv/http/www.example.com\"")))))
19254 @item @code{addresses-and-ports}
19255 The addresses and ports for the @code{VirtualHost} directive.
19257 @item @code{contents}
19258 The contents of the @code{VirtualHost} directive, this should be a list
19259 of strings and G-expressions.
19264 @subsubheading NGINX
19266 @deffn {Scheme Variable} nginx-service-type
19267 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19268 value for this service type is a @code{<nginx-configuration>} record.
19270 A simple example configuration is given below.
19273 (service nginx-service-type
19274 (nginx-configuration
19276 (list (nginx-server-configuration
19277 (server-name '("www.example.com"))
19278 (root "/srv/http/www.example.com"))))))
19281 In addition to adding server blocks to the service configuration
19282 directly, this service can be extended by other services to add server
19283 blocks, as in this example:
19286 (simple-service 'my-extra-server nginx-service-type
19287 (list (nginx-server-configuration
19288 (root "/srv/http/extra-website")
19289 (try-files (list "$uri" "$uri/index.html")))))
19293 At startup, @command{nginx} has not yet read its configuration file, so
19294 it uses a default file to log error messages. If it fails to load its
19295 configuration file, that is where error messages are logged. After the
19296 configuration file is loaded, the default error log file changes as per
19297 configuration. In our case, startup error messages can be found in
19298 @file{/var/run/nginx/logs/error.log}, and after configuration in
19299 @file{/var/log/nginx/error.log}. The second location can be changed
19300 with the @var{log-directory} configuration option.
19302 @deffn {Data Type} nginx-configuration
19303 This data type represents the configuration for NGinx. Some
19304 configuration can be done through this and the other provided record
19305 types, or alternatively, a config file can be provided.
19308 @item @code{nginx} (default: @code{nginx})
19309 The nginx package to use.
19311 @item @code{log-directory} (default: @code{"/var/log/nginx"})
19312 The directory to which NGinx will write log files.
19314 @item @code{run-directory} (default: @code{"/var/run/nginx"})
19315 The directory in which NGinx will create a pid file, and write temporary
19318 @item @code{server-blocks} (default: @code{'()})
19319 A list of @dfn{server blocks} to create in the generated configuration
19320 file, the elements should be of type
19321 @code{<nginx-server-configuration>}.
19323 The following example would setup NGinx to serve @code{www.example.com}
19324 from the @code{/srv/http/www.example.com} directory, without using
19327 (service nginx-service-type
19328 (nginx-configuration
19330 (list (nginx-server-configuration
19331 (server-name '("www.example.com"))
19332 (root "/srv/http/www.example.com"))))))
19335 @item @code{upstream-blocks} (default: @code{'()})
19336 A list of @dfn{upstream blocks} to create in the generated configuration
19337 file, the elements should be of type
19338 @code{<nginx-upstream-configuration>}.
19340 Configuring upstreams through the @code{upstream-blocks} can be useful
19341 when combined with @code{locations} in the
19342 @code{<nginx-server-configuration>} records. The following example
19343 creates a server configuration with one location configuration, that
19344 will proxy requests to a upstream configuration, which will handle
19345 requests with two servers.
19350 (nginx-configuration
19352 (list (nginx-server-configuration
19353 (server-name '("www.example.com"))
19354 (root "/srv/http/www.example.com")
19357 (nginx-location-configuration
19359 (body '("proxy_pass http://server-proxy;"))))))))
19361 (list (nginx-upstream-configuration
19362 (name "server-proxy")
19363 (servers (list "server1.example.com"
19364 "server2.example.com")))))))
19367 @item @code{file} (default: @code{#f})
19368 If a configuration @var{file} is provided, this will be used, rather than
19369 generating a configuration file from the provided @code{log-directory},
19370 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
19371 proper operation, these arguments should match what is in @var{file} to ensure
19372 that the directories are created when the service is activated.
19374 This can be useful if you have an existing configuration file, or it's
19375 not possible to do what is required through the other parts of the
19376 nginx-configuration record.
19378 @item @code{server-names-hash-bucket-size} (default: @code{#f})
19379 Bucket size for the server names hash tables, defaults to @code{#f} to
19380 use the size of the processors cache line.
19382 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
19383 Maximum bucket size for the server names hash tables.
19385 @item @code{extra-content} (default: @code{""})
19386 Extra content for the @code{http} block. Should be string or a string
19387 valued G-expression.
19392 @deftp {Data Type} nginx-server-configuration
19393 Data type representing the configuration of an nginx server block.
19394 This type has the following parameters:
19397 @item @code{listen} (default: @code{'("80" "443 ssl")})
19398 Each @code{listen} directive sets the address and port for IP, or the
19399 path for a UNIX-domain socket on which the server will accept requests.
19400 Both address and port, or only address or only port can be specified.
19401 An address may also be a hostname, for example:
19404 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
19407 @item @code{server-name} (default: @code{(list 'default)})
19408 A list of server names this server represents. @code{'default} represents the
19409 default server for connections matching no other server.
19411 @item @code{root} (default: @code{"/srv/http"})
19412 Root of the website nginx will serve.
19414 @item @code{locations} (default: @code{'()})
19415 A list of @dfn{nginx-location-configuration} or
19416 @dfn{nginx-named-location-configuration} records to use within this
19419 @item @code{index} (default: @code{(list "index.html")})
19420 Index files to look for when clients ask for a directory. If it cannot be found,
19421 Nginx will send the list of files in the directory.
19423 @item @code{try-files} (default: @code{'()})
19424 A list of files whose existence is checked in the specified order.
19425 @code{nginx} will use the first file it finds to process the request.
19427 @item @code{ssl-certificate} (default: @code{#f})
19428 Where to find the certificate for secure connections. Set it to @code{#f} if
19429 you don't have a certificate or you don't want to use HTTPS.
19431 @item @code{ssl-certificate-key} (default: @code{#f})
19432 Where to find the private key for secure connections. Set it to @code{#f} if
19433 you don't have a key or you don't want to use HTTPS.
19435 @item @code{server-tokens?} (default: @code{#f})
19436 Whether the server should add its configuration to response.
19438 @item @code{raw-content} (default: @code{'()})
19439 A list of raw lines added to the server block.
19444 @deftp {Data Type} nginx-upstream-configuration
19445 Data type representing the configuration of an nginx @code{upstream}
19446 block. This type has the following parameters:
19450 Name for this group of servers.
19452 @item @code{servers}
19453 Specify the addresses of the servers in the group. The address can be
19454 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
19455 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
19456 prefix @samp{unix:}. For addresses using an IP address or domain name,
19457 the default port is 80, and a different port can be specified
19463 @deftp {Data Type} nginx-location-configuration
19464 Data type representing the configuration of an nginx @code{location}
19465 block. This type has the following parameters:
19469 URI which this location block matches.
19471 @anchor{nginx-location-configuration body}
19473 Body of the location block, specified as a list of strings. This can contain
19475 configuration directives. For example, to pass requests to a upstream
19476 server group defined using an @code{nginx-upstream-configuration} block,
19477 the following directive would be specified in the body @samp{(list "proxy_pass
19478 http://upstream-name;")}.
19483 @deftp {Data Type} nginx-named-location-configuration
19484 Data type representing the configuration of an nginx named location
19485 block. Named location blocks are used for request redirection, and not
19486 used for regular request processing. This type has the following
19491 Name to identify this location block.
19494 @xref{nginx-location-configuration body}, as the body for named location
19495 blocks can be used in a similar way to the
19496 @code{nginx-location-configuration body}. One restriction is that the
19497 body of a named location block cannot contain location blocks.
19502 @subsubheading Varnish Cache
19504 Varnish is a fast cache server that sits in between web applications
19505 and end users. It proxies requests from clients and caches the
19506 accessed URLs such that multiple requests for the same resource only
19507 creates one request to the back-end.
19509 @defvr {Scheme Variable} varnish-service-type
19510 Service type for the Varnish daemon.
19513 @deftp {Data Type} varnish-configuration
19514 Data type representing the @code{varnish} service configuration.
19515 This type has the following parameters:
19518 @item @code{package} (default: @code{varnish})
19519 The Varnish package to use.
19521 @item @code{name} (default: @code{"default"})
19522 A name for this Varnish instance. Varnish will create a directory in
19523 @file{/var/varnish/} with this name and keep temporary files there. If
19524 the name starts with a forward slash, it is interpreted as an absolute
19527 Pass the @code{-n} argument to other Varnish programs to connect to the
19528 named instance, e.g.@: @command{varnishncsa -n default}.
19530 @item @code{backend} (default: @code{"localhost:8080"})
19531 The backend to use. This option has no effect if @code{vcl} is set.
19533 @item @code{vcl} (default: #f)
19534 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
19535 is @code{#f}, Varnish will proxy @code{backend} using the default
19536 configuration. Otherwise this must be a file-like object with valid
19539 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
19540 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
19541 can do something along these lines:
19544 (define %gnu-mirror
19548 backend gnu @{ .host = "www.gnu.org"; @}"))
19552 (services (cons (service varnish-service-type
19553 (varnish-configuration
19555 (vcl %gnu-mirror)))
19559 The configuration of an already running Varnish instance can be inspected
19560 and changed using the @command{varnishadm} program.
19562 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
19563 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
19564 comprehensive documentation on Varnish and its configuration language.
19566 @item @code{listen} (default: @code{'("localhost:80")})
19567 List of addresses Varnish will listen on.
19569 @item @code{storage} (default: @code{'("malloc,128m")})
19570 List of storage backends that will be available in VCL.
19572 @item @code{parameters} (default: @code{'()})
19573 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
19575 @item @code{extra-options} (default: @code{'()})
19576 Additional arguments to pass to the @command{varnishd} process.
19581 @subsubheading Patchwork
19583 Patchwork is a patch tracking system. It can collect patches sent to a
19584 mailing list, and display them in a web interface.
19586 @defvr {Scheme Variable} patchwork-service-type
19587 Service type for Patchwork.
19590 The following example is an example of a minimal service for Patchwork, for
19591 the @code{patchwork.example.com} domain.
19594 (service patchwork-service-type
19595 (patchwork-configuration
19596 (domain "patchwork.example.com")
19598 (patchwork-settings-module
19599 (allowed-hosts (list domain))
19600 (default-from-email "patchwork@@patchwork.example.com")))
19601 (getmail-retriever-config
19602 (getmail-retriever-configuration
19603 (type "SimpleIMAPSSLRetriever")
19604 (server "imap.example.com")
19606 (username "patchwork")
19608 (list (file-append coreutils "/bin/cat")
19609 "/etc/getmail-patchwork-imap-password"))
19611 '((mailboxes . ("Patches"))))))))
19615 There are three records for configuring the Patchwork service. The
19616 @code{<patchwork-configuration>} relates to the configuration for Patchwork
19617 within the HTTPD service.
19619 The @code{settings-module} field within the @code{<patchwork-configuration>}
19620 record can be populated with the @code{<patchwork-settings-module>} record,
19621 which describes a settings module that is generated within the Guix store.
19623 For the @code{database-configuration} field within the
19624 @code{<patchwork-settings-module>}, the
19625 @code{<patchwork-database-configuration>} must be used.
19627 @deftp {Data Type} patchwork-configuration
19628 Data type representing the Patchwork service configuration. This type has the
19629 following parameters:
19632 @item @code{patchwork} (default: @code{patchwork})
19633 The Patchwork package to use.
19635 @item @code{domain}
19636 The domain to use for Patchwork, this is used in the HTTPD service virtual
19639 @item @code{settings-module}
19640 The settings module to use for Patchwork. As a Django application, Patchwork
19641 is configured with a Python module containing the settings. This can either be
19642 an instance of the @code{<patchwork-settings-module>} record, any other record
19643 that represents the settings in the store, or a directory outside of the
19646 @item @code{static-path} (default: @code{"/static/"})
19647 The path under which the HTTPD service should serve the static files.
19649 @item @code{getmail-retriever-config}
19650 The getmail-retriever-configuration record value to use with
19651 Patchwork. Getmail will be configured with this value, the messages will be
19652 delivered to Patchwork.
19657 @deftp {Data Type} patchwork-settings-module
19658 Data type representing a settings module for Patchwork. Some of these
19659 settings relate directly to Patchwork, but others relate to Django, the web
19660 framework used by Patchwork, or the Django Rest Framework library. This type
19661 has the following parameters:
19664 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
19665 The database connection settings used for Patchwork. See the
19666 @code{<patchwork-database-configuration>} record type for more information.
19668 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
19669 Patchwork, as a Django web application uses a secret key for cryptographically
19670 signing values. This file should contain a unique unpredictable value.
19672 If this file does not exist, it will be created and populated with a random
19673 value by the patchwork-setup shepherd service.
19675 This setting relates to Django.
19677 @item @code{allowed-hosts}
19678 A list of valid hosts for this Patchwork service. This should at least include
19679 the domain specified in the @code{<patchwork-configuration>} record.
19681 This is a Django setting.
19683 @item @code{default-from-email}
19684 The email address from which Patchwork should send email by default.
19686 This is a Patchwork setting.
19688 @item @code{static-url} (default: @code{#f})
19689 The URL to use when serving static assets. It can be part of a URL, or a full
19690 URL, but must end in a @code{/}.
19692 If the default value is used, the @code{static-path} value from the
19693 @code{<patchwork-configuration>} record will be used.
19695 This is a Django setting.
19697 @item @code{admins} (default: @code{'()})
19698 Email addresses to send the details of errors that occur. Each value should
19699 be a list containing two elements, the name and then the email address.
19701 This is a Django setting.
19703 @item @code{debug?} (default: @code{#f})
19704 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
19705 messages will be shown.
19707 This is a Django setting.
19709 @item @code{enable-rest-api?} (default: @code{#t})
19710 Whether to enable the Patchwork REST API.
19712 This is a Patchwork setting.
19714 @item @code{enable-xmlrpc?} (default: @code{#t})
19715 Whether to enable the XML RPC API.
19717 This is a Patchwork setting.
19719 @item @code{force-https-links?} (default: @code{#t})
19720 Whether to use HTTPS links on Patchwork pages.
19722 This is a Patchwork setting.
19724 @item @code{extra-settings} (default: @code{""})
19725 Extra code to place at the end of the Patchwork settings module.
19730 @deftp {Data Type} patchwork-database-configuration
19731 Data type representing the database configuration for Patchwork.
19734 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
19735 The database engine to use.
19737 @item @code{name} (default: @code{"patchwork"})
19738 The name of the database to use.
19740 @item @code{user} (default: @code{"httpd"})
19741 The user to connect to the database as.
19743 @item @code{password} (default: @code{""})
19744 The password to use when connecting to the database.
19746 @item @code{host} (default: @code{""})
19747 The host to make the database connection to.
19749 @item @code{port} (default: @code{""})
19750 The port on which to connect to the database.
19755 @subsubheading FastCGI
19758 FastCGI is an interface between the front-end and the back-end of a web
19759 service. It is a somewhat legacy facility; new web services should
19760 generally just talk HTTP between the front-end and the back-end.
19761 However there are a number of back-end services such as PHP or the
19762 optimized HTTP Git repository access that use FastCGI, so we have
19763 support for it in Guix.
19765 To use FastCGI, you configure the front-end web server (e.g., nginx) to
19766 dispatch some subset of its requests to the fastcgi backend, which
19767 listens on a local TCP or UNIX socket. There is an intermediary
19768 @code{fcgiwrap} program that sits between the actual backend process and
19769 the web server. The front-end indicates which backend program to run,
19770 passing that information to the @code{fcgiwrap} process.
19772 @defvr {Scheme Variable} fcgiwrap-service-type
19773 A service type for the @code{fcgiwrap} FastCGI proxy.
19776 @deftp {Data Type} fcgiwrap-configuration
19777 Data type representing the configuration of the @code{fcgiwrap} service.
19778 This type has the following parameters:
19780 @item @code{package} (default: @code{fcgiwrap})
19781 The fcgiwrap package to use.
19783 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
19784 The socket on which the @code{fcgiwrap} process should listen, as a
19785 string. Valid @var{socket} values include
19786 @code{unix:@var{/path/to/unix/socket}},
19787 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
19788 @code{tcp6:[@var{ipv6_addr}]:port}.
19790 @item @code{user} (default: @code{fcgiwrap})
19791 @itemx @code{group} (default: @code{fcgiwrap})
19792 The user and group names, as strings, under which to run the
19793 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
19794 the user asks for the specific user or group names @code{fcgiwrap} that
19795 the corresponding user and/or group is present on the system.
19797 It is possible to configure a FastCGI-backed web service to pass HTTP
19798 authentication information from the front-end to the back-end, and to
19799 allow @code{fcgiwrap} to run the back-end process as a corresponding
19800 local user. To enable this capability on the back-end., run
19801 @code{fcgiwrap} as the @code{root} user and group. Note that this
19802 capability also has to be configured on the front-end as well.
19807 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
19808 with some additional features useful for sites of any size.
19810 These features include:
19812 @item Adaptive process spawning
19813 @item Basic statistics (similar to Apache's mod_status)
19814 @item Advanced process management with graceful stop/start
19815 @item Ability to start workers with different uid/gid/chroot/environment
19816 and different php.ini (replaces safe_mode)
19817 @item Stdout & stderr logging
19818 @item Emergency restart in case of accidental opcode cache destruction
19819 @item Accelerated upload support
19820 @item Support for a "slowlog"
19821 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
19822 a special function to finish request & flush all data while continuing to do
19823 something time-consuming (video converting, stats processing, etc.)
19825 ...@: and much more.
19827 @defvr {Scheme Variable} php-fpm-service-type
19828 A Service type for @code{php-fpm}.
19831 @deftp {Data Type} php-fpm-configuration
19832 Data Type for php-fpm service configuration.
19834 @item @code{php} (default: @code{php})
19835 The php package to use.
19836 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
19837 The address on which to accept FastCGI requests. Valid syntaxes are:
19839 @item @code{"ip.add.re.ss:port"}
19840 Listen on a TCP socket to a specific address on a specific port.
19841 @item @code{"port"}
19842 Listen on a TCP socket to all addresses on a specific port.
19843 @item @code{"/path/to/unix/socket"}
19844 Listen on a unix socket.
19847 @item @code{user} (default: @code{php-fpm})
19848 User who will own the php worker processes.
19849 @item @code{group} (default: @code{php-fpm})
19850 Group of the worker processes.
19851 @item @code{socket-user} (default: @code{php-fpm})
19852 User who can speak to the php-fpm socket.
19853 @item @code{socket-group} (default: @code{php-fpm})
19854 Group that can speak to the php-fpm socket.
19855 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
19856 The process id of the php-fpm process is written to this file
19857 once the service has started.
19858 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
19859 Log for the php-fpm master process.
19860 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
19861 Detailed settings for the php-fpm process manager.
19864 @item @code{<php-fpm-dynamic-process-manager-configuration>}
19865 @item @code{<php-fpm-static-process-manager-configuration>}
19866 @item @code{<php-fpm-on-demand-process-manager-configuration>}
19868 @item @code{display-errors} (default @code{#f})
19869 Determines whether php errors and warning should be sent to clients
19870 and displayed in their browsers.
19871 This is useful for local php development, but a security risk for public sites,
19872 as error messages can reveal passwords and personal data.
19873 @item @code{timezone} (default @code{#f})
19874 Specifies @code{php_admin_value[date.timezone]} parameter.
19875 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
19876 This file will log the @code{stderr} outputs of php worker processes.
19877 Can be set to @code{#f} to disable logging.
19878 @item @code{file} (default @code{#f})
19879 An optional override of the whole configuration.
19880 You can use the @code{mixed-text-file} function or an absolute filepath for it.
19884 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
19885 Data Type for the @code{dynamic} php-fpm process manager. With the
19886 @code{dynamic} process manager, spare worker processes are kept around
19887 based on it's configured limits.
19889 @item @code{max-children} (default: @code{5})
19890 Maximum of worker processes.
19891 @item @code{start-servers} (default: @code{2})
19892 How many worker processes should be started on start-up.
19893 @item @code{min-spare-servers} (default: @code{1})
19894 How many spare worker processes should be kept around at minimum.
19895 @item @code{max-spare-servers} (default: @code{3})
19896 How many spare worker processes should be kept around at maximum.
19900 @deftp {Data type} php-fpm-static-process-manager-configuration
19901 Data Type for the @code{static} php-fpm process manager. With the
19902 @code{static} process manager, an unchanging number of worker processes
19905 @item @code{max-children} (default: @code{5})
19906 Maximum of worker processes.
19910 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
19911 Data Type for the @code{on-demand} php-fpm process manager. With the
19912 @code{on-demand} process manager, worker processes are only created as
19915 @item @code{max-children} (default: @code{5})
19916 Maximum of worker processes.
19917 @item @code{process-idle-timeout} (default: @code{10})
19918 The time in seconds after which a process with no requests is killed.
19923 @deffn {Scheme Procedure} nginx-php-fpm-location @
19924 [#:nginx-package nginx] @
19925 [socket (string-append "/var/run/php" @
19926 (version-major (package-version php)) @
19928 A helper function to quickly add php to an @code{nginx-server-configuration}.
19931 A simple services setup for nginx with php can look like this:
19933 (services (cons* (service dhcp-client-service-type)
19934 (service php-fpm-service-type)
19935 (service nginx-service-type
19936 (nginx-server-configuration
19937 (server-name '("example.com"))
19938 (root "/srv/http/")
19940 (list (nginx-php-location)))
19942 (ssl-certificate #f)
19943 (ssl-certificate-key #f)))
19947 @cindex cat-avatar-generator
19948 The cat avatar generator is a simple service to demonstrate the use of php-fpm
19949 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
19950 the hash of a user's email address.
19952 @deffn {Scheme Procedure} cat-avatar-generator-service @
19953 [#:cache-dir "/var/cache/cat-avatar-generator"] @
19954 [#:package cat-avatar-generator] @
19955 [#:configuration (nginx-server-configuration)]
19956 Returns an nginx-server-configuration that inherits @code{configuration}. It
19957 extends the nginx configuration to add a server block that serves @code{package},
19958 a version of cat-avatar-generator. During execution, cat-avatar-generator will
19959 be able to use @code{cache-dir} as its cache directory.
19962 A simple setup for cat-avatar-generator can look like this:
19964 (services (cons* (cat-avatar-generator-service
19966 (nginx-server-configuration
19967 (server-name '("example.com"))))
19972 @subsubheading Hpcguix-web
19974 @cindex hpcguix-web
19975 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
19976 program is a customizable web interface to browse Guix packages,
19977 initially designed for users of high-performance computing (HPC)
19980 @defvr {Scheme Variable} hpcguix-web-service-type
19981 The service type for @code{hpcguix-web}.
19984 @deftp {Data Type} hpcguix-web-configuration
19985 Data type for the hpcguix-web service configuration.
19989 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
19990 configuration. The main items available in this spec are:
19993 @item @code{title-prefix} (default: @code{"hpcguix | "})
19994 The page title prefix.
19996 @item @code{guix-command} (default: @code{"guix"})
19997 The @command{guix} command.
19999 @item @code{package-filter-proc} (default: @code{(const #t)})
20000 A procedure specifying how to filter packages that are displayed.
20002 @item @code{package-page-extension-proc} (default: @code{(const '())})
20003 Extension package for @code{hpcguix-web}.
20005 @item @code{menu} (default: @code{'()})
20006 Additional entry in page @code{menu}.
20008 @item @code{channels} (default: @code{%default-channels})
20009 List of channels from which the package list is built (@pxref{Channels}).
20011 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20012 The expiration time, in seconds, after which the package list is rebuilt from
20013 the latest instances of the given channels.
20016 See the hpcguix-web repository for a
20017 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20020 @item @code{package} (default: @code{hpcguix-web})
20021 The hpcguix-web package to use.
20025 A typical hpcguix-web service declaration looks like this:
20028 (service hpcguix-web-service-type
20029 (hpcguix-web-configuration
20031 #~(define site-config
20032 (hpcweb-configuration
20033 (title-prefix "Guix-HPC - ")
20034 (menu '(("/about" "ABOUT"))))))))
20038 The hpcguix-web service periodically updates the package list it publishes by
20039 pulling channels from Git. To that end, it needs to access X.509 certificates
20040 so that it can authenticate Git servers when communicating over HTTPS, and it
20041 assumes that @file{/etc/ssl/certs} contains those certificates.
20043 Thus, make sure to add @code{nss-certs} or another certificate package to the
20044 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20045 more information on X.509 certificates.
20048 @node Certificate Services
20049 @subsection Certificate Services
20052 @cindex HTTP, HTTPS
20053 @cindex Let's Encrypt
20054 @cindex TLS certificates
20055 The @code{(gnu services certbot)} module provides a service to
20056 automatically obtain a valid TLS certificate from the Let's Encrypt
20057 certificate authority. These certificates can then be used to serve
20058 content securely over HTTPS or other TLS-based protocols, with the
20059 knowledge that the client will be able to verify the server's
20062 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20063 @code{certbot} tool to automate the certification process. This tool
20064 first securely generates a key on the server. It then makes a request
20065 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20066 checks that the request originates from the host in question by using a
20067 challenge-response protocol, requiring the server to provide its
20068 response over HTTP. If that protocol completes successfully, the CA
20069 signs the key, resulting in a certificate. That certificate is valid
20070 for a limited period of time, and therefore to continue to provide TLS
20071 services, the server needs to periodically ask the CA to renew its
20074 The certbot service automates this process: the initial key
20075 generation, the initial certification request to the Let's Encrypt
20076 service, the web server challenge/response integration, writing the
20077 certificate to disk, the automated periodic renewals, and the deployment
20078 tasks associated with the renewal (e.g.@: reloading services, copying keys
20079 with different permissions).
20081 Certbot is run twice a day, at a random minute within the hour. It
20082 won't do anything until your certificates are due for renewal or
20083 revoked, but running it regularly would give your service a chance of
20084 staying online in case a Let's Encrypt-initiated revocation happened for
20087 By using this service, you agree to the ACME Subscriber Agreement, which
20088 can be found there:
20089 @url{https://acme-v01.api.letsencrypt.org/directory}.
20091 @defvr {Scheme Variable} certbot-service-type
20092 A service type for the @code{certbot} Let's Encrypt client. Its value
20093 must be a @code{certbot-configuration} record as in this example:
20096 (define %nginx-deploy-hook
20098 "nginx-deploy-hook"
20099 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20100 (kill pid SIGHUP))))
20102 (service certbot-service-type
20103 (certbot-configuration
20104 (email "foo@@example.net")
20107 (certificate-configuration
20108 (domains '("example.net" "www.example.net"))
20109 (deploy-hook %nginx-deploy-hook))
20110 (certificate-configuration
20111 (domains '("bar.example.net")))))))
20114 See below for details about @code{certbot-configuration}.
20117 @deftp {Data Type} certbot-configuration
20118 Data type representing the configuration of the @code{certbot} service.
20119 This type has the following parameters:
20122 @item @code{package} (default: @code{certbot})
20123 The certbot package to use.
20125 @item @code{webroot} (default: @code{/var/www})
20126 The directory from which to serve the Let's Encrypt challenge/response
20129 @item @code{certificates} (default: @code{()})
20130 A list of @code{certificates-configuration}s for which to generate
20131 certificates and request signatures. Each certificate has a @code{name}
20132 and several @code{domains}.
20135 Mandatory email used for registration, recovery contact, and important
20136 account notifications.
20138 @item @code{rsa-key-size} (default: @code{2048})
20139 Size of the RSA key.
20141 @item @code{default-location} (default: @i{see below})
20142 The default @code{nginx-location-configuration}. Because @code{certbot}
20143 needs to be able to serve challenges and responses, it needs to be able
20144 to run a web server. It does so by extending the @code{nginx} web
20145 service with an @code{nginx-server-configuration} listening on the
20146 @var{domains} on port 80, and which has a
20147 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20148 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20149 these nginx configuration data types.
20151 Requests to other URL paths will be matched by the
20152 @code{default-location}, which if present is added to all
20153 @code{nginx-server-configuration}s.
20155 By default, the @code{default-location} will issue a redirect from
20156 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20157 you to define what to serve on your site via @code{https}.
20159 Pass @code{#f} to not issue a default location.
20163 @deftp {Data Type} certificate-configuration
20164 Data type representing the configuration of a certificate.
20165 This type has the following parameters:
20168 @item @code{name} (default: @i{see below})
20169 This name is used by Certbot for housekeeping and in file paths; it
20170 doesn't affect the content of the certificate itself. To see
20171 certificate names, run @code{certbot certificates}.
20173 Its default is the first provided domain.
20175 @item @code{domains} (default: @code{()})
20176 The first domain provided will be the subject CN of the certificate, and
20177 all domains will be Subject Alternative Names on the certificate.
20179 @item @code{challenge} (default: @code{#f})
20180 The challenge type that has to be run by certbot. If @code{#f} is specified,
20181 default to the HTTP challenge. If a value is specified, defaults to the
20182 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20183 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}).
20185 @item @code{authentication-hook} (default: @code{#f})
20186 Command to be run in a shell once for each certificate challenge to be
20187 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20188 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20189 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20190 file name of the resource requested when performing an HTTP-01 challenge.
20192 @item @code{cleanup-hook} (default: @code{#f})
20193 Command to be run in a shell once for each certificate challenge that
20194 have been answered by the @code{auth-hook}. For this command, the shell
20195 variables available in the @code{auth-hook} script are still available, and
20196 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20197 of the @code{auth-hook} script.
20199 @item @code{deploy-hook} (default: @code{#f})
20200 Command to be run in a shell once for each successfully issued
20201 certificate. For this command, the shell variable
20202 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20203 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20204 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20205 contain a space-delimited list of renewed certificate domains (for
20206 example, @samp{"example.com www.example.com"}.
20211 For each @code{certificate-configuration}, the certificate is saved to
20212 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20213 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20215 @subsection DNS Services
20216 @cindex DNS (domain name system)
20217 @cindex domain name system (DNS)
20219 The @code{(gnu services dns)} module provides services related to the
20220 @dfn{domain name system} (DNS). It provides a server service for hosting
20221 an @emph{authoritative} DNS server for multiple zones, slave or master.
20222 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20223 caching and forwarding DNS server for the LAN, which uses
20224 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20226 @subsubheading Knot Service
20228 An example configuration of an authoritative server for two zones, one master
20232 (define-zone-entries example.org.zone
20233 ;; Name TTL Class Type Data
20234 ("@@" "" "IN" "A" "127.0.0.1")
20235 ("@@" "" "IN" "NS" "ns")
20236 ("ns" "" "IN" "A" "127.0.0.1"))
20238 (define master-zone
20239 (knot-zone-configuration
20240 (domain "example.org")
20242 (origin "example.org")
20243 (entries example.org.zone)))))
20246 (knot-zone-configuration
20247 (domain "plop.org")
20248 (dnssec-policy "default")
20249 (master (list "plop-master"))))
20251 (define plop-master
20252 (knot-remote-configuration
20254 (address (list "208.76.58.171"))))
20258 (services (cons* (service knot-service-type
20259 (knot-configuration
20260 (remotes (list plop-master))
20261 (zones (list master-zone slave-zone))))
20266 @deffn {Scheme Variable} knot-service-type
20267 This is the type for the Knot DNS server.
20269 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20270 zones, that is to say domain names you would buy from a registrar. This server
20271 is not a resolver, meaning that it can only resolve names for which it is
20272 authoritative. This server can be configured to serve zones as a master server
20273 or a slave server as a per-zone basis. Slave zones will get their data from
20274 masters, and will serve it as an authoritative server. From the point of view
20275 of a resolver, there is no difference between master and slave.
20277 The following data types are used to configure the Knot DNS server:
20280 @deftp {Data Type} knot-key-configuration
20281 Data type representing a key.
20282 This type has the following parameters:
20285 @item @code{id} (default: @code{""})
20286 An identifier for other configuration fields to refer to this key. IDs must
20287 be unique and must not be empty.
20289 @item @code{algorithm} (default: @code{#f})
20290 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
20291 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
20292 and @code{'hmac-sha512}.
20294 @item @code{secret} (default: @code{""})
20295 The secret key itself.
20300 @deftp {Data Type} knot-acl-configuration
20301 Data type representing an Access Control List (ACL) configuration.
20302 This type has the following parameters:
20305 @item @code{id} (default: @code{""})
20306 An identifier for ether configuration fields to refer to this key. IDs must be
20307 unique and must not be empty.
20309 @item @code{address} (default: @code{'()})
20310 An ordered list of IP addresses, network subnets, or network ranges represented
20311 with strings. The query must match one of them. Empty value means that
20312 address match is not required.
20314 @item @code{key} (default: @code{'()})
20315 An ordered list of references to keys represented with strings. The string
20316 must match a key ID defined in a @code{knot-key-configuration}. No key means
20317 that a key is not require to match that ACL.
20319 @item @code{action} (default: @code{'()})
20320 An ordered list of actions that are permitted or forbidden by this ACL. Possible
20321 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
20322 and @code{'update}.
20324 @item @code{deny?} (default: @code{#f})
20325 When true, the ACL defines restrictions. Listed actions are forbidden. When
20326 false, listed actions are allowed.
20331 @deftp {Data Type} zone-entry
20332 Data type represnting a record entry in a zone file.
20333 This type has the following parameters:
20336 @item @code{name} (default: @code{"@@"})
20337 The name of the record. @code{"@@"} refers to the origin of the zone. Names
20338 are relative to the origin of the zone. For example, in the @code{example.org}
20339 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
20340 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
20341 refers to @code{ns.example.org}.
20343 @item @code{ttl} (default: @code{""})
20344 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
20346 @item @code{class} (default: @code{"IN"})
20347 The class of the record. Knot currently supports only @code{"IN"} and
20348 partially @code{"CH"}.
20350 @item @code{type} (default: @code{"A"})
20351 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
20352 address), NS (Name Server) and MX (Mail eXchange). Many other types are
20355 @item @code{data} (default: @code{""})
20356 The data contained in the record. For instance an IP address associated with
20357 an A record, or a domain name associated with an NS record. Remember that
20358 domain names are relative to the origin unless they end with a dot.
20363 @deftp {Data Type} zone-file
20364 Data type representing the content of a zone file.
20365 This type has the following parameters:
20368 @item @code{entries} (default: @code{'()})
20369 The list of entries. The SOA record is taken care of, so you don't need to
20370 put it in the list of entries. This list should probably contain an entry
20371 for your primary authoritative DNS server. Other than using a list of entries
20372 directly, you can use @code{define-zone-entries} to define a object containing
20373 the list of entries more easily, that you can later pass to the @code{entries}
20374 field of the @code{zone-file}.
20376 @item @code{origin} (default: @code{""})
20377 The name of your zone. This parameter cannot be empty.
20379 @item @code{ns} (default: @code{"ns"})
20380 The domain of your primary authoritative DNS server. The name is relative to
20381 the origin, unless it ends with a dot. It is mandatory that this primary
20382 DNS server corresponds to an NS record in the zone and that it is associated
20383 to an IP address in the list of entries.
20385 @item @code{mail} (default: @code{"hostmaster"})
20386 An email address people can contact you at, as the owner of the zone. This
20387 is translated as @code{<mail>@@<origin>}.
20389 @item @code{serial} (default: @code{1})
20390 The serial number of the zone. As this is used to keep track of changes by
20391 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
20392 Always increment it when you make a change in your zone.
20394 @item @code{refresh} (default: @code{(* 2 24 3600)})
20395 The frequency at which slaves will do a zone transfer. This value is a number
20396 of seconds. It can be computed by multiplications or with
20397 @code{(string->duration)}.
20399 @item @code{retry} (default: @code{(* 15 60)})
20400 The period after which a slave will retry to contact its master when it fails
20401 to do so a first time.
20403 @item @code{expiry} (default: @code{(* 14 24 3600)})
20404 Default TTL of records. Existing records are considered correct for at most
20405 this amount of time. After this period, resolvers will invalidate their cache
20406 and check again that it still exists.
20408 @item @code{nx} (default: @code{3600})
20409 Default TTL of inexistant records. This delay is usually short because you want
20410 your new domains to reach everyone quickly.
20415 @deftp {Data Type} knot-remote-configuration
20416 Data type representing a remote configuration.
20417 This type has the following parameters:
20420 @item @code{id} (default: @code{""})
20421 An identifier for other configuration fields to refer to this remote. IDs must
20422 be unique and must not be empty.
20424 @item @code{address} (default: @code{'()})
20425 An ordered list of destination IP addresses. Addresses are tried in sequence.
20426 An optional port can be given with the @@ separator. For instance:
20427 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
20429 @item @code{via} (default: @code{'()})
20430 An ordered list of source IP addresses. An empty list will have Knot choose
20431 an appropriate source IP. An optional port can be given with the @@ separator.
20432 The default is to choose at random.
20434 @item @code{key} (default: @code{#f})
20435 A reference to a key, that is a string containing the identifier of a key
20436 defined in a @code{knot-key-configuration} field.
20441 @deftp {Data Type} knot-keystore-configuration
20442 Data type representing a keystore to hold dnssec keys.
20443 This type has the following parameters:
20446 @item @code{id} (default: @code{""})
20447 The id of the keystore. It must not be empty.
20449 @item @code{backend} (default: @code{'pem})
20450 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
20452 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
20453 The configuration string of the backend. An example for the PKCS#11 is:
20454 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
20455 For the pem backend, the string reprensents a path in the file system.
20460 @deftp {Data Type} knot-policy-configuration
20461 Data type representing a dnssec policy. Knot DNS is able to automatically
20462 sign your zones. It can either generate and manage your keys automatically or
20463 use keys that you generate.
20465 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
20466 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
20467 zone. In order to be trusted, the KSK needs to be present in the parent zone
20468 (usually a top-level domain). If your registrar supports dnssec, you will
20469 have to send them your KSK's hash so they can add a DS record in their zone.
20470 This is not automated and need to be done each time you change your KSK.
20472 The policy also defines the lifetime of keys. Usually, ZSK can be changed
20473 easily and use weaker cryptographic functions (they use lower parameters) in
20474 order to sign records quickly, so they are changed often. The KSK however
20475 requires manual interaction with the registrar, so they are changed less often
20476 and use stronger parameters because they sign only one record.
20478 This type has the following parameters:
20481 @item @code{id} (default: @code{""})
20482 The id of the policy. It must not be empty.
20484 @item @code{keystore} (default: @code{"default"})
20485 A reference to a keystore, that is a string containing the identifier of a
20486 keystore defined in a @code{knot-keystore-configuration} field. The
20487 @code{"default"} identifier means the default keystore (a kasp database that
20488 was setup by this service).
20490 @item @code{manual?} (default: @code{#f})
20491 Whether the key management is manual or automatic.
20493 @item @code{single-type-signing?} (default: @code{#f})
20494 When @code{#t}, use the Single-Type Signing Scheme.
20496 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
20497 An algorithm of signing keys and issued signatures.
20499 @item @code{ksk-size} (default: @code{256})
20500 The length of the KSK. Note that this value is correct for the default
20501 algorithm, but would be unsecure for other algorithms.
20503 @item @code{zsk-size} (default: @code{256})
20504 The length of the ZSK. Note that this value is correct for the default
20505 algorithm, but would be unsecure for other algorithms.
20507 @item @code{dnskey-ttl} (default: @code{'default})
20508 The TTL value for DNSKEY records added into zone apex. The special
20509 @code{'default} value means same as the zone SOA TTL.
20511 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
20512 The period between ZSK publication and the next rollover initiation.
20514 @item @code{propagation-delay} (default: @code{(* 24 3600)})
20515 An extra delay added for each key rollover step. This value should be high
20516 enough to cover propagation of data from the master server to all slaves.
20518 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
20519 A validity period of newly issued signatures.
20521 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
20522 A period how long before a signature expiration the signature will be refreshed.
20524 @item @code{nsec3?} (default: @code{#f})
20525 When @code{#t}, NSEC3 will be used instead of NSEC.
20527 @item @code{nsec3-iterations} (default: @code{5})
20528 The number of additional times the hashing is performed.
20530 @item @code{nsec3-salt-length} (default: @code{8})
20531 The length of a salt field in octets, which is appended to the original owner
20532 name before hashing.
20534 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
20535 The validity period of newly issued salt field.
20540 @deftp {Data Type} knot-zone-configuration
20541 Data type representing a zone served by Knot.
20542 This type has the following parameters:
20545 @item @code{domain} (default: @code{""})
20546 The domain served by this configuration. It must not be empty.
20548 @item @code{file} (default: @code{""})
20549 The file where this zone is saved. This parameter is ignored by master zones.
20550 Empty means default location that depends on the domain name.
20552 @item @code{zone} (default: @code{(zone-file)})
20553 The content of the zone file. This parameter is ignored by slave zones. It
20554 must contain a zone-file record.
20556 @item @code{master} (default: @code{'()})
20557 A list of master remotes. When empty, this zone is a master. When set, this
20558 zone is a slave. This is a list of remotes identifiers.
20560 @item @code{ddns-master} (default: @code{#f})
20561 The main master. When empty, it defaults to the first master in the list of
20564 @item @code{notify} (default: @code{'()})
20565 A list of slave remote identifiers.
20567 @item @code{acl} (default: @code{'()})
20568 A list of acl identifiers.
20570 @item @code{semantic-checks?} (default: @code{#f})
20571 When set, this adds more semantic checks to the zone.
20573 @item @code{disable-any?} (default: @code{#f})
20574 When set, this forbids queries of the ANY type.
20576 @item @code{zonefile-sync} (default: @code{0})
20577 The delay between a modification in memory and on disk. 0 means immediate
20580 @item @code{zonefile-load} (default: @code{#f})
20581 The way the zone file contents are applied during zone load. Possible values
20585 @item @code{#f} for using the default value from Knot,
20586 @item @code{'none} for not using the zone file at all,
20587 @item @code{'difference} for computing the difference between already available
20588 contents and zone contents and applying it to the current zone contents,
20589 @item @code{'difference-no-serial} for the same as @code{'difference}, but
20590 ignoring the SOA serial in the zone file, while the server takes care of it
20592 @item @code{'whole} for loading zone contents from the zone file.
20595 @item @code{journal-content} (default: @code{#f})
20596 The way the journal is used to store zone and its changes. Possible values
20597 are @code{'none} to not use it at all, @code{'changes} to store changes and
20598 @code{'all} to store contents. @code{#f} does not set this option, so the
20599 default value from Knot is used.
20601 @item @code{max-journal-usage} (default: @code{#f})
20602 The maximum size for the journal on disk. @code{#f} does not set this option,
20603 so the default value from Knot is used.
20605 @item @code{max-journal-depth} (default: @code{#f})
20606 The maximum size of the history. @code{#f} does not set this option, so the
20607 default value from Knot is used.
20609 @item @code{max-zone-size} (default: @code{#f})
20610 The maximum size of the zone file. This limit is enforced for incoming
20611 transfer and updates. @code{#f} does not set this option, so the default
20612 value from Knot is used.
20614 @item @code{dnssec-policy} (default: @code{#f})
20615 A reference to a @code{knot-policy-configuration} record, or the special
20616 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
20619 @item @code{serial-policy} (default: @code{'increment})
20620 A policy between @code{'increment} and @code{'unixtime}.
20625 @deftp {Data Type} knot-configuration
20626 Data type representing the Knot configuration.
20627 This type has the following parameters:
20630 @item @code{knot} (default: @code{knot})
20633 @item @code{run-directory} (default: @code{"/var/run/knot"})
20634 The run directory. This directory will be used for pid file and sockets.
20636 @item @code{includes} (default: @code{'()})
20637 A list of strings or file-like objects denoting other files that must be
20638 included at the top of the configuration file.
20640 @cindex secrets, Knot service
20641 This can be used to manage secrets out-of-band. For example, secret
20642 keys may be stored in an out-of-band file not managed by Guix, and
20643 thus not visible in @file{/gnu/store}---e.g., you could store secret
20644 key configuration in @file{/etc/knot/secrets.conf} and add this file
20645 to the @code{includes} list.
20647 One can generate a secret tsig key (for nsupdate and zone transfers with the
20648 keymgr command from the knot package. Note that the package is not automatically
20649 installed by the service. The following example shows how to generate a new
20653 keymgr -t mysecret > /etc/knot/secrets.conf
20654 chmod 600 /etc/knot/secrets.conf
20657 Also note that the generated key will be named @var{mysecret}, so it is the
20658 name that needs to be used in the @var{key} field of the
20659 @code{knot-acl-configuration} record and in other places that need to refer
20662 It can also be used to add configuration not supported by this interface.
20664 @item @code{listen-v4} (default: @code{"0.0.0.0"})
20665 An ip address on which to listen.
20667 @item @code{listen-v6} (default: @code{"::"})
20668 An ip address on which to listen.
20670 @item @code{listen-port} (default: @code{53})
20671 A port on which to listen.
20673 @item @code{keys} (default: @code{'()})
20674 The list of knot-key-configuration used by this configuration.
20676 @item @code{acls} (default: @code{'()})
20677 The list of knot-acl-configuration used by this configuration.
20679 @item @code{remotes} (default: @code{'()})
20680 The list of knot-remote-configuration used by this configuration.
20682 @item @code{zones} (default: @code{'()})
20683 The list of knot-zone-configuration used by this configuration.
20688 @subsubheading Dnsmasq Service
20690 @deffn {Scheme Variable} dnsmasq-service-type
20691 This is the type of the dnsmasq service, whose value should be an
20692 @code{dnsmasq-configuration} object as in this example:
20695 (service dnsmasq-service-type
20696 (dnsmasq-configuration
20698 (servers '("192.168.1.1"))))
20702 @deftp {Data Type} dnsmasq-configuration
20703 Data type representing the configuration of dnsmasq.
20706 @item @code{package} (default: @var{dnsmasq})
20707 Package object of the dnsmasq server.
20709 @item @code{no-hosts?} (default: @code{#f})
20710 When true, don't read the hostnames in /etc/hosts.
20712 @item @code{port} (default: @code{53})
20713 The port to listen on. Setting this to zero completely disables DNS
20714 responses, leaving only DHCP and/or TFTP functions.
20716 @item @code{local-service?} (default: @code{#t})
20717 Accept DNS queries only from hosts whose address is on a local subnet,
20718 ie a subnet for which an interface exists on the server.
20720 @item @code{listen-addresses} (default: @code{'()})
20721 Listen on the given IP addresses.
20723 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
20724 The file to read the IP address of the upstream nameservers from.
20726 @item @code{no-resolv?} (default: @code{#f})
20727 When true, don't read @var{resolv-file}.
20729 @item @code{servers} (default: @code{'()})
20730 Specify IP address of upstream servers directly.
20732 @item @code{cache-size} (default: @code{150})
20733 Set the size of dnsmasq's cache. Setting the cache size to zero
20736 @item @code{negative-cache?} (default: @code{#t})
20737 When false, disable negative caching.
20742 @subsubheading ddclient Service
20745 The ddclient service described below runs the ddclient daemon, which takes
20746 care of automatically updating DNS entries for service providers such as
20747 @uref{https://dyn.com/dns/, Dyn}.
20749 The following example show instantiates the service with its default
20753 (service ddclient-service-type)
20756 Note that ddclient needs to access credentials that are stored in a
20757 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
20758 @code{secret-file} below.) You are expected to create this file manually, in
20759 an ``out-of-band'' fashion (you @emph{could} make this file part of the
20760 service configuration, for instance by using @code{plain-file}, but it will be
20761 world-readable @i{via} @file{/gnu/store}.) See the examples in the
20762 @file{share/ddclient} directory of the @code{ddclient} package.
20764 @c %start of fragment
20766 Available @code{ddclient-configuration} fields are:
20768 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
20769 The ddclient package.
20773 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
20774 The period after which ddclient will retry to check IP and domain name.
20776 Defaults to @samp{300}.
20780 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
20781 Use syslog for the output.
20783 Defaults to @samp{#t}.
20787 @deftypevr {@code{ddclient-configuration} parameter} string mail
20790 Defaults to @samp{"root"}.
20794 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
20795 Mail failed update to user.
20797 Defaults to @samp{"root"}.
20801 @deftypevr {@code{ddclient-configuration} parameter} string pid
20802 The ddclient PID file.
20804 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
20808 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
20809 Enable SSL support.
20811 Defaults to @samp{#t}.
20815 @deftypevr {@code{ddclient-configuration} parameter} string user
20816 Specifies the user name or ID that is used when running ddclient
20819 Defaults to @samp{"ddclient"}.
20823 @deftypevr {@code{ddclient-configuration} parameter} string group
20824 Group of the user who will run the ddclient program.
20826 Defaults to @samp{"ddclient"}.
20830 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
20831 Secret file which will be appended to @file{ddclient.conf} file. This
20832 file contains credentials for use by ddclient. You are expected to
20833 create it manually.
20835 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
20839 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
20840 Extra options will be appended to @file{ddclient.conf} file.
20842 Defaults to @samp{()}.
20847 @c %end of fragment
20851 @subsection VPN Services
20852 @cindex VPN (virtual private network)
20853 @cindex virtual private network (VPN)
20855 The @code{(gnu services vpn)} module provides services related to
20856 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
20857 your machine to connect to a VPN, and a @emph{server} service for your machine
20858 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
20860 @deffn {Scheme Procedure} openvpn-client-service @
20861 [#:config (openvpn-client-configuration)]
20863 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
20866 @deffn {Scheme Procedure} openvpn-server-service @
20867 [#:config (openvpn-server-configuration)]
20869 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
20871 Both can be run simultaneously.
20874 @c %automatically generated documentation
20876 Available @code{openvpn-client-configuration} fields are:
20878 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
20879 The OpenVPN package.
20883 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
20884 The OpenVPN pid file.
20886 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
20890 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
20891 The protocol (UDP or TCP) used to open a channel between clients and
20894 Defaults to @samp{udp}.
20898 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
20899 The device type used to represent the VPN connection.
20901 Defaults to @samp{tun}.
20905 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
20906 The certificate authority to check connections against.
20908 Defaults to @samp{"/etc/openvpn/ca.crt"}.
20912 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
20913 The certificate of the machine the daemon is running on. It should be
20914 signed by the authority given in @code{ca}.
20916 Defaults to @samp{"/etc/openvpn/client.crt"}.
20920 @deftypevr {@code{openvpn-client-configuration} parameter} string key
20921 The key of the machine the daemon is running on. It must be the key whose
20922 certificate is @code{cert}.
20924 Defaults to @samp{"/etc/openvpn/client.key"}.
20928 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
20929 Whether to use the lzo compression algorithm.
20931 Defaults to @samp{#t}.
20935 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
20936 Don't re-read key files across SIGUSR1 or --ping-restart.
20938 Defaults to @samp{#t}.
20942 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
20943 Don't close and reopen TUN/TAP device or run up/down scripts across
20944 SIGUSR1 or --ping-restart restarts.
20946 Defaults to @samp{#t}.
20950 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
20953 Defaults to @samp{3}.
20957 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
20958 Add an additional layer of HMAC authentication on top of the TLS control
20959 channel to protect against DoS attacks.
20961 Defaults to @samp{#f}.
20965 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
20966 Whether to check the server certificate has server usage extension.
20968 Defaults to @samp{#t}.
20972 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
20973 Bind to a specific local port number.
20975 Defaults to @samp{#f}.
20979 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
20980 Retry resolving server address.
20982 Defaults to @samp{#t}.
20986 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
20987 A list of remote servers to connect to.
20989 Defaults to @samp{()}.
20991 Available @code{openvpn-remote-configuration} fields are:
20993 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
20996 Defaults to @samp{"my-server"}.
21000 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21001 Port number the server listens to.
21003 Defaults to @samp{1194}.
21008 @c %end of automatic openvpn-client documentation
21010 @c %automatically generated documentation
21012 Available @code{openvpn-server-configuration} fields are:
21014 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21015 The OpenVPN package.
21019 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21020 The OpenVPN pid file.
21022 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21026 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21027 The protocol (UDP or TCP) used to open a channel between clients and
21030 Defaults to @samp{udp}.
21034 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
21035 The device type used to represent the VPN connection.
21037 Defaults to @samp{tun}.
21041 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
21042 The certificate authority to check connections against.
21044 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21048 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
21049 The certificate of the machine the daemon is running on. It should be
21050 signed by the authority given in @code{ca}.
21052 Defaults to @samp{"/etc/openvpn/client.crt"}.
21056 @deftypevr {@code{openvpn-server-configuration} parameter} string key
21057 The key of the machine the daemon is running on. It must be the key whose
21058 certificate is @code{cert}.
21060 Defaults to @samp{"/etc/openvpn/client.key"}.
21064 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
21065 Whether to use the lzo compression algorithm.
21067 Defaults to @samp{#t}.
21071 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21072 Don't re-read key files across SIGUSR1 or --ping-restart.
21074 Defaults to @samp{#t}.
21078 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21079 Don't close and reopen TUN/TAP device or run up/down scripts across
21080 SIGUSR1 or --ping-restart restarts.
21082 Defaults to @samp{#t}.
21086 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21089 Defaults to @samp{3}.
21093 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21094 Add an additional layer of HMAC authentication on top of the TLS control
21095 channel to protect against DoS attacks.
21097 Defaults to @samp{#f}.
21101 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21102 Specifies the port number on which the server listens.
21104 Defaults to @samp{1194}.
21108 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21109 An ip and mask specifying the subnet inside the virtual network.
21111 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21115 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21116 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21118 Defaults to @samp{#f}.
21122 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21123 The Diffie-Hellman parameters file.
21125 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21129 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21130 The file that records client IPs.
21132 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21136 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21137 When true, the server will act as a gateway for its clients.
21139 Defaults to @samp{#f}.
21143 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21144 When true, clients are allowed to talk to each other inside the VPN.
21146 Defaults to @samp{#f}.
21150 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21151 Causes ping-like messages to be sent back and forth over the link so
21152 that each side knows when the other side has gone down. @code{keepalive}
21153 requires a pair. The first element is the period of the ping sending,
21154 and the second element is the timeout before considering the other side
21159 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21160 The maximum number of clients.
21162 Defaults to @samp{100}.
21166 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21167 The status file. This file shows a small report on current connection.
21168 It is truncated and rewritten every minute.
21170 Defaults to @samp{"/var/run/openvpn/status"}.
21174 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21175 The list of configuration for some clients.
21177 Defaults to @samp{()}.
21179 Available @code{openvpn-ccd-configuration} fields are:
21181 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21184 Defaults to @samp{"client"}.
21188 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21191 Defaults to @samp{#f}.
21195 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21198 Defaults to @samp{#f}.
21205 @c %end of automatic openvpn-server documentation
21208 @node Network File System
21209 @subsection Network File System
21212 The @code{(gnu services nfs)} module provides the following services,
21213 which are most commonly used in relation to mounting or exporting
21214 directory trees as @dfn{network file systems} (NFS).
21216 @subsubheading RPC Bind Service
21219 The RPC Bind service provides a facility to map program numbers into
21220 universal addresses.
21221 Many NFS related services use this facility. Hence it is automatically
21222 started when a dependent service starts.
21224 @defvr {Scheme Variable} rpcbind-service-type
21225 A service type for the RPC portmapper daemon.
21229 @deftp {Data Type} rpcbind-configuration
21230 Data type representing the configuration of the RPC Bind Service.
21231 This type has the following parameters:
21233 @item @code{rpcbind} (default: @code{rpcbind})
21234 The rpcbind package to use.
21236 @item @code{warm-start?} (default: @code{#t})
21237 If this parameter is @code{#t}, then the daemon will read a
21238 state file on startup thus reloading state information saved by a previous
21244 @subsubheading Pipefs Pseudo File System
21248 The pipefs file system is used to transfer NFS related data
21249 between the kernel and user space programs.
21251 @defvr {Scheme Variable} pipefs-service-type
21252 A service type for the pipefs pseudo file system.
21255 @deftp {Data Type} pipefs-configuration
21256 Data type representing the configuration of the pipefs pseudo file system service.
21257 This type has the following parameters:
21259 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21260 The directory to which the file system is to be attached.
21265 @subsubheading GSS Daemon Service
21268 @cindex global security system
21270 The @dfn{global security system} (GSS) daemon provides strong security for RPC
21272 Before exchanging RPC requests an RPC client must establish a security
21273 context. Typically this is done using the Kerberos command @command{kinit}
21274 or automatically at login time using PAM services (@pxref{Kerberos Services}).
21276 @defvr {Scheme Variable} gss-service-type
21277 A service type for the Global Security System (GSS) daemon.
21280 @deftp {Data Type} gss-configuration
21281 Data type representing the configuration of the GSS daemon service.
21282 This type has the following parameters:
21284 @item @code{nfs-utils} (default: @code{nfs-utils})
21285 The package in which the @command{rpc.gssd} command is to be found.
21287 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21288 The directory where the pipefs file system is mounted.
21294 @subsubheading IDMAP Daemon Service
21296 @cindex name mapper
21298 The idmap daemon service provides mapping between user IDs and user names.
21299 Typically it is required in order to access file systems mounted via NFSv4.
21301 @defvr {Scheme Variable} idmap-service-type
21302 A service type for the Identity Mapper (IDMAP) daemon.
21305 @deftp {Data Type} idmap-configuration
21306 Data type representing the configuration of the IDMAP daemon service.
21307 This type has the following parameters:
21309 @item @code{nfs-utils} (default: @code{nfs-utils})
21310 The package in which the @command{rpc.idmapd} command is to be found.
21312 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21313 The directory where the pipefs file system is mounted.
21315 @item @code{domain} (default: @code{#f})
21316 The local NFSv4 domain name.
21317 This must be a string or @code{#f}.
21318 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
21323 @node Continuous Integration
21324 @subsection Continuous Integration
21326 @cindex continuous integration
21327 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
21328 continuous integration tool for Guix. It can be used both for development and
21329 for providing substitutes to others (@pxref{Substitutes}).
21331 The @code{(gnu services cuirass)} module provides the following service.
21333 @defvr {Scheme Procedure} cuirass-service-type
21334 The type of the Cuirass service. Its value must be a
21335 @code{cuirass-configuration} object, as described below.
21338 To add build jobs, you have to set the @code{specifications} field of the
21339 configuration. Here is an example of a service that polls the Guix repository
21340 and builds the packages from a manifest. Some of the packages are defined in
21341 the @code{"custom-packages"} input, which is the equivalent of
21342 @code{GUIX_PACKAGE_PATH}.
21345 (define %cuirass-specs
21347 '((#:name . "my-manifest")
21348 (#:load-path-inputs . ("guix"))
21349 (#:package-path-inputs . ("custom-packages"))
21350 (#:proc-input . "guix")
21351 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
21352 (#:proc . cuirass-jobs)
21353 (#:proc-args . ((subset . "manifests")
21354 (systems . ("x86_64-linux"))
21355 (manifests . (("config" . "guix/manifest.scm")))))
21356 (#:inputs . (((#:name . "guix")
21357 (#:url . "git://git.savannah.gnu.org/guix.git")
21358 (#:load-path . ".")
21359 (#:branch . "master")
21360 (#:no-compile? . #t))
21361 ((#:name . "config")
21362 (#:url . "git://git.example.org/config.git")
21363 (#:load-path . ".")
21364 (#:branch . "master")
21365 (#:no-compile? . #t))
21366 ((#:name . "custom-packages")
21367 (#:url . "git://git.example.org/custom-packages.git")
21368 (#:load-path . ".")
21369 (#:branch . "master")
21370 (#:no-compile? . #t)))))))
21372 (service cuirass-service-type
21373 (cuirass-configuration
21374 (specifications %cuirass-specs)))
21377 While information related to build jobs is located directly in the
21378 specifications, global settings for the @command{cuirass} process are
21379 accessible in other @code{cuirass-configuration} fields.
21381 @deftp {Data Type} cuirass-configuration
21382 Data type representing the configuration of Cuirass.
21385 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
21386 Location of the log file.
21388 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
21389 Location of the repository cache.
21391 @item @code{user} (default: @code{"cuirass"})
21392 Owner of the @code{cuirass} process.
21394 @item @code{group} (default: @code{"cuirass"})
21395 Owner's group of the @code{cuirass} process.
21397 @item @code{interval} (default: @code{60})
21398 Number of seconds between the poll of the repositories followed by the
21401 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
21402 Location of sqlite database which contains the build results and previously
21403 added specifications.
21405 @item @code{ttl} (default: @code{(* 30 24 3600)})
21406 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
21407 are registered for build results. This means that build results are protected
21408 from garbage collection for at least @var{ttl} seconds.
21410 @item @code{port} (default: @code{8081})
21411 Port number used by the HTTP server.
21413 @item @code{host} (default: @code{"localhost"})
21414 Listen on the network interface for @var{host}. The default is to
21415 accept connections from localhost.
21417 @item @code{specifications} (default: @code{#~'()})
21418 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
21419 where a specification is an association list
21420 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
21421 keys are keywords (@code{#:keyword-example}) as shown in the example
21424 @item @code{use-substitutes?} (default: @code{#f})
21425 This allows using substitutes to avoid building every dependencies of a job
21428 @item @code{one-shot?} (default: @code{#f})
21429 Only evaluate specifications and build derivations once.
21431 @item @code{fallback?} (default: @code{#f})
21432 When substituting a pre-built binary fails, fall back to building
21435 @item @code{cuirass} (default: @code{cuirass})
21436 The Cuirass package to use.
21440 @node Power Management Services
21441 @subsection Power Management Services
21444 @cindex power management with TLP
21445 @subsubheading TLP daemon
21447 The @code{(gnu services pm)} module provides a Guix service definition
21448 for the Linux power management tool TLP.
21450 TLP enables various powersaving modes in userspace and kernel.
21451 Contrary to @code{upower-service}, it is not a passive,
21452 monitoring tool, as it will apply custom settings each time a new power
21453 source is detected. More information can be found at
21454 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
21456 @deffn {Scheme Variable} tlp-service-type
21457 The service type for the TLP tool. Its value should be a valid
21458 TLP configuration (see below). To use the default settings, simply
21461 (service tlp-service-type)
21465 By default TLP does not need much configuration but most TLP parameters
21466 can be tweaked using @code{tlp-configuration}.
21468 Each parameter definition is preceded by its type; for example,
21469 @samp{boolean foo} indicates that the @code{foo} parameter
21470 should be specified as a boolean. Types starting with
21471 @code{maybe-} denote parameters that won't show up in TLP config file
21472 when their value is @code{'disabled}.
21474 @c The following documentation was initially generated by
21475 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
21476 @c documentation is better, so we shouldn't hesitate to edit below as
21477 @c needed. However if the change you want to make to this documentation
21478 @c can be done in an automated way, it's probably easier to change
21479 @c (generate-documentation) than to make it below and have to deal with
21480 @c the churn as TLP updates.
21482 Available @code{tlp-configuration} fields are:
21484 @deftypevr {@code{tlp-configuration} parameter} package tlp
21489 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
21490 Set to true if you wish to enable TLP.
21492 Defaults to @samp{#t}.
21496 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
21497 Default mode when no power supply can be detected. Alternatives are AC
21500 Defaults to @samp{"AC"}.
21504 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
21505 Number of seconds Linux kernel has to wait after the disk goes idle,
21506 before syncing on AC.
21508 Defaults to @samp{0}.
21512 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
21513 Same as @code{disk-idle-ac} but on BAT mode.
21515 Defaults to @samp{2}.
21519 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
21520 Dirty pages flushing periodicity, expressed in seconds.
21522 Defaults to @samp{15}.
21526 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
21527 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
21529 Defaults to @samp{60}.
21533 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
21534 CPU frequency scaling governor on AC mode. With intel_pstate driver,
21535 alternatives are powersave and performance. With acpi-cpufreq driver,
21536 alternatives are ondemand, powersave, performance and conservative.
21538 Defaults to @samp{disabled}.
21542 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
21543 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
21545 Defaults to @samp{disabled}.
21549 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
21550 Set the min available frequency for the scaling governor on AC.
21552 Defaults to @samp{disabled}.
21556 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
21557 Set the max available frequency for the scaling governor on AC.
21559 Defaults to @samp{disabled}.
21563 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
21564 Set the min available frequency for the scaling governor on BAT.
21566 Defaults to @samp{disabled}.
21570 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
21571 Set the max available frequency for the scaling governor on BAT.
21573 Defaults to @samp{disabled}.
21577 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
21578 Limit the min P-state to control the power dissipation of the CPU, in AC
21579 mode. Values are stated as a percentage of the available performance.
21581 Defaults to @samp{disabled}.
21585 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
21586 Limit the max P-state to control the power dissipation of the CPU, in AC
21587 mode. Values are stated as a percentage of the available performance.
21589 Defaults to @samp{disabled}.
21593 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
21594 Same as @code{cpu-min-perf-on-ac} on BAT mode.
21596 Defaults to @samp{disabled}.
21600 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
21601 Same as @code{cpu-max-perf-on-ac} on BAT mode.
21603 Defaults to @samp{disabled}.
21607 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
21608 Enable CPU turbo boost feature on AC mode.
21610 Defaults to @samp{disabled}.
21614 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
21615 Same as @code{cpu-boost-on-ac?} on BAT mode.
21617 Defaults to @samp{disabled}.
21621 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
21622 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
21623 used under light load conditions.
21625 Defaults to @samp{#f}.
21629 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
21630 Same as @code{sched-powersave-on-ac?} but on BAT mode.
21632 Defaults to @samp{#t}.
21636 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
21637 Enable Linux kernel NMI watchdog.
21639 Defaults to @samp{#f}.
21643 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
21644 For Linux kernels with PHC patch applied, change CPU voltages. An
21645 example value would be @samp{"F:V F:V F:V F:V"}.
21647 Defaults to @samp{disabled}.
21651 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
21652 Set CPU performance versus energy saving policy on AC. Alternatives are
21653 performance, normal, powersave.
21655 Defaults to @samp{"performance"}.
21659 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
21660 Same as @code{energy-perf-policy-ac} but on BAT mode.
21662 Defaults to @samp{"powersave"}.
21666 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
21671 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
21672 Hard disk advanced power management level.
21676 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
21677 Same as @code{disk-apm-bat} but on BAT mode.
21681 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
21682 Hard disk spin down timeout. One value has to be specified for each
21683 declared hard disk.
21685 Defaults to @samp{disabled}.
21689 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
21690 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
21692 Defaults to @samp{disabled}.
21696 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
21697 Select IO scheduler for disk devices. One value has to be specified for
21698 each declared hard disk. Example alternatives are cfq, deadline and
21701 Defaults to @samp{disabled}.
21705 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
21706 SATA aggressive link power management (ALPM) level. Alternatives are
21707 min_power, medium_power, max_performance.
21709 Defaults to @samp{"max_performance"}.
21713 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
21714 Same as @code{sata-linkpwr-ac} but on BAT mode.
21716 Defaults to @samp{"min_power"}.
21720 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
21721 Exclude specified SATA host devices for link power management.
21723 Defaults to @samp{disabled}.
21727 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
21728 Enable Runtime Power Management for AHCI controller and disks on AC
21731 Defaults to @samp{disabled}.
21735 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
21736 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
21738 Defaults to @samp{disabled}.
21742 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
21743 Seconds of inactivity before disk is suspended.
21745 Defaults to @samp{15}.
21749 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
21750 PCI Express Active State Power Management level. Alternatives are
21751 default, performance, powersave.
21753 Defaults to @samp{"performance"}.
21757 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
21758 Same as @code{pcie-aspm-ac} but on BAT mode.
21760 Defaults to @samp{"powersave"}.
21764 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
21765 Radeon graphics clock speed level. Alternatives are low, mid, high,
21768 Defaults to @samp{"high"}.
21772 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
21773 Same as @code{radeon-power-ac} but on BAT mode.
21775 Defaults to @samp{"low"}.
21779 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
21780 Radeon dynamic power management method (DPM). Alternatives are battery,
21783 Defaults to @samp{"performance"}.
21787 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
21788 Same as @code{radeon-dpm-state-ac} but on BAT mode.
21790 Defaults to @samp{"battery"}.
21794 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
21795 Radeon DPM performance level. Alternatives are auto, low, high.
21797 Defaults to @samp{"auto"}.
21801 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
21802 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
21804 Defaults to @samp{"auto"}.
21808 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
21809 Wifi power saving mode.
21811 Defaults to @samp{#f}.
21815 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
21816 Same as @code{wifi-power-ac?} but on BAT mode.
21818 Defaults to @samp{#t}.
21822 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
21823 Disable wake on LAN.
21825 Defaults to @samp{#t}.
21829 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
21830 Timeout duration in seconds before activating audio power saving on
21831 Intel HDA and AC97 devices. A value of 0 disables power saving.
21833 Defaults to @samp{0}.
21837 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
21838 Same as @code{sound-powersave-ac} but on BAT mode.
21840 Defaults to @samp{1}.
21844 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
21845 Disable controller in powersaving mode on Intel HDA devices.
21847 Defaults to @samp{#t}.
21851 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
21852 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
21853 powered on again by releasing (and reinserting) the eject lever or by
21854 pressing the disc eject button on newer models.
21856 Defaults to @samp{#f}.
21860 @deftypevr {@code{tlp-configuration} parameter} string bay-device
21861 Name of the optical drive device to power off.
21863 Defaults to @samp{"sr0"}.
21867 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
21868 Runtime Power Management for PCI(e) bus devices. Alternatives are on
21871 Defaults to @samp{"on"}.
21875 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
21876 Same as @code{runtime-pm-ac} but on BAT mode.
21878 Defaults to @samp{"auto"}.
21882 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
21883 Runtime Power Management for all PCI(e) bus devices, except blacklisted
21886 Defaults to @samp{#t}.
21890 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
21891 Exclude specified PCI(e) device addresses from Runtime Power Management.
21893 Defaults to @samp{disabled}.
21897 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
21898 Exclude PCI(e) devices assigned to the specified drivers from Runtime
21903 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
21904 Enable USB autosuspend feature.
21906 Defaults to @samp{#t}.
21910 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
21911 Exclude specified devices from USB autosuspend.
21913 Defaults to @samp{disabled}.
21917 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
21918 Exclude WWAN devices from USB autosuspend.
21920 Defaults to @samp{#t}.
21924 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
21925 Include specified devices into USB autosuspend, even if they are already
21926 excluded by the driver or via @code{usb-blacklist-wwan?}.
21928 Defaults to @samp{disabled}.
21932 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
21933 Enable USB autosuspend before shutdown.
21935 Defaults to @samp{disabled}.
21939 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
21940 Restore radio device state (bluetooth, wifi, wwan) from previous
21941 shutdown on system startup.
21943 Defaults to @samp{#f}.
21948 @cindex CPU frequency scaling with thermald
21949 @subsubheading Thermald daemon
21951 The @code{(gnu services pm)} module provides an interface to
21952 thermald, a CPU frequency scaling service which helps prevent overheating.
21954 @defvr {Scheme Variable} thermald-service-type
21955 This is the service type for
21956 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
21957 Thermal Daemon, which is responsible for controlling the thermal state
21958 of processors and preventing overheating.
21961 @deftp {Data Type} thermald-configuration
21962 Data type representing the configuration of @code{thermald-service-type}.
21965 @item @code{ignore-cpuid-check?} (default: @code{#f})
21966 Ignore cpuid check for supported CPU models.
21968 @item @code{thermald} (default: @var{thermald})
21969 Package object of thermald.
21974 @node Audio Services
21975 @subsection Audio Services
21977 The @code{(gnu services audio)} module provides a service to start MPD
21978 (the Music Player Daemon).
21981 @subsubheading Music Player Daemon
21983 The Music Player Daemon (MPD) is a service that can play music while
21984 being controlled from the local machine or over the network by a variety
21987 The following example shows how one might run @code{mpd} as user
21988 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
21991 (service mpd-service-type
21997 @defvr {Scheme Variable} mpd-service-type
21998 The service type for @command{mpd}
22001 @deftp {Data Type} mpd-configuration
22002 Data type representing the configuration of @command{mpd}.
22005 @item @code{user} (default: @code{"mpd"})
22006 The user to run mpd as.
22008 @item @code{music-dir} (default: @code{"~/Music"})
22009 The directory to scan for music files.
22011 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
22012 The directory to store playlists.
22014 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
22015 The location of the music database.
22017 @item @code{state-file} (default: @code{"~/.mpd/state"})
22018 The location of the file that stores current MPD's state.
22020 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
22021 The location of the sticker database.
22023 @item @code{port} (default: @code{"6600"})
22024 The port to run mpd on.
22026 @item @code{address} (default: @code{"any"})
22027 The address that mpd will bind to. To use a Unix domain socket,
22028 an absolute path can be specified here.
22033 @node Virtualization Services
22034 @subsection Virtualization services
22036 The @code{(gnu services virtualization)} module provides services for
22037 the libvirt and virtlog daemons, as well as other virtualization-related
22040 @subsubheading Libvirt daemon
22041 @code{libvirtd} is the server side daemon component of the libvirt
22042 virtualization management system. This daemon runs on host servers
22043 and performs required management tasks for virtualized guests.
22045 @deffn {Scheme Variable} libvirt-service-type
22046 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
22047 Its value must be a @code{libvirt-configuration}.
22050 (service libvirt-service-type
22051 (libvirt-configuration
22052 (unix-sock-group "libvirt")
22053 (tls-port "16555")))
22057 @c Auto-generated with (generate-libvirt-documentation)
22058 Available @code{libvirt-configuration} fields are:
22060 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
22065 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
22066 Flag listening for secure TLS connections on the public TCP/IP port.
22067 must set @code{listen} for this to have any effect.
22069 It is necessary to setup a CA and issue server certificates before using
22072 Defaults to @samp{#t}.
22076 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22077 Listen for unencrypted TCP connections on the public TCP/IP port. must
22078 set @code{listen} for this to have any effect.
22080 Using the TCP socket requires SASL authentication by default. Only SASL
22081 mechanisms which support data encryption are allowed. This is
22082 DIGEST_MD5 and GSSAPI (Kerberos5)
22084 Defaults to @samp{#f}.
22088 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
22089 Port for accepting secure TLS connections This can be a port number, or
22092 Defaults to @samp{"16514"}.
22096 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
22097 Port for accepting insecure TCP connections This can be a port number,
22100 Defaults to @samp{"16509"}.
22104 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
22105 IP address or hostname used for client connections.
22107 Defaults to @samp{"0.0.0.0"}.
22111 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
22112 Flag toggling mDNS advertisement of the libvirt service.
22114 Alternatively can disable for all services on a host by stopping the
22117 Defaults to @samp{#f}.
22121 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
22122 Default mDNS advertisement name. This must be unique on the immediate
22125 Defaults to @samp{"Virtualization Host <hostname>"}.
22129 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
22130 UNIX domain socket group ownership. This can be used to allow a
22131 'trusted' set of users access to management capabilities without
22134 Defaults to @samp{"root"}.
22138 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
22139 UNIX socket permissions for the R/O socket. This is used for monitoring
22142 Defaults to @samp{"0777"}.
22146 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
22147 UNIX socket permissions for the R/W socket. Default allows only root.
22148 If PolicyKit is enabled on the socket, the default will change to allow
22149 everyone (eg, 0777)
22151 Defaults to @samp{"0770"}.
22155 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
22156 UNIX socket permissions for the admin socket. Default allows only owner
22157 (root), do not change it unless you are sure to whom you are exposing
22160 Defaults to @samp{"0777"}.
22164 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
22165 The directory in which sockets will be found/created.
22167 Defaults to @samp{"/var/run/libvirt"}.
22171 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
22172 Authentication scheme for UNIX read-only sockets. By default socket
22173 permissions allow anyone to connect
22175 Defaults to @samp{"polkit"}.
22179 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
22180 Authentication scheme for UNIX read-write sockets. By default socket
22181 permissions only allow root. If PolicyKit support was compiled into
22182 libvirt, the default will be to use 'polkit' auth.
22184 Defaults to @samp{"polkit"}.
22188 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
22189 Authentication scheme for TCP sockets. If you don't enable SASL, then
22190 all TCP traffic is cleartext. Don't do this outside of a dev/test
22193 Defaults to @samp{"sasl"}.
22197 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
22198 Authentication scheme for TLS sockets. TLS sockets already have
22199 encryption provided by the TLS layer, and limited authentication is done
22202 It is possible to make use of any SASL authentication mechanism as well,
22203 by using 'sasl' for this option
22205 Defaults to @samp{"none"}.
22209 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
22210 API access control scheme.
22212 By default an authenticated user is allowed access to all APIs. Access
22213 drivers can place restrictions on this.
22215 Defaults to @samp{()}.
22219 @deftypevr {@code{libvirt-configuration} parameter} string key-file
22220 Server key file path. If set to an empty string, then no private key is
22223 Defaults to @samp{""}.
22227 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
22228 Server key file path. If set to an empty string, then no certificate is
22231 Defaults to @samp{""}.
22235 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
22236 Server key file path. If set to an empty string, then no CA certificate
22239 Defaults to @samp{""}.
22243 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
22244 Certificate revocation list path. If set to an empty string, then no
22247 Defaults to @samp{""}.
22251 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
22252 Disable verification of our own server certificates.
22254 When libvirtd starts it performs some sanity checks against its own
22257 Defaults to @samp{#f}.
22261 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
22262 Disable verification of client certificates.
22264 Client certificate verification is the primary authentication mechanism.
22265 Any client which does not present a certificate signed by the CA will be
22268 Defaults to @samp{#f}.
22272 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
22273 Whitelist of allowed x509 Distinguished Name.
22275 Defaults to @samp{()}.
22279 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
22280 Whitelist of allowed SASL usernames. The format for username depends on
22281 the SASL authentication mechanism.
22283 Defaults to @samp{()}.
22287 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
22288 Override the compile time default TLS priority string. The default is
22289 usually "NORMAL" unless overridden at build time. Only set this is it
22290 is desired for libvirt to deviate from the global default settings.
22292 Defaults to @samp{"NORMAL"}.
22296 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
22297 Maximum number of concurrent client connections to allow over all
22300 Defaults to @samp{5000}.
22304 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
22305 Maximum length of queue of connections waiting to be accepted by the
22306 daemon. Note, that some protocols supporting retransmission may obey
22307 this so that a later reattempt at connection succeeds.
22309 Defaults to @samp{1000}.
22313 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
22314 Maximum length of queue of accepted but not yet authenticated clients.
22315 Set this to zero to turn this feature off
22317 Defaults to @samp{20}.
22321 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
22322 Number of workers to start up initially.
22324 Defaults to @samp{5}.
22328 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
22329 Maximum number of worker threads.
22331 If the number of active clients exceeds @code{min-workers}, then more
22332 threads are spawned, up to max_workers limit. Typically you'd want
22333 max_workers to equal maximum number of clients allowed.
22335 Defaults to @samp{20}.
22339 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
22340 Number of priority workers. If all workers from above pool are stuck,
22341 some calls marked as high priority (notably domainDestroy) can be
22342 executed in this pool.
22344 Defaults to @samp{5}.
22348 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
22349 Total global limit on concurrent RPC calls.
22351 Defaults to @samp{20}.
22355 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
22356 Limit on concurrent requests from a single client connection. To avoid
22357 one client monopolizing the server this should be a small fraction of
22358 the global max_requests and max_workers parameter.
22360 Defaults to @samp{5}.
22364 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
22365 Same as @code{min-workers} but for the admin interface.
22367 Defaults to @samp{1}.
22371 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
22372 Same as @code{max-workers} but for the admin interface.
22374 Defaults to @samp{5}.
22378 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
22379 Same as @code{max-clients} but for the admin interface.
22381 Defaults to @samp{5}.
22385 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
22386 Same as @code{max-queued-clients} but for the admin interface.
22388 Defaults to @samp{5}.
22392 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
22393 Same as @code{max-client-requests} but for the admin interface.
22395 Defaults to @samp{5}.
22399 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
22400 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
22402 Defaults to @samp{3}.
22406 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
22409 A filter allows to select a different logging level for a given category
22410 of logs The format for a filter is one of:
22421 where @code{name} is a string which is matched against the category
22422 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
22423 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
22424 be a substring of the full category name, in order to match multiple
22425 similar categories), the optional "+" prefix tells libvirt to log stack
22426 trace for each message matching name, and @code{x} is the minimal level
22427 where matching messages should be logged:
22444 Multiple filters can be defined in a single filters statement, they just
22445 need to be separated by spaces.
22447 Defaults to @samp{"3:remote 4:event"}.
22451 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
22454 An output is one of the places to save logging information. The format
22455 for an output can be:
22459 output goes to stderr
22461 @item x:syslog:name
22462 use syslog for the output and use the given name as the ident
22464 @item x:file:file_path
22465 output to a file, with the given filepath
22468 output to journald logging system
22472 In all case the x prefix is the minimal level, acting as a filter
22489 Multiple outputs can be defined, they just need to be separated by
22492 Defaults to @samp{"3:stderr"}.
22496 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
22497 Allows usage of the auditing subsystem to be altered
22501 0: disable all auditing
22504 1: enable auditing, only if enabled on host
22507 2: enable auditing, and exit if disabled on host.
22511 Defaults to @samp{1}.
22515 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
22516 Send audit messages via libvirt logging infrastructure.
22518 Defaults to @samp{#f}.
22522 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
22523 Host UUID. UUID must not have all digits be the same.
22525 Defaults to @samp{""}.
22529 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
22530 Source to read host UUID.
22534 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
22537 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
22541 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
22544 Defaults to @samp{"smbios"}.
22548 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
22549 A keepalive message is sent to a client after @code{keepalive_interval}
22550 seconds of inactivity to check if the client is still responding. If
22551 set to -1, libvirtd will never send keepalive requests; however clients
22552 can still send them and the daemon will send responses.
22554 Defaults to @samp{5}.
22558 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
22559 Maximum number of keepalive messages that are allowed to be sent to the
22560 client without getting any response before the connection is considered
22563 In other words, the connection is automatically closed approximately
22564 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
22565 the last message received from the client. When @code{keepalive-count}
22566 is set to 0, connections will be automatically closed after
22567 @code{keepalive-interval} seconds of inactivity without sending any
22568 keepalive messages.
22570 Defaults to @samp{5}.
22574 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
22575 Same as above but for admin interface.
22577 Defaults to @samp{5}.
22581 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
22582 Same as above but for admin interface.
22584 Defaults to @samp{5}.
22588 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
22589 Timeout for Open vSwitch calls.
22591 The @code{ovs-vsctl} utility is used for the configuration and its
22592 timeout option is set by default to 5 seconds to avoid potential
22593 infinite waits blocking libvirt.
22595 Defaults to @samp{5}.
22599 @c %end of autogenerated docs
22601 @subsubheading Virtlog daemon
22602 The virtlogd service is a server side daemon component of libvirt that is
22603 used to manage logs from virtual machine consoles.
22605 This daemon is not used directly by libvirt client applications, rather it
22606 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
22607 standalone daemon, the main @code{libvirtd} daemon can be restarted without
22608 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
22609 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
22611 @deffn {Scheme Variable} virtlog-service-type
22612 This is the type of the virtlog daemon.
22613 Its value must be a @code{virtlog-configuration}.
22616 (service virtlog-service-type
22617 (virtlog-configuration
22618 (max-clients 1000)))
22622 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
22623 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
22625 Defaults to @samp{3}.
22629 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
22632 A filter allows to select a different logging level for a given category
22633 of logs The format for a filter is one of:
22644 where @code{name} is a string which is matched against the category
22645 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
22646 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
22647 be a substring of the full category name, in order to match multiple
22648 similar categories), the optional "+" prefix tells libvirt to log stack
22649 trace for each message matching name, and @code{x} is the minimal level
22650 where matching messages should be logged:
22667 Multiple filters can be defined in a single filters statement, they just
22668 need to be separated by spaces.
22670 Defaults to @samp{"3:remote 4:event"}.
22674 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
22677 An output is one of the places to save logging information The format
22678 for an output can be:
22682 output goes to stderr
22684 @item x:syslog:name
22685 use syslog for the output and use the given name as the ident
22687 @item x:file:file_path
22688 output to a file, with the given filepath
22691 output to journald logging system
22695 In all case the x prefix is the minimal level, acting as a filter
22712 Multiple outputs can be defined, they just need to be separated by
22715 Defaults to @samp{"3:stderr"}.
22719 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
22720 Maximum number of concurrent client connections to allow over all
22723 Defaults to @samp{1024}.
22727 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
22728 Maximum file size before rolling over.
22730 Defaults to @samp{2MB}
22734 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
22735 Maximum number of backup files to keep.
22737 Defaults to @samp{3}
22741 @subsubheading Transparent Emulation with QEMU
22744 @cindex @code{binfmt_misc}
22745 @code{qemu-binfmt-service-type} provides support for transparent
22746 emulation of program binaries built for different architectures---e.g.,
22747 it allows you to transparently execute an ARMv7 program on an x86_64
22748 machine. It achieves this by combining the @uref{https://www.qemu.org,
22749 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
22751 @defvr {Scheme Variable} qemu-binfmt-service-type
22752 This is the type of the QEMU/binfmt service for transparent emulation.
22753 Its value must be a @code{qemu-binfmt-configuration} object, which
22754 specifies the QEMU package to use as well as the architecture we want to
22758 (service qemu-binfmt-service-type
22759 (qemu-binfmt-configuration
22760 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
22763 In this example, we enable transparent emulation for the ARM and aarch64
22764 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
22765 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
22766 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
22769 @deftp {Data Type} qemu-binfmt-configuration
22770 This is the configuration for the @code{qemu-binfmt} service.
22773 @item @code{platforms} (default: @code{'()})
22774 The list of emulated QEMU platforms. Each item must be a @dfn{platform
22775 object} as returned by @code{lookup-qemu-platforms} (see below).
22777 @item @code{guix-support?} (default: @code{#f})
22778 When it is true, QEMU and all its dependencies are added to the build
22779 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
22780 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
22781 handlers to be used within the build environment, which in turn means
22782 that you can transparently build programs for another architecture.
22784 For example, let's suppose you're on an x86_64 machine and you have this
22788 (service qemu-binfmt-service-type
22789 (qemu-binfmt-configuration
22790 (platforms (lookup-qemu-platforms "arm"))
22791 (guix-support? #t)))
22797 guix build -s armhf-linux inkscape
22801 and it will build Inkscape for ARMv7 @emph{as if it were a native
22802 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
22803 if you'd like to test a package build for an architecture you don't have
22806 @item @code{qemu} (default: @code{qemu})
22807 The QEMU package to use.
22811 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
22812 Return the list of QEMU platform objects corresponding to
22813 @var{platforms}@dots{}. @var{platforms} must be a list of strings
22814 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
22815 @code{"mips64el"}, and so on.
22818 @deffn {Scheme Procedure} qemu-platform? @var{obj}
22819 Return true if @var{obj} is a platform object.
22822 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
22823 Return the name of @var{platform}---a string such as @code{"arm"}.
22826 @node Version Control Services
22827 @subsection Version Control Services
22829 The @code{(gnu services version-control)} module provides a service to
22830 allow remote access to local Git repositories. There are three options:
22831 the @code{git-daemon-service}, which provides access to repositories via
22832 the @code{git://} unsecured TCP-based protocol, extending the
22833 @code{nginx} web server to proxy some requests to
22834 @code{git-http-backend}, or providing a web interface with
22835 @code{cgit-service-type}.
22837 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
22839 Return a service that runs @command{git daemon}, a simple TCP server to
22840 expose repositories over the Git protocol for anonymous access.
22842 The optional @var{config} argument should be a
22843 @code{<git-daemon-configuration>} object, by default it allows read-only
22844 access to exported@footnote{By creating the magic file
22845 "git-daemon-export-ok" in the repository directory.} repositories under
22850 @deftp {Data Type} git-daemon-configuration
22851 Data type representing the configuration for @code{git-daemon-service}.
22854 @item @code{package} (default: @var{git})
22855 Package object of the Git distributed version control system.
22857 @item @code{export-all?} (default: @var{#f})
22858 Whether to allow access for all Git repositories, even if they do not
22859 have the @file{git-daemon-export-ok} file.
22861 @item @code{base-path} (default: @file{/srv/git})
22862 Whether to remap all the path requests as relative to the given path.
22863 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
22864 then if you later try to pull @code{git://example.com/hello.git}, git
22865 daemon will interpret the path as @code{/srv/git/hello.git}.
22867 @item @code{user-path} (default: @var{#f})
22868 Whether to allow @code{~user} notation to be used in requests. When
22869 specified with empty string, requests to @code{git://host/~alice/foo} is
22870 taken as a request to access @code{foo} repository in the home directory
22871 of user @code{alice}. If @var{(user-path "path")} is specified, the
22872 same request is taken as a request to access @code{path/foo} repository
22873 in the home directory of user @code{alice}.
22875 @item @code{listen} (default: @var{'()})
22876 Whether to listen on specific IP addresses or hostnames, defaults to
22879 @item @code{port} (default: @var{#f})
22880 Whether to listen on an alternative port, which defaults to 9418.
22882 @item @code{whitelist} (default: @var{'()})
22883 If not empty, only allow access to this list of directories.
22885 @item @code{extra-options} (default: @var{'()})
22886 Extra options will be passed to @code{git daemon}, please run
22887 @command{man git-daemon} for more information.
22892 The @code{git://} protocol lacks authentication. When you pull from a
22893 repository fetched via @code{git://}, you don't know whether the data you
22894 receive was modified or is even coming from the specified host, and your
22895 connection is subject to eavesdropping. It's better to use an authenticated
22896 and encrypted transport, such as @code{https}. Although Git allows you
22897 to serve repositories using unsophisticated file-based web servers,
22898 there is a faster protocol implemented by the @code{git-http-backend}
22899 program. This program is the back-end of a proper Git web service. It
22900 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
22901 on running the necessary @code{fcgiwrap} daemon.
22903 Guix has a separate configuration data type for serving Git repositories
22906 @deftp {Data Type} git-http-configuration
22907 Data type representing the configuration for @code{git-http-service}.
22910 @item @code{package} (default: @var{git})
22911 Package object of the Git distributed version control system.
22913 @item @code{git-root} (default: @file{/srv/git})
22914 Directory containing the Git repositories to expose to the world.
22916 @item @code{export-all?} (default: @var{#f})
22917 Whether to expose access for all Git repositories in @var{git-root},
22918 even if they do not have the @file{git-daemon-export-ok} file.
22920 @item @code{uri-path} (default: @file{/git/})
22921 Path prefix for Git access. With the default @code{/git/} prefix, this
22922 will map @code{http://@var{server}/git/@var{repo}.git} to
22923 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
22924 with this prefix are not passed on to this Git instance.
22926 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
22927 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
22932 There is no @code{git-http-service-type}, currently; instead you can
22933 create an @code{nginx-location-configuration} from a
22934 @code{git-http-configuration} and then add that location to a web
22937 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
22938 [config=(git-http-configuration)]
22939 Compute an @code{nginx-location-configuration} that corresponds to the
22940 given Git http configuration. An example nginx service definition to
22941 serve the default @file{/srv/git} over HTTPS might be:
22944 (service nginx-service-type
22945 (nginx-configuration
22948 (nginx-server-configuration
22949 (listen '("443 ssl"))
22950 (server-name "git.my-host.org")
22952 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
22953 (ssl-certificate-key
22954 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
22957 (git-http-nginx-location-configuration
22958 (git-http-configuration (uri-path "/"))))))))))
22961 This example assumes that you are using Let's Encrypt to get your TLS
22962 certificate. @xref{Certificate Services}. The default @code{certbot}
22963 service will redirect all HTTP traffic on @code{git.my-host.org} to
22964 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
22965 system services. @xref{Web Services}.
22968 @subsubheading Cgit Service
22970 @cindex Cgit service
22971 @cindex Git, web interface
22972 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
22973 repositories written in C.
22975 The following example will configure the service with default values.
22976 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
22979 (service cgit-service-type)
22982 The @code{file-object} type designates either a file-like object
22983 (@pxref{G-Expressions, file-like objects}) or a string.
22985 @c %start of fragment
22987 Available @code{cgit-configuration} fields are:
22989 @deftypevr {@code{cgit-configuration} parameter} package package
22994 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
22995 NGINX configuration.
22999 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
23000 Specifies a command which will be invoked to format the content of about
23001 pages (both top-level and for each repository).
23003 Defaults to @samp{""}.
23007 @deftypevr {@code{cgit-configuration} parameter} string agefile
23008 Specifies a path, relative to each repository path, which can be used to
23009 specify the date and time of the youngest commit in the repository.
23011 Defaults to @samp{""}.
23015 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
23016 Specifies a command that will be invoked for authenticating repository
23019 Defaults to @samp{""}.
23023 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
23024 Flag which, when set to @samp{age}, enables date ordering in the branch
23025 ref list, and when set @samp{name} enables ordering by branch name.
23027 Defaults to @samp{"name"}.
23031 @deftypevr {@code{cgit-configuration} parameter} string cache-root
23032 Path used to store the cgit cache entries.
23034 Defaults to @samp{"/var/cache/cgit"}.
23038 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
23039 Number which specifies the time-to-live, in minutes, for the cached
23040 version of repository pages accessed with a fixed SHA1.
23042 Defaults to @samp{-1}.
23046 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
23047 Number which specifies the time-to-live, in minutes, for the cached
23048 version of repository pages accessed without a fixed SHA1.
23050 Defaults to @samp{5}.
23054 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
23055 Number which specifies the time-to-live, in minutes, for the cached
23056 version of the repository summary page.
23058 Defaults to @samp{5}.
23062 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
23063 Number which specifies the time-to-live, in minutes, for the cached
23064 version of the repository index page.
23066 Defaults to @samp{5}.
23070 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
23071 Number which specifies the time-to-live, in minutes, for the result of
23072 scanning a path for Git repositories.
23074 Defaults to @samp{15}.
23078 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23079 Number which specifies the time-to-live, in minutes, for the cached
23080 version of the repository about page.
23082 Defaults to @samp{15}.
23086 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
23087 Number which specifies the time-to-live, in minutes, for the cached
23088 version of snapshots.
23090 Defaults to @samp{5}.
23094 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
23095 The maximum number of entries in the cgit cache. When set to @samp{0},
23096 caching is disabled.
23098 Defaults to @samp{0}.
23102 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
23103 Sort items in the repo list case sensitively.
23105 Defaults to @samp{#t}.
23109 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
23110 List of common prefixes which, when combined with a repository URL,
23111 generates valid clone URLs for the repository.
23113 Defaults to @samp{()}.
23117 @deftypevr {@code{cgit-configuration} parameter} list clone-url
23118 List of @code{clone-url} templates.
23120 Defaults to @samp{()}.
23124 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
23125 Command which will be invoked to format commit messages.
23127 Defaults to @samp{""}.
23131 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
23132 Flag which, when set to @samp{date}, enables strict date ordering in the
23133 commit log, and when set to @samp{topo} enables strict topological
23136 Defaults to @samp{"git log"}.
23140 @deftypevr {@code{cgit-configuration} parameter} file-object css
23141 URL which specifies the css document to include in all cgit pages.
23143 Defaults to @samp{"/share/cgit/cgit.css"}.
23147 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
23148 Specifies a command which will be invoked to format names and email
23149 address of committers, authors, and taggers, as represented in various
23150 places throughout the cgit interface.
23152 Defaults to @samp{""}.
23156 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
23157 Flag which, when set to @samp{#t}, will make cgit generate a HTML
23158 fragment suitable for embedding in other HTML pages.
23160 Defaults to @samp{#f}.
23164 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
23165 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
23166 commit history graph to the left of the commit messages in the
23167 repository log page.
23169 Defaults to @samp{#f}.
23173 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
23174 Flag which, when set to @samp{#t}, allows all filter settings to be
23175 overridden in repository-specific cgitrc files.
23177 Defaults to @samp{#f}.
23181 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
23182 Flag which, when set to @samp{#t}, allows users to follow a file in the
23185 Defaults to @samp{#f}.
23189 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
23190 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
23193 Defaults to @samp{#t}.
23197 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
23198 Flag which, when set to @samp{#t}, will make cgit generate extra links
23199 "summary", "commit", "tree" for each repo in the repository index.
23201 Defaults to @samp{#f}.
23205 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
23206 Flag which, when set to @samp{#t}, will make cgit display the owner of
23207 each repo in the repository index.
23209 Defaults to @samp{#t}.
23213 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
23214 Flag which, when set to @samp{#t}, will make cgit print the number of
23215 modified files for each commit on the repository log page.
23217 Defaults to @samp{#f}.
23221 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
23222 Flag which, when set to @samp{#t}, will make cgit print the number of
23223 added and removed lines for each commit on the repository log page.
23225 Defaults to @samp{#f}.
23229 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
23230 Flag which, when set to @code{#t}, will make cgit display remote
23231 branches in the summary and refs views.
23233 Defaults to @samp{#f}.
23237 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
23238 Flag which, when set to @code{1}, will make cgit use the subject of the
23239 parent commit as link text when generating links to parent commits in
23242 Defaults to @samp{#f}.
23246 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
23247 Flag which, when set to @samp{#t}, will make cgit use the subject of the
23248 parent commit as link text when generating links to parent commits in
23251 Defaults to @samp{#f}.
23255 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
23256 Flag which, when set to @samp{#t}, will make cgit generate linenumber
23257 links for plaintext blobs printed in the tree view.
23259 Defaults to @samp{#t}.
23263 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
23264 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
23265 set any repo specific settings.
23267 Defaults to @samp{#f}.
23271 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
23272 URL used as link to a shortcut icon for cgit.
23274 Defaults to @samp{"/favicon.ico"}.
23278 @deftypevr {@code{cgit-configuration} parameter} string footer
23279 The content of the file specified with this option will be included
23280 verbatim at the bottom of all pages (i.e.@: it replaces the standard
23281 "generated by..."@: message).
23283 Defaults to @samp{""}.
23287 @deftypevr {@code{cgit-configuration} parameter} string head-include
23288 The content of the file specified with this option will be included
23289 verbatim in the HTML HEAD section on all pages.
23291 Defaults to @samp{""}.
23295 @deftypevr {@code{cgit-configuration} parameter} string header
23296 The content of the file specified with this option will be included
23297 verbatim at the top of all pages.
23299 Defaults to @samp{""}.
23303 @deftypevr {@code{cgit-configuration} parameter} file-object include
23304 Name of a configfile to include before the rest of the current config-
23307 Defaults to @samp{""}.
23311 @deftypevr {@code{cgit-configuration} parameter} string index-header
23312 The content of the file specified with this option will be included
23313 verbatim above the repository index.
23315 Defaults to @samp{""}.
23319 @deftypevr {@code{cgit-configuration} parameter} string index-info
23320 The content of the file specified with this option will be included
23321 verbatim below the heading on the repository index page.
23323 Defaults to @samp{""}.
23327 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
23328 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
23329 in the servers timezone.
23331 Defaults to @samp{#f}.
23335 @deftypevr {@code{cgit-configuration} parameter} file-object logo
23336 URL which specifies the source of an image which will be used as a logo
23339 Defaults to @samp{"/share/cgit/cgit.png"}.
23343 @deftypevr {@code{cgit-configuration} parameter} string logo-link
23344 URL loaded when clicking on the cgit logo image.
23346 Defaults to @samp{""}.
23350 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
23351 Command which will be invoked to format the Owner column of the main
23354 Defaults to @samp{""}.
23358 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
23359 Number of items to display in atom feeds view.
23361 Defaults to @samp{10}.
23365 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
23366 Number of entries to list per page in "log" view.
23368 Defaults to @samp{50}.
23372 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
23373 Number of commit message characters to display in "log" view.
23375 Defaults to @samp{80}.
23379 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
23380 Specifies the number of entries to list per page on the repository index
23383 Defaults to @samp{50}.
23387 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
23388 Specifies the maximum number of repo description characters to display
23389 on the repository index page.
23391 Defaults to @samp{80}.
23395 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
23396 Specifies the maximum size of a blob to display HTML for in KBytes.
23398 Defaults to @samp{0}.
23402 @deftypevr {@code{cgit-configuration} parameter} string max-stats
23403 Maximum statistics period. Valid values are @samp{week},@samp{month},
23404 @samp{quarter} and @samp{year}.
23406 Defaults to @samp{""}.
23410 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
23411 Mimetype for the specified filename extension.
23413 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
23414 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
23415 "image/png") (svg "image/svg+xml"))}.
23419 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
23420 Specifies the file to use for automatic mimetype lookup.
23422 Defaults to @samp{""}.
23426 @deftypevr {@code{cgit-configuration} parameter} string module-link
23427 Text which will be used as the formatstring for a hyperlink when a
23428 submodule is printed in a directory listing.
23430 Defaults to @samp{""}.
23434 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
23435 If set to the value @samp{#t} caching will be disabled.
23437 Defaults to @samp{#f}.
23441 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
23442 If set to @samp{#t} showing full author email addresses will be
23445 Defaults to @samp{#f}.
23449 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
23450 Flag which, when set to @samp{#t}, will make cgit omit the standard
23451 header on all pages.
23453 Defaults to @samp{#f}.
23457 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
23458 A list of subdirectories inside of @code{repository-directory}, relative
23459 to it, that should loaded as Git repositories. An empty list means that
23460 all subdirectories will be loaded.
23462 Defaults to @samp{()}.
23466 @deftypevr {@code{cgit-configuration} parameter} file-object readme
23467 Text which will be used as default value for @code{cgit-repo-readme}.
23469 Defaults to @samp{""}.
23473 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
23474 If set to @code{#t} and @code{repository-directory} is enabled, if any
23475 repositories are found with a suffix of @code{.git}, this suffix will be
23476 removed for the URL and name.
23478 Defaults to @samp{#f}.
23482 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
23483 Maximum number of files to consider when detecting renames.
23485 Defaults to @samp{-1}.
23489 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
23490 The way in which repositories in each section are sorted.
23492 Defaults to @samp{""}.
23496 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
23497 Text used as content for the @code{robots} meta-tag.
23499 Defaults to @samp{("noindex" "nofollow")}.
23503 @deftypevr {@code{cgit-configuration} parameter} string root-desc
23504 Text printed below the heading on the repository index page.
23506 Defaults to @samp{"a fast webinterface for the git dscm"}.
23510 @deftypevr {@code{cgit-configuration} parameter} string root-readme
23511 The content of the file specified with this option will be included
23512 verbatim below thef "about" link on the repository index page.
23514 Defaults to @samp{""}.
23518 @deftypevr {@code{cgit-configuration} parameter} string root-title
23519 Text printed as heading on the repository index page.
23521 Defaults to @samp{""}.
23525 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
23526 If set to @samp{#t} and repository-directory is enabled,
23527 repository-directory will recurse into directories whose name starts
23528 with a period. Otherwise, repository-directory will stay away from such
23529 directories, considered as "hidden". Note that this does not apply to
23530 the ".git" directory in non-bare repos.
23532 Defaults to @samp{#f}.
23536 @deftypevr {@code{cgit-configuration} parameter} list snapshots
23537 Text which specifies the default set of snapshot formats that cgit
23538 generates links for.
23540 Defaults to @samp{()}.
23544 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
23545 Name of the directory to scan for repositories (represents
23548 Defaults to @samp{"/srv/git"}.
23552 @deftypevr {@code{cgit-configuration} parameter} string section
23553 The name of the current repository section - all repositories defined
23554 after this option will inherit the current section name.
23556 Defaults to @samp{""}.
23560 @deftypevr {@code{cgit-configuration} parameter} string section-sort
23561 Flag which, when set to @samp{1}, will sort the sections on the
23562 repository listing by name.
23564 Defaults to @samp{""}.
23568 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
23569 A number which, if defined prior to repository-directory, specifies how
23570 many path elements from each repo path to use as a default section name.
23572 Defaults to @samp{0}.
23576 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
23577 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
23580 Defaults to @samp{#f}.
23584 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
23585 Specifies a command which will be invoked to format plaintext blobs in
23588 Defaults to @samp{""}.
23592 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
23593 Specifies the number of branches to display in the repository "summary"
23596 Defaults to @samp{10}.
23600 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
23601 Specifies the number of log entries to display in the repository
23604 Defaults to @samp{10}.
23608 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
23609 Specifies the number of tags to display in the repository "summary"
23612 Defaults to @samp{10}.
23616 @deftypevr {@code{cgit-configuration} parameter} string strict-export
23617 Filename which, if specified, needs to be present within the repository
23618 for cgit to allow access to that repository.
23620 Defaults to @samp{""}.
23624 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
23625 URL which, if specified, will be used as root for all cgit links.
23627 Defaults to @samp{"/"}.
23631 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
23632 A list of @dfn{cgit-repo} records to use with config.
23634 Defaults to @samp{()}.
23636 Available @code{repository-cgit-configuration} fields are:
23638 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
23639 A mask of snapshot formats for this repo that cgit generates links for,
23640 restricted by the global @code{snapshots} setting.
23642 Defaults to @samp{()}.
23646 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
23647 Override the default @code{source-filter}.
23649 Defaults to @samp{""}.
23653 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
23654 The relative URL used to access the repository.
23656 Defaults to @samp{""}.
23660 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
23661 Override the default @code{about-filter}.
23663 Defaults to @samp{""}.
23667 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
23668 Flag which, when set to @samp{age}, enables date ordering in the branch
23669 ref list, and when set to @samp{name} enables ordering by branch name.
23671 Defaults to @samp{""}.
23675 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
23676 A list of URLs which can be used to clone repo.
23678 Defaults to @samp{()}.
23682 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
23683 Override the default @code{commit-filter}.
23685 Defaults to @samp{""}.
23689 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
23690 Flag which, when set to @samp{date}, enables strict date ordering in the
23691 commit log, and when set to @samp{topo} enables strict topological
23694 Defaults to @samp{""}.
23698 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
23699 The name of the default branch for this repository. If no such branch
23700 exists in the repository, the first branch name (when sorted) is used as
23701 default instead. By default branch pointed to by HEAD, or "master" if
23702 there is no suitable HEAD.
23704 Defaults to @samp{""}.
23708 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
23709 The value to show as repository description.
23711 Defaults to @samp{""}.
23715 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
23716 The value to show as repository homepage.
23718 Defaults to @samp{""}.
23722 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
23723 Override the default @code{email-filter}.
23725 Defaults to @samp{""}.
23729 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
23730 A flag which can be used to disable the global setting
23731 @code{enable-commit-graph?}.
23733 Defaults to @samp{disabled}.
23737 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
23738 A flag which can be used to disable the global setting
23739 @code{enable-log-filecount?}.
23741 Defaults to @samp{disabled}.
23745 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
23746 A flag which can be used to disable the global setting
23747 @code{enable-log-linecount?}.
23749 Defaults to @samp{disabled}.
23753 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
23754 Flag which, when set to @code{#t}, will make cgit display remote
23755 branches in the summary and refs views.
23757 Defaults to @samp{disabled}.
23761 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
23762 A flag which can be used to override the global setting
23763 @code{enable-subject-links?}.
23765 Defaults to @samp{disabled}.
23769 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
23770 A flag which can be used to override the global setting
23771 @code{enable-html-serving?}.
23773 Defaults to @samp{disabled}.
23777 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
23778 Flag which, when set to @code{#t}, hides the repository from the
23781 Defaults to @samp{#f}.
23785 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
23786 Flag which, when set to @samp{#t}, ignores the repository.
23788 Defaults to @samp{#f}.
23792 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
23793 URL which specifies the source of an image which will be used as a logo
23794 on this repo’s pages.
23796 Defaults to @samp{""}.
23800 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
23801 URL loaded when clicking on the cgit logo image.
23803 Defaults to @samp{""}.
23807 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
23808 Override the default @code{owner-filter}.
23810 Defaults to @samp{""}.
23814 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
23815 Text which will be used as the formatstring for a hyperlink when a
23816 submodule is printed in a directory listing. The arguments for the
23817 formatstring are the path and SHA1 of the submodule commit.
23819 Defaults to @samp{""}.
23823 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
23824 Text which will be used as the formatstring for a hyperlink when a
23825 submodule with the specified subdirectory path is printed in a directory
23828 Defaults to @samp{()}.
23832 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
23833 Override the default maximum statistics period.
23835 Defaults to @samp{""}.
23839 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
23840 The value to show as repository name.
23842 Defaults to @samp{""}.
23846 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
23847 A value used to identify the owner of the repository.
23849 Defaults to @samp{""}.
23853 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
23854 An absolute path to the repository directory.
23856 Defaults to @samp{""}.
23860 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
23861 A path (relative to repo) which specifies a file to include verbatim as
23862 the "About" page for this repo.
23864 Defaults to @samp{""}.
23868 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
23869 The name of the current repository section - all repositories defined
23870 after this option will inherit the current section name.
23872 Defaults to @samp{""}.
23876 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
23877 Extra options will be appended to cgitrc file.
23879 Defaults to @samp{()}.
23885 @deftypevr {@code{cgit-configuration} parameter} list extra-options
23886 Extra options will be appended to cgitrc file.
23888 Defaults to @samp{()}.
23893 @c %end of fragment
23895 However, it could be that you just want to get a @code{cgitrc} up and
23896 running. In that case, you can pass an @code{opaque-cgit-configuration}
23897 as a record to @code{cgit-service-type}. As its name indicates, an
23898 opaque configuration does not have easy reflective capabilities.
23900 Available @code{opaque-cgit-configuration} fields are:
23902 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
23906 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
23907 The contents of the @code{cgitrc}, as a string.
23910 For example, if your @code{cgitrc} is just the empty string, you
23911 could instantiate a cgit service like this:
23914 (service cgit-service-type
23915 (opaque-cgit-configuration
23919 @subsubheading Gitolite Service
23921 @cindex Gitolite service
23922 @cindex Git, hosting
23923 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
23924 repositories on a central server.
23926 Gitolite can handle multiple repositories and users, and supports flexible
23927 configuration of the permissions for the users on the repositories.
23929 The following example will configure Gitolite using the default @code{git}
23930 user, and the provided SSH public key.
23933 (service gitolite-service-type
23934 (gitolite-configuration
23935 (admin-pubkey (plain-file
23937 "ssh-rsa AAAA... guix@@example.com"))))
23940 Gitolite is configured through a special admin repository which you can clone,
23941 for example, if you setup Gitolite on @code{example.com}, you would run the
23942 following command to clone the admin repository.
23945 git clone git@@example.com:gitolite-admin
23948 When the Gitolite service is activated, the provided @code{admin-pubkey} will
23949 be inserted in to the @file{keydir} directory in the gitolite-admin
23950 repository. If this results in a change in the repository, it will be
23951 committed using the message ``gitolite setup by GNU Guix''.
23953 @deftp {Data Type} gitolite-configuration
23954 Data type representing the configuration for @code{gitolite-service-type}.
23957 @item @code{package} (default: @var{gitolite})
23958 Gitolite package to use.
23960 @item @code{user} (default: @var{git})
23961 User to use for Gitolite. This will be user that you use when accessing
23964 @item @code{group} (default: @var{git})
23965 Group to use for Gitolite.
23967 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
23968 Directory in which to store the Gitolite configuration and repositories.
23970 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
23971 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
23972 representing the configuration for Gitolite.
23974 @item @code{admin-pubkey} (default: @var{#f})
23975 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
23976 setup Gitolite. This will be inserted in to the @file{keydir} directory
23977 within the gitolite-admin repository.
23979 To specify the SSH key as a string, use the @code{plain-file} function.
23982 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
23988 @deftp {Data Type} gitolite-rc-file
23989 Data type representing the Gitolite RC file.
23992 @item @code{umask} (default: @code{#o0077})
23993 This controls the permissions Gitolite sets on the repositories and their
23996 A value like @code{#o0027} will give read access to the group used by Gitolite
23997 (by default: @code{git}). This is necessary when using Gitolite with software
23998 like cgit or gitweb.
24000 @item @code{git-config-keys} (default: @code{""})
24001 Gitolite allows you to set git config values using the "config" keyword. This
24002 setting allows control over the config keys to accept.
24004 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
24005 Set the role names allowed to be used by users running the perms command.
24007 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
24008 This setting controls the commands and features to enable within Gitolite.
24014 @node Game Services
24015 @subsection Game Services
24017 @subsubheading The Battle for Wesnoth Service
24019 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
24020 based tactical strategy game, with several single player campaigns, and
24021 multiplayer games (both networked and local).
24023 @defvar {Scheme Variable} wesnothd-service-type
24024 Service type for the wesnothd service. Its value must be a
24025 @code{wesnothd-configuration} object. To run wesnothd in the default
24026 configuration, instantiate it as:
24029 (service wesnothd-service-type)
24033 @deftp {Data Type} wesnothd-configuration
24034 Data type representing the configuration of @command{wesnothd}.
24037 @item @code{package} (default: @code{wesnoth-server})
24038 The wesnoth server package to use.
24040 @item @code{port} (default: @code{15000})
24041 The port to bind the server to.
24045 @node Miscellaneous Services
24046 @subsection Miscellaneous Services
24048 @cindex fingerprint
24049 @subsubheading Fingerprint Service
24051 The @code{(gnu services authentication)} module provides a DBus service to
24052 read and identify fingerprints via a fingerprint sensor.
24054 @defvr {Scheme Variable} fprintd-service-type
24055 The service type for @command{fprintd}, which provides the fingerprint
24056 reading capability.
24059 (service fprintd-service-type)
24064 @subsubheading System Control Service
24066 The @code{(gnu services sysctl)} provides a service to configure kernel
24067 parameters at boot.
24069 @defvr {Scheme Variable} sysctl-service-type
24070 The service type for @command{sysctl}, which modifies kernel parameters
24071 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
24075 (service sysctl-service-type
24076 (sysctl-configuration
24077 (settings '(("net.ipv4.ip_forward" . "1")))))
24081 @deftp {Data Type} sysctl-configuration
24082 The data type representing the configuration of @command{sysctl}.
24085 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
24086 The @command{sysctl} executable to use.
24088 @item @code{settings} (default: @code{'()})
24089 An association list specifies kernel parameters and their values.
24094 @subsubheading PC/SC Smart Card Daemon Service
24096 The @code{(gnu services security-token)} module provides the following service
24097 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
24098 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
24099 manager that coordinates communications with smart card readers, smart cards
24100 and cryptographic tokens that are connected to the system.
24102 @defvr {Scheme Variable} pcscd-service-type
24103 Service type for the @command{pcscd} service. Its value must be a
24104 @code{pcscd-configuration} object. To run pcscd in the default
24105 configuration, instantiate it as:
24108 (service pcscd-service-type)
24112 @deftp {Data Type} pcscd-configuration
24113 The data type representing the configuration of @command{pcscd}.
24116 @item @code{pcsc-lite} (default: @code{pcsc-lite})
24117 The pcsc-lite package that provides pcscd.
24118 @item @code{usb-drivers} (default: @code{(list ccid)})
24119 List of packages that provide USB drivers to pcscd. Drivers are expected to be
24120 under @file{pcsc/drivers} in the store directory of the package.
24125 @subsubheading Lirc Service
24127 The @code{(gnu services lirc)} module provides the following service.
24129 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
24130 [#:device #f] [#:driver #f] [#:config-file #f] @
24131 [#:extra-options '()]
24132 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
24133 decodes infrared signals from remote controls.
24135 Optionally, @var{device}, @var{driver} and @var{config-file}
24136 (configuration file name) may be specified. See @command{lircd} manual
24139 Finally, @var{extra-options} is a list of additional command-line options
24140 passed to @command{lircd}.
24144 @subsubheading Spice Service
24146 The @code{(gnu services spice)} module provides the following service.
24148 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
24149 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
24150 that enables sharing the clipboard with a vm and setting the guest display
24151 resolution when the graphical console window resizes.
24154 @cindex inputattach
24155 @subsubheading inputattach Service
24157 @cindex tablet input, for Xorg
24158 @cindex touchscreen input, for Xorg
24159 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
24160 use input devices such as Wacom tablets, touchscreens, or joysticks with the
24161 Xorg display server.
24163 @deffn {Scheme Variable} inputattach-service-type
24164 Type of a service that runs @command{inputattach} on a device and
24165 dispatches events from it.
24168 @deftp {Data Type} inputattach-configuration
24170 @item @code{device-type} (default: @code{"wacom"})
24171 The type of device to connect to. Run @command{inputattach --help}, from the
24172 @code{inputattach} package, to see the list of supported device types.
24174 @item @code{device} (default: @code{"/dev/ttyS0"})
24175 The device file to connect to the device.
24177 @item @code{log-file} (default: @code{#f})
24178 If true, this must be the name of a file to log messages to.
24182 @subsection Dictionary Services
24184 The @code{(gnu services dict)} module provides the following service:
24186 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
24187 Return a service that runs the @command{dicod} daemon, an implementation
24188 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
24190 The optional @var{config} argument specifies the configuration for
24191 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
24192 default it serves the GNU Collaborative International Dictonary of English.
24194 You can add @command{open localhost} to your @file{~/.dico} file to make
24195 @code{localhost} the default server for @command{dico} client
24196 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
24199 @deftp {Data Type} dicod-configuration
24200 Data type representing the configuration of dicod.
24203 @item @code{dico} (default: @var{dico})
24204 Package object of the GNU Dico dictionary server.
24206 @item @code{interfaces} (default: @var{'("localhost")})
24207 This is the list of IP addresses and ports and possibly socket file
24208 names to listen to (@pxref{Server Settings, @code{listen} directive,,
24209 dico, GNU Dico Manual}).
24211 @item @code{handlers} (default: @var{'()})
24212 List of @code{<dicod-handler>} objects denoting handlers (module instances).
24214 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
24215 List of @code{<dicod-database>} objects denoting dictionaries to be served.
24219 @deftp {Data Type} dicod-handler
24220 Data type representing a dictionary handler (module instance).
24224 Name of the handler (module instance).
24226 @item @code{module} (default: @var{#f})
24227 Name of the dicod module of the handler (instance). If it is @code{#f},
24228 the module has the same name as the handler.
24229 (@pxref{Modules,,, dico, GNU Dico Manual}).
24231 @item @code{options}
24232 List of strings or gexps representing the arguments for the module handler
24236 @deftp {Data Type} dicod-database
24237 Data type representing a dictionary database.
24241 Name of the database, will be used in DICT commands.
24243 @item @code{handler}
24244 Name of the dicod handler (module instance) used by this database
24245 (@pxref{Handlers,,, dico, GNU Dico Manual}).
24247 @item @code{complex?} (default: @var{#f})
24248 Whether the database configuration complex. The complex configuration
24249 will need a corresponding @code{<dicod-handler>} object, otherwise not.
24251 @item @code{options}
24252 List of strings or gexps representing the arguments for the database
24253 (@pxref{Databases,,, dico, GNU Dico Manual}).
24257 @defvr {Scheme Variable} %dicod-database:gcide
24258 A @code{<dicod-database>} object serving the GNU Collaborative International
24259 Dictionary of English using the @code{gcide} package.
24262 The following is an example @code{dicod-service} configuration.
24265 (dicod-service #:config
24266 (dicod-configuration
24267 (handlers (list (dicod-handler
24271 (list #~(string-append "dbdir=" #$wordnet))))))
24272 (databases (list (dicod-database
24275 (handler "wordnet")
24276 (options '("database=wn")))
24277 %dicod-database:gcide))))
24281 @subsubheading Docker Service
24283 The @code{(gnu services docker)} module provides the following services.
24285 @defvr {Scheme Variable} docker-service-type
24287 This is the type of the service that runs @url{https://www.docker.com,Docker},
24288 a daemon that can execute application bundles (sometimes referred to as
24289 ``containers'') in isolated environments.
24293 @deftp {Data Type} docker-configuration
24294 This is the data type representing the configuration of Docker and Containerd.
24298 @item @code{package} (default: @code{docker})
24299 The Docker package to use.
24301 @item @code{containerd} (default: @var{containerd})
24302 The Containerd package to use.
24308 @subsubheading Auditd Service
24310 The @code{(gnu services auditd)} module provides the following service.
24312 @defvr {Scheme Variable} auditd-service-type
24314 This is the type of the service that runs
24315 @url{https://people.redhat.com/sgrubb/audit/,auditd},
24316 a daemon that tracks security-relevant information on your system.
24318 Examples of things that can be tracked:
24328 Failed login attempts
24335 @command{auditctl} from the @code{audit} package can be used in order
24336 to add or remove events to be tracked (until the next reboot).
24337 In order to permanently track events, put the command line arguments
24338 of auditctl into @file{/etc/audit/audit.rules}.
24339 @command{aureport} from the @code{audit} package can be used in order
24340 to view a report of all recorded events.
24341 The audit daemon usually logs into the directory @file{/var/log/audit}.
24345 @deftp {Data Type} auditd-configuration
24346 This is the data type representing the configuration of auditd.
24350 @item @code{audit} (default: @code{audit})
24351 The audit package to use.
24356 @defvr {Scheme Variable} singularity-service-type
24357 This is the type of the service that allows you to run
24358 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
24359 create and run application bundles (aka. ``containers''). The value for this
24360 service is the Singularity package to use.
24362 The service does not install a daemon; instead, it installs helper programs as
24363 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
24364 @command{singularity run} and similar commands.
24368 @subsubheading Nix service
24370 The @code{(gnu services nix)} module provides the following service.
24372 @defvr {Scheme Variable} nix-service-type
24374 This is the type of the service that runs build daemon of the
24375 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
24379 (use-modules (gnu))
24380 (use-service-modules nix)
24381 (use-package-modules package-management)
24385 (packages (append (list nix)
24388 (services (append (list (service nix-service-type))
24392 After @command{guix system reconfigure} configure Nix for your user:
24395 @item Add a Nix channel and update it. See
24396 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
24398 @item Create a symlink to your profile and activate Nix profile:
24402 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
24403 $ source /run/current-system/profile/etc/profile.d/nix.sh
24408 @node Setuid Programs
24409 @section Setuid Programs
24411 @cindex setuid programs
24412 Some programs need to run with ``root'' privileges, even when they are
24413 launched by unprivileged users. A notorious example is the
24414 @command{passwd} program, which users can run to change their
24415 password, and which needs to access the @file{/etc/passwd} and
24416 @file{/etc/shadow} files---something normally restricted to root, for
24417 obvious security reasons. To address that, these executables are
24418 @dfn{setuid-root}, meaning that they always run with root privileges
24419 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
24420 for more info about the setuid mechanism.)
24422 The store itself @emph{cannot} contain setuid programs: that would be a
24423 security issue since any user on the system can write derivations that
24424 populate the store (@pxref{The Store}). Thus, a different mechanism is
24425 used: instead of changing the setuid bit directly on files that are in
24426 the store, we let the system administrator @emph{declare} which programs
24427 should be setuid root.
24429 The @code{setuid-programs} field of an @code{operating-system}
24430 declaration contains a list of G-expressions denoting the names of
24431 programs to be setuid-root (@pxref{Using the Configuration System}).
24432 For instance, the @command{passwd} program, which is part of the Shadow
24433 package, can be designated by this G-expression (@pxref{G-Expressions}):
24436 #~(string-append #$shadow "/bin/passwd")
24439 A default set of setuid programs is defined by the
24440 @code{%setuid-programs} variable of the @code{(gnu system)} module.
24442 @defvr {Scheme Variable} %setuid-programs
24443 A list of G-expressions denoting common programs that are setuid-root.
24445 The list includes commands such as @command{passwd}, @command{ping},
24446 @command{su}, and @command{sudo}.
24449 Under the hood, the actual setuid programs are created in the
24450 @file{/run/setuid-programs} directory at system activation time. The
24451 files in this directory refer to the ``real'' binaries, which are in the
24454 @node X.509 Certificates
24455 @section X.509 Certificates
24457 @cindex HTTPS, certificates
24458 @cindex X.509 certificates
24460 Web servers available over HTTPS (that is, HTTP over the transport-layer
24461 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
24462 that the client can then use to @emph{authenticate} the server. To do
24463 that, clients verify that the server's certificate is signed by a
24464 so-called @dfn{certificate authority} (CA). But to verify the CA's
24465 signature, clients must have first acquired the CA's certificate.
24467 Web browsers such as GNU@tie{}IceCat include their own set of CA
24468 certificates, such that they are able to verify CA signatures
24471 However, most other programs that can talk HTTPS---@command{wget},
24472 @command{git}, @command{w3m}, etc.---need to be told where CA
24473 certificates can be found.
24475 @cindex @code{nss-certs}
24476 In Guix, this is done by adding a package that provides certificates
24477 to the @code{packages} field of the @code{operating-system} declaration
24478 (@pxref{operating-system Reference}). Guix includes one such package,
24479 @code{nss-certs}, which is a set of CA certificates provided as part of
24480 Mozilla's Network Security Services.
24482 Note that it is @emph{not} part of @code{%base-packages}, so you need to
24483 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
24484 most applications and libraries look for certificates by default, points
24485 to the certificates installed globally.
24487 Unprivileged users, including users of Guix on a foreign distro,
24488 can also install their own certificate package in
24489 their profile. A number of environment variables need to be defined so
24490 that applications and libraries know where to find them. Namely, the
24491 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
24492 variables. Some applications add their own environment variables; for
24493 instance, the Git version control system honors the certificate bundle
24494 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
24495 would typically run something like:
24498 $ guix install nss-certs
24499 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
24500 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
24501 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
24504 As another example, R requires the @code{CURL_CA_BUNDLE} environment
24505 variable to point to a certificate bundle, so you would have to run
24506 something like this:
24509 $ guix install nss-certs
24510 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
24513 For other applications you may want to look up the required environment
24514 variable in the relevant documentation.
24517 @node Name Service Switch
24518 @section Name Service Switch
24520 @cindex name service switch
24522 The @code{(gnu system nss)} module provides bindings to the
24523 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
24524 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
24525 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
24526 extended with new ``name'' lookup methods for system databases, which
24527 includes host names, service names, user accounts, and more (@pxref{Name
24528 Service Switch, System Databases and Name Service Switch,, libc, The GNU
24529 C Library Reference Manual}).
24531 The NSS configuration specifies, for each system database, which lookup
24532 method is to be used, and how the various methods are chained
24533 together---for instance, under which circumstances NSS should try the
24534 next method in the list. The NSS configuration is given in the
24535 @code{name-service-switch} field of @code{operating-system} declarations
24536 (@pxref{operating-system Reference, @code{name-service-switch}}).
24539 @cindex .local, host name lookup
24540 As an example, the declaration below configures the NSS to use the
24541 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
24542 back-end}, which supports host name lookups over multicast DNS (mDNS)
24543 for host names ending in @code{.local}:
24546 (name-service-switch
24547 (hosts (list %files ;first, check /etc/hosts
24549 ;; If the above did not succeed, try
24550 ;; with 'mdns_minimal'.
24552 (name "mdns_minimal")
24554 ;; 'mdns_minimal' is authoritative for
24555 ;; '.local'. When it returns "not found",
24556 ;; no need to try the next methods.
24557 (reaction (lookup-specification
24558 (not-found => return))))
24560 ;; Then fall back to DNS.
24564 ;; Finally, try with the "full" 'mdns'.
24569 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
24570 contains this configuration, so you will not have to type it if all you
24571 want is to have @code{.local} host lookup working.
24573 Note that, in this case, in addition to setting the
24574 @code{name-service-switch} of the @code{operating-system} declaration,
24575 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
24576 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
24577 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
24578 to the name service cache daemon (@pxref{Base Services,
24579 @code{nscd-service}}).
24581 For convenience, the following variables provide typical NSS
24584 @defvr {Scheme Variable} %default-nss
24585 This is the default name service switch configuration, a
24586 @code{name-service-switch} object.
24589 @defvr {Scheme Variable} %mdns-host-lookup-nss
24590 This is the name service switch configuration with support for host name
24591 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
24594 The reference for name service switch configuration is given below. It
24595 is a direct mapping of the configuration file format of the C library , so
24596 please refer to the C library manual for more information (@pxref{NSS
24597 Configuration File,,, libc, The GNU C Library Reference Manual}).
24598 Compared to the configuration file format of libc NSS, it has the advantage
24599 not only of adding this warm parenthetic feel that we like, but also
24600 static checks: you will know about syntax errors and typos as soon as you
24601 run @command{guix system}.
24603 @deftp {Data Type} name-service-switch
24605 This is the data type representation the configuration of libc's name
24606 service switch (NSS). Each field below represents one of the supported
24623 The system databases handled by the NSS. Each of these fields must be a
24624 list of @code{<name-service>} objects (see below).
24628 @deftp {Data Type} name-service
24630 This is the data type representing an actual name service and the
24631 associated lookup action.
24635 A string denoting the name service (@pxref{Services in the NSS
24636 configuration,,, libc, The GNU C Library Reference Manual}).
24638 Note that name services listed here must be visible to nscd. This is
24639 achieved by passing the @code{#:name-services} argument to
24640 @code{nscd-service} the list of packages providing the needed name
24641 services (@pxref{Base Services, @code{nscd-service}}).
24644 An action specified using the @code{lookup-specification} macro
24645 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
24646 Reference Manual}). For example:
24649 (lookup-specification (unavailable => continue)
24650 (success => return))
24655 @node Initial RAM Disk
24656 @section Initial RAM Disk
24659 @cindex initial RAM disk
24660 For bootstrapping purposes, the Linux-Libre kernel is passed an
24661 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
24662 root file system as well as an initialization script. The latter is
24663 responsible for mounting the real root file system, and for loading any
24664 kernel modules that may be needed to achieve that.
24666 The @code{initrd-modules} field of an @code{operating-system}
24667 declaration allows you to specify Linux-libre kernel modules that must
24668 be available in the initrd. In particular, this is where you would list
24669 modules needed to actually drive the hard disk where your root partition
24670 is---although the default value of @code{initrd-modules} should cover
24671 most use cases. For example, assuming you need the @code{megaraid_sas}
24672 module in addition to the default modules to be able to access your root
24673 file system, you would write:
24678 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
24681 @defvr {Scheme Variable} %base-initrd-modules
24682 This is the list of kernel modules included in the initrd by default.
24685 Furthermore, if you need lower-level customization, the @code{initrd}
24686 field of an @code{operating-system} declaration allows
24687 you to specify which initrd you would like to use. The @code{(gnu
24688 system linux-initrd)} module provides three ways to build an initrd: the
24689 high-level @code{base-initrd} procedure and the low-level
24690 @code{raw-initrd} and @code{expression->initrd} procedures.
24692 The @code{base-initrd} procedure is intended to cover most common uses.
24693 For example, if you want to add a bunch of kernel modules to be loaded
24694 at boot time, you can define the @code{initrd} field of the operating
24695 system declaration like this:
24698 (initrd (lambda (file-systems . rest)
24699 ;; Create a standard initrd but set up networking
24700 ;; with the parameters QEMU expects by default.
24701 (apply base-initrd file-systems
24702 #:qemu-networking? #t
24706 The @code{base-initrd} procedure also handles common use cases that
24707 involves using the system as a QEMU guest, or as a ``live'' system with
24708 volatile root file system.
24710 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
24711 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
24712 such as trying to guess which kernel modules and packages should be included
24713 to the initrd. An example use of @code{raw-initrd} is when a user has
24714 a custom Linux kernel configuration and default kernel modules included by
24715 @code{base-initrd} are not available.
24717 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
24718 honors several options passed on the Linux kernel command line
24719 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
24720 @code{-append} option of QEMU), notably:
24723 @item --load=@var{boot}
24724 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
24725 program, once it has mounted the root file system.
24727 Guix uses this option to yield control to a boot program that runs the
24728 service activation programs and then spawns the GNU@tie{}Shepherd, the
24729 initialization system.
24731 @item --root=@var{root}
24732 Mount @var{root} as the root file system. @var{root} can be a
24733 device name like @code{/dev/sda1}, a file system label, or a file system
24736 @item --system=@var{system}
24737 Have @file{/run/booted-system} and @file{/run/current-system} point to
24740 @item modprobe.blacklist=@var{modules}@dots{}
24741 @cindex module, black-listing
24742 @cindex black list, of kernel modules
24743 Instruct the initial RAM disk as well as the @command{modprobe} command
24744 (from the kmod package) to refuse to load @var{modules}. @var{modules}
24745 must be a comma-separated list of module names---e.g.,
24746 @code{usbkbd,9pnet}.
24749 Start a read-eval-print loop (REPL) from the initial RAM disk before it
24750 tries to load kernel modules and to mount the root file system. Our
24751 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
24752 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
24753 Manual}, for more information on Guile's REPL.
24757 Now that you know all the features that initial RAM disks produced by
24758 @code{base-initrd} and @code{raw-initrd} provide,
24759 here is how to use it and customize it further.
24762 @cindex initial RAM disk
24763 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
24764 [#:linux-modules '()] [#:mapped-devices '()] @
24765 [#:keyboard-layout #f] @
24766 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
24767 Return a derivation that builds a raw initrd. @var{file-systems} is
24768 a list of file systems to be mounted by the initrd, possibly in addition to
24769 the root file system specified on the kernel command line via @code{--root}.
24770 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
24771 @var{mapped-devices} is a list of device mappings to realize before
24772 @var{file-systems} are mounted (@pxref{Mapped Devices}).
24773 @var{helper-packages} is a list of packages to be copied in the initrd. It may
24774 include @code{e2fsck/static} or other packages needed by the initrd to check
24775 the root file system.
24777 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24778 the desired console keyboard layout. This is done before @var{mapped-devices}
24779 are set up and before @var{file-systems} are mounted such that, should the
24780 user need to enter a passphrase or use the REPL, this happens using the
24781 intended keyboard layout.
24783 When @var{qemu-networking?} is true, set up networking with the standard QEMU
24784 parameters. When @var{virtio?} is true, load additional modules so that the
24785 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
24787 When @var{volatile-root?} is true, the root file system is writable but any changes
24791 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
24792 [#:mapped-devices '()] [#:keyboard-layout #f] @
24793 [#:qemu-networking? #f] [#:volatile-root? #f] @
24794 [#:linux-modules '()]
24795 Return as a file-like object a generic initrd, with kernel
24796 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
24797 mounted by the initrd, possibly in addition to the root file system specified
24798 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
24799 mappings to realize before @var{file-systems} are mounted.
24801 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
24802 the desired console keyboard layout. This is done before @var{mapped-devices}
24803 are set up and before @var{file-systems} are mounted such that, should the
24804 user need to enter a passphrase or use the REPL, this happens using the
24805 intended keyboard layout.
24807 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
24809 The initrd is automatically populated with all the kernel modules necessary
24810 for @var{file-systems} and for the given options. Additional kernel
24811 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
24812 loaded at boot time in the order in which they appear.
24815 Needless to say, the initrds we produce and use embed a
24816 statically-linked Guile, and the initialization program is a Guile
24817 program. That gives a lot of flexibility. The
24818 @code{expression->initrd} procedure builds such an initrd, given the
24819 program to run in that initrd.
24821 @deffn {Scheme Procedure} expression->initrd @var{exp} @
24822 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
24823 Return as a file-like object a Linux initrd (a gzipped cpio archive)
24824 containing @var{guile} and that evaluates @var{exp}, a G-expression,
24825 upon booting. All the derivations referenced by @var{exp} are
24826 automatically copied to the initrd.
24829 @node Bootloader Configuration
24830 @section Bootloader Configuration
24833 @cindex boot loader
24835 The operating system supports multiple bootloaders. The bootloader is
24836 configured using @code{bootloader-configuration} declaration. All the
24837 fields of this structure are bootloader agnostic except for one field,
24838 @code{bootloader} that indicates the bootloader to be configured and
24841 Some of the bootloaders do not honor every field of
24842 @code{bootloader-configuration}. For instance, the extlinux
24843 bootloader does not support themes and thus ignores the @code{theme}
24846 @deftp {Data Type} bootloader-configuration
24847 The type of a bootloader configuration declaration.
24851 @item @code{bootloader}
24852 @cindex EFI, bootloader
24853 @cindex UEFI, bootloader
24854 @cindex BIOS, bootloader
24855 The bootloader to use, as a @code{bootloader} object. For now
24856 @code{grub-bootloader}, @code{grub-efi-bootloader},
24857 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
24859 @vindex grub-efi-bootloader
24860 @code{grub-efi-bootloader} allows to boot on modern systems using the
24861 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
24862 use if the installation image contains a @file{/sys/firmware/efi} directory
24863 when you boot it on your system.
24865 @vindex grub-bootloader
24866 @code{grub-bootloader} allows you to boot in particular Intel-based machines
24867 in ``legacy'' BIOS mode.
24869 @cindex ARM, bootloaders
24870 @cindex AArch64, bootloaders
24871 Available bootloaders are described in @code{(gnu bootloader @dots{})}
24872 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
24873 of bootloaders for a wide range of ARM and AArch64 systems, using the
24874 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
24876 @item @code{target}
24877 This is a string denoting the target onto which to install the
24880 The interpretation depends on the bootloader in question. For
24881 @code{grub-bootloader}, for example, it should be a device name understood by
24882 the bootloader @command{installer} command, such as @code{/dev/sda} or
24883 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
24884 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
24885 system, usually @file{/boot/efi}.
24887 @item @code{menu-entries} (default: @code{()})
24888 A possibly empty list of @code{menu-entry} objects (see below), denoting
24889 entries to appear in the bootloader menu, in addition to the current
24890 system entry and the entry pointing to previous system generations.
24892 @item @code{default-entry} (default: @code{0})
24893 The index of the default boot menu entry. Index 0 is for the entry of the
24896 @item @code{timeout} (default: @code{5})
24897 The number of seconds to wait for keyboard input before booting. Set to
24898 0 to boot immediately, and to -1 to wait indefinitely.
24900 @cindex keyboard layout, for the bootloader
24901 @item @code{keyboard-layout} (default: @code{#f})
24902 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
24903 layout, usually US@tie{}English (``qwerty'').
24905 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
24909 This option is currently ignored by bootloaders other than @code{grub} and
24913 @item @code{theme} (default: @var{#f})
24914 The bootloader theme object describing the theme to use. If no theme
24915 is provided, some bootloaders might use a default theme, that's true
24918 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
24919 The output terminals used for the bootloader boot menu, as a list of
24920 symbols. GRUB accepts the values: @code{console}, @code{serial},
24921 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
24922 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
24923 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
24924 configuration,,, grub,GNU GRUB manual}).
24926 @item @code{terminal-inputs} (default: @code{'()})
24927 The input terminals used for the bootloader boot menu, as a list of
24928 symbols. For GRUB, the default is the native platform terminal as
24929 determined at run-time. GRUB accepts the values: @code{console},
24930 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
24931 @code{usb_keyboard}. This field corresponds to the GRUB variable
24932 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
24935 @item @code{serial-unit} (default: @code{#f})
24936 The serial unit used by the bootloader, as an integer from 0 to 3.
24937 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
24938 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24940 @item @code{serial-speed} (default: @code{#f})
24941 The speed of the serial interface, as an integer. For GRUB, the
24942 default value is chosen at run-time; currently GRUB chooses
24943 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
24950 Should you want to list additional boot menu entries @i{via} the
24951 @code{menu-entries} field above, you will need to create them with the
24952 @code{menu-entry} form. For example, imagine you want to be able to
24953 boot another distro (hard to imagine!), you can define a menu entry
24958 (label "The Other Distro")
24959 (linux "/boot/old/vmlinux-2.6.32")
24960 (linux-arguments '("root=/dev/sda2"))
24961 (initrd "/boot/old/initrd"))
24966 @deftp {Data Type} menu-entry
24967 The type of an entry in the bootloader menu.
24972 The label to show in the menu---e.g., @code{"GNU"}.
24975 The Linux kernel image to boot, for example:
24978 (file-append linux-libre "/bzImage")
24981 For GRUB, it is also possible to specify a device explicitly in the
24982 file path using GRUB's device naming convention (@pxref{Naming
24983 convention,,, grub, GNU GRUB manual}), for example:
24986 "(hd0,msdos1)/boot/vmlinuz"
24989 If the device is specified explicitly as above, then the @code{device}
24990 field is ignored entirely.
24992 @item @code{linux-arguments} (default: @code{()})
24993 The list of extra Linux kernel command-line arguments---e.g.,
24994 @code{("console=ttyS0")}.
24996 @item @code{initrd}
24997 A G-Expression or string denoting the file name of the initial RAM disk
24998 to use (@pxref{G-Expressions}).
24999 @item @code{device} (default: @code{#f})
25000 The device where the kernel and initrd are to be found---i.e., for GRUB,
25001 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
25003 This may be a file system label (a string), a file system UUID (a
25004 bytevector, @pxref{File Systems}), or @code{#f}, in which case
25005 the bootloader will search the device containing the file specified by
25006 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
25007 must @emph{not} be an OS device name such as @file{/dev/sda1}.
25012 @c FIXME: Write documentation once it's stable.
25013 For now only GRUB has theme support. GRUB themes are created using
25014 the @code{grub-theme} form, which is not documented yet.
25016 @defvr {Scheme Variable} %default-theme
25017 This is the default GRUB theme used by the operating system if no
25018 @code{theme} field is specified in @code{bootloader-configuration}
25021 It comes with a fancy background image displaying the GNU and Guix
25026 @node Invoking guix system
25027 @section Invoking @code{guix system}
25029 Once you have written an operating system declaration as seen in the
25030 previous section, it can be @dfn{instantiated} using the @command{guix
25031 system} command. The synopsis is:
25034 guix system @var{options}@dots{} @var{action} @var{file}
25037 @var{file} must be the name of a file containing an
25038 @code{operating-system} declaration. @var{action} specifies how the
25039 operating system is instantiated. Currently the following values are
25044 Display available service type definitions that match the given regular
25045 expressions, sorted by relevance:
25048 $ guix system search console font
25049 name: console-fonts
25050 location: gnu/services/base.scm:729:2
25051 extends: shepherd-root
25052 description: Install the given fonts on the specified ttys (fonts are
25053 + per virtual console on GNU/Linux). The value of this service is a list
25054 + of tty/font pairs like:
25056 + '(("tty1" . "LatGrkCyr-8x16"))
25060 location: gnu/services/base.scm:1048:2
25061 extends: shepherd-root
25062 description: Provide console login using the `mingetty' program.
25066 location: gnu/services/base.scm:775:2
25068 description: Provide a console log-in service as specified by its
25069 + configuration value, a `login-configuration' object.
25075 As for @command{guix package --search}, the result is written in
25076 @code{recutils} format, which makes it easy to filter the output
25077 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
25080 Build the operating system described in @var{file}, activate it, and
25081 switch to it@footnote{This action (and the related actions
25082 @code{switch-generation} and @code{roll-back}) are usable only on
25083 systems already running Guix System.}.
25085 This effects all the configuration specified in @var{file}: user
25086 accounts, system services, global package list, setuid programs, etc.
25087 The command starts system services specified in @var{file} that are not
25088 currently running; if a service is currently running this command will
25089 arrange for it to be upgraded the next time it is stopped (e.g.@: by
25090 @code{herd stop X} or @code{herd restart X}).
25092 This command creates a new generation whose number is one greater than
25093 the current generation (as reported by @command{guix system
25094 list-generations}). If that generation already exists, it will be
25095 overwritten. This behavior mirrors that of @command{guix package}
25096 (@pxref{Invoking guix package}).
25098 It also adds a bootloader menu entry for the new OS configuration,
25099 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
25100 entries for older configurations to a submenu, allowing you to choose
25101 an older system generation at boot time should you need it.
25104 @c The paragraph below refers to the problem discussed at
25105 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
25106 It is highly recommended to run @command{guix pull} once before you run
25107 @command{guix system reconfigure} for the first time (@pxref{Invoking
25108 guix pull}). Failing to do that you would see an older version of Guix
25109 once @command{reconfigure} has completed.
25112 @item switch-generation
25113 @cindex generations
25114 Switch to an existing system generation. This action atomically
25115 switches the system profile to the specified system generation. It
25116 also rearranges the system's existing bootloader menu entries. It
25117 makes the menu entry for the specified system generation the default,
25118 and it moves the entries for the other generatiors to a submenu, if
25119 supported by the bootloader being used. The next time the system
25120 boots, it will use the specified system generation.
25122 The bootloader itself is not being reinstalled when using this
25123 command. Thus, the installed bootloader is used with an updated
25124 configuration file.
25126 The target generation can be specified explicitly by its generation
25127 number. For example, the following invocation would switch to system
25131 guix system switch-generation 7
25134 The target generation can also be specified relative to the current
25135 generation with the form @code{+N} or @code{-N}, where @code{+3} means
25136 ``3 generations ahead of the current generation,'' and @code{-1} means
25137 ``1 generation prior to the current generation.'' When specifying a
25138 negative value such as @code{-1}, you must precede it with @code{--} to
25139 prevent it from being parsed as an option. For example:
25142 guix system switch-generation -- -1
25145 Currently, the effect of invoking this action is @emph{only} to switch
25146 the system profile to an existing generation and rearrange the
25147 bootloader menu entries. To actually start using the target system
25148 generation, you must reboot after running this action. In the future,
25149 it will be updated to do the same things as @command{reconfigure},
25150 like activating and deactivating services.
25152 This action will fail if the specified generation does not exist.
25155 @cindex rolling back
25156 Switch to the preceding system generation. The next time the system
25157 boots, it will use the preceding system generation. This is the inverse
25158 of @command{reconfigure}, and it is exactly the same as invoking
25159 @command{switch-generation} with an argument of @code{-1}.
25161 Currently, as with @command{switch-generation}, you must reboot after
25162 running this action to actually start using the preceding system
25165 @item delete-generations
25166 @cindex deleting system generations
25167 @cindex saving space
25168 Delete system generations, making them candidates for garbage collection
25169 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
25172 This works in the same way as @command{guix package --delete-generations}
25173 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
25174 arguments, all system generations but the current one are deleted:
25177 guix system delete-generations
25180 You can also select the generations you want to delete. The example below
25181 deletes all the system generations that are more than two month old:
25184 guix system delete-generations 2m
25187 Running this command automatically reinstalls the bootloader with an updated
25188 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
25189 longer lists the generations that have been deleted.
25192 Build the derivation of the operating system, which includes all the
25193 configuration files and programs needed to boot and run the system.
25194 This action does not actually install anything.
25197 Populate the given directory with all the files necessary to run the
25198 operating system specified in @var{file}. This is useful for first-time
25199 installations of Guix System. For instance:
25202 guix system init my-os-config.scm /mnt
25205 copies to @file{/mnt} all the store items required by the configuration
25206 specified in @file{my-os-config.scm}. This includes configuration
25207 files, packages, and so on. It also creates other essential files
25208 needed for the system to operate correctly---e.g., the @file{/etc},
25209 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
25211 This command also installs bootloader on the target specified in
25212 @file{my-os-config}, unless the @option{--no-bootloader} option was
25216 @cindex virtual machine
25218 @anchor{guix system vm}
25219 Build a virtual machine that contains the operating system declared in
25220 @var{file}, and return a script to run that virtual machine (VM).
25223 The @code{vm} action and others below
25224 can use KVM support in the Linux-libre kernel. Specifically, if the
25225 machine has hardware virtualization support, the corresponding
25226 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
25227 must exist and be readable and writable by the user and by the
25228 build users of the daemon (@pxref{Build Environment Setup}).
25231 Arguments given to the script are passed to QEMU as in the example
25232 below, which enables networking and requests 1@tie{}GiB of RAM for the
25236 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
25239 The VM shares its store with the host system.
25241 Additional file systems can be shared between the host and the VM using
25242 the @code{--share} and @code{--expose} command-line options: the former
25243 specifies a directory to be shared with write access, while the latter
25244 provides read-only access to the shared directory.
25246 The example below creates a VM in which the user's home directory is
25247 accessible read-only, and where the @file{/exchange} directory is a
25248 read-write mapping of @file{$HOME/tmp} on the host:
25251 guix system vm my-config.scm \
25252 --expose=$HOME --share=$HOME/tmp=/exchange
25255 On GNU/Linux, the default is to boot directly to the kernel; this has
25256 the advantage of requiring only a very tiny root disk image since the
25257 store of the host can then be mounted.
25259 The @code{--full-boot} option forces a complete boot sequence, starting
25260 with the bootloader. This requires more disk space since a root image
25261 containing at least the kernel, initrd, and bootloader data files must
25262 be created. The @code{--image-size} option can be used to specify the
25265 @cindex System images, creation in various formats
25266 @cindex Creating system images in various formats
25269 @itemx docker-image
25270 Return a virtual machine, disk image, or Docker image of the operating
25271 system declared in @var{file} that stands alone. By default,
25272 @command{guix system} estimates the size of the image needed to store
25273 the system, but you can use the @option{--image-size} option to specify
25274 a value. Docker images are built to contain exactly what they need, so
25275 the @option{--image-size} option is ignored in the case of
25276 @code{docker-image}.
25278 You can specify the root file system type by using the
25279 @option{--file-system-type} option. It defaults to @code{ext4}.
25281 When using @code{vm-image}, the returned image is in qcow2 format, which
25282 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
25283 for more information on how to run the image in a virtual machine.
25285 When using @code{disk-image}, a raw disk image is produced; it can be
25286 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
25287 the device corresponding to a USB stick, one can copy the image to it
25288 using the following command:
25291 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
25294 When using @code{docker-image}, a Docker image is produced. Guix builds
25295 the image from scratch, not from a pre-existing Docker base image. As a
25296 result, it contains @emph{exactly} what you define in the operating
25297 system configuration file. You can then load the image and launch a
25298 Docker container using commands like the following:
25301 image_id="`docker load < guix-system-docker-image.tar.gz`"
25302 container_id="`docker create $image_id`"
25303 docker start $container_id
25306 This command starts a new Docker container from the specified image. It
25307 will boot the Guix system in the usual manner, which means it will
25308 start any services you have defined in the operating system
25309 configuration. You can get an interactive shell running in the container
25310 using @command{docker exec}:
25313 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
25316 Depending on what you run in the Docker container, it
25317 may be necessary to give the container additional permissions. For
25318 example, if you intend to build software using Guix inside of the Docker
25319 container, you may need to pass the @option{--privileged} option to
25320 @code{docker create}.
25323 Return a script to run the operating system declared in @var{file}
25324 within a container. Containers are a set of lightweight isolation
25325 mechanisms provided by the kernel Linux-libre. Containers are
25326 substantially less resource-demanding than full virtual machines since
25327 the kernel, shared objects, and other resources can be shared with the
25328 host system; this also means they provide thinner isolation.
25330 Currently, the script must be run as root in order to support more than
25331 a single user and group. The container shares its store with the host
25334 As with the @code{vm} action (@pxref{guix system vm}), additional file
25335 systems to be shared between the host and container can be specified
25336 using the @option{--share} and @option{--expose} options:
25339 guix system container my-config.scm \
25340 --expose=$HOME --share=$HOME/tmp=/exchange
25344 This option requires Linux-libre 3.19 or newer.
25349 @var{options} can contain any of the common build options (@pxref{Common
25350 Build Options}). In addition, @var{options} can contain one of the
25354 @item --expression=@var{expr}
25355 @itemx -e @var{expr}
25356 Consider the operating-system @var{expr} evaluates to.
25357 This is an alternative to specifying a file which evaluates to an
25359 This is used to generate the Guix system installer @pxref{Building the
25360 Installation Image}).
25362 @item --system=@var{system}
25363 @itemx -s @var{system}
25364 Attempt to build for @var{system} instead of the host system type.
25365 This works as per @command{guix build} (@pxref{Invoking guix build}).
25369 Return the derivation file name of the given operating system without
25372 @item --file-system-type=@var{type}
25373 @itemx -t @var{type}
25374 For the @code{disk-image} action, create a file system of the given
25375 @var{type} on the image.
25377 When this option is omitted, @command{guix system} uses @code{ext4}.
25379 @cindex ISO-9660 format
25380 @cindex CD image format
25381 @cindex DVD image format
25382 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
25383 for burning on CDs and DVDs.
25385 @item --image-size=@var{size}
25386 For the @code{vm-image} and @code{disk-image} actions, create an image
25387 of the given @var{size}. @var{size} may be a number of bytes, or it may
25388 include a unit as a suffix (@pxref{Block size, size specifications,,
25389 coreutils, GNU Coreutils}).
25391 When this option is omitted, @command{guix system} computes an estimate
25392 of the image size as a function of the size of the system declared in
25397 For the @code{container} action, allow containers to access the host network,
25398 that is, do not create a network namespace.
25400 @item --root=@var{file}
25401 @itemx -r @var{file}
25402 Make @var{file} a symlink to the result, and register it as a garbage
25405 @item --skip-checks
25406 Skip pre-installation safety checks.
25408 By default, @command{guix system init} and @command{guix system
25409 reconfigure} perform safety checks: they make sure the file systems that
25410 appear in the @code{operating-system} declaration actually exist
25411 (@pxref{File Systems}), and that any Linux kernel modules that may be
25412 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
25413 RAM Disk}). Passing this option skips these tests altogether.
25416 @cindex on-error strategy
25417 @cindex error strategy
25418 @item --on-error=@var{strategy}
25419 Apply @var{strategy} when an error occurs when reading @var{file}.
25420 @var{strategy} may be one of the following:
25423 @item nothing-special
25424 Report the error concisely and exit. This is the default strategy.
25427 Likewise, but also display a backtrace.
25430 Report the error and enter Guile's debugger. From there, you can run
25431 commands such as @code{,bt} to get a backtrace, @code{,locals} to
25432 display local variable values, and more generally inspect the state of the
25433 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
25434 a list of available debugging commands.
25438 Once you have built, configured, re-configured, and re-re-configured
25439 your Guix installation, you may find it useful to list the operating
25440 system generations available on disk---and that you can choose from the
25441 bootloader boot menu:
25445 @item list-generations
25446 List a summary of each generation of the operating system available on
25447 disk, in a human-readable way. This is similar to the
25448 @option{--list-generations} option of @command{guix package}
25449 (@pxref{Invoking guix package}).
25451 Optionally, one can specify a pattern, with the same syntax that is used
25452 in @command{guix package --list-generations}, to restrict the list of
25453 generations displayed. For instance, the following command displays
25454 generations that are up to 10 days old:
25457 $ guix system list-generations 10d
25462 The @command{guix system} command has even more to offer! The following
25463 sub-commands allow you to visualize how your system services relate to
25466 @anchor{system-extension-graph}
25469 @item extension-graph
25470 Emit in Dot/Graphviz format to standard output the @dfn{service
25471 extension graph} of the operating system defined in @var{file}
25472 (@pxref{Service Composition}, for more information on service
25478 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
25481 produces a PDF file showing the extension relations among services.
25483 @anchor{system-shepherd-graph}
25484 @item shepherd-graph
25485 Emit in Dot/Graphviz format to standard output the @dfn{dependency
25486 graph} of shepherd services of the operating system defined in
25487 @var{file}. @xref{Shepherd Services}, for more information and for an
25492 @node Invoking guix deploy
25493 @section Invoking @code{guix deploy}
25495 We've already seen @code{operating-system} declarations used to manage a
25496 machine's configuration locally. Suppose you need to configure multiple
25497 machines, though---perhaps you're managing a service on the web that's
25498 comprised of several servers. @command{guix deploy} enables you to use those
25499 same @code{operating-system} declarations to manage multiple remote hosts at
25500 once as a logical ``deployment''.
25503 The functionality described in this section is still under development
25504 and is subject to change. Get in touch with us on
25505 @email{guix-devel@@gnu.org}!
25509 guix deploy @var{file}
25512 Such an invocation will deploy the machines that the code within @var{file}
25513 evaluates to. As an example, @var{file} might contain a definition like this:
25516 ;; This is a Guix deployment of a "bare bones" setup, with
25517 ;; no X11 display server, to a machine with an SSH daemon
25518 ;; listening on localhost:2222. A configuration such as this
25519 ;; may be appropriate for virtual machine with ports
25520 ;; forwarded to the host's loopback interface.
25522 (use-service-modules networking ssh)
25523 (use-package-modules bootloaders)
25527 (host-name "gnu-deployed")
25528 (timezone "Etc/UTC")
25529 (bootloader (bootloader-configuration
25530 (bootloader grub-bootloader)
25531 (target "/dev/vda")
25532 (terminal-outputs '(console))))
25533 (file-systems (cons (file-system
25535 (device "/dev/vda1")
25537 %base-file-systems))
25539 (append (list (service dhcp-client-service-type)
25540 (service openssh-service-type
25541 (openssh-configuration
25542 (permit-root-login #t)
25543 (allow-empty-passwords? #t))))
25547 (operating-system %system)
25548 (environment managed-host-environment-type)
25549 (configuration (machine-ssh-configuration
25550 (host-name "localhost")
25552 (identity "./id_rsa")
25556 The file should evaluate to a list of @var{machine} objects. This example,
25557 upon being deployed, will create a new generation on the remote system
25558 realizing the @code{operating-system} declaration @var{%system}.
25559 @var{environment} and @var{configuration} specify how the machine should be
25560 provisioned---that is, how the computing resources should be created and
25561 managed. The above example does not create any resources, as a
25562 @code{'managed-host} is a machine that is already running the Guix system and
25563 available over the network. This is a particularly simple case; a more
25564 complex deployment may involve, for example, starting virtual machines through
25565 a Virtual Private Server (VPS) provider. In such a case, a different
25566 @var{environment} type would be used.
25568 Do note that you first need to generate a key pair on the coordinator machine
25569 to allow the daemon to export signed archives of files from the store
25570 (@pxref{Invoking guix archive}).
25573 # guix archive --generate-key
25577 Each target machine must authorize the key of the master machine so that it
25578 accepts store items it receives from the coordinator:
25581 # guix archive --authorize < coordinator-public-key.txt
25584 @code{user}, in this example, specifies the name of the user account to log in
25585 as to perform the deployment. Its default value is @code{root}, but root
25586 login over SSH may be forbidden in some cases. To work around this,
25587 @command{guix deploy} can log in as an unprivileged user and employ
25588 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
25589 currently installed on the remote and can be invoked non-interactively as
25590 @code{user}. That is: the line in @code{sudoers} granting @code{user} the
25591 ability to use @code{sudo} must contain the @code{NOPASSWD} tag.
25593 @deftp {Data Type} machine
25594 This is the data type representing a single machine in a heterogeneous Guix
25598 @item @code{operating-system}
25599 The object of the operating system configuration to deploy.
25601 @item @code{environment}
25602 An @code{environment-type} describing how the machine should be provisioned.
25603 At the moment, the only supported value is
25604 @code{managed-host-environment-type}.
25606 @item @code{configuration} (default: @code{#f})
25607 An object describing the configuration for the machine's @code{environment}.
25608 If the @code{environment} has a default configuration, @code{#f} maybe used.
25609 If @code{#f} is used for an environment with no default configuration,
25610 however, an error will be thrown.
25614 @deftp {Data Type} machine-ssh-configuration
25615 This is the data type representing the SSH client parameters for a machine
25616 with an @code{environment} of @code{managed-host-environment-type}.
25619 @item @code{host-name}
25620 @item @code{build-locally?} (default: @code{#t})
25621 If false, system derivations will be built on the machine being deployed to.
25622 @item @code{system}
25623 The Nix system type describing the architecture of the machine being deployed
25624 to. This should look something like ``x86_64-linux''.
25625 @item @code{authorize?} (default: @code{#t})
25626 If true, the coordinator's signing key will be added to the remote's ACL
25628 @item @code{port} (default: @code{22})
25629 @item @code{user} (default: @code{"root"})
25630 @item @code{identity} (default: @code{#f})
25631 If specified, the path to the SSH private key to use to authenticate with the
25636 @node Running Guix in a VM
25637 @section Running Guix in a Virtual Machine
25639 @cindex virtual machine
25640 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
25642 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
25643 This image is a compressed image in QCOW format. You will first need to
25644 decompress with @command{xz -d}, and then you can pass it to an emulator such
25645 as QEMU (see below for details).
25647 This image boots the Xfce graphical environment and it contains some
25648 commonly-used tools. You can install more software in the image by running
25649 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
25650 also reconfigure the system based on its initial configuration file available
25651 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
25653 Instead of using this pre-built image, one can also build their own virtual
25654 machine image using @command{guix system vm-image} (@pxref{Invoking guix
25655 system}). The returned image is in qcow2 format, which the
25656 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
25659 If you built your own image, you must copy it out of the store
25660 (@pxref{The Store}) and give yourself permission to write to the copy
25661 before you can use it. When invoking QEMU, you must choose a system
25662 emulator that is suitable for your hardware platform. Here is a minimal
25663 QEMU invocation that will boot the result of @command{guix system
25664 vm-image} on x86_64 hardware:
25667 $ qemu-system-x86_64 \
25668 -net user -net nic,model=virtio \
25669 -enable-kvm -m 1024 \
25670 -device virtio-blk,drive=myhd \
25671 -drive if=none,file=/tmp/qemu-image,id=myhd
25674 Here is what each of these options means:
25677 @item qemu-system-x86_64
25678 This specifies the hardware platform to emulate. This should match the
25682 Enable the unprivileged user-mode network stack. The guest OS can
25683 access the host but not vice versa. This is the simplest way to get the
25686 @item -net nic,model=virtio
25687 You must create a network interface of a given model. If you do not
25688 create a NIC, the boot will fail. Assuming your hardware platform is
25689 x86_64, you can get a list of available NIC models by running
25690 @command{qemu-system-x86_64 -net nic,model=help}.
25693 If your system has hardware virtualization extensions, enabling the
25694 virtual machine support (KVM) of the Linux kernel will make things run
25697 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
25699 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
25700 which may be insufficient for some operations.
25702 @item -device virtio-blk,drive=myhd
25703 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
25704 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
25705 better performance than if it were emulating a complete disk drive. See the
25706 QEMU and KVM documentation for more info.
25708 @item -drive if=none,file=/tmp/qemu-image,id=myhd
25709 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
25710 the ``myhd'' drive.
25713 The default @command{run-vm.sh} script that is returned by an invocation of
25714 @command{guix system vm} does not add a @command{-net user} flag by default.
25715 To get network access from within the vm add the @code{(dhcp-client-service)}
25716 to your system definition and start the VM using
25717 @command{`guix system vm config.scm` -net user}. An important caveat of using
25718 @command{-net user} for networking is that @command{ping} will not work, because
25719 it uses the ICMP protocol. You'll have to use a different command to check for
25720 network connectivity, for example @command{guix download}.
25722 @subsection Connecting Through SSH
25726 To enable SSH inside a VM you need to add an SSH server like
25727 @code{openssh-service-type} to your VM (@pxref{Networking Services,
25728 @code{openssh-service-type}}). In addition you need to forward the SSH port,
25729 22 by default, to the host. You can do this with
25732 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
25735 To connect to the VM you can run
25738 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
25741 The @command{-p} tells @command{ssh} the port you want to connect to.
25742 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
25743 every time you modify your @command{config.scm} file and the
25744 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
25745 connection to an unknown host every time you connect.
25747 @subsection Using @command{virt-viewer} with Spice
25749 As an alternative to the default @command{qemu} graphical client you can
25750 use the @command{remote-viewer} from the @command{virt-viewer} package. To
25751 connect pass the @command{-spice port=5930,disable-ticketing} flag to
25752 @command{qemu}. See previous section for further information on how to do this.
25754 Spice also allows you to do some nice stuff like share your clipboard with your
25755 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
25758 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
25759 -chardev spicevmc,name=vdagent,id=vdagent
25760 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
25761 name=com.redhat.spice.0
25764 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
25766 @node Defining Services
25767 @section Defining Services
25769 The previous sections show the available services and how one can combine
25770 them in an @code{operating-system} declaration. But how do we define
25771 them in the first place? And what is a service anyway?
25774 * Service Composition:: The model for composing services.
25775 * Service Types and Services:: Types and services.
25776 * Service Reference:: API reference.
25777 * Shepherd Services:: A particular type of service.
25780 @node Service Composition
25781 @subsection Service Composition
25785 Here we define a @dfn{service} as, broadly, something that extends the
25786 functionality of the operating system. Often a service is a process---a
25787 @dfn{daemon}---started when the system boots: a secure shell server, a
25788 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
25789 whose execution can be triggered by another daemon---e.g., an FTP server
25790 started by @command{inetd} or a D-Bus service activated by
25791 @command{dbus-daemon}. Occasionally, a service does not map to a
25792 daemon. For instance, the ``account'' service collects user accounts
25793 and makes sure they exist when the system runs; the ``udev'' service
25794 collects device management rules and makes them available to the eudev
25795 daemon; the @file{/etc} service populates the @file{/etc} directory
25798 @cindex service extensions
25799 Guix system services are connected by @dfn{extensions}. For instance, the
25800 secure shell service @emph{extends} the Shepherd---the
25801 initialization system, running as PID@tie{}1---by giving it the command
25802 lines to start and stop the secure shell daemon (@pxref{Networking
25803 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
25804 service by passing it its @file{.service} specification, and extends the
25805 udev service by passing it device management rules (@pxref{Desktop
25806 Services, @code{upower-service}}); the Guix daemon service extends the
25807 Shepherd by passing it the command lines to start and stop the daemon,
25808 and extends the account service by passing it a list of required build
25809 user accounts (@pxref{Base Services}).
25811 All in all, services and their ``extends'' relations form a directed
25812 acyclic graph (DAG). If we represent services as boxes and extensions
25813 as arrows, a typical system might provide something like this:
25815 @image{images/service-graph,,5in,Typical service extension graph.}
25817 @cindex system service
25818 At the bottom, we see the @dfn{system service}, which produces the
25819 directory containing everything to run and boot the system, as returned
25820 by the @command{guix system build} command. @xref{Service Reference},
25821 to learn about the other service types shown here.
25822 @xref{system-extension-graph, the @command{guix system extension-graph}
25823 command}, for information on how to generate this representation for a
25824 particular operating system definition.
25826 @cindex service types
25827 Technically, developers can define @dfn{service types} to express these
25828 relations. There can be any number of services of a given type on the
25829 system---for instance, a system running two instances of the GNU secure
25830 shell server (lsh) has two instances of @code{lsh-service-type}, with
25831 different parameters.
25833 The following section describes the programming interface for service
25834 types and services.
25836 @node Service Types and Services
25837 @subsection Service Types and Services
25839 A @dfn{service type} is a node in the DAG described above. Let us start
25840 with a simple example, the service type for the Guix build daemon
25841 (@pxref{Invoking guix-daemon}):
25844 (define guix-service-type
25848 (list (service-extension shepherd-root-service-type guix-shepherd-service)
25849 (service-extension account-service-type guix-accounts)
25850 (service-extension activation-service-type guix-activation)))
25851 (default-value (guix-configuration))))
25855 It defines three things:
25859 A name, whose sole purpose is to make inspection and debugging easier.
25862 A list of @dfn{service extensions}, where each extension designates the
25863 target service type and a procedure that, given the parameters of the
25864 service, returns a list of objects to extend the service of that type.
25866 Every service type has at least one service extension. The only
25867 exception is the @dfn{boot service type}, which is the ultimate service.
25870 Optionally, a default value for instances of this type.
25873 In this example, @code{guix-service-type} extends three services:
25876 @item shepherd-root-service-type
25877 The @code{guix-shepherd-service} procedure defines how the Shepherd
25878 service is extended. Namely, it returns a @code{<shepherd-service>}
25879 object that defines how @command{guix-daemon} is started and stopped
25880 (@pxref{Shepherd Services}).
25882 @item account-service-type
25883 This extension for this service is computed by @code{guix-accounts},
25884 which returns a list of @code{user-group} and @code{user-account}
25885 objects representing the build user accounts (@pxref{Invoking
25888 @item activation-service-type
25889 Here @code{guix-activation} is a procedure that returns a gexp, which is
25890 a code snippet to run at ``activation time''---e.g., when the service is
25894 A service of this type is instantiated like this:
25897 (service guix-service-type
25898 (guix-configuration
25900 (use-substitutes? #f)))
25903 The second argument to the @code{service} form is a value representing
25904 the parameters of this specific service instance.
25905 @xref{guix-configuration-type, @code{guix-configuration}}, for
25906 information about the @code{guix-configuration} data type. When the
25907 value is omitted, the default value specified by
25908 @code{guix-service-type} is used:
25911 (service guix-service-type)
25914 @code{guix-service-type} is quite simple because it extends other
25915 services but is not extensible itself.
25917 @c @subsubsubsection Extensible Service Types
25919 The service type for an @emph{extensible} service looks like this:
25922 (define udev-service-type
25923 (service-type (name 'udev)
25925 (list (service-extension shepherd-root-service-type
25926 udev-shepherd-service)))
25928 (compose concatenate) ;concatenate the list of rules
25929 (extend (lambda (config rules)
25931 (($ <udev-configuration> udev initial-rules)
25932 (udev-configuration
25933 (udev udev) ;the udev package to use
25934 (rules (append initial-rules rules)))))))))
25937 This is the service type for the
25938 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
25939 management daemon}. Compared to the previous example, in addition to an
25940 extension of @code{shepherd-root-service-type}, we see two new fields:
25944 This is the procedure to @dfn{compose} the list of extensions to
25945 services of this type.
25947 Services can extend the udev service by passing it lists of rules; we
25948 compose those extensions simply by concatenating them.
25951 This procedure defines how the value of the service is @dfn{extended} with
25952 the composition of the extensions.
25954 Udev extensions are composed into a list of rules, but the udev service
25955 value is itself a @code{<udev-configuration>} record. So here, we
25956 extend that record by appending the list of rules it contains to the
25957 list of contributed rules.
25960 This is a string giving an overview of the service type. The string can
25961 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
25962 @command{guix system search} command searches these strings and displays
25963 them (@pxref{Invoking guix system}).
25966 There can be only one instance of an extensible service type such as
25967 @code{udev-service-type}. If there were more, the
25968 @code{service-extension} specifications would be ambiguous.
25970 Still here? The next section provides a reference of the programming
25971 interface for services.
25973 @node Service Reference
25974 @subsection Service Reference
25976 We have seen an overview of service types (@pxref{Service Types and
25977 Services}). This section provides a reference on how to manipulate
25978 services and service types. This interface is provided by the
25979 @code{(gnu services)} module.
25981 @deffn {Scheme Procedure} service @var{type} [@var{value}]
25982 Return a new service of @var{type}, a @code{<service-type>} object (see
25983 below.) @var{value} can be any object; it represents the parameters of
25984 this particular service instance.
25986 When @var{value} is omitted, the default value specified by @var{type}
25987 is used; if @var{type} does not specify a default value, an error is
25990 For instance, this:
25993 (service openssh-service-type)
25997 is equivalent to this:
26000 (service openssh-service-type
26001 (openssh-configuration))
26004 In both cases the result is an instance of @code{openssh-service-type}
26005 with the default configuration.
26008 @deffn {Scheme Procedure} service? @var{obj}
26009 Return true if @var{obj} is a service.
26012 @deffn {Scheme Procedure} service-kind @var{service}
26013 Return the type of @var{service}---i.e., a @code{<service-type>} object.
26016 @deffn {Scheme Procedure} service-value @var{service}
26017 Return the value associated with @var{service}. It represents its
26021 Here is an example of how a service is created and manipulated:
26025 (service nginx-service-type
26026 (nginx-configuration
26028 (log-directory log-directory)
26029 (run-directory run-directory)
26030 (file config-file))))
26035 (eq? (service-kind s) nginx-service-type)
26039 The @code{modify-services} form provides a handy way to change the
26040 parameters of some of the services of a list such as
26041 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
26042 evaluates to a list of services. Of course, you could always use
26043 standard list combinators such as @code{map} and @code{fold} to do that
26044 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
26045 @code{modify-services} simply provides a more concise form for this
26048 @deffn {Scheme Syntax} modify-services @var{services} @
26049 (@var{type} @var{variable} => @var{body}) @dots{}
26051 Modify the services listed in @var{services} according to the given
26052 clauses. Each clause has the form:
26055 (@var{type} @var{variable} => @var{body})
26058 where @var{type} is a service type---e.g.,
26059 @code{guix-service-type}---and @var{variable} is an identifier that is
26060 bound within the @var{body} to the service parameters---e.g., a
26061 @code{guix-configuration} instance---of the original service of that
26064 The @var{body} should evaluate to the new service parameters, which will
26065 be used to configure the new service. This new service will replace the
26066 original in the resulting list. Because a service's service parameters
26067 are created using @code{define-record-type*}, you can write a succinct
26068 @var{body} that evaluates to the new service parameters by using the
26069 @code{inherit} feature that @code{define-record-type*} provides.
26071 @xref{Using the Configuration System}, for example usage.
26075 Next comes the programming interface for service types. This is
26076 something you want to know when writing new service definitions, but not
26077 necessarily when simply looking for ways to customize your
26078 @code{operating-system} declaration.
26080 @deftp {Data Type} service-type
26081 @cindex service type
26082 This is the representation of a @dfn{service type} (@pxref{Service Types
26087 This is a symbol, used only to simplify inspection and debugging.
26089 @item @code{extensions}
26090 A non-empty list of @code{<service-extension>} objects (see below).
26092 @item @code{compose} (default: @code{#f})
26093 If this is @code{#f}, then the service type denotes services that cannot
26094 be extended---i.e., services that do not receive ``values'' from other
26097 Otherwise, it must be a one-argument procedure. The procedure is called
26098 by @code{fold-services} and is passed a list of values collected from
26099 extensions. It may return any single value.
26101 @item @code{extend} (default: @code{#f})
26102 If this is @code{#f}, services of this type cannot be extended.
26104 Otherwise, it must be a two-argument procedure: @code{fold-services}
26105 calls it, passing it the initial value of the service as the first
26106 argument and the result of applying @code{compose} to the extension
26107 values as the second argument. It must return a value that is a valid
26108 parameter value for the service instance.
26111 @xref{Service Types and Services}, for examples.
26114 @deffn {Scheme Procedure} service-extension @var{target-type} @
26116 Return a new extension for services of type @var{target-type}.
26117 @var{compute} must be a one-argument procedure: @code{fold-services}
26118 calls it, passing it the value associated with the service that provides
26119 the extension; it must return a valid value for the target service.
26122 @deffn {Scheme Procedure} service-extension? @var{obj}
26123 Return true if @var{obj} is a service extension.
26126 Occasionally, you might want to simply extend an existing service. This
26127 involves creating a new service type and specifying the extension of
26128 interest, which can be verbose; the @code{simple-service} procedure
26129 provides a shorthand for this.
26131 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
26132 Return a service that extends @var{target} with @var{value}. This works
26133 by creating a singleton service type @var{name}, of which the returned
26134 service is an instance.
26136 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
26140 (simple-service 'my-mcron-job mcron-service-type
26141 #~(job '(next-hour (3)) "guix gc -F 2G"))
26145 At the core of the service abstraction lies the @code{fold-services}
26146 procedure, which is responsible for ``compiling'' a list of services
26147 down to a single directory that contains everything needed to boot and
26148 run the system---the directory shown by the @command{guix system build}
26149 command (@pxref{Invoking guix system}). In essence, it propagates
26150 service extensions down the service graph, updating each node parameters
26151 on the way, until it reaches the root node.
26153 @deffn {Scheme Procedure} fold-services @var{services} @
26154 [#:target-type @var{system-service-type}]
26155 Fold @var{services} by propagating their extensions down to the root of
26156 type @var{target-type}; return the root service adjusted accordingly.
26159 Lastly, the @code{(gnu services)} module also defines several essential
26160 service types, some of which are listed below.
26162 @defvr {Scheme Variable} system-service-type
26163 This is the root of the service graph. It produces the system directory
26164 as returned by the @command{guix system build} command.
26167 @defvr {Scheme Variable} boot-service-type
26168 The type of the ``boot service'', which produces the @dfn{boot script}.
26169 The boot script is what the initial RAM disk runs when booting.
26172 @defvr {Scheme Variable} etc-service-type
26173 The type of the @file{/etc} service. This service is used to create
26174 files under @file{/etc} and can be extended by
26175 passing it name/file tuples such as:
26178 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
26181 In this example, the effect would be to add an @file{/etc/issue} file
26182 pointing to the given file.
26185 @defvr {Scheme Variable} setuid-program-service-type
26186 Type for the ``setuid-program service''. This service collects lists of
26187 executable file names, passed as gexps, and adds them to the set of
26188 setuid-root programs on the system (@pxref{Setuid Programs}).
26191 @defvr {Scheme Variable} profile-service-type
26192 Type of the service that populates the @dfn{system profile}---i.e., the
26193 programs under @file{/run/current-system/profile}. Other services can
26194 extend it by passing it lists of packages to add to the system profile.
26198 @node Shepherd Services
26199 @subsection Shepherd Services
26201 @cindex shepherd services
26203 @cindex init system
26204 The @code{(gnu services shepherd)} module provides a way to define
26205 services managed by the GNU@tie{}Shepherd, which is the
26206 initialization system---the first process that is started when the
26207 system boots, also known as PID@tie{}1
26208 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
26210 Services in the Shepherd can depend on each other. For instance, the
26211 SSH daemon may need to be started after the syslog daemon has been
26212 started, which in turn can only happen once all the file systems have
26213 been mounted. The simple operating system defined earlier (@pxref{Using
26214 the Configuration System}) results in a service graph like this:
26216 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
26218 You can actually generate such a graph for any operating system
26219 definition using the @command{guix system shepherd-graph} command
26220 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
26222 The @code{%shepherd-root-service} is a service object representing
26223 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
26224 by passing it lists of @code{<shepherd-service>} objects.
26226 @deftp {Data Type} shepherd-service
26227 The data type representing a service managed by the Shepherd.
26230 @item @code{provision}
26231 This is a list of symbols denoting what the service provides.
26233 These are the names that may be passed to @command{herd start},
26234 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
26235 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
26236 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
26238 @item @code{requirement} (default: @code{'()})
26239 List of symbols denoting the Shepherd services this one depends on.
26241 @cindex one-shot services, for the Shepherd
26242 @item @code{one-shot?} (default: @code{#f})
26243 Whether this service is @dfn{one-shot}. One-shot services stop immediately
26244 after their @code{start} action has completed. @xref{Slots of services,,,
26245 shepherd, The GNU Shepherd Manual}, for more info.
26247 @item @code{respawn?} (default: @code{#t})
26248 Whether to restart the service when it stops, for instance when the
26249 underlying process dies.
26252 @itemx @code{stop} (default: @code{#~(const #f)})
26253 The @code{start} and @code{stop} fields refer to the Shepherd's
26254 facilities to start and stop processes (@pxref{Service De- and
26255 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
26256 G-expressions that get expanded in the Shepherd configuration file
26257 (@pxref{G-Expressions}).
26259 @item @code{actions} (default: @code{'()})
26260 @cindex actions, of Shepherd services
26261 This is a list of @code{shepherd-action} objects (see below) defining
26262 @dfn{actions} supported by the service, in addition to the standard
26263 @code{start} and @code{stop} actions. Actions listed here become available as
26264 @command{herd} sub-commands:
26267 herd @var{action} @var{service} [@var{arguments}@dots{}]
26270 @item @code{auto-start?} (default: @code{#t})
26271 Whether this service should be started automatically by the Shepherd. If it
26272 is @code{#f} the service has to be started manually with @code{herd start}.
26274 @item @code{documentation}
26275 A documentation string, as shown when running:
26278 herd doc @var{service-name}
26281 where @var{service-name} is one of the symbols in @code{provision}
26282 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
26284 @item @code{modules} (default: @code{%default-modules})
26285 This is the list of modules that must be in scope when @code{start} and
26286 @code{stop} are evaluated.
26291 @deftp {Data Type} shepherd-action
26292 This is the data type that defines additional actions implemented by a
26293 Shepherd service (see above).
26297 Symbol naming the action.
26299 @item documentation
26300 This is a documentation string for the action. It can be viewed by running:
26303 herd doc @var{service} action @var{action}
26307 This should be a gexp that evaluates to a procedure of at least one argument,
26308 which is the ``running value'' of the service (@pxref{Slots of services,,,
26309 shepherd, The GNU Shepherd Manual}).
26312 The following example defines an action called @code{say-hello} that kindly
26318 (documentation "Say hi!")
26319 (procedure #~(lambda (running . args)
26320 (format #t "Hello, friend! arguments: ~s\n"
26325 Assuming this action is added to the @code{example} service, then you can do:
26328 # herd say-hello example
26329 Hello, friend! arguments: ()
26330 # herd say-hello example a b c
26331 Hello, friend! arguments: ("a" "b" "c")
26334 This, as you can see, is a fairly sophisticated way to say hello.
26335 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
26339 @defvr {Scheme Variable} shepherd-root-service-type
26340 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
26342 This is the service type that extensions target when they want to create
26343 shepherd services (@pxref{Service Types and Services}, for an example).
26344 Each extension must pass a list of @code{<shepherd-service>}.
26347 @defvr {Scheme Variable} %shepherd-root-service
26348 This service represents PID@tie{}1.
26352 @node Documentation
26353 @chapter Documentation
26355 @cindex documentation, searching for
26356 @cindex searching for documentation
26357 @cindex Info, documentation format
26359 @cindex manual pages
26360 In most cases packages installed with Guix come with documentation.
26361 There are two main documentation formats: ``Info'', a browseable
26362 hypertext format used for GNU software, and ``manual pages'' (or ``man
26363 pages''), the linear documentation format traditionally found on Unix.
26364 Info manuals are accessed with the @command{info} command or with Emacs,
26365 and man pages are accessed using @command{man}.
26367 You can look for documentation of software installed on your system by
26368 keyword. For example, the following command searches for information
26369 about ``TLS'' in Info manuals:
26373 "(emacs)Network Security" -- STARTTLS
26374 "(emacs)Network Security" -- TLS
26375 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
26376 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
26381 The command below searches for the same keyword in man pages:
26385 SSL (7) - OpenSSL SSL/TLS library
26386 certtool (1) - GnuTLS certificate tool
26390 These searches are purely local to your computer so you have the
26391 guarantee that documentation you find corresponds to what you have
26392 actually installed, you can access it off-line, and your privacy is
26395 Once you have these results, you can view the relevant documentation by
26399 $ info "(gnutls)Core TLS API"
26409 Info manuals contain sections and indices as well as hyperlinks like
26410 those found in Web pages. The @command{info} reader (@pxref{Top, Info
26411 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
26412 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
26413 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
26414 Introduction}, for an introduction to Info navigation.
26416 @node Installing Debugging Files
26417 @chapter Installing Debugging Files
26419 @cindex debugging files
26420 Program binaries, as produced by the GCC compilers for instance, are
26421 typically written in the ELF format, with a section containing
26422 @dfn{debugging information}. Debugging information is what allows the
26423 debugger, GDB, to map binary code to source code; it is required to
26424 debug a compiled program in good conditions.
26426 The problem with debugging information is that is takes up a fair amount
26427 of disk space. For example, debugging information for the GNU C Library
26428 weighs in at more than 60 MiB. Thus, as a user, keeping all the
26429 debugging info of all the installed programs is usually not an option.
26430 Yet, space savings should not come at the cost of an impediment to
26431 debugging---especially in the GNU system, which should make it easier
26432 for users to exert their computing freedom (@pxref{GNU Distribution}).
26434 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
26435 mechanism that allows users to get the best of both worlds: debugging
26436 information can be stripped from the binaries and stored in separate
26437 files. GDB is then able to load debugging information from those files,
26438 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
26441 The GNU distribution takes advantage of this by storing debugging
26442 information in the @code{lib/debug} sub-directory of a separate package
26443 output unimaginatively called @code{debug} (@pxref{Packages with
26444 Multiple Outputs}). Users can choose to install the @code{debug} output
26445 of a package when they need it. For instance, the following command
26446 installs the debugging information for the GNU C Library and for GNU
26450 guix install glibc:debug guile:debug
26453 GDB must then be told to look for debug files in the user's profile, by
26454 setting the @code{debug-file-directory} variable (consider setting it
26455 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
26459 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
26462 From there on, GDB will pick up debugging information from the
26463 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
26465 In addition, you will most likely want GDB to be able to show the source
26466 code being debugged. To do that, you will have to unpack the source
26467 code of the package of interest (obtained with @code{guix build
26468 --source}, @pxref{Invoking guix build}), and to point GDB to that source
26469 directory using the @code{directory} command (@pxref{Source Path,
26470 @code{directory},, gdb, Debugging with GDB}).
26472 @c XXX: keep me up-to-date
26473 The @code{debug} output mechanism in Guix is implemented by the
26474 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
26475 opt-in---debugging information is available only for the packages
26476 with definitions explicitly declaring a @code{debug} output. This may be
26477 changed to opt-out in the future if our build farm servers can handle
26478 the load. To check whether a package has a @code{debug} output, use
26479 @command{guix package --list-available} (@pxref{Invoking guix package}).
26482 @node Security Updates
26483 @chapter Security Updates
26485 @cindex security updates
26486 @cindex security vulnerabilities
26487 Occasionally, important security vulnerabilities are discovered in software
26488 packages and must be patched. Guix developers try hard to keep track of
26489 known vulnerabilities and to apply fixes as soon as possible in the
26490 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
26491 containing only security updates.) The @command{guix lint} tool helps
26492 developers find out about vulnerable versions of software packages in the
26497 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
26498 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
26499 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
26503 @xref{Invoking guix lint}, for more information.
26505 Guix follows a functional
26506 package management discipline (@pxref{Introduction}), which implies
26507 that, when a package is changed, @emph{every package that depends on it}
26508 must be rebuilt. This can significantly slow down the deployment of
26509 fixes in core packages such as libc or Bash, since basically the whole
26510 distribution would need to be rebuilt. Using pre-built binaries helps
26511 (@pxref{Substitutes}), but deployment may still take more time than
26515 To address this, Guix implements @dfn{grafts}, a mechanism that allows
26516 for fast deployment of critical updates without the costs associated
26517 with a whole-distribution rebuild. The idea is to rebuild only the
26518 package that needs to be patched, and then to ``graft'' it onto packages
26519 explicitly installed by the user and that were previously referring to
26520 the original package. The cost of grafting is typically very low, and
26521 order of magnitudes lower than a full rebuild of the dependency chain.
26523 @cindex replacements of packages, for grafts
26524 For instance, suppose a security update needs to be applied to Bash.
26525 Guix developers will provide a package definition for the ``fixed''
26526 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
26527 Packages}). Then, the original package definition is augmented with a
26528 @code{replacement} field pointing to the package containing the bug fix:
26535 (replacement bash-fixed)))
26538 From there on, any package depending directly or indirectly on Bash---as
26539 reported by @command{guix gc --requisites} (@pxref{Invoking guix
26540 gc})---that is installed is automatically ``rewritten'' to refer to
26541 @code{bash-fixed} instead of @code{bash}. This grafting process takes
26542 time proportional to the size of the package, usually less than a
26543 minute for an ``average'' package on a recent machine. Grafting is
26544 recursive: when an indirect dependency requires grafting, then grafting
26545 ``propagates'' up to the package that the user is installing.
26547 Currently, the length of the name and version of the graft and that of
26548 the package it replaces (@code{bash-fixed} and @code{bash} in the example
26549 above) must be equal. This restriction mostly comes from the fact that
26550 grafting works by patching files, including binary files, directly.
26551 Other restrictions may apply: for instance, when adding a graft to a
26552 package providing a shared library, the original shared library and its
26553 replacement must have the same @code{SONAME} and be binary-compatible.
26555 The @option{--no-grafts} command-line option allows you to forcefully
26556 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
26560 guix build bash --no-grafts
26564 returns the store file name of the original Bash, whereas:
26571 returns the store file name of the ``fixed'', replacement Bash. This
26572 allows you to distinguish between the two variants of Bash.
26574 To verify which Bash your whole profile refers to, you can run
26575 (@pxref{Invoking guix gc}):
26578 guix gc -R `readlink -f ~/.guix-profile` | grep bash
26582 @dots{} and compare the store file names that you get with those above.
26583 Likewise for a complete Guix system generation:
26586 guix gc -R `guix system build my-config.scm` | grep bash
26589 Lastly, to check which Bash running processes are using, you can use the
26590 @command{lsof} command:
26593 lsof | grep /gnu/store/.*bash
26597 @node Bootstrapping
26598 @chapter Bootstrapping
26600 @c Adapted from the ELS 2013 paper.
26602 @cindex bootstrapping
26604 Bootstrapping in our context refers to how the distribution gets built
26605 ``from nothing''. Remember that the build environment of a derivation
26606 contains nothing but its declared inputs (@pxref{Introduction}). So
26607 there's an obvious chicken-and-egg problem: how does the first package
26608 get built? How does the first compiler get compiled? Note that this is
26609 a question of interest only to the curious hacker, not to the regular
26610 user, so you can shamelessly skip this section if you consider yourself
26611 a ``regular user''.
26613 @cindex bootstrap binaries
26614 The GNU system is primarily made of C code, with libc at its core. The
26615 GNU build system itself assumes the availability of a Bourne shell and
26616 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
26617 `grep'. Furthermore, build programs---programs that run
26618 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
26619 (@pxref{Derivations}). Consequently, to be able to build anything at
26620 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
26621 Binutils, libc, and the other packages mentioned above---the
26622 @dfn{bootstrap binaries}.
26624 These bootstrap binaries are ``taken for granted'', though we can also
26625 re-create them if needed (more on that later).
26627 @unnumberedsec Preparing to Use the Bootstrap Binaries
26629 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
26630 @c large image, it's hard to scroll. Oh well.
26631 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
26633 The figure above shows the very beginning of the dependency graph of the
26634 distribution, corresponding to the package definitions of the @code{(gnu
26635 packages bootstrap)} module. A similar figure can be generated with
26636 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
26639 guix graph -t derivation \
26640 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
26644 At this level of detail, things are
26645 slightly complex. First, Guile itself consists of an ELF executable,
26646 along with many source and compiled Scheme files that are dynamically
26647 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
26648 tarball shown in this graph. This tarball is part of Guix's ``source''
26649 distribution, and gets inserted into the store with @code{add-to-store}
26650 (@pxref{The Store}).
26652 But how do we write a derivation that unpacks this tarball and adds it
26653 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
26654 derivation---the first one that gets built---uses @code{bash} as its
26655 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
26656 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
26657 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
26658 the Guix source distribution, whose sole purpose is to allow the Guile
26659 tarball to be unpacked.
26661 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
26662 Guile that can be used to run subsequent build programs. Its first task
26663 is to download tarballs containing the other pre-built binaries---this
26664 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
26665 @code{ftp-client.scm} are used for this purpose. The
26666 @code{module-import.drv} derivations import those modules in a directory
26667 in the store, using the original layout. The
26668 @code{module-import-compiled.drv} derivations compile those modules, and
26669 write them in an output directory with the right layout. This
26670 corresponds to the @code{#:modules} argument of
26671 @code{build-expression->derivation} (@pxref{Derivations}).
26673 Finally, the various tarballs are unpacked by the
26674 derivations @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv},
26675 etc., at which point we have a working C tool chain.
26678 @unnumberedsec Building the Build Tools
26680 Bootstrapping is complete when we have a full tool chain that does not
26681 depend on the pre-built bootstrap tools discussed above. This
26682 no-dependency requirement is verified by checking whether the files of
26683 the final tool chain contain references to the @file{/gnu/store}
26684 directories of the bootstrap inputs. The process that leads to this
26685 ``final'' tool chain is described by the package definitions found in
26686 the @code{(gnu packages commencement)} module.
26688 The @command{guix graph} command allows us to ``zoom out'' compared to
26689 the graph above, by looking at the level of package objects instead of
26690 individual derivations---remember that a package may translate to
26691 several derivations, typically one derivation to download its source,
26692 one to build the Guile modules it needs, and one to actually build the
26693 package from source. The command:
26696 guix graph -t bag \
26697 -e '(@@@@ (gnu packages commencement)
26698 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
26702 produces the dependency graph leading to the ``final'' C
26703 library@footnote{You may notice the @code{glibc-intermediate} label,
26704 suggesting that it is not @emph{quite} final, but as a good
26705 approximation, we will consider it final.}, depicted below.
26707 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
26709 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
26710 The first tool that gets built with the bootstrap binaries is
26711 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
26712 for all the following packages. From there Findutils and Diffutils get
26715 Then come the first-stage Binutils and GCC, built as pseudo cross
26716 tools---i.e., with @code{--target} equal to @code{--host}. They are
26717 used to build libc. Thanks to this cross-build trick, this libc is
26718 guaranteed not to hold any reference to the initial tool chain.
26720 From there the final Binutils and GCC (not shown above) are built.
26722 from the final Binutils, and links programs against the just-built libc.
26723 This tool chain is used to build the other packages used by Guix and by
26724 the GNU Build System: Guile, Bash, Coreutils, etc.
26726 And voilà! At this point we have the complete set of build tools that
26727 the GNU Build System expects. These are in the @code{%final-inputs}
26728 variable of the @code{(gnu packages commencement)} module, and are
26729 implicitly used by any package that uses @code{gnu-build-system}
26730 (@pxref{Build Systems, @code{gnu-build-system}}).
26733 @unnumberedsec Building the Bootstrap Binaries
26735 @cindex bootstrap binaries
26736 Because the final tool chain does not depend on the bootstrap binaries,
26737 those rarely need to be updated. Nevertheless, it is useful to have an
26738 automated way to produce them, should an update occur, and this is what
26739 the @code{(gnu packages make-bootstrap)} module provides.
26741 The following command builds the tarballs containing the bootstrap
26742 binaries (Guile, Binutils, GCC, libc, and a tarball containing a mixture
26743 of Coreutils and other basic command-line tools):
26746 guix build bootstrap-tarballs
26749 The generated tarballs are those that should be referred to in the
26750 @code{(gnu packages bootstrap)} module mentioned at the beginning of
26753 Still here? Then perhaps by now you've started to wonder: when do we
26754 reach a fixed point? That is an interesting question! The answer is
26755 unknown, but if you would like to investigate further (and have
26756 significant computational and storage resources to do so), then let us
26759 @unnumberedsec Reducing the Set of Bootstrap Binaries
26761 Our bootstrap binaries currently include GCC, Guile, etc. That's a lot
26762 of binary code! Why is that a problem? It's a problem because these
26763 big chunks of binary code are practically non-auditable, which makes it
26764 hard to establish what source code produced them. Every unauditable
26765 binary also leaves us vulnerable to compiler backdoors as described by
26766 Ken Thompson in the 1984 paper @emph{Reflections on Trusting Trust}.
26768 This is mitigated by the fact that our bootstrap binaries were generated
26769 from an earlier Guix revision. Nevertheless it lacks the level of
26770 transparency that we get in the rest of the package dependency graph,
26771 where Guix always gives us a source-to-binary mapping. Thus, our goal
26772 is to reduce the set of bootstrap binaries to the bare minimum.
26774 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
26775 on-going projects to do that. One of these is about replacing the
26776 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
26777 of increasing complexity, which could be built from source starting from
26778 a simple and auditable assembler. Your help is welcome!
26782 @chapter Porting to a New Platform
26784 As discussed above, the GNU distribution is self-contained, and
26785 self-containment is achieved by relying on pre-built ``bootstrap
26786 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
26787 operating system kernel, CPU architecture, and application binary
26788 interface (ABI). Thus, to port the distribution to a platform that is
26789 not yet supported, one must build those bootstrap binaries, and update
26790 the @code{(gnu packages bootstrap)} module to use them on that platform.
26792 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
26793 When everything goes well, and assuming the GNU tool chain supports the
26794 target platform, this can be as simple as running a command like this
26798 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
26801 For this to work, the @code{glibc-dynamic-linker} procedure in
26802 @code{(gnu packages bootstrap)} must be augmented to return the right
26803 file name for libc's dynamic linker on that platform; likewise,
26804 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
26805 taught about the new platform.
26807 Once these are built, the @code{(gnu packages bootstrap)} module needs
26808 to be updated to refer to these binaries on the target platform. That
26809 is, the hashes and URLs of the bootstrap tarballs for the new platform
26810 must be added alongside those of the currently supported platforms. The
26811 bootstrap Guile tarball is treated specially: it is expected to be
26812 available locally, and @file{gnu/local.mk} has rules to download it for
26813 the supported architectures; a rule for the new platform must be added
26816 In practice, there may be some complications. First, it may be that the
26817 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
26818 above) is not recognized by all the GNU tools. Typically, glibc
26819 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
26820 configure flag (see @code{gcc.scm} for examples of how to handle this).
26821 Second, some of the required packages could fail to build for that
26822 platform. Lastly, the generated binaries could be broken for some
26825 @c *********************************************************************
26826 @include contributing.texi
26828 @c *********************************************************************
26829 @node Acknowledgments
26830 @chapter Acknowledgments
26832 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
26833 which was designed and
26834 implemented by Eelco Dolstra, with contributions from other people (see
26835 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
26836 management, and promoted unprecedented features, such as transactional
26837 package upgrades and rollbacks, per-user profiles, and referentially
26838 transparent build processes. Without this work, Guix would not exist.
26840 The Nix-based software distributions, Nixpkgs and NixOS, have also been
26841 an inspiration for Guix.
26843 GNU@tie{}Guix itself is a collective work with contributions from a
26844 number of people. See the @file{AUTHORS} file in Guix for more
26845 information on these fine people. The @file{THANKS} file lists people
26846 who have helped by reporting bugs, taking care of the infrastructure,
26847 providing artwork and themes, making suggestions, and more---thank you!
26850 @c *********************************************************************
26851 @node GNU Free Documentation License
26852 @appendix GNU Free Documentation License
26853 @cindex license, GNU Free Documentation License
26854 @include fdl-1.3.texi
26856 @c *********************************************************************
26857 @node Concept Index
26858 @unnumbered Concept Index
26861 @node Programming Index
26862 @unnumbered Programming Index
26863 @syncodeindex tp fn
26864 @syncodeindex vr fn
26869 @c Local Variables:
26870 @c ispell-local-dictionary: "american";