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, 2019 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018 Oleg Pykhalov@*
59 Copyright @copyright{} 2018 Mike Gerwitz@*
60 Copyright @copyright{} 2018 Pierre-Antoine Rouby@*
61 Copyright @copyright{} 2018, 2019 Gábor Boskovits@*
62 Copyright @copyright{} 2018, 2019 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
72 Permission is granted to copy, distribute and/or modify this document
73 under the terms of the GNU Free Documentation License, Version 1.3 or
74 any later version published by the Free Software Foundation; with no
75 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
76 copy of the license is included in the section entitled ``GNU Free
77 Documentation License''.
80 @dircategory System administration
82 * Guix: (guix). Manage installed software and system configuration.
83 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
84 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
85 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
86 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
87 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
90 @dircategory Software development
92 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
93 * guix build: (guix)Invoking guix build. Building packages.
94 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
98 @title GNU Guix Reference Manual
99 @subtitle Using the GNU Guix Functional Package Manager
100 @author The GNU Guix Developers
103 @vskip 0pt plus 1filll
104 Edition @value{EDITION} @*
112 @c *********************************************************************
116 This document describes GNU Guix version @value{VERSION}, a functional
117 package management tool written for the GNU system.
119 @c TRANSLATORS: You can replace the following paragraph with information on
120 @c how to join your own translation team and how to report issues with the
122 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
123 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
124 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
125 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
126 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
127 would like to translate it in your native language, consider joining the
128 @uref{https://translationproject.org/domain/guix-manual.html, Translation
132 * Introduction:: What is Guix about?
133 * Installation:: Installing Guix.
134 * System Installation:: Installing the whole operating system.
135 * Package Management:: Package installation, upgrade, etc.
136 * Development:: Guix-aided software development.
137 * Programming Interface:: Using Guix in Scheme.
138 * Utilities:: Package management commands.
139 * System Configuration:: Configuring the operating system.
140 * Documentation:: Browsing software user manuals.
141 * Installing Debugging Files:: Feeding the debugger.
142 * Security Updates:: Deploying security fixes quickly.
143 * Bootstrapping:: GNU/Linux built from scratch.
144 * Porting:: Targeting another platform or kernel.
145 * Contributing:: Your help needed!
147 * Acknowledgments:: Thanks!
148 * GNU Free Documentation License:: The license of this manual.
149 * Concept Index:: Concepts.
150 * Programming Index:: Data types, functions, and variables.
153 --- The Detailed Node Listing ---
157 * Managing Software the Guix Way:: What's special.
158 * GNU Distribution:: The packages and tools.
162 * Binary Installation:: Getting Guix running in no time!
163 * Requirements:: Software needed to build and run Guix.
164 * Running the Test Suite:: Testing Guix.
165 * Setting Up the Daemon:: Preparing the build daemon's environment.
166 * Invoking guix-daemon:: Running the build daemon.
167 * Application Setup:: Application-specific setup.
169 Setting Up the Daemon
171 * Build Environment Setup:: Preparing the isolated build environment.
172 * Daemon Offload Setup:: Offloading builds to remote machines.
173 * SELinux Support:: Using an SELinux policy for the daemon.
177 * Limitations:: What you can expect.
178 * Hardware Considerations:: Supported hardware.
179 * USB Stick and DVD Installation:: Preparing the installation medium.
180 * Preparing for Installation:: Networking, partitioning, etc.
181 * Guided Graphical Installation:: Easy graphical installation.
182 * Manual Installation:: Manual installation for wizards.
183 * After System Installation:: When installation succeeded.
184 * Installing Guix in a VM:: Guix System playground.
185 * Building the Installation Image:: How this comes to be.
189 * Keyboard Layout and Networking and Partitioning:: Initial setup.
190 * Proceeding with the Installation:: Installing.
194 * Features:: How Guix will make your life brighter.
195 * Invoking guix package:: Package installation, removal, etc.
196 * Substitutes:: Downloading pre-built binaries.
197 * Packages with Multiple Outputs:: Single source package, multiple outputs.
198 * Invoking guix gc:: Running the garbage collector.
199 * Invoking guix pull:: Fetching the latest Guix and distribution.
200 * Channels:: Customizing the package collection.
201 * Invoking guix time-machine:: Running an older revision of Guix.
202 * Inferiors:: Interacting with another revision of Guix.
203 * Invoking guix describe:: Display information about your Guix revision.
204 * Invoking guix archive:: Exporting and importing store files.
208 * Official Substitute Server:: One particular source of substitutes.
209 * Substitute Server Authorization:: How to enable or disable substitutes.
210 * Substitute Authentication:: How Guix verifies substitutes.
211 * Proxy Settings:: How to get substitutes via proxy.
212 * Substitution Failure:: What happens when substitution fails.
213 * On Trusting Binaries:: How can you trust that binary blob?
217 * Invoking guix environment:: Setting up development environments.
218 * Invoking guix pack:: Creating software bundles.
220 Programming Interface
222 * Package Modules:: Packages from the programmer's viewpoint.
223 * Defining Packages:: Defining new packages.
224 * Build Systems:: Specifying how packages are built.
225 * The Store:: Manipulating the package store.
226 * Derivations:: Low-level interface to package derivations.
227 * The Store Monad:: Purely functional interface to the store.
228 * G-Expressions:: Manipulating build expressions.
229 * Invoking guix repl:: Fiddling with Guix interactively.
233 * package Reference:: The package data type.
234 * origin Reference:: The origin data type.
238 * Invoking guix build:: Building packages from the command line.
239 * Invoking guix edit:: Editing package definitions.
240 * Invoking guix download:: Downloading a file and printing its hash.
241 * Invoking guix hash:: Computing the cryptographic hash of a file.
242 * Invoking guix import:: Importing package definitions.
243 * Invoking guix refresh:: Updating package definitions.
244 * Invoking guix lint:: Finding errors in package definitions.
245 * Invoking guix size:: Profiling disk usage.
246 * Invoking guix graph:: Visualizing the graph of packages.
247 * Invoking guix publish:: Sharing substitutes.
248 * Invoking guix challenge:: Challenging substitute servers.
249 * Invoking guix copy:: Copying to and from a remote store.
250 * Invoking guix container:: Process isolation.
251 * Invoking guix weather:: Assessing substitute availability.
252 * Invoking guix processes:: Listing client processes.
254 Invoking @command{guix build}
256 * Common Build Options:: Build options for most commands.
257 * Package Transformation Options:: Creating variants of packages.
258 * Additional Build Options:: Options specific to 'guix build'.
259 * Debugging Build Failures:: Real life packaging experience.
263 * Using the Configuration System:: Customizing your GNU system.
264 * operating-system Reference:: Detail of operating-system declarations.
265 * File Systems:: Configuring file system mounts.
266 * Mapped Devices:: Block device extra processing.
267 * User Accounts:: Specifying user accounts.
268 * Keyboard Layout:: How the system interprets key strokes.
269 * Locales:: Language and cultural convention settings.
270 * Services:: Specifying system services.
271 * Setuid Programs:: Programs running with root privileges.
272 * X.509 Certificates:: Authenticating HTTPS servers.
273 * Name Service Switch:: Configuring libc's name service switch.
274 * Initial RAM Disk:: Linux-Libre bootstrapping.
275 * Bootloader Configuration:: Configuring the boot loader.
276 * Invoking guix system:: Instantiating a system configuration.
277 * Invoking guix deploy:: Deploying a system configuration to a remote host.
278 * Running Guix in a VM:: How to run Guix System in a virtual machine.
279 * Defining Services:: Adding new service definitions.
283 * Base Services:: Essential system services.
284 * Scheduled Job Execution:: The mcron service.
285 * Log Rotation:: The rottlog service.
286 * Networking Services:: Network setup, SSH daemon, etc.
287 * X Window:: Graphical display.
288 * Printing Services:: Local and remote printer support.
289 * Desktop Services:: D-Bus and desktop services.
290 * Sound Services:: ALSA and Pulseaudio services.
291 * Database Services:: SQL databases, key-value stores, etc.
292 * Mail Services:: IMAP, POP3, SMTP, and all that.
293 * Messaging Services:: Messaging services.
294 * Telephony Services:: Telephony services.
295 * Monitoring Services:: Monitoring services.
296 * Kerberos Services:: Kerberos services.
297 * Web Services:: Web servers.
298 * Certificate Services:: TLS certificates via Let's Encrypt.
299 * DNS Services:: DNS daemons.
300 * VPN Services:: VPN daemons.
301 * Network File System:: NFS related services.
302 * Continuous Integration:: The Cuirass service.
303 * Power Management Services:: Extending battery life.
304 * Audio Services:: The MPD.
305 * Virtualization Services:: Virtualization services.
306 * Version Control Services:: Providing remote access to Git repositories.
307 * Game Services:: Game servers.
308 * Miscellaneous Services:: Other services.
312 * Service Composition:: The model for composing services.
313 * Service Types and Services:: Types and services.
314 * Service Reference:: API reference.
315 * Shepherd Services:: A particular type of service.
320 @c *********************************************************************
322 @chapter Introduction
325 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
326 using the international phonetic alphabet (IPA).} is a package
327 management tool for and distribution of the GNU system.
328 Guix makes it easy for unprivileged
329 users to install, upgrade, or remove software packages, to roll back to a
330 previous package set, to build packages from source, and generally
331 assists with the creation and maintenance of software environments.
334 @cindex GuixSD, now Guix System
335 @cindex Guix System Distribution, now Guix System
336 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
337 complements the available tools without interference (@pxref{Installation}),
338 or you can use it as a standalone operating system distribution,
339 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
340 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
341 group everything under the ``Guix'' banner since, after all, Guix System is
342 readily available through the @command{guix system} command, even if you're
343 using a different distro underneath!}. @xref{GNU Distribution}.
346 * Managing Software the Guix Way:: What's special.
347 * GNU Distribution:: The packages and tools.
350 @node Managing Software the Guix Way
351 @section Managing Software the Guix Way
353 @cindex user interfaces
354 Guix provides a command-line package management interface
355 (@pxref{Package Management}), tools to help with software development
356 (@pxref{Development}), command-line utilities for more advanced usage,
357 (@pxref{Utilities}), as well as Scheme programming interfaces
358 (@pxref{Programming Interface}).
360 Its @dfn{build daemon} is responsible for building packages on behalf of
361 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
362 binaries from authorized sources (@pxref{Substitutes}).
364 @cindex extensibility of the distribution
365 @cindex customization, of packages
366 Guix includes package definitions for many GNU and non-GNU packages, all
367 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
368 user's computing freedom}. It is @emph{extensible}: users can write
369 their own package definitions (@pxref{Defining Packages}) and make them
370 available as independent package modules (@pxref{Package Modules}). It
371 is also @emph{customizable}: users can @emph{derive} specialized package
372 definitions from existing ones, including from the command line
373 (@pxref{Package Transformation Options}).
375 @cindex functional package management
377 Under the hood, Guix implements the @dfn{functional package management}
378 discipline pioneered by Nix (@pxref{Acknowledgments}).
379 In Guix, the package build and installation process is seen
380 as a @emph{function}, in the mathematical sense. That function takes inputs,
381 such as build scripts, a compiler, and libraries, and
382 returns an installed package. As a pure function, its result depends
383 solely on its inputs---for instance, it cannot refer to software or
384 scripts that were not explicitly passed as inputs. A build function
385 always produces the same result when passed a given set of inputs. It
386 cannot alter the environment of the running system in
387 any way; for instance, it cannot create, modify, or delete files outside
388 of its build and installation directories. This is achieved by running
389 build processes in isolated environments (or @dfn{containers}), where only their
390 explicit inputs are visible.
393 The result of package build functions is @dfn{cached} in the file
394 system, in a special directory called @dfn{the store} (@pxref{The
395 Store}). Each package is installed in a directory of its own in the
396 store---by default under @file{/gnu/store}. The directory name contains
397 a hash of all the inputs used to build that package; thus, changing an
398 input yields a different directory name.
400 This approach is the foundation for the salient features of Guix: support
401 for transactional package upgrade and rollback, per-user installation, and
402 garbage collection of packages (@pxref{Features}).
405 @node GNU Distribution
406 @section GNU Distribution
409 Guix comes with a distribution of the GNU system consisting entirely of
410 free software@footnote{The term ``free'' here refers to the
411 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
412 users of that software}.}. The
413 distribution can be installed on its own (@pxref{System Installation}),
414 but it is also possible to install Guix as a package manager on top of
415 an installed GNU/Linux system (@pxref{Installation}). When we need to
416 distinguish between the two, we refer to the standalone distribution as
419 The distribution provides core GNU packages such as GNU libc, GCC, and
420 Binutils, as well as many GNU and non-GNU applications. The complete
421 list of available packages can be browsed
422 @url{https://www.gnu.org/software/guix/packages,on-line} or by
423 running @command{guix package} (@pxref{Invoking guix package}):
426 guix package --list-available
429 Our goal is to provide a practical 100% free software distribution of
430 Linux-based and other variants of GNU, with a focus on the promotion and
431 tight integration of GNU components, and an emphasis on programs and
432 tools that help users exert that freedom.
434 Packages are currently available on the following platforms:
439 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
442 Intel 32-bit architecture (IA32), Linux-Libre kernel;
445 ARMv7-A architecture with hard float, Thumb-2 and NEON,
446 using the EABI hard-float application binary interface (ABI),
447 and Linux-Libre kernel.
450 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
453 little-endian 64-bit MIPS processors, specifically the Loongson series,
454 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
455 supported; in particular, the project's build farms no longer provide
456 substitutes for this architecture.
460 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
461 configuration and Guix takes care of instantiating the configuration in a
462 transactional, reproducible, and stateless fashion (@pxref{System
463 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
464 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
465 Manual}), the well-known GNU utilities and tool chain, as well as the
466 graphical environment or system services of your choice.
468 Guix System is available on all the above platforms except
469 @code{mips64el-linux}.
472 For information on porting to other architectures or kernels,
475 Building this distribution is a cooperative effort, and you are invited
476 to join! @xref{Contributing}, for information about how you can help.
479 @c *********************************************************************
481 @chapter Installation
483 @cindex installing Guix
486 We recommend the use of this
487 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
488 shell installer script} to install Guix on top of a running GNU/Linux system,
489 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
490 with the installation of the package manager, which can be done on top of a
491 running GNU/Linux system. If, instead, you want to install the complete GNU
492 operating system, @pxref{System Installation}.} The script automates the
493 download, installation, and initial configuration of Guix. It should be run
497 @cindex foreign distro
498 @cindex directories related to foreign distro
499 When installed on a foreign distro, GNU@tie{}Guix complements the available
500 tools without interference. Its data lives exclusively in two directories,
501 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
502 such as @file{/etc}, are left untouched.
504 Once installed, Guix can be updated by running @command{guix pull}
505 (@pxref{Invoking guix pull}).
507 If you prefer to perform the installation steps manually or want to tweak
508 them, you may find the following subsections useful. They describe the
509 software requirements of Guix, as well as how to install it manually and get
513 * Binary Installation:: Getting Guix running in no time!
514 * Requirements:: Software needed to build and run Guix.
515 * Running the Test Suite:: Testing Guix.
516 * Setting Up the Daemon:: Preparing the build daemon's environment.
517 * Invoking guix-daemon:: Running the build daemon.
518 * Application Setup:: Application-specific setup.
519 * Upgrading Guix:: Upgrading Guix and its build daemon.
522 @node Binary Installation
523 @section Binary Installation
525 @cindex installing Guix from binaries
526 @cindex installer script
527 This section describes how to install Guix on an arbitrary system from a
528 self-contained tarball providing binaries for Guix and for all its
529 dependencies. This is often quicker than installing from source, which
530 is described in the next sections. The only requirement is to have
533 @c Note duplicated from the ``Installation'' node.
535 We recommend the use of this
536 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
537 shell installer script}. The script automates the download, installation, and
538 initial configuration steps described below. It should be run as the root
542 Installing goes along these lines:
546 @cindex downloading Guix binary
547 Download the binary tarball from
548 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz},
549 where @var{system} is @code{x86_64-linux} for an @code{x86_64} machine
550 already running the kernel Linux, and so on.
552 @c The following is somewhat duplicated in ``System Installation''.
553 Make sure to download the associated @file{.sig} file and to verify the
554 authenticity of the tarball against it, along these lines:
557 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
558 $ gpg --verify guix-binary-@value{VERSION}.@var{system}.tar.xz.sig
561 If that command fails because you do not have the required public key,
562 then run this command to import it:
565 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
566 -qO - | gpg --import -
570 and rerun the @code{gpg --verify} command.
572 Take note that a warning like ``This key is not certified with a trusted
573 signature!'' is normal.
575 @c end authentication part
578 Now, you need to become the @code{root} user. Depending on your distribution,
579 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
583 # tar --warning=no-timestamp -xf \
584 /path/to/guix-binary-@value{VERSION}.@var{system}.tar.xz
585 # mv var/guix /var/ && mv gnu /
588 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
589 The latter contains a ready-to-use profile for @code{root} (see next
592 Do @emph{not} unpack the tarball on a working Guix system since that
593 would overwrite its own essential files.
595 The @code{--warning=no-timestamp} option makes sure GNU@tie{}tar does
596 not emit warnings about ``implausibly old time stamps'' (such
597 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
599 They stem from the fact that all the
600 files in the archive have their modification time set to zero (which
601 means January 1st, 1970.) This is done on purpose to make sure the
602 archive content is independent of its creation time, thus making it
606 Make the profile available under @file{~root/.config/guix/current}, which is
607 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
610 # mkdir -p ~root/.config/guix
611 # ln -sf /var/guix/profiles/per-user/root/current-guix \
612 ~root/.config/guix/current
615 Source @file{etc/profile} to augment @code{PATH} and other relevant
616 environment variables:
619 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
620 source $GUIX_PROFILE/etc/profile
624 Create the group and user accounts for build users as explained below
625 (@pxref{Build Environment Setup}).
628 Run the daemon, and set it to automatically start on boot.
630 If your host distro uses the systemd init system, this can be achieved
633 @c Versions of systemd that supported symlinked service files are not
634 @c yet widely deployed, so we should suggest that users copy the service
637 @c See this thread for more information:
638 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
641 # cp ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
643 # systemctl start guix-daemon && systemctl enable guix-daemon
646 If your host distro uses the Upstart init system:
649 # initctl reload-configuration
650 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
655 Otherwise, you can still start the daemon manually with:
658 # ~root/.config/guix/current/bin/guix-daemon \
659 --build-users-group=guixbuild
663 Make the @command{guix} command available to other users on the machine,
667 # mkdir -p /usr/local/bin
669 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
672 It is also a good idea to make the Info version of this manual available
676 # mkdir -p /usr/local/share/info
677 # cd /usr/local/share/info
678 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
682 That way, assuming @file{/usr/local/share/info} is in the search path,
683 running @command{info guix} will open this manual (@pxref{Other Info
684 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
688 @cindex substitutes, authorization thereof
689 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
690 (@pxref{Substitutes}), authorize them:
693 # guix archive --authorize < \
694 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
698 Each user may need to perform a few additional steps to make their Guix
699 environment ready for use, @pxref{Application Setup}.
702 Voilà, the installation is complete!
704 You can confirm that Guix is working by installing a sample package into
711 The binary installation tarball can be (re)produced and verified simply
712 by running the following command in the Guix source tree:
715 make guix-binary.@var{system}.tar.xz
719 ...@: which, in turn, runs:
722 guix pack -s @var{system} --localstatedir \
723 --profile-name=current-guix guix
726 @xref{Invoking guix pack}, for more info on this handy tool.
729 @section Requirements
731 This section lists requirements when building Guix from source. The
732 build procedure for Guix is the same as for other GNU software, and is
733 not covered here. Please see the files @file{README} and @file{INSTALL}
734 in the Guix source tree for additional details.
736 @cindex official website
737 GNU Guix is available for download from its website at
738 @url{https://www.gnu.org/software/guix/}.
740 GNU Guix depends on the following packages:
743 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 2.2.x;
744 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
747 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
748 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
749 Guile,, gnutls-guile, GnuTLS-Guile});
751 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
754 @c FIXME: Specify a version number once a release has been made.
755 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
757 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON} 3.x;
758 @item @url{https://zlib.net, zlib};
759 @item @url{https://www.gnu.org/software/make/, GNU Make}.
762 The following dependencies are optional:
766 @c Note: We need at least 0.10.2 for 'channel-send-eof'.
767 Support for build offloading (@pxref{Daemon Offload Setup}) and
768 @command{guix copy} (@pxref{Invoking guix copy}) depends on
769 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
770 version 0.10.2 or later.
773 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
774 substitutes can be used and @command{guix publish} can compress substitutes
778 When @url{http://www.bzip.org, libbz2} is available,
779 @command{guix-daemon} can use it to compress build logs.
782 Unless @code{--disable-daemon} was passed to @command{configure}, the
783 following packages are also needed:
786 @item @url{https://gnupg.org/, GNU libgcrypt};
787 @item @url{https://sqlite.org, SQLite 3};
788 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
792 @cindex state directory
793 When configuring Guix on a system that already has a Guix installation,
794 be sure to specify the same state directory as the existing installation
795 using the @code{--localstatedir} option of the @command{configure}
796 script (@pxref{Directory Variables, @code{localstatedir},, standards,
797 GNU Coding Standards}). Usually, this @var{localstatedir} option is
798 set to the value @file{/var}. The @command{configure} script protects
799 against unintended misconfiguration of @var{localstatedir} so you do not
800 inadvertently corrupt your store (@pxref{The Store}).
802 @node Running the Test Suite
803 @section Running the Test Suite
806 After a successful @command{configure} and @code{make} run, it is a good
807 idea to run the test suite. It can help catch issues with the setup or
808 environment, or bugs in Guix itself---and really, reporting test
809 failures is a good way to help improve the software. To run the test
816 Test cases can run in parallel: you can use the @code{-j} option of
817 GNU@tie{}make to speed things up. The first run may take a few minutes
818 on a recent machine; subsequent runs will be faster because the store
819 that is created for test purposes will already have various things in
822 It is also possible to run a subset of the tests by defining the
823 @code{TESTS} makefile variable as in this example:
826 make check TESTS="tests/store.scm tests/cpio.scm"
829 By default, tests results are displayed at a file level. In order to
830 see the details of every individual test cases, it is possible to define
831 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
834 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
837 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
838 @file{test-suite.log} file. Please specify the Guix version being used
839 as well as version numbers of the dependencies (@pxref{Requirements}) in
842 Guix also comes with a whole-system test suite that tests complete
843 Guix System instances. It can only run on systems where
844 Guix is already installed, using:
851 or, again, by defining @code{TESTS} to select a subset of tests to run:
854 make check-system TESTS="basic mcron"
857 These system tests are defined in the @code{(gnu tests @dots{})}
858 modules. They work by running the operating systems under test with
859 lightweight instrumentation in a virtual machine (VM). They can be
860 computationally intensive or rather cheap, depending on whether
861 substitutes are available for their dependencies (@pxref{Substitutes}).
862 Some of them require a lot of storage space to hold VM images.
864 Again in case of test failures, please send @email{bug-guix@@gnu.org}
867 @node Setting Up the Daemon
868 @section Setting Up the Daemon
871 Operations such as building a package or running the garbage collector
872 are all performed by a specialized process, the @dfn{build daemon}, on
873 behalf of clients. Only the daemon may access the store and its
874 associated database. Thus, any operation that manipulates the store
875 goes through the daemon. For instance, command-line tools such as
876 @command{guix package} and @command{guix build} communicate with the
877 daemon (@i{via} remote procedure calls) to instruct it what to do.
879 The following sections explain how to prepare the build daemon's
880 environment. See also @ref{Substitutes}, for information on how to allow
881 the daemon to download pre-built binaries.
884 * Build Environment Setup:: Preparing the isolated build environment.
885 * Daemon Offload Setup:: Offloading builds to remote machines.
886 * SELinux Support:: Using an SELinux policy for the daemon.
889 @node Build Environment Setup
890 @subsection Build Environment Setup
892 @cindex build environment
893 In a standard multi-user setup, Guix and its daemon---the
894 @command{guix-daemon} program---are installed by the system
895 administrator; @file{/gnu/store} is owned by @code{root} and
896 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
897 Guix tools to build packages or otherwise access the store, and the
898 daemon will do it on their behalf, ensuring that the store is kept in a
899 consistent state, and allowing built packages to be shared among users.
902 When @command{guix-daemon} runs as @code{root}, you may not want package
903 build processes themselves to run as @code{root} too, for obvious
904 security reasons. To avoid that, a special pool of @dfn{build users}
905 should be created for use by build processes started by the daemon.
906 These build users need not have a shell and a home directory: they will
907 just be used when the daemon drops @code{root} privileges in build
908 processes. Having several such users allows the daemon to launch
909 distinct build processes under separate UIDs, which guarantees that they
910 do not interfere with each other---an essential feature since builds are
911 regarded as pure functions (@pxref{Introduction}).
913 On a GNU/Linux system, a build user pool may be created like this (using
914 Bash syntax and the @code{shadow} commands):
916 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
917 @c for why `-G' is needed.
919 # groupadd --system guixbuild
920 # for i in `seq -w 1 10`;
922 useradd -g guixbuild -G guixbuild \
923 -d /var/empty -s `which nologin` \
924 -c "Guix build user $i" --system \
930 The number of build users determines how many build jobs may run in
931 parallel, as specified by the @option{--max-jobs} option
932 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
933 @command{guix system vm} and related commands, you may need to add the
934 build users to the @code{kvm} group so they can access @file{/dev/kvm},
935 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
936 (@pxref{Invoking guix system}).
938 The @code{guix-daemon} program may then be run as @code{root} with the
939 following command@footnote{If your machine uses the systemd init system,
940 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
941 file in @file{/etc/systemd/system} will ensure that
942 @command{guix-daemon} is automatically started. Similarly, if your
943 machine uses the Upstart init system, drop the
944 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
945 file in @file{/etc/init}.}:
948 # guix-daemon --build-users-group=guixbuild
953 This way, the daemon starts build processes in a chroot, under one of
954 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
955 environment contains nothing but:
957 @c Keep this list in sync with libstore/build.cc! -----------------------
960 a minimal @code{/dev} directory, created mostly independently from the
961 host @code{/dev}@footnote{``Mostly'', because while the set of files
962 that appear in the chroot's @code{/dev} is fixed, most of these files
963 can only be created if the host has them.};
966 the @code{/proc} directory; it only shows the processes of the container
967 since a separate PID name space is used;
970 @file{/etc/passwd} with an entry for the current user and an entry for
974 @file{/etc/group} with an entry for the user's group;
977 @file{/etc/hosts} with an entry that maps @code{localhost} to
981 a writable @file{/tmp} directory.
984 You can influence the directory where the daemon stores build trees
985 @i{via} the @code{TMPDIR} environment variable. However, the build tree
986 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
987 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
988 This way, the value of @code{TMPDIR} does not leak inside build
989 environments, which avoids discrepancies in cases where build processes
990 capture the name of their build tree.
993 The daemon also honors the @code{http_proxy} environment variable for
994 HTTP downloads it performs, be it for fixed-output derivations
995 (@pxref{Derivations}) or for substitutes (@pxref{Substitutes}).
997 If you are installing Guix as an unprivileged user, it is still possible
998 to run @command{guix-daemon} provided you pass @code{--disable-chroot}.
999 However, build processes will not be isolated from one another, and not
1000 from the rest of the system. Thus, build processes may interfere with
1001 each other, and may access programs, libraries, and other files
1002 available on the system---making it much harder to view them as
1003 @emph{pure} functions.
1006 @node Daemon Offload Setup
1007 @subsection Using the Offload Facility
1011 When desired, the build daemon can @dfn{offload} derivation builds to
1012 other machines running Guix, using the @code{offload} @dfn{build
1013 hook}@footnote{This feature is available only when
1014 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1015 present.}. When that
1016 feature is enabled, a list of user-specified build machines is read from
1017 @file{/etc/guix/machines.scm}; every time a build is requested, for
1018 instance via @code{guix build}, the daemon attempts to offload it to one
1019 of the machines that satisfy the constraints of the derivation, in
1020 particular its system type---e.g., @file{x86_64-linux}. Missing
1021 prerequisites for the build are copied over SSH to the target machine,
1022 which then proceeds with the build; upon success the output(s) of the
1023 build are copied back to the initial machine.
1025 The @file{/etc/guix/machines.scm} file typically looks like this:
1028 (list (build-machine
1029 (name "eightysix.example.org")
1030 (system "x86_64-linux")
1031 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1033 (speed 2.)) ;incredibly fast!
1036 (name "meeps.example.org")
1037 (system "mips64el-linux")
1038 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1041 (string-append (getenv "HOME")
1042 "/.ssh/identity-for-guix"))))
1046 In the example above we specify a list of two build machines, one for
1047 the @code{x86_64} architecture and one for the @code{mips64el}
1050 In fact, this file is---not surprisingly!---a Scheme file that is
1051 evaluated when the @code{offload} hook is started. Its return value
1052 must be a list of @code{build-machine} objects. While this example
1053 shows a fixed list of build machines, one could imagine, say, using
1054 DNS-SD to return a list of potential build machines discovered in the
1055 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1056 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1059 @deftp {Data Type} build-machine
1060 This data type represents build machines to which the daemon may offload
1061 builds. The important fields are:
1066 The host name of the remote machine.
1069 The system type of the remote machine---e.g., @code{"x86_64-linux"}.
1072 The user account to use when connecting to the remote machine over SSH.
1073 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1074 allow non-interactive logins.
1077 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1078 This is used to authenticate the machine when we connect to it. It is a
1079 long string that looks like this:
1082 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1085 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1086 key can be found in a file such as
1087 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1089 If the machine is running the SSH daemon of GNU@tie{}lsh,
1090 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1091 similar file. It can be converted to the OpenSSH format using
1092 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1095 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1096 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1101 A number of optional fields may be specified:
1105 @item @code{port} (default: @code{22})
1106 Port number of SSH server on the machine.
1108 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1109 The SSH private key file to use when connecting to the machine, in
1110 OpenSSH format. This key must not be protected with a passphrase.
1112 Note that the default value is the private key @emph{of the root
1113 account}. Make sure it exists if you use the default.
1115 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1116 @itemx @code{compression-level} (default: @code{3})
1117 The SSH-level compression methods and compression level requested.
1119 Note that offloading relies on SSH compression to reduce bandwidth usage
1120 when transferring files to and from build machines.
1122 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1123 File name of the Unix-domain socket @command{guix-daemon} is listening
1126 @item @code{parallel-builds} (default: @code{1})
1127 The number of builds that may run in parallel on the machine.
1129 @item @code{speed} (default: @code{1.0})
1130 A ``relative speed factor''. The offload scheduler will tend to prefer
1131 machines with a higher speed factor.
1133 @item @code{features} (default: @code{'()})
1134 A list of strings denoting specific features supported by the machine.
1135 An example is @code{"kvm"} for machines that have the KVM Linux modules
1136 and corresponding hardware support. Derivations can request features by
1137 name, and they will be scheduled on matching build machines.
1142 The @command{guix} command must be in the search path on the build
1143 machines. You can check whether this is the case by running:
1146 ssh build-machine guix repl --version
1149 There is one last thing to do once @file{machines.scm} is in place. As
1150 explained above, when offloading, files are transferred back and forth
1151 between the machine stores. For this to work, you first need to
1152 generate a key pair on each machine to allow the daemon to export signed
1153 archives of files from the store (@pxref{Invoking guix archive}):
1156 # guix archive --generate-key
1160 Each build machine must authorize the key of the master machine so that
1161 it accepts store items it receives from the master:
1164 # guix archive --authorize < master-public-key.txt
1168 Likewise, the master machine must authorize the key of each build machine.
1170 All the fuss with keys is here to express pairwise mutual trust
1171 relations between the master and the build machines. Concretely, when
1172 the master receives files from a build machine (and @i{vice versa}), its
1173 build daemon can make sure they are genuine, have not been tampered
1174 with, and that they are signed by an authorized key.
1176 @cindex offload test
1177 To test whether your setup is operational, run this command on the
1184 This will attempt to connect to each of the build machines specified in
1185 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1186 available on each machine, attempt to export to the machine and import
1187 from it, and report any error in the process.
1189 If you want to test a different machine file, just specify it on the
1193 # guix offload test machines-qualif.scm
1196 Last, you can test the subset of the machines whose name matches a
1197 regular expression like this:
1200 # guix offload test machines.scm '\.gnu\.org$'
1203 @cindex offload status
1204 To display the current load of all build hosts, run this command on the
1208 # guix offload status
1212 @node SELinux Support
1213 @subsection SELinux Support
1215 @cindex SELinux, daemon policy
1216 @cindex mandatory access control, SELinux
1217 @cindex security, guix-daemon
1218 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1219 can be installed on a system where SELinux is enabled, in order to label
1220 Guix files and to specify the expected behavior of the daemon. Since
1221 Guix System does not provide an SELinux base policy, the daemon policy cannot
1222 be used on Guix System.
1224 @subsubsection Installing the SELinux policy
1225 @cindex SELinux, policy installation
1226 To install the policy run this command as root:
1229 semodule -i etc/guix-daemon.cil
1232 Then relabel the file system with @code{restorecon} or by a different
1233 mechanism provided by your system.
1235 Once the policy is installed, the file system has been relabeled, and
1236 the daemon has been restarted, it should be running in the
1237 @code{guix_daemon_t} context. You can confirm this with the following
1241 ps -Zax | grep guix-daemon
1244 Monitor the SELinux log files as you run a command like @code{guix build
1245 hello} to convince yourself that SELinux permits all necessary
1248 @subsubsection Limitations
1249 @cindex SELinux, limitations
1251 This policy is not perfect. Here is a list of limitations or quirks
1252 that should be considered when deploying the provided SELinux policy for
1257 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1258 operations involve contexts that have anything to do with
1259 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1260 but it would be preferrable to define socket rules for only this label.
1263 @code{guix gc} cannot access arbitrary links to profiles. By design,
1264 the file label of the destination of a symlink is independent of the
1265 file label of the link itself. Although all profiles under
1266 $localstatedir are labelled, the links to these profiles inherit the
1267 label of the directory they are in. For links in the user’s home
1268 directory this will be @code{user_home_t}. But for links from the root
1269 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1270 directory, etc, this won’t work. @code{guix gc} would be prevented from
1271 reading and following these links.
1274 The daemon’s feature to listen for TCP connections might no longer work.
1275 This might require extra rules, because SELinux treats network sockets
1276 differently from files.
1279 Currently all files with a name matching the regular expression
1280 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1281 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1282 that name in any profile would be permitted to run in the
1283 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1284 build a package that provides this executable and convince a user to
1285 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1286 At that point SELinux could not prevent it from accessing files that are
1287 allowed for processes in that domain.
1289 We could generate a much more restrictive policy at installation time,
1290 so that only the @emph{exact} file name of the currently installed
1291 @code{guix-daemon} executable would be labelled with
1292 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1293 The downside is that root would have to install or upgrade the policy at
1294 installation time whenever the Guix package that provides the
1295 effectively running @code{guix-daemon} executable is upgraded.
1298 @node Invoking guix-daemon
1299 @section Invoking @command{guix-daemon}
1301 The @command{guix-daemon} program implements all the functionality to
1302 access the store. This includes launching build processes, running the
1303 garbage collector, querying the availability of a build result, etc. It
1304 is normally run as @code{root} like this:
1307 # guix-daemon --build-users-group=guixbuild
1311 For details on how to set it up, @pxref{Setting Up the Daemon}.
1314 @cindex container, build environment
1315 @cindex build environment
1316 @cindex reproducible builds
1317 By default, @command{guix-daemon} launches build processes under
1318 different UIDs, taken from the build group specified with
1319 @code{--build-users-group}. In addition, each build process is run in a
1320 chroot environment that only contains the subset of the store that the
1321 build process depends on, as specified by its derivation
1322 (@pxref{Programming Interface, derivation}), plus a set of specific
1323 system directories. By default, the latter contains @file{/dev} and
1324 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1325 @dfn{container}: in addition to having its own file system tree, it has
1326 a separate mount name space, its own PID name space, network name space,
1327 etc. This helps achieve reproducible builds (@pxref{Features}).
1329 When the daemon performs a build on behalf of the user, it creates a
1330 build directory under @file{/tmp} or under the directory specified by
1331 its @code{TMPDIR} environment variable. This directory is shared with
1332 the container for the duration of the build, though within the container,
1333 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1335 The build directory is automatically deleted upon completion, unless the
1336 build failed and the client specified @option{--keep-failed}
1337 (@pxref{Invoking guix build, @option{--keep-failed}}).
1339 The daemon listens for connections and spawns one sub-process for each session
1340 started by a client (one of the @command{guix} sub-commands.) The
1341 @command{guix processes} command allows you to get an overview of the activity
1342 on your system by viewing each of the active sessions and clients.
1343 @xref{Invoking guix processes}, for more information.
1345 The following command-line options are supported:
1348 @item --build-users-group=@var{group}
1349 Take users from @var{group} to run build processes (@pxref{Setting Up
1350 the Daemon, build users}).
1352 @item --no-substitutes
1354 Do not use substitutes for build products. That is, always build things
1355 locally instead of allowing downloads of pre-built binaries
1356 (@pxref{Substitutes}).
1358 When the daemon runs with @code{--no-substitutes}, clients can still
1359 explicitly enable substitution @i{via} the @code{set-build-options}
1360 remote procedure call (@pxref{The Store}).
1362 @item --substitute-urls=@var{urls}
1363 @anchor{daemon-substitute-urls}
1364 Consider @var{urls} the default whitespace-separated list of substitute
1365 source URLs. When this option is omitted,
1366 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1368 This means that substitutes may be downloaded from @var{urls}, as long
1369 as they are signed by a trusted signature (@pxref{Substitutes}).
1373 Do not use offload builds to other machines (@pxref{Daemon Offload
1374 Setup}). That is, always build things locally instead of offloading
1375 builds to remote machines.
1377 @item --cache-failures
1378 Cache build failures. By default, only successful builds are cached.
1380 When this option is used, @command{guix gc --list-failures} can be used
1381 to query the set of store items marked as failed; @command{guix gc
1382 --clear-failures} removes store items from the set of cached failures.
1383 @xref{Invoking guix gc}.
1385 @item --cores=@var{n}
1387 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1390 The default value is @code{0}, but it may be overridden by clients, such
1391 as the @code{--cores} option of @command{guix build} (@pxref{Invoking
1394 The effect is to define the @code{NIX_BUILD_CORES} environment variable
1395 in the build process, which can then use it to exploit internal
1396 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1398 @item --max-jobs=@var{n}
1400 Allow at most @var{n} build jobs in parallel. The default value is
1401 @code{1}. Setting it to @code{0} means that no builds will be performed
1402 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1403 Setup}), or simply fail.
1405 @item --max-silent-time=@var{seconds}
1406 When the build or substitution process remains silent for more than
1407 @var{seconds}, terminate it and report a build failure.
1409 The default value is @code{0}, which disables the timeout.
1411 The value specified here can be overridden by clients (@pxref{Common
1412 Build Options, @code{--max-silent-time}}).
1414 @item --timeout=@var{seconds}
1415 Likewise, when the build or substitution process lasts for more than
1416 @var{seconds}, terminate it and report a build failure.
1418 The default value is @code{0}, which disables the timeout.
1420 The value specified here can be overridden by clients (@pxref{Common
1421 Build Options, @code{--timeout}}).
1423 @item --rounds=@var{N}
1424 Build each derivation @var{n} times in a row, and raise an error if
1425 consecutive build results are not bit-for-bit identical. Note that this
1426 setting can be overridden by clients such as @command{guix build}
1427 (@pxref{Invoking guix build}).
1429 When used in conjunction with @option{--keep-failed}, the differing
1430 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1431 This makes it easy to look for differences between the two results.
1434 Produce debugging output.
1436 This is useful to debug daemon start-up issues, but then it may be
1437 overridden by clients, for example the @code{--verbosity} option of
1438 @command{guix build} (@pxref{Invoking guix build}).
1440 @item --chroot-directory=@var{dir}
1441 Add @var{dir} to the build chroot.
1443 Doing this may change the result of build processes---for instance if
1444 they use optional dependencies found in @var{dir} when it is available,
1445 and not otherwise. For that reason, it is not recommended to do so.
1446 Instead, make sure that each derivation declares all the inputs that it
1449 @item --disable-chroot
1450 Disable chroot builds.
1452 Using this option is not recommended since, again, it would allow build
1453 processes to gain access to undeclared dependencies. It is necessary,
1454 though, when @command{guix-daemon} is running under an unprivileged user
1457 @item --log-compression=@var{type}
1458 Compress build logs according to @var{type}, one of @code{gzip},
1459 @code{bzip2}, or @code{none}.
1461 Unless @code{--lose-logs} is used, all the build logs are kept in the
1462 @var{localstatedir}. To save space, the daemon automatically compresses
1463 them with bzip2 by default.
1465 @item --disable-deduplication
1466 @cindex deduplication
1467 Disable automatic file ``deduplication'' in the store.
1469 By default, files added to the store are automatically ``deduplicated'':
1470 if a newly added file is identical to another one found in the store,
1471 the daemon makes the new file a hard link to the other file. This can
1472 noticeably reduce disk usage, at the expense of slightly increased
1473 input/output load at the end of a build process. This option disables
1476 @item --gc-keep-outputs[=yes|no]
1477 Tell whether the garbage collector (GC) must keep outputs of live
1481 @cindex garbage collector roots
1482 When set to ``yes'', the GC will keep the outputs of any live derivation
1483 available in the store---the @code{.drv} files. The default is ``no'',
1484 meaning that derivation outputs are kept only if they are reachable from a GC
1485 root. @xref{Invoking guix gc}, for more on GC roots.
1487 @item --gc-keep-derivations[=yes|no]
1488 Tell whether the garbage collector (GC) must keep derivations
1489 corresponding to live outputs.
1491 When set to ``yes'', as is the case by default, the GC keeps
1492 derivations---i.e., @code{.drv} files---as long as at least one of their
1493 outputs is live. This allows users to keep track of the origins of
1494 items in their store. Setting it to ``no'' saves a bit of disk space.
1496 In this way, setting @code{--gc-keep-derivations} to ``yes'' causes liveness
1497 to flow from outputs to derivations, and setting @code{--gc-keep-outputs} to
1498 ``yes'' causes liveness to flow from derivations to outputs. When both are
1499 set to ``yes'', the effect is to keep all the build prerequisites (the
1500 sources, compiler, libraries, and other build-time tools) of live objects in
1501 the store, regardless of whether these prerequisites are reachable from a GC
1502 root. This is convenient for developers since it saves rebuilds or downloads.
1504 @item --impersonate-linux-2.6
1505 On Linux-based systems, impersonate Linux 2.6. This means that the
1506 kernel's @code{uname} system call will report 2.6 as the release number.
1508 This might be helpful to build programs that (usually wrongfully) depend
1509 on the kernel version number.
1512 Do not keep build logs. By default they are kept under
1513 @code{@var{localstatedir}/guix/log}.
1515 @item --system=@var{system}
1516 Assume @var{system} as the current system type. By default it is the
1517 architecture/kernel pair found at configure time, such as
1518 @code{x86_64-linux}.
1520 @item --listen=@var{endpoint}
1521 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1522 as the file name of a Unix-domain socket if it starts with
1523 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1524 host name or host name and port to listen to. Here are a few examples:
1527 @item --listen=/gnu/var/daemon
1528 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1529 creating it if needed.
1531 @item --listen=localhost
1532 @cindex daemon, remote access
1533 @cindex remote access to the daemon
1534 @cindex daemon, cluster setup
1535 @cindex clusters, daemon setup
1536 Listen for TCP connections on the network interface corresponding to
1537 @code{localhost}, on port 44146.
1539 @item --listen=128.0.0.42:1234
1540 Listen for TCP connections on the network interface corresponding to
1541 @code{128.0.0.42}, on port 1234.
1544 This option can be repeated multiple times, in which case
1545 @command{guix-daemon} accepts connections on all the specified
1546 endpoints. Users can tell client commands what endpoint to connect to
1547 by setting the @code{GUIX_DAEMON_SOCKET} environment variable
1548 (@pxref{The Store, @code{GUIX_DAEMON_SOCKET}}).
1551 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1552 @code{--listen=@var{host}} is suitable on local networks, such as
1553 clusters, where only trusted nodes may connect to the build daemon. In
1554 other cases where remote access to the daemon is needed, we recommend
1555 using Unix-domain sockets along with SSH.
1558 When @code{--listen} is omitted, @command{guix-daemon} listens for
1559 connections on the Unix-domain socket located at
1560 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1564 @node Application Setup
1565 @section Application Setup
1567 @cindex foreign distro
1568 When using Guix on top of GNU/Linux distribution other than Guix System---a
1569 so-called @dfn{foreign distro}---a few additional steps are needed to
1570 get everything in place. Here are some of them.
1574 @anchor{locales-and-locpath}
1575 @cindex locales, when not on Guix System
1577 @vindex GUIX_LOCPATH
1578 Packages installed @i{via} Guix will not use the locale data of the
1579 host system. Instead, you must first install one of the locale packages
1580 available with Guix and then define the @code{GUIX_LOCPATH} environment
1584 $ guix install glibc-locales
1585 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1588 Note that the @code{glibc-locales} package contains data for all the
1589 locales supported by the GNU@tie{}libc and weighs in at around
1590 110@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1591 limited to a few UTF-8 locales.
1593 The @code{GUIX_LOCPATH} variable plays a role similar to @code{LOCPATH}
1594 (@pxref{Locale Names, @code{LOCPATH},, libc, The GNU C Library Reference
1595 Manual}). There are two important differences though:
1599 @code{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1600 provided by foreign distros. Thus, using @code{GUIX_LOCPATH} allows you
1601 to make sure the programs of the foreign distro will not end up loading
1602 incompatible locale data.
1605 libc suffixes each entry of @code{GUIX_LOCPATH} with @code{/X.Y}, where
1606 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1607 should your Guix profile contain a mixture of programs linked against
1608 different libc version, each libc version will only try to load locale
1609 data in the right format.
1612 This is important because the locale data format used by different libc
1613 versions may be incompatible.
1615 @subsection Name Service Switch
1617 @cindex name service switch, glibc
1618 @cindex NSS (name service switch), glibc
1619 @cindex nscd (name service caching daemon)
1620 @cindex name service caching daemon (nscd)
1621 When using Guix on a foreign distro, we @emph{strongly recommend} that
1622 the system run the GNU C library's @dfn{name service cache daemon},
1623 @command{nscd}, which should be listening on the
1624 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1625 installed with Guix may fail to look up host names or user accounts, or
1626 may even crash. The next paragraphs explain why.
1628 @cindex @file{nsswitch.conf}
1629 The GNU C library implements a @dfn{name service switch} (NSS), which is
1630 an extensible mechanism for ``name lookups'' in general: host name
1631 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1632 The GNU C Library Reference Manual}).
1634 @cindex Network information service (NIS)
1635 @cindex NIS (Network information service)
1636 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1637 lookup implementations: for example, the @code{nss-mdns} plugin allow
1638 resolution of @code{.local} host names, the @code{nis} plugin allows
1639 user account lookup using the Network information service (NIS), and so
1640 on. These extra ``lookup services'' are configured system-wide in
1641 @file{/etc/nsswitch.conf}, and all the programs running on the system
1642 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1645 When they perform a name lookup---for instance by calling the
1646 @code{getaddrinfo} function in C---applications first try to connect to
1647 the nscd; on success, nscd performs name lookups on their behalf. If
1648 the nscd is not running, then they perform the name lookup by
1649 themselves, by loading the name lookup services into their own address
1650 space and running it. These name lookup services---the
1651 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1652 the host system's C library, rather than from the C library the
1653 application is linked against (the C library coming from Guix).
1655 And this is where the problem is: if your application is linked against
1656 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1657 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1658 likely crash or have its name lookups fail unexpectedly.
1660 Running @command{nscd} on the system, among other advantages, eliminates
1661 this binary incompatibility problem because those @code{libnss_*.so}
1662 files are loaded in the @command{nscd} process, not in applications
1665 @subsection X11 Fonts
1668 The majority of graphical applications use Fontconfig to locate and
1669 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1670 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1671 by default. Thus, to allow graphical applications installed with Guix
1672 to display fonts, you have to install fonts with Guix as well.
1673 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1674 @code{font-gnu-freefont-ttf}.
1676 To display text written in Chinese languages, Japanese, or Korean in
1677 graphical applications, consider installing
1678 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1679 has multiple outputs, one per language family (@pxref{Packages with
1680 Multiple Outputs}). For instance, the following command installs fonts
1681 for Chinese languages:
1684 guix install font-adobe-source-han-sans:cn
1687 @cindex @code{xterm}
1688 Older programs such as @command{xterm} do not use Fontconfig and instead
1689 rely on server-side font rendering. Such programs require to specify a
1690 full name of a font using XLFD (X Logical Font Description), like this:
1693 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1696 To be able to use such full names for the TrueType fonts installed in
1697 your Guix profile, you need to extend the font path of the X server:
1699 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1700 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1702 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1705 @cindex @code{xlsfonts}
1706 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1707 to make sure your TrueType fonts are listed there.
1709 @cindex @code{fc-cache}
1711 After installing fonts you may have to refresh the font cache to use
1712 them in applications. The same applies when applications installed via
1713 Guix do not seem to find fonts. To force rebuilding of the font cache
1714 run @code{fc-cache -rv}. The @code{fc-cache} command is provided by
1715 the @code{fontconfig} package.
1717 @subsection X.509 Certificates
1719 @cindex @code{nss-certs}
1720 The @code{nss-certs} package provides X.509 certificates, which allow
1721 programs to authenticate Web servers accessed over HTTPS.
1723 When using Guix on a foreign distro, you can install this package and
1724 define the relevant environment variables so that packages know where to
1725 look for certificates. @xref{X.509 Certificates}, for detailed
1728 @subsection Emacs Packages
1730 @cindex @code{emacs}
1731 When you install Emacs packages with Guix, the elisp files may be placed
1732 either in @file{$HOME/.guix-profile/share/emacs/site-lisp/} or in
1734 @file{$HOME/.guix-profile/share/emacs/site-lisp/guix.d/}. The latter
1735 directory exists because potentially there may exist thousands of Emacs
1736 packages and storing all their files in a single directory may not be
1737 reliable (because of name conflicts). So we think using a separate
1738 directory for each package is a good idea. It is very similar to how
1739 the Emacs package system organizes the file structure (@pxref{Package
1740 Files,,, emacs, The GNU Emacs Manual}).
1742 By default, Emacs (installed with Guix) ``knows'' where these packages
1743 are placed, so you do not need to perform any configuration. If, for
1744 some reason, you want to avoid auto-loading Emacs packages installed
1745 with Guix, you can do so by running Emacs with @code{--no-site-file}
1746 option (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1748 @subsection The GCC toolchain
1753 Guix offers individual compiler packages such as @code{gcc} but if you
1754 are in need of a complete toolchain for compiling and linking source
1755 code what you really want is the @code{gcc-toolchain} package. This
1756 package provides a complete GCC toolchain for C/C++ development,
1757 including GCC itself, the GNU C Library (headers and binaries, plus
1758 debugging symbols in the @code{debug} output), Binutils, and a linker
1761 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
1762 passed to the linker, add corresponding @code{-rpath} arguments, and
1763 invoke the actual linker with this new set of arguments. You can instruct the
1764 wrapper to refuse to link against libraries not in the store by setting the
1765 @code{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
1767 @node Upgrading Guix
1768 @section Upgrading Guix
1770 @cindex Upgrading Guix, on a foreign distro
1772 To upgrade Guix, run:
1778 @xref{Invoking guix pull}, for more information.
1780 @cindex upgrading Guix for the root user, on a foreign distro
1781 @cindex upgrading the Guix daemon, on a foreign distro
1782 @cindex @command{guix pull} for the root user, on a foreign distro
1784 On a foreign distro, you can upgrade the build daemon by running:
1791 followed by (assuming your distro uses the systemd service management
1795 systemctl restart guix-daemon.service
1798 On Guix System, upgrading the daemon is achieved by reconfiguring the
1799 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1803 @c *********************************************************************
1804 @node System Installation
1805 @chapter System Installation
1807 @cindex installing Guix System
1808 @cindex Guix System, installation
1809 This section explains how to install Guix System
1810 on a machine. Guix, as a package manager, can
1811 also be installed on top of a running GNU/Linux system,
1812 @pxref{Installation}.
1816 @c This paragraph is for people reading this from tty2 of the
1817 @c installation image.
1818 You are reading this documentation with an Info reader. For details on
1819 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1820 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1821 Info}. Hit @kbd{l} afterwards to come back here.
1823 Alternately, run @command{info info} in another tty to keep the manual
1829 * Limitations:: What you can expect.
1830 * Hardware Considerations:: Supported hardware.
1831 * USB Stick and DVD Installation:: Preparing the installation medium.
1832 * Preparing for Installation:: Networking, partitioning, etc.
1833 * Guided Graphical Installation:: Easy graphical installation.
1834 * Manual Installation:: Manual installation for wizards.
1835 * After System Installation:: When installation succeeded.
1836 * Installing Guix in a VM:: Guix System playground.
1837 * Building the Installation Image:: How this comes to be.
1841 @section Limitations
1843 We consider Guix System to be ready for a wide range of ``desktop'' and server
1844 use cases. The reliability guarantees it provides---transactional upgrades
1845 and rollbacks, reproducibility---make it a solid foundation.
1847 Nevertheless, before you proceed with the installation, be aware of the
1848 following noteworthy limitations applicable to version @value{VERSION}:
1852 Support for the Logical Volume Manager (LVM) is missing.
1855 More and more system services are provided (@pxref{Services}), but some
1859 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1860 as well as a number of X11 window managers. However, KDE is currently
1864 More than a disclaimer, this is an invitation to report issues (and success
1865 stories!), and to join us in improving it. @xref{Contributing}, for more
1869 @node Hardware Considerations
1870 @section Hardware Considerations
1872 @cindex hardware support on Guix System
1873 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1874 builds around the kernel Linux-libre, which means that only hardware for
1875 which free software drivers and firmware exist is supported. Nowadays,
1876 a wide range of off-the-shelf hardware is supported on
1877 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1878 Ethernet controllers. Unfortunately, there are still areas where
1879 hardware vendors deny users control over their own computing, and such
1880 hardware is not supported on Guix System.
1882 @cindex WiFi, hardware support
1883 One of the main areas where free drivers or firmware are lacking is WiFi
1884 devices. WiFi devices known to work include those using Atheros chips
1885 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1886 driver, and those using Broadcom/AirForce chips (BCM43xx with
1887 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1888 Linux-libre driver. Free firmware exists for both and is available
1889 out-of-the-box on Guix System, as part of @code{%base-firmware}
1890 (@pxref{operating-system Reference, @code{firmware}}).
1892 @cindex RYF, Respects Your Freedom
1893 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1894 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1895 certification program for hardware products that respect your freedom
1896 and your privacy and ensure that you have control over your device. We
1897 encourage you to check the list of RYF-certified devices.
1899 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1900 web site. It contains a catalog of hardware devices with information
1901 about their support in GNU/Linux.
1904 @node USB Stick and DVD Installation
1905 @section USB Stick and DVD Installation
1907 An ISO-9660 installation image that can be written to a USB stick or
1908 burnt to a DVD can be downloaded from
1909 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz},
1910 where @var{system} is one of:
1914 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1917 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1920 @c start duplication of authentication part from ``Binary Installation''
1921 Make sure to download the associated @file{.sig} file and to verify the
1922 authenticity of the image against it, along these lines:
1925 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1926 $ gpg --verify guix-system-install-@value{VERSION}.@var{system}.iso.xz.sig
1929 If that command fails because you do not have the required public key,
1930 then run this command to import it:
1933 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1934 -qO - | gpg --import -
1938 and rerun the @code{gpg --verify} command.
1940 Take note that a warning like ``This key is not certified with a trusted
1941 signature!'' is normal.
1945 This image contains the tools necessary for an installation.
1946 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1948 @unnumberedsubsec Copying to a USB Stick
1950 To copy the image to a USB stick, follow these steps:
1954 Decompress the image using the @command{xz} command:
1957 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1961 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1962 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1963 copy the image with:
1966 dd if=guix-system-install-@value{VERSION}.@var{system}.iso of=/dev/sdX
1970 Access to @file{/dev/sdX} usually requires root privileges.
1973 @unnumberedsubsec Burning on a DVD
1975 To copy the image to a DVD, follow these steps:
1979 Decompress the image using the @command{xz} command:
1982 xz -d guix-system-install-@value{VERSION}.@var{system}.iso.xz
1986 Insert a blank DVD into your machine, and determine
1987 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
1988 copy the image with:
1991 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.@var{system}.iso
1994 Access to @file{/dev/srX} usually requires root privileges.
1997 @unnumberedsubsec Booting
1999 Once this is done, you should be able to reboot the system and boot from
2000 the USB stick or DVD. The latter usually requires you to get in the
2001 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2003 @xref{Installing Guix in a VM}, if, instead, you would like to install
2004 Guix System in a virtual machine (VM).
2007 @node Preparing for Installation
2008 @section Preparing for Installation
2010 Once you have booted, you can use the guided graphical installer, which makes
2011 it easy to get started (@pxref{Guided Graphical Installation}). Alternately,
2012 if you are already familiar with GNU/Linux and if you want more control than
2013 what the graphical installer provides, you can choose the ``manual''
2014 installation process (@pxref{Manual Installation}).
2016 The graphical installer is available on TTY1. You can obtain root shells on
2017 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2018 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2019 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2020 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2021 which allows you to select text with the left mouse button and to paste it
2022 with the middle button.
2025 Installation requires access to the Internet so that any missing
2026 dependencies of your system configuration can be downloaded. See the
2027 ``Networking'' section below.
2030 @node Guided Graphical Installation
2031 @section Guided Graphical Installation
2033 The graphical installer is a text-based user interface. It will guide you,
2034 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2036 The first dialog boxes allow you to set up the system as you use it during the
2037 installation: you can choose the language, keyboard layout, and set up
2038 networking, which will be used during the installation. The image below shows
2039 the networking dialog.
2041 @image{images/installer-network,5in,, networking setup with the graphical installer}
2043 Later steps allow you to partition your hard disk, as shown in the image
2044 below, to choose whether or not to use encrypted file systems, to enter the
2045 host name and root password, and to create an additional account, among other
2048 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2050 Note that, at any time, the installer allows you to exit the current
2051 installation step and resume at a previous step, as show in the image below.
2053 @image{images/installer-resume,5in,, resuming the installation process}
2055 Once you're done, the installer produces an operating system configuration and
2056 displays it (@pxref{Using the Configuration System}). At that point you can
2057 hit ``OK'' and installation will proceed. On success, you can reboot into the
2058 new system and enjoy. @xref{After System Installation}, for what's next!
2061 @node Manual Installation
2062 @section Manual Installation
2064 This section describes how you would ``manually'' install GNU@tie{}Guix System
2065 on your machine. This option requires familiarity with GNU/Linux, with the
2066 shell, and with common administration tools. If you think this is not for
2067 you, consider using the guided graphical installer (@pxref{Guided Graphical
2070 The installation system provides root shells on TTYs 3 to 6; press
2071 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2072 many common tools needed to install the system. But it is also a full-blown
2073 Guix System, which means that you can install additional packages, should you
2074 need it, using @command{guix package} (@pxref{Invoking guix package}).
2077 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2078 * Proceeding with the Installation:: Installing.
2081 @node Keyboard Layout and Networking and Partitioning
2082 @subsection Keyboard Layout, Networking, and Partitioning
2084 Before you can install the system, you may want to adjust the keyboard layout,
2085 set up networking, and partition your target hard disk. This section will
2086 guide you through this.
2088 @subsubsection Keyboard Layout
2090 @cindex keyboard layout
2091 The installation image uses the US qwerty keyboard layout. If you want
2092 to change it, you can use the @command{loadkeys} command. For example,
2093 the following command selects the Dvorak keyboard layout:
2099 See the files under @file{/run/current-system/profile/share/keymaps} for
2100 a list of available keyboard layouts. Run @command{man loadkeys} for
2103 @subsubsection Networking
2105 Run the following command to see what your network interfaces are called:
2112 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2118 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2119 Wired interfaces have a name starting with @samp{e}; for example, the
2120 interface corresponding to the first on-board Ethernet controller is
2121 called @samp{eno1}. Wireless interfaces have a name starting with
2122 @samp{w}, like @samp{w1p2s0}.
2125 @item Wired connection
2126 To configure a wired network run the following command, substituting
2127 @var{interface} with the name of the wired interface you want to use.
2130 ifconfig @var{interface} up
2134 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2137 ip link set @var{interface} up
2140 @item Wireless connection
2143 To configure wireless networking, you can create a configuration file
2144 for the @command{wpa_supplicant} configuration tool (its location is not
2145 important) using one of the available text editors such as
2149 nano wpa_supplicant.conf
2152 As an example, the following stanza can go to this file and will work
2153 for many wireless networks, provided you give the actual SSID and
2154 passphrase for the network you are connecting to:
2158 ssid="@var{my-ssid}"
2160 psk="the network's secret passphrase"
2164 Start the wireless service and run it in the background with the
2165 following command (substitute @var{interface} with the name of the
2166 network interface you want to use):
2169 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2172 Run @command{man wpa_supplicant} for more information.
2176 At this point, you need to acquire an IP address. On a network where IP
2177 addresses are automatically assigned @i{via} DHCP, you can run:
2180 dhclient -v @var{interface}
2183 Try to ping a server to see if networking is up and running:
2189 Setting up network access is almost always a requirement because the
2190 image does not contain all the software and tools that may be needed.
2192 @cindex installing over SSH
2193 If you want to, you can continue the installation remotely by starting
2197 herd start ssh-daemon
2200 Make sure to either set a password with @command{passwd}, or configure
2201 OpenSSH public key authentication before logging in.
2203 @subsubsection Disk Partitioning
2205 Unless this has already been done, the next step is to partition, and
2206 then format the target partition(s).
2208 The installation image includes several partitioning tools, including
2209 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2210 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2211 the partition layout you want:
2217 If your disk uses the GUID Partition Table (GPT) format and you plan to
2218 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2219 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2222 @cindex EFI, installation
2223 @cindex UEFI, installation
2224 @cindex ESP, EFI system partition
2225 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2226 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2227 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2230 parted /dev/sda set 1 esp on
2234 @vindex grub-bootloader
2235 @vindex grub-efi-bootloader
2236 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2237 @file{/sys/firmware/efi} exists in the installation image, then you should
2238 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2239 Otherwise you should use the BIOS-based GRUB, known as
2240 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2244 Once you are done partitioning the target hard disk drive, you have to
2245 create a file system on the relevant partition(s)@footnote{Currently
2246 Guix System only supports ext4 and btrfs file systems. In particular, code
2247 that reads file system UUIDs and labels only works for these file system
2248 types.}. For the ESP, if you have one and assuming it is
2249 @file{/dev/sda1}, run:
2252 mkfs.fat -F32 /dev/sda1
2255 Preferably, assign file systems a label so that you can easily and
2256 reliably refer to them in @code{file-system} declarations (@pxref{File
2257 Systems}). This is typically done using the @code{-L} option of
2258 @command{mkfs.ext4} and related commands. So, assuming the target root
2259 partition lives at @file{/dev/sda2}, a file system with the label
2260 @code{my-root} can be created with:
2263 mkfs.ext4 -L my-root /dev/sda2
2266 @cindex encrypted disk
2267 If you are instead planning to encrypt the root partition, you can use
2268 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2269 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2270 @code{man cryptsetup}} for more information.) Assuming you want to
2271 store the root partition on @file{/dev/sda2}, the command sequence would
2272 be along these lines:
2275 cryptsetup luksFormat /dev/sda2
2276 cryptsetup open --type luks /dev/sda2 my-partition
2277 mkfs.ext4 -L my-root /dev/mapper/my-partition
2280 Once that is done, mount the target file system under @file{/mnt}
2281 with a command like (again, assuming @code{my-root} is the label of the
2285 mount LABEL=my-root /mnt
2288 Also mount any other file systems you would like to use on the target
2289 system relative to this path. If you have opted for @file{/boot/efi} as an
2290 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2291 found by @code{guix system init} afterwards.
2293 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2294 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2295 sure to initialize them with @command{mkswap}. Assuming you have one
2296 swap partition on @file{/dev/sda3}, you would run:
2303 Alternatively, you may use a swap file. For example, assuming that in
2304 the new system you want to use the file @file{/swapfile} as a swap file,
2305 you would run@footnote{This example will work for many types of file
2306 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2307 btrfs), the required steps may be different. For details, see the
2308 manual pages for @command{mkswap} and @command{swapon}.}:
2311 # This is 10 GiB of swap space. Adjust "count" to change the size.
2312 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2313 # For security, make the file readable and writable only by root.
2314 chmod 600 /mnt/swapfile
2315 mkswap /mnt/swapfile
2316 swapon /mnt/swapfile
2319 Note that if you have encrypted the root partition and created a swap
2320 file in its file system as described above, then the encryption also
2321 protects the swap file, just like any other file in that file system.
2323 @node Proceeding with the Installation
2324 @subsection Proceeding with the Installation
2326 With the target partitions ready and the target root mounted on
2327 @file{/mnt}, we're ready to go. First, run:
2330 herd start cow-store /mnt
2333 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2334 during the installation phase are written to the target disk on @file{/mnt}
2335 rather than kept in memory. This is necessary because the first phase of
2336 the @command{guix system init} command (see below) entails downloads or
2337 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2339 Next, you have to edit a file and
2340 provide the declaration of the operating system to be installed. To
2341 that end, the installation system comes with three text editors. We
2342 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2343 supports syntax highlighting and parentheses matching; other editors
2344 include GNU Zile (an Emacs clone), and
2345 nvi (a clone of the original BSD @command{vi} editor).
2346 We strongly recommend storing that file on the target root file system, say,
2347 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2348 configuration file once you have rebooted into the newly-installed system.
2350 @xref{Using the Configuration System}, for an overview of the
2351 configuration file. The example configurations discussed in that
2352 section are available under @file{/etc/configuration} in the
2353 installation image. Thus, to get started with a system configuration
2354 providing a graphical display server (a ``desktop'' system), you can run
2355 something along these lines:
2359 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2360 # nano /mnt/etc/config.scm
2363 You should pay attention to what your configuration file contains, and
2368 Make sure the @code{bootloader-configuration} form refers to the target
2369 you want to install GRUB on. It should mention @code{grub-bootloader} if
2370 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2371 for newer UEFI systems. For legacy systems, the @code{target} field
2372 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2373 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2374 currently mounted and a @code{file-system} entry is specified in your
2378 Be sure that your file system labels match the value of their respective
2379 @code{device} fields in your @code{file-system} configuration, assuming
2380 your @code{file-system} configuration uses the @code{file-system-label}
2381 procedure in its @code{device} field.
2384 If there are encrypted or RAID partitions, make sure to add a
2385 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2388 Once you are done preparing the configuration file, the new system must
2389 be initialized (remember that the target root file system is mounted
2393 guix system init /mnt/etc/config.scm /mnt
2397 This copies all the necessary files and installs GRUB on
2398 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2399 more information, @pxref{Invoking guix system}. This command may trigger
2400 downloads or builds of missing packages, which can take some time.
2402 Once that command has completed---and hopefully succeeded!---you can run
2403 @command{reboot} and boot into the new system. The @code{root} password
2404 in the new system is initially empty; other users' passwords need to be
2405 initialized by running the @command{passwd} command as @code{root},
2406 unless your configuration specifies otherwise
2407 (@pxref{user-account-password, user account passwords}).
2408 @xref{After System Installation}, for what's next!
2411 @node After System Installation
2412 @section After System Installation
2414 Success, you've now booted into Guix System! From then on, you can update the
2415 system whenever you want by running, say:
2419 sudo guix system reconfigure /etc/config.scm
2423 This builds a new system generation with the latest packages and services
2424 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2425 your system includes the latest security updates (@pxref{Security Updates}).
2427 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2429 @cindex sudo vs. @command{guix pull}
2430 Note that @command{sudo guix} runs your user's @command{guix} command and
2431 @emph{not} root's, because @command{sudo} leaves @code{PATH} unchanged. To
2432 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2435 Join us on @code{#guix} on the Freenode IRC network or on
2436 @email{guix-devel@@gnu.org} to share your experience!
2439 @node Installing Guix in a VM
2440 @section Installing Guix in a Virtual Machine
2442 @cindex virtual machine, Guix System installation
2443 @cindex virtual private server (VPS)
2444 @cindex VPS (virtual private server)
2445 If you'd like to install Guix System in a virtual machine (VM) or on a
2446 virtual private server (VPS) rather than on your beloved machine, this
2449 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2450 disk image, follow these steps:
2454 First, retrieve and decompress the Guix system installation image as
2455 described previously (@pxref{USB Stick and DVD Installation}).
2458 Create a disk image that will hold the installed system. To make a
2459 qcow2-formatted disk image, use the @command{qemu-img} command:
2462 qemu-img create -f qcow2 guix-system.img 50G
2465 The resulting file will be much smaller than 50 GB (typically less than
2466 1 MB), but it will grow as the virtualized storage device is filled up.
2469 Boot the USB installation image in an VM:
2472 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2473 -net user -net nic,model=virtio -boot menu=on,order=d \
2474 -drive file=guix-system.img \
2475 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2478 @code{-enable-kvm} is optional, but significantly improves performance,
2479 @pxref{Running Guix in a VM}.
2482 You're now root in the VM, proceed with the installation process.
2483 @xref{Preparing for Installation}, and follow the instructions.
2486 Once installation is complete, you can boot the system that's on your
2487 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2490 @node Building the Installation Image
2491 @section Building the Installation Image
2493 @cindex installation image
2494 The installation image described above was built using the @command{guix
2495 system} command, specifically:
2498 guix system disk-image --file-system-type=iso9660 \
2499 gnu/system/install.scm
2502 Have a look at @file{gnu/system/install.scm} in the source tree,
2503 and see also @ref{Invoking guix system} for more information
2504 about the installation image.
2506 @section Building the Installation Image for ARM Boards
2508 Many ARM boards require a specific variant of the
2509 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2511 If you build a disk image and the bootloader is not available otherwise
2512 (on another boot drive etc), it's advisable to build an image that
2513 includes the bootloader, specifically:
2516 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2519 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2520 board, a list of possible boards will be printed.
2522 @c *********************************************************************
2523 @node Package Management
2524 @chapter Package Management
2527 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2528 remove software packages, without having to know about their build
2529 procedures or dependencies. Guix also goes beyond this obvious set of
2532 This chapter describes the main features of Guix, as well as the
2533 package management tools it provides. Along with the command-line
2534 interface described below (@pxref{Invoking guix package, @code{guix
2535 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2536 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2537 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2541 guix install emacs-guix
2545 * Features:: How Guix will make your life brighter.
2546 * Invoking guix package:: Package installation, removal, etc.
2547 * Substitutes:: Downloading pre-built binaries.
2548 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2549 * Invoking guix gc:: Running the garbage collector.
2550 * Invoking guix pull:: Fetching the latest Guix and distribution.
2551 * Channels:: Customizing the package collection.
2552 * Invoking guix time-machine:: Running an older revision of Guix.
2553 * Inferiors:: Interacting with another revision of Guix.
2554 * Invoking guix describe:: Display information about your Guix revision.
2555 * Invoking guix archive:: Exporting and importing store files.
2561 When using Guix, each package ends up in the @dfn{package store}, in its
2562 own directory---something that resembles
2563 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2565 Instead of referring to these directories, users have their own
2566 @dfn{profile}, which points to the packages that they actually want to
2567 use. These profiles are stored within each user's home directory, at
2568 @code{$HOME/.guix-profile}.
2570 For example, @code{alice} installs GCC 4.7.2. As a result,
2571 @file{/home/alice/.guix-profile/bin/gcc} points to
2572 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2573 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2574 simply continues to point to
2575 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2576 coexist on the same system without any interference.
2578 The @command{guix package} command is the central tool to manage
2579 packages (@pxref{Invoking guix package}). It operates on the per-user
2580 profiles, and can be used @emph{with normal user privileges}.
2582 @cindex transactions
2583 The command provides the obvious install, remove, and upgrade
2584 operations. Each invocation is actually a @emph{transaction}: either
2585 the specified operation succeeds, or nothing happens. Thus, if the
2586 @command{guix package} process is terminated during the transaction,
2587 or if a power outage occurs during the transaction, then the user's
2588 profile remains in its previous state, and remains usable.
2590 In addition, any package transaction may be @emph{rolled back}. So, if,
2591 for example, an upgrade installs a new version of a package that turns
2592 out to have a serious bug, users may roll back to the previous instance
2593 of their profile, which was known to work well. Similarly, the global
2594 system configuration on Guix is subject to
2595 transactional upgrades and roll-back
2596 (@pxref{Using the Configuration System}).
2598 All packages in the package store may be @emph{garbage-collected}.
2599 Guix can determine which packages are still referenced by user
2600 profiles, and remove those that are provably no longer referenced
2601 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2602 generations of their profile so that the packages they refer to can be
2605 @cindex reproducibility
2606 @cindex reproducible builds
2607 Guix takes a @dfn{purely functional} approach to package
2608 management, as described in the introduction (@pxref{Introduction}).
2609 Each @file{/gnu/store} package directory name contains a hash of all the
2610 inputs that were used to build that package---compiler, libraries, build
2611 scripts, etc. This direct correspondence allows users to make sure a
2612 given package installation matches the current state of their
2613 distribution. It also helps maximize @dfn{build reproducibility}:
2614 thanks to the isolated build environments that are used, a given build
2615 is likely to yield bit-identical files when performed on different
2616 machines (@pxref{Invoking guix-daemon, container}).
2619 This foundation allows Guix to support @dfn{transparent binary/source
2620 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2621 available from an external source---a @dfn{substitute}, Guix just
2622 downloads it and unpacks it;
2623 otherwise, it builds the package from source, locally
2624 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2625 reproducible, users do not have to trust servers that provide
2626 substitutes: they can force a local build and @emph{challenge} providers
2627 (@pxref{Invoking guix challenge}).
2629 Control over the build environment is a feature that is also useful for
2630 developers. The @command{guix environment} command allows developers of
2631 a package to quickly set up the right development environment for their
2632 package, without having to manually install the dependencies of the
2633 package into their profile (@pxref{Invoking guix environment}).
2635 @cindex replication, of software environments
2636 @cindex provenance tracking, of software artifacts
2637 All of Guix and its package definitions is version-controlled, and
2638 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2639 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2640 Guix instance on a different machine or at a later point in time, which in
2641 turn allows you to @emph{replicate complete software environments}, while
2642 retaining precise @dfn{provenance tracking} of the software.
2644 @node Invoking guix package
2645 @section Invoking @command{guix package}
2647 @cindex installing packages
2648 @cindex removing packages
2649 @cindex package installation
2650 @cindex package removal
2651 The @command{guix package} command is the tool that allows users to
2652 install, upgrade, and remove packages, as well as rolling back to
2653 previous configurations. It operates only on the user's own profile,
2654 and works with normal user privileges (@pxref{Features}). Its syntax
2658 guix package @var{options}
2661 @cindex transactions
2662 Primarily, @var{options} specifies the operations to be performed during
2663 the transaction. Upon completion, a new profile is created, but
2664 previous @dfn{generations} of the profile remain available, should the user
2667 For example, to remove @code{lua} and install @code{guile} and
2668 @code{guile-cairo} in a single transaction:
2671 guix package -r lua -i guile guile-cairo
2674 @cindex aliases, for @command{guix package}
2675 For your convenience, we also provide the following aliases:
2679 @command{guix search} is an alias for @command{guix package -s},
2681 @command{guix install} is an alias for @command{guix package -i},
2683 @command{guix remove} is an alias for @command{guix package -r},
2685 @command{guix upgrade} is an alias for @command{guix package -u},
2687 and @command{guix show} is an alias for @command{guix package --show=}.
2690 These aliases are less expressive than @command{guix package} and provide
2691 fewer options, so in some cases you'll probably want to use @command{guix
2694 @command{guix package} also supports a @dfn{declarative approach}
2695 whereby the user specifies the exact set of packages to be available and
2696 passes it @i{via} the @option{--manifest} option
2697 (@pxref{profile-manifest, @option{--manifest}}).
2700 For each user, a symlink to the user's default profile is automatically
2701 created in @file{$HOME/.guix-profile}. This symlink always points to the
2702 current generation of the user's default profile. Thus, users can add
2703 @file{$HOME/.guix-profile/bin} to their @code{PATH} environment
2704 variable, and so on.
2705 @cindex search paths
2706 If you are not using Guix System, consider adding the
2707 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2708 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2709 shells get all the right environment variable definitions:
2712 GUIX_PROFILE="$HOME/.guix-profile" ; \
2713 source "$HOME/.guix-profile/etc/profile"
2716 In a multi-user setup, user profiles are stored in a place registered as
2717 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2718 to (@pxref{Invoking guix gc}). That directory is normally
2719 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2720 @var{localstatedir} is the value passed to @code{configure} as
2721 @code{--localstatedir}, and @var{user} is the user name. The
2722 @file{per-user} directory is created when @command{guix-daemon} is
2723 started, and the @var{user} sub-directory is created by @command{guix
2726 The @var{options} can be among the following:
2730 @item --install=@var{package} @dots{}
2731 @itemx -i @var{package} @dots{}
2732 Install the specified @var{package}s.
2734 Each @var{package} may specify either a simple package name, such as
2735 @code{guile}, or a package name followed by an at-sign and version number,
2736 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2737 case, the newest version prefixed by @code{1.8} is selected.)
2739 If no version number is specified, the
2740 newest available version will be selected. In addition, @var{package}
2741 may contain a colon, followed by the name of one of the outputs of the
2742 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
2743 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
2744 name (and optionally version) are searched for among the GNU
2745 distribution modules (@pxref{Package Modules}).
2747 @cindex propagated inputs
2748 Sometimes packages have @dfn{propagated inputs}: these are dependencies
2749 that automatically get installed along with the required package
2750 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
2751 @code{package} objects}, for information about propagated inputs in
2752 package definitions).
2754 @anchor{package-cmd-propagated-inputs}
2755 An example is the GNU MPC library: its C header files refer to those of
2756 the GNU MPFR library, which in turn refer to those of the GMP library.
2757 Thus, when installing MPC, the MPFR and GMP libraries also get installed
2758 in the profile; removing MPC also removes MPFR and GMP---unless they had
2759 also been explicitly installed by the user.
2761 Besides, packages sometimes rely on the definition of environment
2762 variables for their search paths (see explanation of
2763 @code{--search-paths} below). Any missing or possibly incorrect
2764 environment variable definitions are reported here.
2766 @item --install-from-expression=@var{exp}
2768 Install the package @var{exp} evaluates to.
2770 @var{exp} must be a Scheme expression that evaluates to a
2771 @code{<package>} object. This option is notably useful to disambiguate
2772 between same-named variants of a package, with expressions such as
2773 @code{(@@ (gnu packages base) guile-final)}.
2775 Note that this option installs the first output of the specified
2776 package, which may be insufficient when needing a specific output of a
2777 multiple-output package.
2779 @item --install-from-file=@var{file}
2780 @itemx -f @var{file}
2781 Install the package that the code within @var{file} evaluates to.
2783 As an example, @var{file} might contain a definition like this
2784 (@pxref{Defining Packages}):
2787 @include package-hello.scm
2790 Developers may find it useful to include such a @file{guix.scm} file
2791 in the root of their project source tree that can be used to test
2792 development snapshots and create reproducible development environments
2793 (@pxref{Invoking guix environment}).
2795 @item --remove=@var{package} @dots{}
2796 @itemx -r @var{package} @dots{}
2797 Remove the specified @var{package}s.
2799 As for @code{--install}, each @var{package} may specify a version number
2800 and/or output name in addition to the package name. For instance,
2801 @code{-r glibc:debug} would remove the @code{debug} output of
2804 @item --upgrade[=@var{regexp} @dots{}]
2805 @itemx -u [@var{regexp} @dots{}]
2806 @cindex upgrading packages
2807 Upgrade all the installed packages. If one or more @var{regexp}s are
2808 specified, upgrade only installed packages whose name matches a
2809 @var{regexp}. Also see the @code{--do-not-upgrade} option below.
2811 Note that this upgrades package to the latest version of packages found
2812 in the distribution currently installed. To update your distribution,
2813 you should regularly run @command{guix pull} (@pxref{Invoking guix
2816 @item --do-not-upgrade[=@var{regexp} @dots{}]
2817 When used together with the @code{--upgrade} option, do @emph{not}
2818 upgrade any packages whose name matches a @var{regexp}. For example, to
2819 upgrade all packages in the current profile except those containing the
2820 substring ``emacs'':
2823 $ guix package --upgrade . --do-not-upgrade emacs
2826 @item @anchor{profile-manifest}--manifest=@var{file}
2827 @itemx -m @var{file}
2828 @cindex profile declaration
2829 @cindex profile manifest
2830 Create a new generation of the profile from the manifest object
2831 returned by the Scheme code in @var{file}. This option can be repeated
2832 several times, in which case the manifests are concatenated.
2834 This allows you to @emph{declare} the profile's contents rather than
2835 constructing it through a sequence of @code{--install} and similar
2836 commands. The advantage is that @var{file} can be put under version
2837 control, copied to different machines to reproduce the same profile, and
2840 @c FIXME: Add reference to (guix profile) documentation when available.
2841 @var{file} must return a @dfn{manifest} object, which is roughly a list
2844 @findex packages->manifest
2846 (use-package-modules guile emacs)
2851 ;; Use a specific package output.
2852 (list guile-2.0 "debug")))
2855 @findex specifications->manifest
2856 In this example we have to know which modules define the @code{emacs}
2857 and @code{guile-2.0} variables to provide the right
2858 @code{use-package-modules} line, which can be cumbersome. We can
2859 instead provide regular package specifications and let
2860 @code{specifications->manifest} look up the corresponding package
2864 (specifications->manifest
2865 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
2869 @cindex rolling back
2870 @cindex undoing transactions
2871 @cindex transactions, undoing
2872 Roll back to the previous @dfn{generation} of the profile---i.e., undo
2873 the last transaction.
2875 When combined with options such as @code{--install}, roll back occurs
2876 before any other actions.
2878 When rolling back from the first generation that actually contains
2879 installed packages, the profile is made to point to the @dfn{zeroth
2880 generation}, which contains no files apart from its own metadata.
2882 After having rolled back, installing, removing, or upgrading packages
2883 overwrites previous future generations. Thus, the history of the
2884 generations in a profile is always linear.
2886 @item --switch-generation=@var{pattern}
2887 @itemx -S @var{pattern}
2889 Switch to a particular generation defined by @var{pattern}.
2891 @var{pattern} may be either a generation number or a number prefixed
2892 with ``+'' or ``-''. The latter means: move forward/backward by a
2893 specified number of generations. For example, if you want to return to
2894 the latest generation after @code{--roll-back}, use
2895 @code{--switch-generation=+1}.
2897 The difference between @code{--roll-back} and
2898 @code{--switch-generation=-1} is that @code{--switch-generation} will
2899 not make a zeroth generation, so if a specified generation does not
2900 exist, the current generation will not be changed.
2902 @item --search-paths[=@var{kind}]
2903 @cindex search paths
2904 Report environment variable definitions, in Bash syntax, that may be
2905 needed in order to use the set of installed packages. These environment
2906 variables are used to specify @dfn{search paths} for files used by some
2907 of the installed packages.
2909 For example, GCC needs the @code{CPATH} and @code{LIBRARY_PATH}
2910 environment variables to be defined so it can look for headers and
2911 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
2912 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
2913 library are installed in the profile, then @code{--search-paths} will
2914 suggest setting these variables to @code{@var{profile}/include} and
2915 @code{@var{profile}/lib}, respectively.
2917 The typical use case is to define these environment variables in the
2921 $ eval `guix package --search-paths`
2924 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
2925 meaning that the returned environment variable definitions will either
2926 be exact settings, or prefixes or suffixes of the current value of these
2927 variables. When omitted, @var{kind} defaults to @code{exact}.
2929 This option can also be used to compute the @emph{combined} search paths
2930 of several profiles. Consider this example:
2933 $ guix package -p foo -i guile
2934 $ guix package -p bar -i guile-json
2935 $ guix package -p foo -p bar --search-paths
2938 The last command above reports about the @code{GUILE_LOAD_PATH}
2939 variable, even though, taken individually, neither @file{foo} nor
2940 @file{bar} would lead to that recommendation.
2943 @item --profile=@var{profile}
2944 @itemx -p @var{profile}
2945 Use @var{profile} instead of the user's default profile.
2947 @var{profile} must be the name of a file that will be created upon
2948 completion. Concretely, @var{profile} will be a mere symbolic link
2949 (``symlink'') pointing to the actual profile where packages are
2953 $ guix install hello -p ~/code/my-profile
2955 $ ~/code/my-profile/bin/hello
2959 All it takes to get rid of the profile is to remove this symlink and its
2960 siblings that point to specific generations:
2963 $ rm ~/code/my-profile ~/code/my-profile-*-link
2966 @item --list-profiles
2967 List all the user's profiles:
2970 $ guix package --list-profiles
2971 /home/charlie/.guix-profile
2972 /home/charlie/code/my-profile
2973 /home/charlie/code/devel-profile
2974 /home/charlie/tmp/test
2977 When running as root, list all the profiles of all the users.
2979 @cindex collisions, in a profile
2980 @cindex colliding packages in profiles
2981 @cindex profile collisions
2982 @item --allow-collisions
2983 Allow colliding packages in the new profile. Use at your own risk!
2985 By default, @command{guix package} reports as an error @dfn{collisions}
2986 in the profile. Collisions happen when two or more different versions
2987 or variants of a given package end up in the profile.
2990 Use the bootstrap Guile to build the profile. This option is only
2991 useful to distribution developers.
2995 In addition to these actions, @command{guix package} supports the
2996 following options to query the current state of a profile, or the
2997 availability of packages:
3001 @item --search=@var{regexp}
3002 @itemx -s @var{regexp}
3003 @cindex searching for packages
3004 List the available packages whose name, synopsis, or description matches
3005 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3006 Print all the metadata of matching packages in
3007 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3008 GNU recutils manual}).
3010 This allows specific fields to be extracted using the @command{recsel}
3011 command, for instance:
3014 $ guix package -s malloc | recsel -p name,version,relevance
3028 Similarly, to show the name of all the packages available under the
3029 terms of the GNU@tie{}LGPL version 3:
3032 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3039 It is also possible to refine search results using several @code{-s} flags to
3040 @command{guix package}, or several arguments to @command{guix search}. For
3041 example, the following command returns a list of board games (this time using
3042 the @command{guix search} alias):
3045 $ guix search '\<board\>' game | recsel -p name
3050 If we were to omit @code{-s game}, we would also get software packages
3051 that deal with printed circuit boards; removing the angle brackets
3052 around @code{board} would further add packages that have to do with
3055 And now for a more elaborate example. The following command searches
3056 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3057 libraries, and prints the name and synopsis of the matching packages:
3060 $ guix search crypto library | \
3061 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3065 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3066 information on @dfn{selection expressions} for @code{recsel -e}.
3068 @item --show=@var{package}
3069 Show details about @var{package}, taken from the list of available packages, in
3070 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3074 $ guix package --show=python | recsel -p name,version
3082 You may also specify the full name of a package to only get details about a
3083 specific version of it (this time using the @command{guix show} alias):
3085 $ guix show python@@3.4 | recsel -p name,version
3092 @item --list-installed[=@var{regexp}]
3093 @itemx -I [@var{regexp}]
3094 List the currently installed packages in the specified profile, with the
3095 most recently installed packages shown last. When @var{regexp} is
3096 specified, list only installed packages whose name matches @var{regexp}.
3098 For each installed package, print the following items, separated by
3099 tabs: the package name, its version string, the part of the package that
3100 is installed (for instance, @code{out} for the default output,
3101 @code{include} for its headers, etc.), and the path of this package in
3104 @item --list-available[=@var{regexp}]
3105 @itemx -A [@var{regexp}]
3106 List packages currently available in the distribution for this system
3107 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3108 installed packages whose name matches @var{regexp}.
3110 For each package, print the following items separated by tabs: its name,
3111 its version string, the parts of the package (@pxref{Packages with
3112 Multiple Outputs}), and the source location of its definition.
3114 @item --list-generations[=@var{pattern}]
3115 @itemx -l [@var{pattern}]
3117 Return a list of generations along with their creation dates; for each
3118 generation, show the installed packages, with the most recently
3119 installed packages shown last. Note that the zeroth generation is never
3122 For each installed package, print the following items, separated by
3123 tabs: the name of a package, its version string, the part of the package
3124 that is installed (@pxref{Packages with Multiple Outputs}), and the
3125 location of this package in the store.
3127 When @var{pattern} is used, the command returns only matching
3128 generations. Valid patterns include:
3131 @item @emph{Integers and comma-separated integers}. Both patterns denote
3132 generation numbers. For instance, @code{--list-generations=1} returns
3135 And @code{--list-generations=1,8,2} outputs three generations in the
3136 specified order. Neither spaces nor trailing commas are allowed.
3138 @item @emph{Ranges}. @code{--list-generations=2..9} prints the
3139 specified generations and everything in between. Note that the start of
3140 a range must be smaller than its end.
3142 It is also possible to omit the endpoint. For example,
3143 @code{--list-generations=2..}, returns all generations starting from the
3146 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3147 or months by passing an integer along with the first letter of the
3148 duration. For example, @code{--list-generations=20d} lists generations
3149 that are up to 20 days old.
3152 @item --delete-generations[=@var{pattern}]
3153 @itemx -d [@var{pattern}]
3154 When @var{pattern} is omitted, delete all generations except the current
3157 This command accepts the same patterns as @option{--list-generations}.
3158 When @var{pattern} is specified, delete the matching generations. When
3159 @var{pattern} specifies a duration, generations @emph{older} than the
3160 specified duration match. For instance, @code{--delete-generations=1m}
3161 deletes generations that are more than one month old.
3163 If the current generation matches, it is @emph{not} deleted. Also, the
3164 zeroth generation is never deleted.
3166 Note that deleting generations prevents rolling back to them.
3167 Consequently, this command must be used with care.
3171 Finally, since @command{guix package} may actually start build
3172 processes, it supports all the common build options (@pxref{Common Build
3173 Options}). It also supports package transformation options, such as
3174 @option{--with-source} (@pxref{Package Transformation Options}).
3175 However, note that package transformations are lost when upgrading; to
3176 preserve transformations across upgrades, you should define your own
3177 package variant in a Guile module and add it to @code{GUIX_PACKAGE_PATH}
3178 (@pxref{Defining Packages}).
3181 @section Substitutes
3184 @cindex pre-built binaries
3185 Guix supports transparent source/binary deployment, which means that it
3186 can either build things locally, or download pre-built items from a
3187 server, or both. We call these pre-built items @dfn{substitutes}---they
3188 are substitutes for local build results. In many cases, downloading a
3189 substitute is much faster than building things locally.
3191 Substitutes can be anything resulting from a derivation build
3192 (@pxref{Derivations}). Of course, in the common case, they are
3193 pre-built package binaries, but source tarballs, for instance, which
3194 also result from derivation builds, can be available as substitutes.
3197 * Official Substitute Server:: One particular source of substitutes.
3198 * Substitute Server Authorization:: How to enable or disable substitutes.
3199 * Substitute Authentication:: How Guix verifies substitutes.
3200 * Proxy Settings:: How to get substitutes via proxy.
3201 * Substitution Failure:: What happens when substitution fails.
3202 * On Trusting Binaries:: How can you trust that binary blob?
3205 @node Official Substitute Server
3206 @subsection Official Substitute Server
3209 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3210 that builds packages from Guix continuously for some
3211 architectures, and makes them available as substitutes. This is the
3212 default source of substitutes; it can be overridden by passing the
3213 @option{--substitute-urls} option either to @command{guix-daemon}
3214 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3215 or to client tools such as @command{guix package}
3216 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3219 Substitute URLs can be either HTTP or HTTPS.
3220 HTTPS is recommended because communications are encrypted; conversely,
3221 using HTTP makes all communications visible to an eavesdropper, who
3222 could use the information gathered to determine, for instance, whether
3223 your system has unpatched security vulnerabilities.
3225 Substitutes from the official build farm are enabled by default when
3226 using Guix System (@pxref{GNU Distribution}). However,
3227 they are disabled by default when using Guix on a foreign distribution,
3228 unless you have explicitly enabled them via one of the recommended
3229 installation steps (@pxref{Installation}). The following paragraphs
3230 describe how to enable or disable substitutes for the official build
3231 farm; the same procedure can also be used to enable substitutes for any
3232 other substitute server.
3234 @node Substitute Server Authorization
3235 @subsection Substitute Server Authorization
3238 @cindex substitutes, authorization thereof
3239 @cindex access control list (ACL), for substitutes
3240 @cindex ACL (access control list), for substitutes
3241 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3243 must add its public key to the access control list (ACL) of archive
3244 imports, using the @command{guix archive} command (@pxref{Invoking guix
3245 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3246 be compromised and to serve genuine substitutes.
3248 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3249 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3250 the installation prefix of Guix. If you installed Guix from source,
3251 make sure you checked the GPG signature of
3252 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3253 Then, you can run something like this:
3256 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3259 Once this is in place, the output of a command like @code{guix build}
3260 should change from something like:
3263 $ guix build emacs --dry-run
3264 The following derivations would be built:
3265 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3266 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3267 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3268 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3276 $ guix build emacs --dry-run
3277 112.3 MB would be downloaded:
3278 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3279 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3280 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3281 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3286 This indicates that substitutes from @code{@value{SUBSTITUTE-SERVER}} are usable and
3287 will be downloaded, when possible, for future builds.
3289 @cindex substitutes, how to disable
3290 The substitute mechanism can be disabled globally by running
3291 @code{guix-daemon} with @code{--no-substitutes} (@pxref{Invoking
3292 guix-daemon}). It can also be disabled temporarily by passing the
3293 @code{--no-substitutes} option to @command{guix package}, @command{guix
3294 build}, and other command-line tools.
3296 @node Substitute Authentication
3297 @subsection Substitute Authentication
3299 @cindex digital signatures
3300 Guix detects and raises an error when attempting to use a substitute
3301 that has been tampered with. Likewise, it ignores substitutes that are
3302 not signed, or that are not signed by one of the keys listed in the ACL.
3304 There is one exception though: if an unauthorized server provides
3305 substitutes that are @emph{bit-for-bit identical} to those provided by
3306 an authorized server, then the unauthorized server becomes eligible for
3307 downloads. For example, assume we have chosen two substitute servers
3311 --substitute-urls="https://a.example.org https://b.example.org"
3315 @cindex reproducible builds
3316 If the ACL contains only the key for @code{b.example.org}, and if
3317 @code{a.example.org} happens to serve the @emph{exact same} substitutes,
3318 then Guix will download substitutes from @code{a.example.org} because it
3319 comes first in the list and can be considered a mirror of
3320 @code{b.example.org}. In practice, independent build machines usually
3321 produce the same binaries, thanks to bit-reproducible builds (see
3324 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3325 (in other words, the server is not authenticated), contrary to what
3326 HTTPS clients such as Web browsers usually do. This is because Guix
3327 authenticates substitute information itself, as explained above, which
3328 is what we care about (whereas X.509 certificates are about
3329 authenticating bindings between domain names and public keys.)
3331 @node Proxy Settings
3332 @subsection Proxy Settings
3335 Substitutes are downloaded over HTTP or HTTPS.
3336 The @code{http_proxy} environment
3337 variable can be set in the environment of @command{guix-daemon} and is
3338 honored for downloads of substitutes. Note that the value of
3339 @code{http_proxy} in the environment where @command{guix build},
3340 @command{guix package}, and other client commands are run has
3341 @emph{absolutely no effect}.
3343 @node Substitution Failure
3344 @subsection Substitution Failure
3346 Even when a substitute for a derivation is available, sometimes the
3347 substitution attempt will fail. This can happen for a variety of
3348 reasons: the substitute server might be offline, the substitute may
3349 recently have been deleted, the connection might have been interrupted,
3352 When substitutes are enabled and a substitute for a derivation is
3353 available, but the substitution attempt fails, Guix will attempt to
3354 build the derivation locally depending on whether or not
3355 @code{--fallback} was given (@pxref{fallback-option,, common build
3356 option @code{--fallback}}). Specifically, if @code{--fallback} was
3357 omitted, then no local build will be performed, and the derivation is
3358 considered to have failed. However, if @code{--fallback} was given,
3359 then Guix will attempt to build the derivation locally, and the success
3360 or failure of the derivation depends on the success or failure of the
3361 local build. Note that when substitutes are disabled or no substitute
3362 is available for the derivation in question, a local build will
3363 @emph{always} be performed, regardless of whether or not
3364 @code{--fallback} was given.
3366 To get an idea of how many substitutes are available right now, you can
3367 try running the @command{guix weather} command (@pxref{Invoking guix
3368 weather}). This command provides statistics on the substitutes provided
3371 @node On Trusting Binaries
3372 @subsection On Trusting Binaries
3374 @cindex trust, of pre-built binaries
3375 Today, each individual's control over their own computing is at the
3376 mercy of institutions, corporations, and groups with enough power and
3377 determination to subvert the computing infrastructure and exploit its
3378 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3379 convenient, we encourage users to also build on their own, or even run
3380 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3381 interesting target. One way to help is by publishing the software you
3382 build using @command{guix publish} so that others have one more choice
3383 of server to download substitutes from (@pxref{Invoking guix publish}).
3385 Guix has the foundations to maximize build reproducibility
3386 (@pxref{Features}). In most cases, independent builds of a given
3387 package or derivation should yield bit-identical results. Thus, through
3388 a diverse set of independent package builds, we can strengthen the
3389 integrity of our systems. The @command{guix challenge} command aims to
3390 help users assess substitute servers, and to assist developers in
3391 finding out about non-deterministic package builds (@pxref{Invoking guix
3392 challenge}). Similarly, the @option{--check} option of @command{guix
3393 build} allows users to check whether previously-installed substitutes
3394 are genuine by rebuilding them locally (@pxref{build-check,
3395 @command{guix build --check}}).
3397 In the future, we want Guix to have support to publish and retrieve
3398 binaries to/from other users, in a peer-to-peer fashion. If you would
3399 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3401 @node Packages with Multiple Outputs
3402 @section Packages with Multiple Outputs
3404 @cindex multiple-output packages
3405 @cindex package outputs
3408 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3409 source package leads to exactly one directory in the store. When running
3410 @command{guix install glibc}, one installs the default output of the
3411 GNU libc package; the default output is called @code{out}, but its name
3412 can be omitted as shown in this command. In this particular case, the
3413 default output of @code{glibc} contains all the C header files, shared
3414 libraries, static libraries, Info documentation, and other supporting
3417 Sometimes it is more appropriate to separate the various types of files
3418 produced from a single source package into separate outputs. For
3419 instance, the GLib C library (used by GTK+ and related packages)
3420 installs more than 20 MiB of reference documentation as HTML pages.
3421 To save space for users who do not need it, the documentation goes to a
3422 separate output, called @code{doc}. To install the main GLib output,
3423 which contains everything but the documentation, one would run:
3429 @cindex documentation
3430 The command to install its documentation is:
3433 guix install glib:doc
3436 Some packages install programs with different ``dependency footprints''.
3437 For instance, the WordNet package installs both command-line tools and
3438 graphical user interfaces (GUIs). The former depend solely on the C
3439 library, whereas the latter depend on Tcl/Tk and the underlying X
3440 libraries. In this case, we leave the command-line tools in the default
3441 output, whereas the GUIs are in a separate output. This allows users
3442 who do not need the GUIs to save space. The @command{guix size} command
3443 can help find out about such situations (@pxref{Invoking guix size}).
3444 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3446 There are several such multiple-output packages in the GNU distribution.
3447 Other conventional output names include @code{lib} for libraries and
3448 possibly header files, @code{bin} for stand-alone programs, and
3449 @code{debug} for debugging information (@pxref{Installing Debugging
3450 Files}). The outputs of a packages are listed in the third column of
3451 the output of @command{guix package --list-available} (@pxref{Invoking
3455 @node Invoking guix gc
3456 @section Invoking @command{guix gc}
3458 @cindex garbage collector
3460 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3461 The @command{guix gc} command allows users to explicitly run the garbage
3462 collector to reclaim space from the @file{/gnu/store} directory. It is
3463 the @emph{only} way to remove files from @file{/gnu/store}---removing
3464 files or directories manually may break it beyond repair!
3467 @cindex garbage collector roots
3468 The garbage collector has a set of known @dfn{roots}: any file under
3469 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3470 cannot be deleted; any other file is considered @dfn{dead} and may be
3471 deleted. The set of garbage collector roots (``GC roots'' for short)
3472 includes default user profiles; by default, the symlinks under
3473 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3474 added with @command{guix build --root}, for example (@pxref{Invoking
3475 guix build}). The @command{guix gc --list-roots} command lists them.
3477 Prior to running @code{guix gc --collect-garbage} to make space, it is
3478 often useful to remove old generations from user profiles; that way, old
3479 package builds referenced by those generations can be reclaimed. This
3480 is achieved by running @code{guix package --delete-generations}
3481 (@pxref{Invoking guix package}).
3483 Our recommendation is to run a garbage collection periodically, or when
3484 you are short on disk space. For instance, to guarantee that at least
3485 5@tie{}GB are available on your disk, simply run:
3491 It is perfectly safe to run as a non-interactive periodic job
3492 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3493 Running @command{guix gc} with no arguments will collect as
3494 much garbage as it can, but that is often inconvenient: you may find
3495 yourself having to rebuild or re-download software that is ``dead'' from
3496 the GC viewpoint but that is necessary to build other pieces of
3497 software---e.g., the compiler tool chain.
3499 The @command{guix gc} command has three modes of operation: it can be
3500 used to garbage-collect any dead files (the default), to delete specific
3501 files (the @code{--delete} option), to print garbage-collector
3502 information, or for more advanced queries. The garbage collection
3503 options are as follows:
3506 @item --collect-garbage[=@var{min}]
3507 @itemx -C [@var{min}]
3508 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3509 sub-directories. This is the default operation when no option is
3512 When @var{min} is given, stop once @var{min} bytes have been collected.
3513 @var{min} may be a number of bytes, or it may include a unit as a
3514 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3515 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3517 When @var{min} is omitted, collect all the garbage.
3519 @item --free-space=@var{free}
3520 @itemx -F @var{free}
3521 Collect garbage until @var{free} space is available under
3522 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3523 as @code{500MiB}, as described above.
3525 When @var{free} or more is already available in @file{/gnu/store}, do
3526 nothing and exit immediately.
3528 @item --delete-generations[=@var{duration}]
3529 @itemx -d [@var{duration}]
3530 Before starting the garbage collection process, delete all the generations
3531 older than @var{duration}, for all the user profiles; when run as root, this
3532 applies to all the profiles @emph{of all the users}.
3534 For example, this command deletes all the generations of all your profiles
3535 that are older than 2 months (except generations that are current), and then
3536 proceeds to free space until at least 10 GiB are available:
3539 guix gc -d 2m -F 10G
3544 Attempt to delete all the store files and directories specified as
3545 arguments. This fails if some of the files are not in the store, or if
3546 they are still live.
3548 @item --list-failures
3549 List store items corresponding to cached build failures.
3551 This prints nothing unless the daemon was started with
3552 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3553 @option{--cache-failures}}).
3556 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3560 List store items in use by currently running processes. These store
3561 items are effectively considered GC roots: they cannot be deleted.
3563 @item --clear-failures
3564 Remove the specified store items from the failed-build cache.
3566 Again, this option only makes sense when the daemon is started with
3567 @option{--cache-failures}. Otherwise, it does nothing.
3570 Show the list of dead files and directories still present in the
3571 store---i.e., files and directories no longer reachable from any root.
3574 Show the list of live store files and directories.
3578 In addition, the references among existing store files can be queried:
3584 @cindex package dependencies
3585 List the references (respectively, the referrers) of store files given
3591 List the requisites of the store files passed as arguments. Requisites
3592 include the store files themselves, their references, and the references
3593 of these, recursively. In other words, the returned list is the
3594 @dfn{transitive closure} of the store files.
3596 @xref{Invoking guix size}, for a tool to profile the size of the closure
3597 of an element. @xref{Invoking guix graph}, for a tool to visualize
3598 the graph of references.
3602 Return the derivation(s) leading to the given store items
3603 (@pxref{Derivations}).
3605 For example, this command:
3608 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3612 returns the @file{.drv} file(s) leading to the @code{emacs} package
3613 installed in your profile.
3615 Note that there may be zero matching @file{.drv} files, for instance
3616 because these files have been garbage-collected. There can also be more
3617 than one matching @file{.drv} due to fixed-output derivations.
3620 Lastly, the following options allow you to check the integrity of the
3621 store and to control disk usage.
3625 @item --verify[=@var{options}]
3626 @cindex integrity, of the store
3627 @cindex integrity checking
3628 Verify the integrity of the store.
3630 By default, make sure that all the store items marked as valid in the
3631 database of the daemon actually exist in @file{/gnu/store}.
3633 When provided, @var{options} must be a comma-separated list containing one
3634 or more of @code{contents} and @code{repair}.
3636 When passing @option{--verify=contents}, the daemon computes the
3637 content hash of each store item and compares it against its hash in the
3638 database. Hash mismatches are reported as data corruptions. Because it
3639 traverses @emph{all the files in the store}, this command can take a
3640 long time, especially on systems with a slow disk drive.
3642 @cindex repairing the store
3643 @cindex corruption, recovering from
3644 Using @option{--verify=repair} or @option{--verify=contents,repair}
3645 causes the daemon to try to repair corrupt store items by fetching
3646 substitutes for them (@pxref{Substitutes}). Because repairing is not
3647 atomic, and thus potentially dangerous, it is available only to the
3648 system administrator. A lightweight alternative, when you know exactly
3649 which items in the store are corrupt, is @command{guix build --repair}
3650 (@pxref{Invoking guix build}).
3653 @cindex deduplication
3654 Optimize the store by hard-linking identical files---this is
3655 @dfn{deduplication}.
3657 The daemon performs deduplication after each successful build or archive
3658 import, unless it was started with @code{--disable-deduplication}
3659 (@pxref{Invoking guix-daemon, @code{--disable-deduplication}}). Thus,
3660 this option is primarily useful when the daemon was running with
3661 @code{--disable-deduplication}.
3665 @node Invoking guix pull
3666 @section Invoking @command{guix pull}
3668 @cindex upgrading Guix
3669 @cindex updating Guix
3670 @cindex @command{guix pull}
3672 Packages are installed or upgraded to the latest version available in
3673 the distribution currently available on your local machine. To update
3674 that distribution, along with the Guix tools, you must run @command{guix
3675 pull}: the command downloads the latest Guix source code and package
3676 descriptions, and deploys it. Source code is downloaded from a
3677 @uref{https://git-scm.com, Git} repository, by default the official
3678 GNU@tie{}Guix repository, though this can be customized.
3680 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3681 (@pxref{Channels}) specified by one of the followings, in this order:
3685 the @option{--channels} option;
3687 the user's @file{~/.config/guix/channels.scm} file;
3689 the system-wide @file{/etc/guix/channels.scm} file;
3691 the built-in default channels specified in the @code{%default-channels}
3695 On completion, @command{guix package} will use packages and package
3696 versions from this just-retrieved copy of Guix. Not only that, but all
3697 the Guix commands and Scheme modules will also be taken from that latest
3698 version. New @command{guix} sub-commands added by the update also
3701 Any user can update their Guix copy using @command{guix pull}, and the
3702 effect is limited to the user who ran @command{guix pull}. For
3703 instance, when user @code{root} runs @command{guix pull}, this has no
3704 effect on the version of Guix that user @code{alice} sees, and vice
3707 The result of running @command{guix pull} is a @dfn{profile} available
3708 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3709 make sure to add it to the beginning of your search path so that you use
3710 the latest version, and similarly for the Info manual
3711 (@pxref{Documentation}):
3714 export PATH="$HOME/.config/guix/current/bin:$PATH"
3715 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3718 The @code{--list-generations} or @code{-l} option lists past generations
3719 produced by @command{guix pull}, along with details about their provenance:
3723 Generation 1 Jun 10 2018 00:18:18
3725 repository URL: https://git.savannah.gnu.org/git/guix.git
3726 branch: origin/master
3727 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
3729 Generation 2 Jun 11 2018 11:02:49
3731 repository URL: https://git.savannah.gnu.org/git/guix.git
3732 branch: origin/master
3733 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
3734 2 new packages: keepalived, libnfnetlink
3735 6 packages upgraded: emacs-nix-mode@@2.0.4,
3736 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
3737 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
3739 Generation 3 Jun 13 2018 23:31:07 (current)
3741 repository URL: https://git.savannah.gnu.org/git/guix.git
3742 branch: origin/master
3743 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
3744 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
3745 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
3748 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
3749 describe the current status of Guix.
3751 This @code{~/.config/guix/current} profile works exactly like the profiles
3752 created by @command{guix package} (@pxref{Invoking guix package}). That
3753 is, you can list generations, roll back to the previous
3754 generation---i.e., the previous Guix---and so on:
3757 $ guix pull --roll-back
3758 switched from generation 3 to 2
3759 $ guix pull --delete-generations=1
3760 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3763 You can also use @command{guix package} (@pxref{Invoking guix package})
3764 to manage the profile by naming it explicitly:
3766 $ guix package -p ~/.config/guix/current --roll-back
3767 switched from generation 3 to 2
3768 $ guix package -p ~/.config/guix/current --delete-generations=1
3769 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
3772 The @command{guix pull} command is usually invoked with no arguments,
3773 but it supports the following options:
3776 @item --url=@var{url}
3777 @itemx --commit=@var{commit}
3778 @itemx --branch=@var{branch}
3779 Download code for the @code{guix} channel from the specified @var{url}, at the
3780 given @var{commit} (a valid Git commit ID represented as a hexadecimal
3781 string), or @var{branch}.
3783 @cindex @file{channels.scm}, configuration file
3784 @cindex configuration file for channels
3785 These options are provided for convenience, but you can also specify your
3786 configuration in the @file{~/.config/guix/channels.scm} file or using the
3787 @option{--channels} option (see below).
3789 @item --channels=@var{file}
3790 @itemx -C @var{file}
3791 Read the list of channels from @var{file} instead of
3792 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
3793 @var{file} must contain Scheme code that
3794 evaluates to a list of channel objects. @xref{Channels}, for more
3797 @cindex channel news
3800 Display the list of packages added or upgraded since the previous
3801 generation, as well as, occasionally, news written by channel authors
3802 for their users (@pxref{Channels, Writing Channel News}).
3804 The package information is the same as displayed upon @command{guix
3805 pull} completion, but without ellipses; it is also similar to the output
3806 of @command{guix pull -l} for the last generation (see below).
3808 @item --list-generations[=@var{pattern}]
3809 @itemx -l [@var{pattern}]
3810 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
3811 is provided, the subset of generations that match @var{pattern}.
3812 The syntax of @var{pattern} is the same as with @code{guix package
3813 --list-generations} (@pxref{Invoking guix package}).
3816 @cindex rolling back
3817 @cindex undoing transactions
3818 @cindex transactions, undoing
3819 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
3820 undo the last transaction.
3822 @item --switch-generation=@var{pattern}
3823 @itemx -S @var{pattern}
3825 Switch to a particular generation defined by @var{pattern}.
3827 @var{pattern} may be either a generation number or a number prefixed
3828 with ``+'' or ``-''. The latter means: move forward/backward by a
3829 specified number of generations. For example, if you want to return to
3830 the latest generation after @code{--roll-back}, use
3831 @code{--switch-generation=+1}.
3833 @item --delete-generations[=@var{pattern}]
3834 @itemx -d [@var{pattern}]
3835 When @var{pattern} is omitted, delete all generations except the current
3838 This command accepts the same patterns as @option{--list-generations}.
3839 When @var{pattern} is specified, delete the matching generations. When
3840 @var{pattern} specifies a duration, generations @emph{older} than the
3841 specified duration match. For instance, @code{--delete-generations=1m}
3842 deletes generations that are more than one month old.
3844 If the current generation matches, it is @emph{not} deleted.
3846 Note that deleting generations prevents rolling back to them.
3847 Consequently, this command must be used with care.
3849 @xref{Invoking guix describe}, for a way to display information about the
3850 current generation only.
3852 @item --profile=@var{profile}
3853 @itemx -p @var{profile}
3854 Use @var{profile} instead of @file{~/.config/guix/current}.
3858 Show which channel commit(s) would be used and what would be built or
3859 substituted but do not actually do it.
3861 @item --system=@var{system}
3862 @itemx -s @var{system}
3863 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
3864 the system type of the build host.
3867 Produce verbose output, writing build logs to the standard error output.
3870 Use the bootstrap Guile to build the latest Guix. This option is only
3871 useful to Guix developers.
3874 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
3875 repository and branch to pull from, as well as @emph{additional} repositories
3876 containing package modules that should be deployed. @xref{Channels}, for more
3879 In addition, @command{guix pull} supports all the common build options
3880 (@pxref{Common Build Options}).
3886 @cindex @file{channels.scm}, configuration file
3887 @cindex configuration file for channels
3888 @cindex @command{guix pull}, configuration file
3889 @cindex configuration of @command{guix pull}
3890 Guix and its package collection are updated by running @command{guix pull}
3891 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
3892 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
3893 customized by defining @dfn{channels} in the
3894 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
3895 of a Git repository to be deployed, and @command{guix pull} can be instructed
3896 to pull from one or more channels. In other words, channels can be used to
3897 @emph{customize} and to @emph{extend} Guix, as we will see below.
3899 @subsection Using a Custom Guix Channel
3901 The channel called @code{guix} specifies where Guix itself---its command-line
3902 tools as well as its package collection---should be downloaded. For instance,
3903 suppose you want to update from your own copy of the Guix repository at
3904 @code{example.org}, and specifically the @code{super-hacks} branch, you can
3905 write in @code{~/.config/guix/channels.scm} this specification:
3908 ;; Tell 'guix pull' to use my own repo.
3911 (url "https://example.org/my-guix.git")
3912 (branch "super-hacks")))
3916 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
3917 branch of the repository at @code{example.org}.
3919 @subsection Specifying Additional Channels
3921 @cindex extending the package collection (channels)
3922 @cindex personal packages (channels)
3923 @cindex channels, for personal packages
3924 You can also specify @emph{additional channels} to pull from. Let's say you
3925 have a bunch of custom package variants or personal packages that you think
3926 would make little sense to contribute to the Guix project, but would like to
3927 have these packages transparently available to you at the command line. You
3928 would first write modules containing those package definitions (@pxref{Package
3929 Modules}), maintain them in a Git repository, and then you and anyone else can
3930 use it as an additional channel to get packages from. Neat, no?
3932 @c What follows stems from discussions at
3933 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
3934 @c earlier discussions on guix-devel@gnu.org.
3936 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
3937 publish your personal channel to the world, we would like to share a few words
3942 Before publishing a channel, please consider contributing your package
3943 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
3944 to free software of all sorts, and packages in Guix proper are readily
3945 available to all Guix users and benefit from the project's quality assurance
3949 When you maintain package definitions outside Guix, we, Guix developers,
3950 consider that @emph{the compatibility burden is on you}. Remember that
3951 package modules and package definitions are just Scheme code that uses various
3952 programming interfaces (APIs). We want to remain free to change these APIs to
3953 keep improving Guix, possibly in ways that break your channel. We never
3954 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
3958 Corollary: if you're using an external channel and that channel breaks, please
3959 @emph{report the issue to the channel authors}, not to the Guix project.
3962 You've been warned! Having said this, we believe external channels are a
3963 practical way to exert your freedom to augment Guix' package collection and to
3964 share your improvements, which are basic tenets of
3965 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
3966 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
3969 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
3970 @command{guix pull} to pull from it @emph{in addition} to the default Guix
3973 @vindex %default-channels
3975 ;; Add my personal packages to those Guix provides.
3977 (name 'my-personal-packages)
3978 (url "https://example.org/personal-packages.git"))
3983 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
3984 add a channel the list of channels that the variable @code{%default-channels}
3985 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
3986 Manual}). With this file in place, @command{guix pull} builds not only Guix
3987 but also the package modules from your own repository. The result in
3988 @file{~/.config/guix/current} is the union of Guix with your own package
3992 $ guix pull --list-generations
3994 Generation 19 Aug 27 2018 16:20:48
3996 repository URL: https://git.savannah.gnu.org/git/guix.git
3998 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
3999 my-personal-packages dd3df5e
4000 repository URL: https://example.org/personal-packages.git
4002 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4003 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4004 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4008 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4009 both Guix and packages from the @code{my-personal-packages} channel. Among
4010 the new and upgraded packages that are listed, some like @code{my-gimp} and
4011 @code{my-emacs-with-cool-features} might come from
4012 @code{my-personal-packages}, while others come from the Guix default channel.
4014 To create a channel, create a Git repository containing your own package
4015 modules and make it available. The repository can contain anything, but a
4016 useful channel will contain Guile modules that export packages. Once you
4017 start using a channel, Guix will behave as if the root directory of that
4018 channel's Git repository has been added to the Guile load path (@pxref{Load
4019 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4020 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4021 module, then the module will be available under the name @code{(my-packages
4022 my-tools)}, and you will be able to use it like any other module
4023 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4025 @cindex dependencies, channels
4026 @cindex meta-data, channels
4027 @subsection Declaring Channel Dependencies
4029 Channel authors may decide to augment a package collection provided by other
4030 channels. They can declare their channel to be dependent on other channels in
4031 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4032 the channel repository.
4034 The meta-data file should contain a simple S-expression like this:
4041 (name some-collection)
4042 (url "https://example.org/first-collection.git"))
4044 (name some-other-collection)
4045 (url "https://example.org/second-collection.git")
4046 (branch "testing"))))
4049 In the above example this channel is declared to depend on two other channels,
4050 which will both be fetched automatically. The modules provided by the channel
4051 will be compiled in an environment where the modules of all these declared
4052 channels are available.
4054 For the sake of reliability and maintainability, you should avoid dependencies
4055 on channels that you don't control, and you should aim to keep the number of
4056 dependencies to a minimum.
4058 @cindex subdirectory, channels
4059 @subsection Package Modules in a Sub-directory
4061 As a channel author, you may want to keep your channel modules in a
4062 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4063 add a meta-data file @file{.guix-channel} that contains:
4071 @cindex news, for channels
4072 @subsection Writing Channel News
4074 Channel authors may occasionally want to communicate to their users
4075 information about important changes in the channel. You'd send them all
4076 an email, but that's not convenient.
4078 Instead, channels can provide a @dfn{news file}; when the channel users
4079 run @command{guix pull}, that news file is automatically read and
4080 @command{guix pull --news} can display the announcements that correspond
4081 to the new commits that have been pulled, if any.
4083 To do that, channel authors must first declare the name of the news file
4084 in their @file{.guix-channel} file:
4089 (news-file "etc/news.txt"))
4092 The news file itself, @file{etc/news.txt} in this example, must look
4093 something like this:
4098 (entry (tag "the-bug-fix")
4099 (title (en "Fixed terrible bug")
4101 (body (en "@@emph@{Good news@}! It's fixed!")
4102 (eo "Certe ĝi pli bone funkcias nun!")))
4103 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4104 (title (en "Added a great package")
4105 (ca "Què vol dir guix?"))
4106 (body (en "Don't miss the @@code@{hello@} package!"))))
4109 The file consists of a list of @dfn{news entries}. Each entry is
4110 associated with a commit or tag: it describes changes made in this
4111 commit, possibly in preceding commits as well. Users see entries only
4112 the first time they obtain the commit the entry refers to.
4114 The @code{title} field should be a one-line summary while @code{body}
4115 can be arbitrarily long, and both can contain Texinfo markup
4116 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4117 a list of language tag/message tuples, which allows @command{guix pull}
4118 to display news in the language that corresponds to the user's locale.
4120 If you want to translate news using a gettext-based workflow, you can
4121 extract translatable strings with @command{xgettext} (@pxref{xgettext
4122 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4123 you write news entries in English first, the command below creates a PO
4124 file containing the strings to translate:
4127 xgettext -o news.po -l scheme -ken etc/news.scm
4130 To sum up, yes, you could use your channel as a blog. But beware, this
4131 is @emph{not quite} what your users might expect.
4133 @subsection Replicating Guix
4135 @cindex pinning, channels
4136 @cindex replicating Guix
4137 @cindex reproducibility, of Guix
4138 The @command{guix pull --list-generations} output above shows precisely which
4139 commits were used to build this instance of Guix. We can thus replicate it,
4140 say, on another machine, by providing a channel specification in
4141 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4144 ;; Deploy specific commits of my channels of interest.
4147 (url "https://git.savannah.gnu.org/git/guix.git")
4148 (commit "d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300"))
4150 (name 'my-personal-packages)
4151 (url "https://example.org/personal-packages.git")
4152 (branch "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4155 The @command{guix describe --format=channels} command can even generate this
4156 list of channels directly (@pxref{Invoking guix describe}). The resulting
4157 file can be used with the -C options of @command{guix pull}
4158 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4159 (@pxref{Invoking guix time-machine}).
4161 At this point the two machines run the @emph{exact same Guix}, with access to
4162 the @emph{exact same packages}. The output of @command{guix build gimp} on
4163 one machine will be exactly the same, bit for bit, as the output of the same
4164 command on the other machine. It also means both machines have access to all
4165 the source code of Guix and, transitively, to all the source code of every
4168 This gives you super powers, allowing you to track the provenance of binary
4169 artifacts with very fine grain, and to reproduce software environments at
4170 will---some sort of ``meta reproducibility'' capabilities, if you will.
4171 @xref{Inferiors}, for another way to take advantage of these super powers.
4173 @node Invoking guix time-machine
4174 @section Invoking @command{guix time-machine}
4176 @cindex @command{guix time-machine}
4177 @cindex pinning, channels
4178 @cindex replicating Guix
4179 @cindex reproducibility, of Guix
4181 The @command{guix time-machine} command provides access to other
4182 revisions of Guix, for example to install older versions of packages,
4183 or to reproduce a computation in an identical environment. The revision
4184 of Guix to be used is defined by a commit or by a channel
4185 description file created by @command{guix describe}
4186 (@pxref{Invoking guix describe}).
4188 The general syntax is:
4191 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4194 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4195 @command{guix} command if the specified revision. The @var{options} that define
4196 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4199 @item --url=@var{url}
4200 @itemx --commit=@var{commit}
4201 @itemx --branch=@var{branch}
4202 Use the @code{guix} channel from the specified @var{url}, at the
4203 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4204 string), or @var{branch}.
4206 @item --channels=@var{file}
4207 @itemx -C @var{file}
4208 Read the list of channels from @var{file}. @var{file} must contain
4209 Scheme code that evaluates to a list of channel objects.
4210 @xref{Channels} for more information.
4213 As for @command{guix pull}, the absence of any options means that the
4214 the latest commit on the master branch will be used. The command
4217 guix time-machine -- build hello
4220 will thus build the package @code{hello} as defined in the master branch,
4221 which is in general a newer revison of Guix than you have installed.
4222 Time travel works in both directions!
4224 Note that @command{guix time-machine} can trigger builds of channels and
4225 their dependencies, and these are controlled by the standard build
4226 options (@pxref{Common Build Options}).
4231 @c TODO: Remove this once we're more confident about API stability.
4233 The functionality described here is a ``technology preview'' as of version
4234 @value{VERSION}. As such, the interface is subject to change.
4238 @cindex composition of Guix revisions
4239 Sometimes you might need to mix packages from the revision of Guix you're
4240 currently running with packages available in a different revision of Guix.
4241 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4242 revisions in arbitrary ways.
4244 @cindex inferior packages
4245 Technically, an ``inferior'' is essentially a separate Guix process connected
4246 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4247 @code{(guix inferior)} module allows you to create inferiors and to
4248 communicate with them. It also provides a high-level interface to browse and
4249 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4251 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4252 to interact with a separate revision of Guix. For example, let's assume you
4253 want to install in your profile the current @code{guile} package, along with
4254 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4255 because the newer @code{guile-json} has an incompatible API and you want to
4256 run your code against the old API@. To do that, you could write a manifest for
4257 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4258 manifest, you would create an inferior for that old Guix revision you care
4259 about, and you would look up the @code{guile-json} package in the inferior:
4262 (use-modules (guix inferior) (guix channels)
4263 (srfi srfi-1)) ;for 'first'
4266 ;; This is the old revision from which we want to
4267 ;; extract guile-json.
4270 (url "https://git.savannah.gnu.org/git/guix.git")
4272 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4275 ;; An inferior representing the above revision.
4276 (inferior-for-channels channels))
4278 ;; Now create a manifest with the current "guile" package
4279 ;; and the old "guile-json" package.
4281 (list (first (lookup-inferior-packages inferior "guile-json"))
4282 (specification->package "guile")))
4285 On its first run, @command{guix package --manifest} might have to build the
4286 channel you specified before it can create the inferior; subsequent runs will
4287 be much faster because the Guix revision will be cached.
4289 The @code{(guix inferior)} module provides the following procedures to open an
4292 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4293 [#:cache-directory] [#:ttl]
4294 Return an inferior for @var{channels}, a list of channels. Use the cache at
4295 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4296 This procedure opens a new connection to the build daemon.
4298 As a side effect, this procedure may build or substitute binaries for
4299 @var{channels}, which can take time.
4302 @deffn {Scheme Procedure} open-inferior @var{directory} @
4303 [#:command "bin/guix"]
4304 Open the inferior Guix in @var{directory}, running
4305 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4306 the inferior could not be launched.
4309 @cindex inferior packages
4310 The procedures listed below allow you to obtain and manipulate inferior
4313 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4314 Return the list of packages known to @var{inferior}.
4317 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4319 Return the sorted list of inferior packages matching @var{name} in
4320 @var{inferior}, with highest version numbers first. If @var{version} is true,
4321 return only packages with a version number prefixed by @var{version}.
4324 @deffn {Scheme Procedure} inferior-package? @var{obj}
4325 Return true if @var{obj} is an inferior package.
4328 @deffn {Scheme Procedure} inferior-package-name @var{package}
4329 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4330 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4331 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4332 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4333 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4334 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4335 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4336 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4337 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4338 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4339 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4340 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4341 These procedures are the counterpart of package record accessors
4342 (@pxref{package Reference}). Most of them work by querying the inferior
4343 @var{package} comes from, so the inferior must still be live when you call
4347 Inferior packages can be used transparently like any other package or
4348 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4349 transparently handled by the @code{packages->manifest} procedure, which is
4350 commonly use in manifests (@pxref{Invoking guix package, the
4351 @option{--manifest} option of @command{guix package}}). Thus you can insert
4352 an inferior package pretty much anywhere you would insert a regular package:
4353 in manifests, in the @code{packages} field of your @code{operating-system}
4354 declaration, and so on.
4356 @node Invoking guix describe
4357 @section Invoking @command{guix describe}
4359 @cindex reproducibility
4360 @cindex replicating Guix
4361 Often you may want to answer questions like: ``Which revision of Guix am I
4362 using?'' or ``Which channels am I using?'' This is useful information in many
4363 situations: if you want to @emph{replicate} an environment on a different
4364 machine or user account, if you want to report a bug or to determine what
4365 change in the channels you are using caused it, or if you want to record your
4366 system state for reproducibility purposes. The @command{guix describe}
4367 command answers these questions.
4369 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4370 displays the channel(s) that it was built from, including their repository URL
4371 and commit IDs (@pxref{Channels}):
4375 Generation 10 Sep 03 2018 17:32:44 (current)
4377 repository URL: https://git.savannah.gnu.org/git/guix.git
4379 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4382 If you're familiar with the Git version control system, this is similar in
4383 spirit to @command{git describe}; the output is also similar to that of
4384 @command{guix pull --list-generations}, but limited to the current generation
4385 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4386 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4387 information is all it takes to describe the revision of Guix you're using, and
4388 also to replicate it.
4390 To make it easier to replicate Guix, @command{guix describe} can also be asked
4391 to return a list of channels instead of the human-readable description above:
4394 $ guix describe -f channels
4397 (url "https://git.savannah.gnu.org/git/guix.git")
4399 "e0fa68c7718fffd33d81af415279d6ddb518f727")))
4403 You can save this to a file and feed it to @command{guix pull -C} on some
4404 other machine or at a later point in time, which will instantiate @emph{this
4405 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4406 From there on, since you're able to deploy the same revision of Guix, you can
4407 just as well @emph{replicate a complete software environment}. We humbly
4408 think that this is @emph{awesome}, and we hope you'll like it too!
4410 The details of the options supported by @command{guix describe} are as
4414 @item --format=@var{format}
4415 @itemx -f @var{format}
4416 Produce output in the specified @var{format}, one of:
4420 produce human-readable output;
4422 produce a list of channel specifications that can be passed to @command{guix
4423 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4427 produce a list of channel specifications in JSON format;
4429 produce a list of channel specifications in Recutils format.
4432 @item --profile=@var{profile}
4433 @itemx -p @var{profile}
4434 Display information about @var{profile}.
4437 @node Invoking guix archive
4438 @section Invoking @command{guix archive}
4440 @cindex @command{guix archive}
4442 The @command{guix archive} command allows users to @dfn{export} files
4443 from the store into a single archive, and to later @dfn{import} them on
4444 a machine that runs Guix.
4445 In particular, it allows store files to be transferred from one machine
4446 to the store on another machine.
4449 If you're looking for a way to produce archives in a format suitable for
4450 tools other than Guix, @pxref{Invoking guix pack}.
4453 @cindex exporting store items
4454 To export store files as an archive to standard output, run:
4457 guix archive --export @var{options} @var{specifications}...
4460 @var{specifications} may be either store file names or package
4461 specifications, as for @command{guix package} (@pxref{Invoking guix
4462 package}). For instance, the following command creates an archive
4463 containing the @code{gui} output of the @code{git} package and the main
4464 output of @code{emacs}:
4467 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4470 If the specified packages are not built yet, @command{guix archive}
4471 automatically builds them. The build process may be controlled with the
4472 common build options (@pxref{Common Build Options}).
4474 To transfer the @code{emacs} package to a machine connected over SSH,
4478 guix archive --export -r emacs | ssh the-machine guix archive --import
4482 Similarly, a complete user profile may be transferred from one machine
4483 to another like this:
4486 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4487 ssh the-machine guix archive --import
4491 However, note that, in both examples, all of @code{emacs} and the
4492 profile as well as all of their dependencies are transferred (due to
4493 @code{-r}), regardless of what is already available in the store on the
4494 target machine. The @code{--missing} option can help figure out which
4495 items are missing from the target store. The @command{guix copy}
4496 command simplifies and optimizes this whole process, so this is probably
4497 what you should use in this case (@pxref{Invoking guix copy}).
4499 @cindex nar, archive format
4500 @cindex normalized archive (nar)
4501 Archives are stored in the ``normalized archive'' or ``nar'' format, which is
4502 comparable in spirit to `tar', but with differences
4503 that make it more appropriate for our purposes. First, rather than
4504 recording all Unix metadata for each file, the nar format only mentions
4505 the file type (regular, directory, or symbolic link); Unix permissions
4506 and owner/group are dismissed. Second, the order in which directory
4507 entries are stored always follows the order of file names according to
4508 the C locale collation order. This makes archive production fully
4511 When exporting, the daemon digitally signs the contents of the archive,
4512 and that digital signature is appended. When importing, the daemon
4513 verifies the signature and rejects the import in case of an invalid
4514 signature or if the signing key is not authorized.
4515 @c FIXME: Add xref to daemon doc about signatures.
4517 The main options are:
4521 Export the specified store files or packages (see below.) Write the
4522 resulting archive to the standard output.
4524 Dependencies are @emph{not} included in the output, unless
4525 @code{--recursive} is passed.
4529 When combined with @code{--export}, this instructs @command{guix
4530 archive} to include dependencies of the given items in the archive.
4531 Thus, the resulting archive is self-contained: it contains the closure
4532 of the exported store items.
4535 Read an archive from the standard input, and import the files listed
4536 therein into the store. Abort if the archive has an invalid digital
4537 signature, or if it is signed by a public key not among the authorized
4538 keys (see @code{--authorize} below.)
4541 Read a list of store file names from the standard input, one per line,
4542 and write on the standard output the subset of these files missing from
4545 @item --generate-key[=@var{parameters}]
4546 @cindex signing, archives
4547 Generate a new key pair for the daemon. This is a prerequisite before
4548 archives can be exported with @code{--export}. Note that this operation
4549 usually takes time, because it needs to gather enough entropy to
4550 generate the key pair.
4552 The generated key pair is typically stored under @file{/etc/guix}, in
4553 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4554 key, which must be kept secret.) When @var{parameters} is omitted,
4555 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4556 versions before 1.6.0, it is a 4096-bit RSA key.
4557 Alternatively, @var{parameters} can specify
4558 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4559 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4560 Libgcrypt Reference Manual}).
4563 @cindex authorizing, archives
4564 Authorize imports signed by the public key passed on standard input.
4565 The public key must be in ``s-expression advanced format''---i.e., the
4566 same format as the @file{signing-key.pub} file.
4568 The list of authorized keys is kept in the human-editable file
4569 @file{/etc/guix/acl}. The file contains
4570 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4571 s-expressions''} and is structured as an access-control list in the
4572 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4575 @item --extract=@var{directory}
4576 @itemx -x @var{directory}
4577 Read a single-item archive as served by substitute servers
4578 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4579 low-level operation needed in only very narrow use cases; see below.
4581 For example, the following command extracts the substitute for Emacs
4582 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4586 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-emacs-24.5 \
4587 | bunzip2 | guix archive -x /tmp/emacs
4590 Single-item archives are different from multiple-item archives produced
4591 by @command{guix archive --export}; they contain a single store item,
4592 and they do @emph{not} embed a signature. Thus this operation does
4593 @emph{no} signature verification and its output should be considered
4596 The primary purpose of this operation is to facilitate inspection of
4597 archive contents coming from possibly untrusted substitute servers.
4602 @c *********************************************************************
4604 @chapter Development
4606 @cindex software development
4607 If you are a software developer, Guix provides tools that you should find
4608 helpful---independently of the language you're developing in. This is what
4609 this chapter is about.
4611 The @command{guix environment} command provides a convenient way to set up
4612 @dfn{development environments} containing all the dependencies and tools
4613 necessary to work on the software package of your choice. The @command{guix
4614 pack} command allows you to create @dfn{application bundles} that can be
4615 easily distributed to users who do not run Guix.
4618 * Invoking guix environment:: Setting up development environments.
4619 * Invoking guix pack:: Creating software bundles.
4622 @node Invoking guix environment
4623 @section Invoking @command{guix environment}
4625 @cindex reproducible build environments
4626 @cindex development environments
4627 @cindex @command{guix environment}
4628 @cindex environment, package build environment
4629 The purpose of @command{guix environment} is to assist hackers in
4630 creating reproducible development environments without polluting their
4631 package profile. The @command{guix environment} tool takes one or more
4632 packages, builds all of their inputs, and creates a shell
4633 environment to use them.
4635 The general syntax is:
4638 guix environment @var{options} @var{package}@dots{}
4641 The following example spawns a new shell set up for the development of
4645 guix environment guile
4648 If the needed dependencies are not built yet, @command{guix environment}
4649 automatically builds them. The environment of the new shell is an augmented
4650 version of the environment that @command{guix environment} was run in.
4651 It contains the necessary search paths for building the given package
4652 added to the existing environment variables. To create a ``pure''
4653 environment, in which the original environment variables have been unset,
4654 use the @code{--pure} option@footnote{Users sometimes wrongfully augment
4655 environment variables such as @code{PATH} in their @file{~/.bashrc}
4656 file. As a consequence, when @code{guix environment} launches it, Bash
4657 may read @file{~/.bashrc}, thereby introducing ``impurities'' in these
4658 environment variables. It is an error to define such environment
4659 variables in @file{.bashrc}; instead, they should be defined in
4660 @file{.bash_profile}, which is sourced only by log-in shells.
4661 @xref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}, for
4662 details on Bash start-up files.}.
4664 @vindex GUIX_ENVIRONMENT
4665 @command{guix environment} defines the @code{GUIX_ENVIRONMENT}
4666 variable in the shell it spawns; its value is the file name of the
4667 profile of this environment. This allows users to, say, define a
4668 specific prompt for development environments in their @file{.bashrc}
4669 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
4672 if [ -n "$GUIX_ENVIRONMENT" ]
4674 export PS1="\u@@\h \w [dev]\$ "
4679 ...@: or to browse the profile:
4682 $ ls "$GUIX_ENVIRONMENT/bin"
4685 Additionally, more than one package may be specified, in which case the
4686 union of the inputs for the given packages are used. For example, the
4687 command below spawns a shell where all of the dependencies of both Guile
4688 and Emacs are available:
4691 guix environment guile emacs
4694 Sometimes an interactive shell session is not desired. An arbitrary
4695 command may be invoked by placing the @code{--} token to separate the
4696 command from the rest of the arguments:
4699 guix environment guile -- make -j4
4702 In other situations, it is more convenient to specify the list of
4703 packages needed in the environment. For example, the following command
4704 runs @command{python} from an environment containing Python@tie{}2.7 and
4708 guix environment --ad-hoc python2-numpy python-2.7 -- python
4711 Furthermore, one might want the dependencies of a package and also some
4712 additional packages that are not build-time or runtime dependencies, but
4713 are useful when developing nonetheless. Because of this, the
4714 @code{--ad-hoc} flag is positional. Packages appearing before
4715 @code{--ad-hoc} are interpreted as packages whose dependencies will be
4716 added to the environment. Packages appearing after are interpreted as
4717 packages that will be added to the environment directly. For example,
4718 the following command creates a Guix development environment that
4719 additionally includes Git and strace:
4722 guix environment guix --ad-hoc git strace
4725 Sometimes it is desirable to isolate the environment as much as
4726 possible, for maximal purity and reproducibility. In particular, when
4727 using Guix on a host distro that is not Guix System, it is desirable to
4728 prevent access to @file{/usr/bin} and other system-wide resources from
4729 the development environment. For example, the following command spawns
4730 a Guile REPL in a ``container'' where only the store and the current
4731 working directory are mounted:
4734 guix environment --ad-hoc --container guile -- guile
4738 The @code{--container} option requires Linux-libre 3.19 or newer.
4741 The available options are summarized below.
4744 @item --root=@var{file}
4745 @itemx -r @var{file}
4746 @cindex persistent environment
4747 @cindex garbage collector root, for environments
4748 Make @var{file} a symlink to the profile for this environment, and
4749 register it as a garbage collector root.
4751 This is useful if you want to protect your environment from garbage
4752 collection, to make it ``persistent''.
4754 When this option is omitted, the environment is protected from garbage
4755 collection only for the duration of the @command{guix environment}
4756 session. This means that next time you recreate the same environment,
4757 you could have to rebuild or re-download packages. @xref{Invoking guix
4758 gc}, for more on GC roots.
4760 @item --expression=@var{expr}
4761 @itemx -e @var{expr}
4762 Create an environment for the package or list of packages that
4763 @var{expr} evaluates to.
4765 For example, running:
4768 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
4771 starts a shell with the environment for this specific variant of the
4777 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
4780 starts a shell with all the base system packages available.
4782 The above commands only use the default output of the given packages.
4783 To select other outputs, two element tuples can be specified:
4786 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
4789 @item --load=@var{file}
4790 @itemx -l @var{file}
4791 Create an environment for the package or list of packages that the code
4792 within @var{file} evaluates to.
4794 As an example, @var{file} might contain a definition like this
4795 (@pxref{Defining Packages}):
4798 @verbatiminclude environment-gdb.scm
4801 @item --manifest=@var{file}
4802 @itemx -m @var{file}
4803 Create an environment for the packages contained in the manifest object
4804 returned by the Scheme code in @var{file}. This option can be repeated
4805 several times, in which case the manifests are concatenated.
4807 This is similar to the same-named option in @command{guix package}
4808 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
4812 Include all specified packages in the resulting environment, as if an
4813 @i{ad hoc} package were defined with them as inputs. This option is
4814 useful for quickly creating an environment without having to write a
4815 package expression to contain the desired inputs.
4817 For instance, the command:
4820 guix environment --ad-hoc guile guile-sdl -- guile
4823 runs @command{guile} in an environment where Guile and Guile-SDL are
4826 Note that this example implicitly asks for the default output of
4827 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
4828 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
4829 of @code{glib} (@pxref{Packages with Multiple Outputs}).
4831 This option may be composed with the default behavior of @command{guix
4832 environment}. Packages appearing before @code{--ad-hoc} are interpreted
4833 as packages whose dependencies will be added to the environment, the
4834 default behavior. Packages appearing after are interpreted as packages
4835 that will be added to the environment directly.
4838 Unset existing environment variables when building the new environment, except
4839 those specified with @option{--preserve} (see below.) This has the effect of
4840 creating an environment in which search paths only contain package inputs.
4842 @item --preserve=@var{regexp}
4843 @itemx -E @var{regexp}
4844 When used alongside @option{--pure}, preserve the environment variables
4845 matching @var{regexp}---in other words, put them on a ``white list'' of
4846 environment variables that must be preserved. This option can be repeated
4850 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
4854 This example runs @command{mpirun} in a context where the only environment
4855 variables defined are @code{PATH}, environment variables whose name starts
4856 with @code{SLURM}, as well as the usual ``precious'' variables (@code{HOME},
4859 @item --search-paths
4860 Display the environment variable definitions that make up the
4863 @item --system=@var{system}
4864 @itemx -s @var{system}
4865 Attempt to build for @var{system}---e.g., @code{i686-linux}.
4870 Run @var{command} within an isolated container. The current working
4871 directory outside the container is mapped inside the container.
4872 Additionally, unless overridden with @code{--user}, a dummy home
4873 directory is created that matches the current user's home directory, and
4874 @file{/etc/passwd} is configured accordingly.
4876 The spawned process runs as the current user outside the container. Inside
4877 the container, it has the same UID and GID as the current user, unless
4878 @option{--user} is passed (see below.)
4882 For containers, share the network namespace with the host system.
4883 Containers created without this flag only have access to the loopback
4886 @item --link-profile
4888 For containers, link the environment profile to
4889 @file{~/.guix-profile} within the container. This is equivalent to
4890 running the command @command{ln -s $GUIX_ENVIRONMENT ~/.guix-profile}
4891 within the container. Linking will fail and abort the environment if
4892 the directory already exists, which will certainly be the case if
4893 @command{guix environment} was invoked in the user's home directory.
4895 Certain packages are configured to look in
4896 @code{~/.guix-profile} for configuration files and data;@footnote{For
4897 example, the @code{fontconfig} package inspects
4898 @file{~/.guix-profile/share/fonts} for additional fonts.}
4899 @code{--link-profile} allows these programs to behave as expected within
4902 @item --user=@var{user}
4903 @itemx -u @var{user}
4904 For containers, use the username @var{user} in place of the current
4905 user. The generated @file{/etc/passwd} entry within the container will
4906 contain the name @var{user}, the home directory will be
4907 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
4908 the UID and GID inside the container are 1000. @var{user}
4909 need not exist on the system.
4911 Additionally, any shared or exposed path (see @code{--share} and
4912 @code{--expose} respectively) whose target is within the current user's
4913 home directory will be remapped relative to @file{/home/USER}; this
4914 includes the automatic mapping of the current working directory.
4917 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
4919 guix environment --container --user=foo \
4920 --expose=$HOME/test \
4921 --expose=/tmp/target=$HOME/target
4924 While this will limit the leaking of user identity through home paths
4925 and each of the user fields, this is only one useful component of a
4926 broader privacy/anonymity solution---not one in and of itself.
4929 For containers, the default behavior is to share the current working
4930 directory with the isolated container and immediately change to that
4931 directory within the container. If this is undesirable, @code{--no-cwd}
4932 will cause the current working directory to @emph{not} be automatically
4933 shared and will change to the user's home directory within the container
4934 instead. See also @code{--user}.
4936 @item --expose=@var{source}[=@var{target}]
4937 For containers, expose the file system @var{source} from the host system
4938 as the read-only file system @var{target} within the container. If
4939 @var{target} is not specified, @var{source} is used as the target mount
4940 point in the container.
4942 The example below spawns a Guile REPL in a container in which the user's
4943 home directory is accessible read-only via the @file{/exchange}
4947 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
4950 @item --share=@var{source}[=@var{target}]
4951 For containers, share the file system @var{source} from the host system
4952 as the writable file system @var{target} within the container. If
4953 @var{target} is not specified, @var{source} is used as the target mount
4954 point in the container.
4956 The example below spawns a Guile REPL in a container in which the user's
4957 home directory is accessible for both reading and writing via the
4958 @file{/exchange} directory:
4961 guix environment --container --share=$HOME=/exchange --ad-hoc guile -- guile
4965 @command{guix environment}
4966 also supports all of the common build options that @command{guix
4967 build} supports (@pxref{Common Build Options}) as well as package
4968 transformation options (@pxref{Package Transformation Options}).
4970 @node Invoking guix pack
4971 @section Invoking @command{guix pack}
4973 Occasionally you want to pass software to people who are not (yet!)
4974 lucky enough to be using Guix. You'd tell them to run @command{guix
4975 package -i @var{something}}, but that's not possible in this case. This
4976 is where @command{guix pack} comes in.
4979 If you are looking for ways to exchange binaries among machines that
4980 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
4981 publish}, and @ref{Invoking guix archive}.
4986 @cindex application bundle
4987 @cindex software bundle
4988 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
4989 @dfn{software bundle}: it creates a tarball or some other archive
4990 containing the binaries of the software you're interested in, and all
4991 its dependencies. The resulting archive can be used on any machine that
4992 does not have Guix, and people can run the exact same binaries as those
4993 you have with Guix. The pack itself is created in a bit-reproducible
4994 fashion, so anyone can verify that it really contains the build results
4995 that you pretend to be shipping.
4997 For example, to create a bundle containing Guile, Emacs, Geiser, and all
4998 their dependencies, you can run:
5001 $ guix pack guile emacs geiser
5003 /gnu/store/@dots{}-pack.tar.gz
5006 The result here is a tarball containing a @file{/gnu/store} directory
5007 with all the relevant packages. The resulting tarball contains a
5008 @dfn{profile} with the three packages of interest; the profile is the
5009 same as would be created by @command{guix package -i}. It is this
5010 mechanism that is used to create Guix's own standalone binary tarball
5011 (@pxref{Binary Installation}).
5013 Users of this pack would have to run
5014 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5015 find inconvenient. To work around it, you can create, say, a
5016 @file{/opt/gnu/bin} symlink to the profile:
5019 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5023 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5025 @cindex relocatable binaries, with @command{guix pack}
5026 What if the recipient of your pack does not have root privileges on
5027 their machine, and thus cannot unpack it in the root file system? In
5028 that case, you will want to use the @code{--relocatable} option (see
5029 below). This option produces @dfn{relocatable binaries}, meaning they
5030 they can be placed anywhere in the file system hierarchy: in the example
5031 above, users can unpack your tarball in their home directory and
5032 directly run @file{./opt/gnu/bin/guile}.
5034 @cindex Docker, build an image with guix pack
5035 Alternatively, you can produce a pack in the Docker image format using
5036 the following command:
5039 guix pack -f docker guile emacs geiser
5043 The result is a tarball that can be passed to the @command{docker load}
5045 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5046 documentation} for more information.
5048 @cindex Singularity, build an image with guix pack
5049 @cindex SquashFS, build an image with guix pack
5050 Yet another option is to produce a SquashFS image with the following
5054 guix pack -f squashfs guile emacs geiser
5058 The result is a SquashFS file system image that can either be mounted or
5059 directly be used as a file system container image with the
5060 @uref{https://singularity.lbl.gov, Singularity container execution
5061 environment}, using commands like @command{singularity shell} or
5062 @command{singularity exec}.
5064 Several command-line options allow you to customize your pack:
5067 @item --format=@var{format}
5068 @itemx -f @var{format}
5069 Produce a pack in the given @var{format}.
5071 The available formats are:
5075 This is the default format. It produces a tarball containing all the
5076 specified binaries and symlinks.
5079 This produces a tarball that follows the
5080 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5081 Docker Image Specification}. The ``repository name'' as it appears in
5082 the output of the @command{docker images} command is computed from
5083 package names passed on the command line or in the manifest file.
5086 This produces a SquashFS image containing all the specified binaries and
5087 symlinks, as well as empty mount points for virtual file systems like
5091 @cindex relocatable binaries
5094 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5095 anywhere in the file system hierarchy and run from there.
5097 When this option is passed once, the resulting binaries require support for
5098 @dfn{user namespaces} in the kernel Linux; when passed
5099 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5100 PRoot support, can be thought of as the abbreviation of ``Really
5101 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to PRoot
5102 if user namespaces are unavailable, and essentially work anywhere---see below
5103 for the implications.
5105 For example, if you create a pack containing Bash with:
5108 guix pack -RR -S /mybin=bin bash
5112 ...@: you can copy that pack to a machine that lacks Guix, and from your
5113 home directory as a normal user, run:
5121 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5122 @file{/gnu/store} shows up and contains all the dependencies of
5123 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5124 altogether! That is probably the simplest way to deploy Guix-built
5125 software on a non-Guix machine.
5128 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5129 the kernel Linux, which allows unprivileged users to mount or change root.
5130 Old versions of Linux did not support it, and some GNU/Linux distributions
5133 To produce relocatable binaries that work even in the absence of user
5134 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5135 case, binaries will try user namespace support and fall back to PRoot if user
5136 namespaces are not supported.
5138 The @uref{https://proot-me.github.io/, PRoot} program provides the necessary
5139 support for file system virtualization. It achieves that by using the
5140 @code{ptrace} system call on the running program. This approach has the
5141 advantage to work without requiring special kernel support, but it incurs
5142 run-time overhead every time a system call is made.
5145 @cindex entry point, for Docker images
5146 @item --entry-point=@var{command}
5147 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5148 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5149 support it. @var{command} must be relative to the profile contained in the
5152 The entry point specifies the command that tools like @code{docker run} or
5153 @code{singularity run} automatically start by default. For example, you can
5157 guix pack -f docker --entry-point=bin/guile guile
5160 The resulting pack can easily be loaded and @code{docker run} with no extra
5161 arguments will spawn @code{bin/guile}:
5164 docker load -i pack.tar.gz
5165 docker run @var{image-id}
5168 @item --expression=@var{expr}
5169 @itemx -e @var{expr}
5170 Consider the package @var{expr} evaluates to.
5172 This has the same purpose as the same-named option in @command{guix
5173 build} (@pxref{Additional Build Options, @code{--expression} in
5174 @command{guix build}}).
5176 @item --manifest=@var{file}
5177 @itemx -m @var{file}
5178 Use the packages contained in the manifest object returned by the Scheme
5179 code in @var{file}. This option can be repeated several times, in which
5180 case the manifests are concatenated.
5182 This has a similar purpose as the same-named option in @command{guix
5183 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5184 same manifest files. It allows you to define a collection of packages
5185 once and use it both for creating profiles and for creating archives
5186 for use on machines that do not have Guix installed. Note that you can
5187 specify @emph{either} a manifest file @emph{or} a list of packages,
5190 @item --system=@var{system}
5191 @itemx -s @var{system}
5192 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5193 the system type of the build host.
5195 @item --target=@var{triplet}
5196 @cindex cross-compilation
5197 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5198 as @code{"mips64el-linux-gnu"} (@pxref{Specifying target triplets, GNU
5199 configuration triplets,, autoconf, Autoconf}).
5201 @item --compression=@var{tool}
5202 @itemx -C @var{tool}
5203 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5204 @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no compression.
5206 @item --symlink=@var{spec}
5207 @itemx -S @var{spec}
5208 Add the symlinks specified by @var{spec} to the pack. This option can
5209 appear several times.
5211 @var{spec} has the form @code{@var{source}=@var{target}}, where
5212 @var{source} is the symlink that will be created and @var{target} is the
5215 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5216 symlink pointing to the @file{bin} sub-directory of the profile.
5218 @item --save-provenance
5219 Save provenance information for the packages passed on the command line.
5220 Provenance information includes the URL and commit of the channels in use
5223 Provenance information is saved in the
5224 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5225 usual package metadata---the name and version of each package, their
5226 propagated inputs, and so on. It is useful information to the recipient of
5227 the pack, who then knows how the pack was (supposedly) obtained.
5229 This option is not enabled by default because, like timestamps, provenance
5230 information contributes nothing to the build process. In other words, there
5231 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5232 Recording such ``silent'' metadata in the output thus potentially breaks the
5233 source-to-binary bitwise reproducibility property.
5235 @item --root=@var{file}
5236 @itemx -r @var{file}
5237 @cindex garbage collector root, for packs
5238 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5241 @item --localstatedir
5242 @itemx --profile-name=@var{name}
5243 Include the ``local state directory'', @file{/var/guix}, in the resulting
5244 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5245 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5246 @file{~root/.guix-profile}.
5248 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5249 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5250 the pack means that the store is ``complete'' and manageable by Guix;
5251 not providing it pack means that the store is ``dead'': items cannot be
5252 added to it or removed from it after extraction of the pack.
5254 One use case for this is the Guix self-contained binary tarball
5255 (@pxref{Binary Installation}).
5259 Print the name of the derivation that builds the pack.
5262 Use the bootstrap binaries to build the pack. This option is only
5263 useful to Guix developers.
5266 In addition, @command{guix pack} supports all the common build options
5267 (@pxref{Common Build Options}) and all the package transformation
5268 options (@pxref{Package Transformation Options}).
5271 @c *********************************************************************
5272 @node Programming Interface
5273 @chapter Programming Interface
5275 GNU Guix provides several Scheme programming interfaces (APIs) to
5276 define, build, and query packages. The first interface allows users to
5277 write high-level package definitions. These definitions refer to
5278 familiar packaging concepts, such as the name and version of a package,
5279 its build system, and its dependencies. These definitions can then be
5280 turned into concrete build actions.
5282 Build actions are performed by the Guix daemon, on behalf of users. In a
5283 standard setup, the daemon has write access to the store---the
5284 @file{/gnu/store} directory---whereas users do not. The recommended
5285 setup also has the daemon perform builds in chroots, under a specific
5286 build users, to minimize interference with the rest of the system.
5289 Lower-level APIs are available to interact with the daemon and the
5290 store. To instruct the daemon to perform a build action, users actually
5291 provide it with a @dfn{derivation}. A derivation is a low-level
5292 representation of the build actions to be taken, and the environment in
5293 which they should occur---derivations are to package definitions what
5294 assembly is to C programs. The term ``derivation'' comes from the fact
5295 that build results @emph{derive} from them.
5297 This chapter describes all these APIs in turn, starting from high-level
5298 package definitions.
5301 * Package Modules:: Packages from the programmer's viewpoint.
5302 * Defining Packages:: Defining new packages.
5303 * Build Systems:: Specifying how packages are built.
5304 * The Store:: Manipulating the package store.
5305 * Derivations:: Low-level interface to package derivations.
5306 * The Store Monad:: Purely functional interface to the store.
5307 * G-Expressions:: Manipulating build expressions.
5308 * Invoking guix repl:: Fiddling with Guix interactively.
5311 @node Package Modules
5312 @section Package Modules
5314 From a programming viewpoint, the package definitions of the
5315 GNU distribution are provided by Guile modules in the @code{(gnu packages
5316 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5317 packages @dots{})} module name space are not necessarily ``GNU
5318 packages''. This module naming scheme follows the usual Guile module
5319 naming convention: @code{gnu} means that these modules are distributed
5320 as part of the GNU system, and @code{packages} identifies modules that
5321 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5322 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5323 module exports a variable named @code{emacs}, which is bound to a
5324 @code{<package>} object (@pxref{Defining Packages}).
5326 The @code{(gnu packages @dots{})} module name space is
5327 automatically scanned for packages by the command-line tools. For
5328 instance, when running @code{guix install emacs}, all the @code{(gnu
5329 packages @dots{})} modules are scanned until one that exports a package
5330 object whose name is @code{emacs} is found. This package search
5331 facility is implemented in the @code{(gnu packages)} module.
5333 @cindex customization, of packages
5334 @cindex package module search path
5335 Users can store package definitions in modules with different
5336 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
5337 name and module name must match. For instance, the @code{(my-packages
5338 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
5339 relative to the load path specified with @option{--load-path} or
5340 @code{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
5341 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
5342 these package definitions visible to the user interfaces:
5346 By adding the directory containing your package modules to the search path
5347 with the @code{-L} flag of @command{guix package} and other commands
5348 (@pxref{Common Build Options}), or by setting the @code{GUIX_PACKAGE_PATH}
5349 environment variable described below.
5352 By defining a @dfn{channel} and configuring @command{guix pull} so that it
5353 pulls from it. A channel is essentially a Git repository containing package
5354 modules. @xref{Channels}, for more information on how to define and use
5358 @code{GUIX_PACKAGE_PATH} works similarly to other search path variables:
5360 @defvr {Environment Variable} GUIX_PACKAGE_PATH
5361 This is a colon-separated list of directories to search for additional
5362 package modules. Directories listed in this variable take precedence
5363 over the own modules of the distribution.
5366 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
5367 each package is built based solely on other packages in the
5368 distribution. The root of this dependency graph is a small set of
5369 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
5370 bootstrap)} module. For more information on bootstrapping,
5371 @pxref{Bootstrapping}.
5373 @node Defining Packages
5374 @section Defining Packages
5376 The high-level interface to package definitions is implemented in the
5377 @code{(guix packages)} and @code{(guix build-system)} modules. As an
5378 example, the package definition, or @dfn{recipe}, for the GNU Hello
5379 package looks like this:
5382 (define-module (gnu packages hello)
5383 #:use-module (guix packages)
5384 #:use-module (guix download)
5385 #:use-module (guix build-system gnu)
5386 #:use-module (guix licenses)
5387 #:use-module (gnu packages gawk))
5389 (define-public hello
5395 (uri (string-append "mirror://gnu/hello/hello-" version
5399 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
5400 (build-system gnu-build-system)
5401 (arguments '(#:configure-flags '("--enable-silent-rules")))
5402 (inputs `(("gawk" ,gawk)))
5403 (synopsis "Hello, GNU world: An example GNU package")
5404 (description "Guess what GNU Hello prints!")
5405 (home-page "https://www.gnu.org/software/hello/")
5410 Without being a Scheme expert, the reader may have guessed the meaning
5411 of the various fields here. This expression binds the variable
5412 @code{hello} to a @code{<package>} object, which is essentially a record
5413 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
5414 This package object can be inspected using procedures found in the
5415 @code{(guix packages)} module; for instance, @code{(package-name hello)}
5416 returns---surprise!---@code{"hello"}.
5418 With luck, you may be able to import part or all of the definition of
5419 the package you are interested in from another repository, using the
5420 @code{guix import} command (@pxref{Invoking guix import}).
5422 In the example above, @var{hello} is defined in a module of its own,
5423 @code{(gnu packages hello)}. Technically, this is not strictly
5424 necessary, but it is convenient to do so: all the packages defined in
5425 modules under @code{(gnu packages @dots{})} are automatically known to
5426 the command-line tools (@pxref{Package Modules}).
5428 There are a few points worth noting in the above package definition:
5432 The @code{source} field of the package is an @code{<origin>} object
5433 (@pxref{origin Reference}, for the complete reference).
5434 Here, the @code{url-fetch} method from @code{(guix download)} is used,
5435 meaning that the source is a file to be downloaded over FTP or HTTP.
5437 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
5438 the GNU mirrors defined in @code{(guix download)}.
5440 The @code{sha256} field specifies the expected SHA256 hash of the file
5441 being downloaded. It is mandatory, and allows Guix to check the
5442 integrity of the file. The @code{(base32 @dots{})} form introduces the
5443 base32 representation of the hash. You can obtain this information with
5444 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
5445 hash} (@pxref{Invoking guix hash}).
5448 When needed, the @code{origin} form can also have a @code{patches} field
5449 listing patches to be applied, and a @code{snippet} field giving a
5450 Scheme expression to modify the source code.
5453 @cindex GNU Build System
5454 The @code{build-system} field specifies the procedure to build the
5455 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
5456 represents the familiar GNU Build System, where packages may be
5457 configured, built, and installed with the usual @code{./configure &&
5458 make && make check && make install} command sequence.
5461 The @code{arguments} field specifies options for the build system
5462 (@pxref{Build Systems}). Here it is interpreted by
5463 @var{gnu-build-system} as a request run @file{configure} with the
5464 @code{--enable-silent-rules} flag.
5470 What about these quote (@code{'}) characters? They are Scheme syntax to
5471 introduce a literal list; @code{'} is synonymous with @code{quote}.
5472 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
5473 for details. Here the value of the @code{arguments} field is a list of
5474 arguments passed to the build system down the road, as with @code{apply}
5475 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
5478 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
5479 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
5480 @code{#:configure-flags} is a keyword used to pass a keyword argument
5481 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
5485 The @code{inputs} field specifies inputs to the build process---i.e.,
5486 build-time or run-time dependencies of the package. Here, we define an
5487 input called @code{"gawk"} whose value is that of the @var{gawk}
5488 variable; @var{gawk} is itself bound to a @code{<package>} object.
5490 @cindex backquote (quasiquote)
5493 @cindex comma (unquote)
5497 @findex unquote-splicing
5498 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
5499 us to introduce a literal list in the @code{inputs} field, while
5500 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
5501 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
5504 Note that GCC, Coreutils, Bash, and other essential tools do not need to
5505 be specified as inputs here. Instead, @var{gnu-build-system} takes care
5506 of ensuring that they are present (@pxref{Build Systems}).
5508 However, any other dependencies need to be specified in the
5509 @code{inputs} field. Any dependency not specified here will simply be
5510 unavailable to the build process, possibly leading to a build failure.
5513 @xref{package Reference}, for a full description of possible fields.
5515 Once a package definition is in place, the
5516 package may actually be built using the @code{guix build} command-line
5517 tool (@pxref{Invoking guix build}), troubleshooting any build failures
5518 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
5519 package definition using the @command{guix edit} command
5520 (@pxref{Invoking guix edit}).
5521 @xref{Packaging Guidelines}, for
5522 more information on how to test package definitions, and
5523 @ref{Invoking guix lint}, for information on how to check a definition
5524 for style conformance.
5525 @vindex GUIX_PACKAGE_PATH
5526 Lastly, @pxref{Channels}, for information
5527 on how to extend the distribution by adding your own package definitions
5530 Finally, updating the package definition to a new upstream version
5531 can be partly automated by the @command{guix refresh} command
5532 (@pxref{Invoking guix refresh}).
5534 Behind the scenes, a derivation corresponding to the @code{<package>}
5535 object is first computed by the @code{package-derivation} procedure.
5536 That derivation is stored in a @code{.drv} file under @file{/gnu/store}.
5537 The build actions it prescribes may then be realized by using the
5538 @code{build-derivations} procedure (@pxref{The Store}).
5540 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
5541 Return the @code{<derivation>} object of @var{package} for @var{system}
5542 (@pxref{Derivations}).
5544 @var{package} must be a valid @code{<package>} object, and @var{system}
5545 must be a string denoting the target system type---e.g.,
5546 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
5547 must be a connection to the daemon, which operates on the store
5548 (@pxref{The Store}).
5552 @cindex cross-compilation
5553 Similarly, it is possible to compute a derivation that cross-builds a
5554 package for some other system:
5556 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
5557 @var{package} @var{target} [@var{system}]
5558 Return the @code{<derivation>} object of @var{package} cross-built from
5559 @var{system} to @var{target}.
5561 @var{target} must be a valid GNU triplet denoting the target hardware
5562 and operating system, such as @code{"mips64el-linux-gnu"}
5563 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
5566 @cindex package transformations
5567 @cindex input rewriting
5568 @cindex dependency tree rewriting
5569 Packages can be manipulated in arbitrary ways. An example of a useful
5570 transformation is @dfn{input rewriting}, whereby the dependency tree of
5571 a package is rewritten by replacing specific inputs by others:
5573 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
5574 [@var{rewrite-name}]
5575 Return a procedure that, when passed a package, replaces its direct and
5576 indirect dependencies (but not its implicit inputs) according to
5577 @var{replacements}. @var{replacements} is a list of package pairs; the
5578 first element of each pair is the package to replace, and the second one
5581 Optionally, @var{rewrite-name} is a one-argument procedure that takes
5582 the name of a package and returns its new name after rewrite.
5586 Consider this example:
5589 (define libressl-instead-of-openssl
5590 ;; This is a procedure to replace OPENSSL by LIBRESSL,
5592 (package-input-rewriting `((,openssl . ,libressl))))
5594 (define git-with-libressl
5595 (libressl-instead-of-openssl git))
5599 Here we first define a rewriting procedure that replaces @var{openssl}
5600 with @var{libressl}. Then we use it to define a @dfn{variant} of the
5601 @var{git} package that uses @var{libressl} instead of @var{openssl}.
5602 This is exactly what the @option{--with-input} command-line option does
5603 (@pxref{Package Transformation Options, @option{--with-input}}).
5605 The following variant of @code{package-input-rewriting} can match packages to
5606 be replaced by name rather than by identity.
5608 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
5609 Return a procedure that, given a package, applies the given @var{replacements} to
5610 all the package graph (excluding implicit inputs). @var{replacements} is a list of
5611 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
5612 @code{"guile@@2"}, and each procedure takes a matching package and returns a
5613 replacement for that package.
5616 The example above could be rewritten this way:
5619 (define libressl-instead-of-openssl
5620 ;; Replace all the packages called "openssl" with LibreSSL.
5621 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
5624 The key difference here is that, this time, packages are matched by spec and
5625 not by identity. In other words, any package in the graph that is called
5626 @code{openssl} will be replaced.
5628 A more generic procedure to rewrite a package dependency graph is
5629 @code{package-mapping}: it supports arbitrary changes to nodes in the
5632 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
5633 Return a procedure that, given a package, applies @var{proc} to all the packages
5634 depended on and returns the resulting package. The procedure stops recursion
5635 when @var{cut?} returns true for a given package.
5639 * package Reference:: The package data type.
5640 * origin Reference:: The origin data type.
5644 @node package Reference
5645 @subsection @code{package} Reference
5647 This section summarizes all the options available in @code{package}
5648 declarations (@pxref{Defining Packages}).
5650 @deftp {Data Type} package
5651 This is the data type representing a package recipe.
5655 The name of the package, as a string.
5657 @item @code{version}
5658 The version of the package, as a string.
5661 An object telling how the source code for the package should be
5662 acquired. Most of the time, this is an @code{origin} object, which
5663 denotes a file fetched from the Internet (@pxref{origin Reference}). It
5664 can also be any other ``file-like'' object such as a @code{local-file},
5665 which denotes a file from the local file system (@pxref{G-Expressions,
5666 @code{local-file}}).
5668 @item @code{build-system}
5669 The build system that should be used to build the package (@pxref{Build
5672 @item @code{arguments} (default: @code{'()})
5673 The arguments that should be passed to the build system. This is a
5674 list, typically containing sequential keyword-value pairs.
5676 @item @code{inputs} (default: @code{'()})
5677 @itemx @code{native-inputs} (default: @code{'()})
5678 @itemx @code{propagated-inputs} (default: @code{'()})
5679 @cindex inputs, of packages
5680 These fields list dependencies of the package. Each one is a list of
5681 tuples, where each tuple has a label for the input (a string) as its
5682 first element, a package, origin, or derivation as its second element,
5683 and optionally the name of the output thereof that should be used, which
5684 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
5685 more on package outputs). For example, the list below specifies three
5689 `(("libffi" ,libffi)
5690 ("libunistring" ,libunistring)
5691 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
5694 @cindex cross compilation, package dependencies
5695 The distinction between @code{native-inputs} and @code{inputs} is
5696 necessary when considering cross-compilation. When cross-compiling,
5697 dependencies listed in @code{inputs} are built for the @emph{target}
5698 architecture; conversely, dependencies listed in @code{native-inputs}
5699 are built for the architecture of the @emph{build} machine.
5701 @code{native-inputs} is typically used to list tools needed at
5702 build time, but not at run time, such as Autoconf, Automake, pkg-config,
5703 Gettext, or Bison. @command{guix lint} can report likely mistakes in
5704 this area (@pxref{Invoking guix lint}).
5706 @anchor{package-propagated-inputs}
5707 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
5708 specified packages will be automatically installed alongside the package
5709 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
5710 package}}, for information on how @command{guix package} deals with
5713 For example this is necessary when a C/C++ library needs headers of
5714 another library to compile, or when a pkg-config file refers to another
5715 one @i{via} its @code{Requires} field.
5717 Another example where @code{propagated-inputs} is useful is for languages
5718 that lack a facility to record the run-time search path akin to the
5719 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
5720 more. To ensure that libraries written in those languages can find
5721 library code they depend on at run time, run-time dependencies must be
5722 listed in @code{propagated-inputs} rather than @code{inputs}.
5724 @item @code{outputs} (default: @code{'("out")})
5725 The list of output names of the package. @xref{Packages with Multiple
5726 Outputs}, for typical uses of additional outputs.
5728 @item @code{native-search-paths} (default: @code{'()})
5729 @itemx @code{search-paths} (default: @code{'()})
5730 A list of @code{search-path-specification} objects describing
5731 search-path environment variables honored by the package.
5733 @item @code{replacement} (default: @code{#f})
5734 This must be either @code{#f} or a package object that will be used as a
5735 @dfn{replacement} for this package. @xref{Security Updates, grafts},
5738 @item @code{synopsis}
5739 A one-line description of the package.
5741 @item @code{description}
5742 A more elaborate description of the package.
5744 @item @code{license}
5745 @cindex license, of packages
5746 The license of the package; a value from @code{(guix licenses)},
5747 or a list of such values.
5749 @item @code{home-page}
5750 The URL to the home-page of the package, as a string.
5752 @item @code{supported-systems} (default: @var{%supported-systems})
5753 The list of systems supported by the package, as strings of the form
5754 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
5756 @item @code{location} (default: source location of the @code{package} form)
5757 The source location of the package. It is useful to override this when
5758 inheriting from another package, in which case this field is not
5759 automatically corrected.
5763 @deffn {Scheme Syntax} this-package
5764 When used in the @emph{lexical scope} of a package field definition, this
5765 identifier resolves to the package being defined.
5767 The example below shows how to add a package as a native input of itself when
5775 ;; When cross-compiled, Guile, for example, depends on
5776 ;; a native version of itself. Add it here.
5777 (native-inputs (if (%current-target-system)
5778 `(("self" ,this-package))
5782 It is an error to refer to @code{this-package} outside a package definition.
5785 @node origin Reference
5786 @subsection @code{origin} Reference
5788 This section summarizes all the options available in @code{origin}
5789 declarations (@pxref{Defining Packages}).
5791 @deftp {Data Type} origin
5792 This is the data type representing a source code origin.
5796 An object containing the URI of the source. The object type depends on
5797 the @code{method} (see below). For example, when using the
5798 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
5799 values are: a URL represented as a string, or a list thereof.
5802 A procedure that handles the URI.
5807 @item @var{url-fetch} from @code{(guix download)}
5808 download a file from the HTTP, HTTPS, or FTP URL specified in the
5812 @item @var{git-fetch} from @code{(guix git-download)}
5813 clone the Git version control repository, and check out the revision
5814 specified in the @code{uri} field as a @code{git-reference} object; a
5815 @code{git-reference} looks like this:
5819 (url "https://git.savannah.gnu.org/git/hello.git")
5825 A bytevector containing the SHA-256 hash of the source. Typically the
5826 @code{base32} form is used here to generate the bytevector from a
5829 You can obtain this information using @code{guix download}
5830 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
5833 @item @code{file-name} (default: @code{#f})
5834 The file name under which the source code should be saved. When this is
5835 @code{#f}, a sensible default value will be used in most cases. In case
5836 the source is fetched from a URL, the file name from the URL will be
5837 used. For version control checkouts, it is recommended to provide the
5838 file name explicitly because the default is not very descriptive.
5840 @item @code{patches} (default: @code{'()})
5841 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
5842 file-like objects}) pointing to patches to be applied to the source.
5844 This list of patches must be unconditional. In particular, it cannot
5845 depend on the value of @code{%current-system} or
5846 @code{%current-target-system}.
5848 @item @code{snippet} (default: @code{#f})
5849 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
5850 in the source directory. This is a convenient way to modify the source,
5851 sometimes more convenient than a patch.
5853 @item @code{patch-flags} (default: @code{'("-p1")})
5854 A list of command-line flags that should be passed to the @code{patch}
5857 @item @code{patch-inputs} (default: @code{#f})
5858 Input packages or derivations to the patching process. When this is
5859 @code{#f}, the usual set of inputs necessary for patching are provided,
5860 such as GNU@tie{}Patch.
5862 @item @code{modules} (default: @code{'()})
5863 A list of Guile modules that should be loaded during the patching
5864 process and while running the code in the @code{snippet} field.
5866 @item @code{patch-guile} (default: @code{#f})
5867 The Guile package that should be used in the patching process. When
5868 this is @code{#f}, a sensible default is used.
5874 @section Build Systems
5876 @cindex build system
5877 Each package definition specifies a @dfn{build system} and arguments for
5878 that build system (@pxref{Defining Packages}). This @code{build-system}
5879 field represents the build procedure of the package, as well as implicit
5880 dependencies of that build procedure.
5882 Build systems are @code{<build-system>} objects. The interface to
5883 create and manipulate them is provided by the @code{(guix build-system)}
5884 module, and actual build systems are exported by specific modules.
5886 @cindex bag (low-level package representation)
5887 Under the hood, build systems first compile package objects to
5888 @dfn{bags}. A @dfn{bag} is like a package, but with less
5889 ornamentation---in other words, a bag is a lower-level representation of
5890 a package, which includes all the inputs of that package, including some
5891 that were implicitly added by the build system. This intermediate
5892 representation is then compiled to a derivation (@pxref{Derivations}).
5894 Build systems accept an optional list of @dfn{arguments}. In package
5895 definitions, these are passed @i{via} the @code{arguments} field
5896 (@pxref{Defining Packages}). They are typically keyword arguments
5897 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
5898 Guile Reference Manual}). The value of these arguments is usually
5899 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
5900 by the daemon (@pxref{Derivations}).
5902 The main build system is @var{gnu-build-system}, which implements the
5903 standard build procedure for GNU and many other packages. It
5904 is provided by the @code{(guix build-system gnu)} module.
5906 @defvr {Scheme Variable} gnu-build-system
5907 @var{gnu-build-system} represents the GNU Build System, and variants
5908 thereof (@pxref{Configuration, configuration and makefile conventions,,
5909 standards, GNU Coding Standards}).
5911 @cindex build phases
5912 In a nutshell, packages using it are configured, built, and installed with
5913 the usual @code{./configure && make && make check && make install}
5914 command sequence. In practice, a few additional steps are often needed.
5915 All these steps are split up in separate @dfn{phases},
5916 notably@footnote{Please see the @code{(guix build gnu-build-system)}
5917 modules for more details about the build phases.}:
5921 Unpack the source tarball, and change the current directory to the
5922 extracted source tree. If the source is actually a directory, copy it
5923 to the build tree, and enter that directory.
5925 @item patch-source-shebangs
5926 Patch shebangs encountered in source files so they refer to the right
5927 store file names. For instance, this changes @code{#!/bin/sh} to
5928 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
5931 Run the @file{configure} script with a number of default options, such
5932 as @code{--prefix=/gnu/store/@dots{}}, as well as the options specified
5933 by the @code{#:configure-flags} argument.
5936 Run @code{make} with the list of flags specified with
5937 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
5938 (the default), build with @code{make -j}.
5941 Run @code{make check}, or some other target specified with
5942 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
5943 @code{#:parallel-tests?} argument is true (the default), run @code{make
5947 Run @code{make install} with the flags listed in @code{#:make-flags}.
5949 @item patch-shebangs
5950 Patch shebangs on the installed executable files.
5953 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
5954 is false), copying them to the @code{debug} output when available
5955 (@pxref{Installing Debugging Files}).
5958 @vindex %standard-phases
5959 The build-side module @code{(guix build gnu-build-system)} defines
5960 @var{%standard-phases} as the default list of build phases.
5961 @var{%standard-phases} is a list of symbol/procedure pairs, where the
5962 procedure implements the actual phase.
5964 The list of phases used for a particular package can be changed with the
5965 @code{#:phases} parameter. For instance, passing:
5968 #:phases (modify-phases %standard-phases (delete 'configure))
5971 means that all the phases described above will be used, except the
5972 @code{configure} phase.
5974 In addition, this build system ensures that the ``standard'' environment
5975 for GNU packages is available. This includes tools such as GCC, libc,
5976 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
5977 build-system gnu)} module for a complete list). We call these the
5978 @dfn{implicit inputs} of a package, because package definitions do not
5979 have to mention them.
5982 Other @code{<build-system>} objects are defined to support other
5983 conventions and tools used by free software packages. They inherit most
5984 of @var{gnu-build-system}, and differ mainly in the set of inputs
5985 implicitly added to the build process, and in the list of phases
5986 executed. Some of these build systems are listed below.
5988 @defvr {Scheme Variable} ant-build-system
5989 This variable is exported by @code{(guix build-system ant)}. It
5990 implements the build procedure for Java packages that can be built with
5991 @url{https://ant.apache.org/, Ant build tool}.
5993 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
5994 provided by the @code{icedtea} package to the set of inputs. Different
5995 packages can be specified with the @code{#:ant} and @code{#:jdk}
5996 parameters, respectively.
5998 When the original package does not provide a suitable Ant build file,
5999 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6000 build file @file{build.xml} with tasks to build the specified jar
6001 archive. In this case the parameter @code{#:source-dir} can be used to
6002 specify the source sub-directory, defaulting to ``src''.
6004 The @code{#:main-class} parameter can be used with the minimal ant
6005 buildfile to specify the main class of the resulting jar. This makes the
6006 jar file executable. The @code{#:test-include} parameter can be used to
6007 specify the list of junit tests to run. It defaults to
6008 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6009 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6010 because abstract classes cannot be run as tests.
6012 The parameter @code{#:build-target} can be used to specify the Ant task
6013 that should be run during the @code{build} phase. By default the
6014 ``jar'' task will be run.
6018 @defvr {Scheme Variable} android-ndk-build-system
6019 @cindex Android distribution
6020 @cindex Android NDK build system
6021 This variable is exported by @code{(guix build-system android-ndk)}. It
6022 implements a build procedure for Android NDK (native development kit)
6023 packages using a Guix-specific build process.
6025 The build system assumes that packages install their public interface
6026 (header) files to the subdirectory "include" of the "out" output and
6027 their libraries to the subdirectory "lib" of the "out" output.
6029 It's also assumed that the union of all the dependencies of a package
6030 has no conflicting files.
6032 For the time being, cross-compilation is not supported - so right now
6033 the libraries and header files are assumed to be host tools.
6037 @defvr {Scheme Variable} asdf-build-system/source
6038 @defvrx {Scheme Variable} asdf-build-system/sbcl
6039 @defvrx {Scheme Variable} asdf-build-system/ecl
6041 These variables, exported by @code{(guix build-system asdf)}, implement
6042 build procedures for Common Lisp packages using
6043 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6044 definition facility for Common Lisp programs and libraries.
6046 The @code{asdf-build-system/source} system installs the packages in
6047 source form, and can be loaded using any common lisp implementation, via
6048 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6049 systems in the format which a particular implementation understands.
6050 These build systems can also be used to produce executable programs, or
6051 lisp images which contain a set of packages pre-loaded.
6053 The build system uses naming conventions. For binary packages, the
6054 package name should be prefixed with the lisp implementation, such as
6055 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6057 Additionally, the corresponding source package should be labeled using
6058 the same convention as python packages (see @ref{Python Modules}), using
6059 the @code{cl-} prefix.
6061 For binary packages, each system should be defined as a Guix package.
6062 If one package @code{origin} contains several systems, package variants
6063 can be created in order to build all the systems. Source packages,
6064 which use @code{asdf-build-system/source}, may contain several systems.
6066 In order to create executable programs and images, the build-side
6067 procedures @code{build-program} and @code{build-image} can be used.
6068 They should be called in a build phase after the @code{create-symlinks}
6069 phase, so that the system which was just built can be used within the
6070 resulting image. @code{build-program} requires a list of Common Lisp
6071 expressions to be passed as the @code{#:entry-program} argument.
6073 If the system is not defined within its own @code{.asd} file of the same
6074 name, then the @code{#:asd-file} parameter should be used to specify
6075 which file the system is defined in. Furthermore, if the package
6076 defines a system for its tests in a separate file, it will be loaded
6077 before the tests are run if it is specified by the
6078 @code{#:test-asd-file} parameter. If it is not set, the files
6079 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6080 and @code{test.asd} will be tried if they exist.
6082 If for some reason the package must be named in a different way than the
6083 naming conventions suggest, the @code{#:asd-system-name} parameter can
6084 be used to specify the name of the system.
6088 @defvr {Scheme Variable} cargo-build-system
6089 @cindex Rust programming language
6090 @cindex Cargo (Rust build system)
6091 This variable is exported by @code{(guix build-system cargo)}. It
6092 supports builds of packages using Cargo, the build tool of the
6093 @uref{https://www.rust-lang.org, Rust programming language}.
6095 It adds @code{rustc} and @code{cargo} to the set of inputs.
6096 A different Rust package can be specified with the @code{#:rust} parameter.
6098 Regular cargo dependencies should be added to the package definition via the
6099 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6100 spec can be a package or a source definition. Note that the spec must
6101 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6102 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6103 should be added to the package definition via the
6104 @code{#:cargo-development-inputs} parameter.
6106 In its @code{configure} phase, this build system will make any source inputs
6107 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6108 parameters available to cargo. It will also remove an included
6109 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6110 @code{build} phase. The @code{install} phase installs any crate the binaries
6111 if they are defined by the crate.
6114 @cindex Clojure (programming language)
6115 @cindex simple Clojure build system
6116 @defvr {Scheme Variable} clojure-build-system
6117 This variable is exported by @code{(guix build-system clojure)}. It implements
6118 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6119 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6122 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6123 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6124 @code{#:zip} parameters, respectively.
6126 A list of source directories, test directories and jar names can be specified
6127 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6128 parameters, respectively. Compile directory and main class can be specified
6129 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6130 Other parameters are documented below.
6132 This build system is an extension of @var{ant-build-system}, but with the
6133 following phases changed:
6138 This phase calls @code{compile} in Clojure to compile source files and runs
6139 @command{jar} to create jars from both source files and compiled files
6140 according to the include list and exclude list specified in
6141 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6142 has priority over the include list. These lists consist of symbols
6143 representing Clojure libraries or the special keyword @code{#:all} representing
6144 all Clojure libraries found under the source directories. The parameter
6145 @code{#:omit-source?} decides if source should be included into the jars.
6148 This phase runs tests according to the include list and exclude list specified
6149 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6150 meanings are analogous to that of @code{#:aot-include} and
6151 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6152 stands for all Clojure libraries found under the test directories. The
6153 parameter @code{#:tests?} decides if tests should be run.
6156 This phase installs all jars built previously.
6159 Apart from the above, this build system also contains an additional phase:
6164 This phase installs all top-level files with base name matching
6165 @var{%doc-regex}. A different regex can be specified with the
6166 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6167 directories specified in @code{#:doc-dirs} are installed as well.
6171 @defvr {Scheme Variable} cmake-build-system
6172 This variable is exported by @code{(guix build-system cmake)}. It
6173 implements the build procedure for packages using the
6174 @url{https://www.cmake.org, CMake build tool}.
6176 It automatically adds the @code{cmake} package to the set of inputs.
6177 Which package is used can be specified with the @code{#:cmake}
6180 The @code{#:configure-flags} parameter is taken as a list of flags
6181 passed to the @command{cmake} command. The @code{#:build-type}
6182 parameter specifies in abstract terms the flags passed to the compiler;
6183 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6184 debugging information''), which roughly means that code is compiled with
6185 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6188 @defvr {Scheme Variable} dune-build-system
6189 This variable is exported by @code{(guix build-system dune)}. It
6190 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6191 tool for the OCaml programming language. It is implemented as an extension
6192 of the @code{ocaml-build-system} which is described below. As such, the
6193 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6196 It automatically adds the @code{dune} package to the set of inputs.
6197 Which package is used can be specified with the @code{#:dune}
6200 There is no @code{configure} phase because dune packages typically don't
6201 need to be configured. The @code{#:build-flags} parameter is taken as a
6202 list of flags passed to the @code{dune} command during the build.
6204 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6205 command instead of the more recent @code{dune} command while building
6206 a package. Its default value is @code{#f}.
6208 The @code{#:package} parameter can be passed to specify a package name, which
6209 is useful when a package contains multiple packages and you want to build
6210 only one of them. This is equivalent to passing the @code{-p} argument to
6214 @defvr {Scheme Variable} go-build-system
6215 This variable is exported by @code{(guix build-system go)}. It
6216 implements a build procedure for Go packages using the standard
6217 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6218 Go build mechanisms}.
6220 The user is expected to provide a value for the key @code{#:import-path}
6221 and, in some cases, @code{#:unpack-path}. The
6222 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6223 corresponds to the file system path expected by the package's build
6224 scripts and any referring packages, and provides a unique way to
6225 refer to a Go package. It is typically based on a combination of the
6226 package source code's remote URI and file system hierarchy structure. In
6227 some cases, you will need to unpack the package's source code to a
6228 different directory structure than the one indicated by the import path,
6229 and @code{#:unpack-path} should be used in such cases.
6231 Packages that provide Go libraries should install their source code into
6232 the built output. The key @code{#:install-source?}, which defaults to
6233 @code{#t}, controls whether or not the source code is installed. It can
6234 be set to @code{#f} for packages that only provide executable files.
6237 @defvr {Scheme Variable} glib-or-gtk-build-system
6238 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6239 is intended for use with packages making use of GLib or GTK+.
6241 This build system adds the following two phases to the ones defined by
6242 @var{gnu-build-system}:
6245 @item glib-or-gtk-wrap
6246 The phase @code{glib-or-gtk-wrap} ensures that programs in
6247 @file{bin/} are able to find GLib ``schemas'' and
6248 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
6249 modules}. This is achieved by wrapping the programs in launch scripts
6250 that appropriately set the @code{XDG_DATA_DIRS} and @code{GTK_PATH}
6251 environment variables.
6253 It is possible to exclude specific package outputs from that wrapping
6254 process by listing their names in the
6255 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
6256 when an output is known not to contain any GLib or GTK+ binaries, and
6257 where wrapping would gratuitously add a dependency of that output on
6260 @item glib-or-gtk-compile-schemas
6261 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
6262 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
6263 GSettings schemas} of GLib are compiled. Compilation is performed by the
6264 @command{glib-compile-schemas} program. It is provided by the package
6265 @code{glib:bin} which is automatically imported by the build system.
6266 The @code{glib} package providing @command{glib-compile-schemas} can be
6267 specified with the @code{#:glib} parameter.
6270 Both phases are executed after the @code{install} phase.
6273 @defvr {Scheme Variable} guile-build-system
6274 This build system is for Guile packages that consist exclusively of Scheme
6275 code and that are so lean that they don't even have a makefile, let alone a
6276 @file{configure} script. It compiles Scheme code using @command{guild
6277 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
6278 installs the @file{.scm} and @file{.go} files in the right place. It also
6279 installs documentation.
6281 This build system supports cross-compilation by using the @code{--target}
6282 option of @command{guild compile}.
6284 Packages built with @code{guile-build-system} must provide a Guile package in
6285 their @code{native-inputs} field.
6288 @defvr {Scheme Variable} julia-build-system
6289 This variable is exported by @code{(guix build-system julia)}. It implements
6290 the build procedure used by @uref{https://julialang.org/, julia} packages,
6291 which essentially is similar to running @command{julia -e 'using Pkg;
6292 Pkg.add(package)'} in an environment where @code{JULIA_LOAD_PATH} contains the
6293 paths to all Julia package inputs. Tests are run not run.
6295 Julia packages require the source @code{file-name} to be the real name of the
6296 package, correctly capitalized.
6298 For packages requiring shared library dependencies, you may need to write the
6299 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
6300 variable = /gnu/store/library.so} for each dependency, plus a void function
6301 @code{check_deps() = nothing}.
6303 Some older packages that aren't using @file{Package.toml} yet, will require
6304 this file to be created, too. The function @code{julia-create-package-toml}
6305 helps creating the file. You need to pass the outputs and the source of the
6306 package, it's name (the same as the @code{file-name} parameter), the package
6307 uuid, the package version, and a list of dependencies specified by their name
6311 @defvr {Scheme Variable} minify-build-system
6312 This variable is exported by @code{(guix build-system minify)}. It
6313 implements a minification procedure for simple JavaScript packages.
6315 It adds @code{uglify-js} to the set of inputs and uses it to compress
6316 all JavaScript files in the @file{src} directory. A different minifier
6317 package can be specified with the @code{#:uglify-js} parameter, but it
6318 is expected that the package writes the minified code to the standard
6321 When the input JavaScript files are not all located in the @file{src}
6322 directory, the parameter @code{#:javascript-files} can be used to
6323 specify a list of file names to feed to the minifier.
6326 @defvr {Scheme Variable} ocaml-build-system
6327 This variable is exported by @code{(guix build-system ocaml)}. It implements
6328 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
6329 of choosing the correct set of commands to run for each package. OCaml
6330 packages can expect many different commands to be run. This build system will
6333 When the package has a @file{setup.ml} file present at the top-level, it will
6334 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
6335 @code{ocaml setup.ml -install}. The build system will assume that this file
6336 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
6337 care of setting the prefix and enabling tests if they are not disabled. You
6338 can pass configure and build flags with the @code{#:configure-flags} and
6339 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
6340 set of flags used to enable tests. The @code{#:use-make?} key can be used to
6341 bypass this system in the build and install phases.
6343 When the package has a @file{configure} file, it is assumed that it is a
6344 hand-made configure script that requires a different argument format than
6345 in the @code{gnu-build-system}. You can add more flags with the
6346 @code{#:configure-flags} key.
6348 When the package has a @file{Makefile} file (or @code{#:use-make?} is
6349 @code{#t}), it will be used and more flags can be passed to the build and
6350 install phases with the @code{#:make-flags} key.
6352 Finally, some packages do not have these files and use a somewhat standard
6353 location for its build system. In that case, the build system will run
6354 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
6355 providing the path to the required findlib module. Additional flags can
6356 be passed via the @code{#:build-flags} key. Install is taken care of by
6357 @command{opam-installer}. In this case, the @code{opam} package must
6358 be added to the @code{native-inputs} field of the package definition.
6360 Note that most OCaml packages assume they will be installed in the same
6361 directory as OCaml, which is not what we want in guix. In particular, they
6362 will install @file{.so} files in their module's directory, which is usually
6363 fine because it is in the OCaml compiler directory. In guix though, these
6364 libraries cannot be found and we use @code{CAML_LD_LIBRARY_PATH}. This
6365 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
6366 @file{.so} libraries should be installed.
6369 @defvr {Scheme Variable} python-build-system
6370 This variable is exported by @code{(guix build-system python)}. It
6371 implements the more or less standard build procedure used by Python
6372 packages, which consists in running @code{python setup.py build} and
6373 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
6375 For packages that install stand-alone Python programs under @code{bin/},
6376 it takes care of wrapping these programs so that their @code{PYTHONPATH}
6377 environment variable points to all the Python libraries they depend on.
6379 Which Python package is used to perform the build can be specified with
6380 the @code{#:python} parameter. This is a useful way to force a package
6381 to be built for a specific version of the Python interpreter, which
6382 might be necessary if the package is only compatible with a single
6383 interpreter version.
6385 By default guix calls @code{setup.py} under control of
6386 @code{setuptools}, much like @command{pip} does. Some packages are not
6387 compatible with setuptools (and pip), thus you can disable this by
6388 setting the @code{#:use-setuptools?} parameter to @code{#f}.
6391 @defvr {Scheme Variable} perl-build-system
6392 This variable is exported by @code{(guix build-system perl)}. It
6393 implements the standard build procedure for Perl packages, which either
6394 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
6395 followed by @code{Build} and @code{Build install}; or in running
6396 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
6397 @code{make} and @code{make install}, depending on which of
6398 @code{Build.PL} or @code{Makefile.PL} is present in the package
6399 distribution. Preference is given to the former if both @code{Build.PL}
6400 and @code{Makefile.PL} exist in the package distribution. This
6401 preference can be reversed by specifying @code{#t} for the
6402 @code{#:make-maker?} parameter.
6404 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
6405 passes flags specified by the @code{#:make-maker-flags} or
6406 @code{#:module-build-flags} parameter, respectively.
6408 Which Perl package is used can be specified with @code{#:perl}.
6411 @defvr {Scheme Variable} r-build-system
6412 This variable is exported by @code{(guix build-system r)}. It
6413 implements the build procedure used by @uref{https://r-project.org, R}
6414 packages, which essentially is little more than running @code{R CMD
6415 INSTALL --library=/gnu/store/@dots{}} in an environment where
6416 @code{R_LIBS_SITE} contains the paths to all R package inputs. Tests
6417 are run after installation using the R function
6418 @code{tools::testInstalledPackage}.
6421 @defvr {Scheme Variable} rakudo-build-system
6422 This variable is exported by @code{(guix build-system rakudo)}. It
6423 implements the build procedure used by @uref{https://rakudo.org/,
6424 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
6425 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
6426 installs the binaries, library files and the resources, as well as wrap
6427 the files under the @code{bin/} directory. Tests can be skipped by
6428 passing @code{#f} to the @code{tests?} parameter.
6430 Which rakudo package is used can be specified with @code{rakudo}.
6431 Which perl6-tap-harness package used for the tests can be specified with
6432 @code{#:prove6} or removed by passing @code{#f} to the
6433 @code{with-prove6?} parameter.
6434 Which perl6-zef package used for tests and installing can be specified
6435 with @code{#:zef} or removed by passing @code{#f} to the
6436 @code{with-zef?} parameter.
6439 @defvr {Scheme Variable} texlive-build-system
6440 This variable is exported by @code{(guix build-system texlive)}. It is
6441 used to build TeX packages in batch mode with a specified engine. The
6442 build system sets the @code{TEXINPUTS} variable to find all TeX source
6443 files in the inputs.
6445 By default it runs @code{luatex} on all files ending on @code{ins}. A
6446 different engine and format can be specified with the
6447 @code{#:tex-format} argument. Different build targets can be specified
6448 with the @code{#:build-targets} argument, which expects a list of file
6449 names. The build system adds only @code{texlive-bin} and
6450 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
6451 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
6452 and @code{#:texlive-latex-base}, respectively.
6454 The @code{#:tex-directory} parameter tells the build system where to
6455 install the built files under the texmf tree.
6458 @defvr {Scheme Variable} ruby-build-system
6459 This variable is exported by @code{(guix build-system ruby)}. It
6460 implements the RubyGems build procedure used by Ruby packages, which
6461 involves running @code{gem build} followed by @code{gem install}.
6463 The @code{source} field of a package that uses this build system
6464 typically references a gem archive, since this is the format that Ruby
6465 developers use when releasing their software. The build system unpacks
6466 the gem archive, potentially patches the source, runs the test suite,
6467 repackages the gem, and installs it. Additionally, directories and
6468 tarballs may be referenced to allow building unreleased gems from Git or
6469 a traditional source release tarball.
6471 Which Ruby package is used can be specified with the @code{#:ruby}
6472 parameter. A list of additional flags to be passed to the @command{gem}
6473 command can be specified with the @code{#:gem-flags} parameter.
6476 @defvr {Scheme Variable} waf-build-system
6477 This variable is exported by @code{(guix build-system waf)}. It
6478 implements a build procedure around the @code{waf} script. The common
6479 phases---@code{configure}, @code{build}, and @code{install}---are
6480 implemented by passing their names as arguments to the @code{waf}
6483 The @code{waf} script is executed by the Python interpreter. Which
6484 Python package is used to run the script can be specified with the
6485 @code{#:python} parameter.
6488 @defvr {Scheme Variable} scons-build-system
6489 This variable is exported by @code{(guix build-system scons)}. It
6490 implements the build procedure used by the SCons software construction
6491 tool. This build system runs @code{scons} to build the package,
6492 @code{scons test} to run tests, and then @code{scons install} to install
6495 Additional flags to be passed to @code{scons} can be specified with the
6496 @code{#:scons-flags} parameter. The default build and install targets
6497 can be overridden with @code{#:build-targets} and
6498 @code{#:install-targets} respectively. The version of Python used to
6499 run SCons can be specified by selecting the appropriate SCons package
6500 with the @code{#:scons} parameter.
6503 @defvr {Scheme Variable} haskell-build-system
6504 This variable is exported by @code{(guix build-system haskell)}. It
6505 implements the Cabal build procedure used by Haskell packages, which
6506 involves running @code{runhaskell Setup.hs configure
6507 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
6508 Instead of installing the package by running @code{runhaskell Setup.hs
6509 install}, to avoid trying to register libraries in the read-only
6510 compiler store directory, the build system uses @code{runhaskell
6511 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
6512 addition, the build system generates the package documentation by
6513 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
6514 is passed. Optional Haddock parameters can be passed with the help of
6515 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
6516 not found, the build system looks for @code{Setup.lhs} instead.
6518 Which Haskell compiler is used can be specified with the @code{#:haskell}
6519 parameter which defaults to @code{ghc}.
6522 @defvr {Scheme Variable} dub-build-system
6523 This variable is exported by @code{(guix build-system dub)}. It
6524 implements the Dub build procedure used by D packages, which
6525 involves running @code{dub build} and @code{dub run}.
6526 Installation is done by copying the files manually.
6528 Which D compiler is used can be specified with the @code{#:ldc}
6529 parameter which defaults to @code{ldc}.
6532 @defvr {Scheme Variable} emacs-build-system
6533 This variable is exported by @code{(guix build-system emacs)}. It
6534 implements an installation procedure similar to the packaging system
6535 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
6537 It first creates the @code{@var{package}-autoloads.el} file, then it
6538 byte compiles all Emacs Lisp files. Differently from the Emacs
6539 packaging system, the Info documentation files are moved to the standard
6540 documentation directory and the @file{dir} file is deleted. Each
6541 package is installed in its own directory under
6542 @file{share/emacs/site-lisp/guix.d}.
6545 @defvr {Scheme Variable} font-build-system
6546 This variable is exported by @code{(guix build-system font)}. It
6547 implements an installation procedure for font packages where upstream
6548 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
6549 need to be copied into place. It copies font files to standard
6550 locations in the output directory.
6553 @defvr {Scheme Variable} meson-build-system
6554 This variable is exported by @code{(guix build-system meson)}. It
6555 implements the build procedure for packages that use
6556 @url{https://mesonbuild.com, Meson} as their build system.
6558 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
6559 of inputs, and they can be changed with the parameters @code{#:meson}
6560 and @code{#:ninja} if needed. The default Meson is
6561 @code{meson-for-build}, which is special because it doesn't clear the
6562 @code{RUNPATH} of binaries and libraries when they are installed.
6564 This build system is an extension of @var{gnu-build-system}, but with the
6565 following phases changed to some specific for Meson:
6570 The phase runs @code{meson} with the flags specified in
6571 @code{#:configure-flags}. The flag @code{--build-type} is always set to
6572 @code{plain} unless something else is specified in @code{#:build-type}.
6575 The phase runs @code{ninja} to build the package in parallel by default, but
6576 this can be changed with @code{#:parallel-build?}.
6579 The phase runs @code{ninja} with the target specified in @code{#:test-target},
6580 which is @code{"test"} by default.
6583 The phase runs @code{ninja install} and can not be changed.
6586 Apart from that, the build system also adds the following phases:
6591 This phase ensures that all binaries can find the libraries they need.
6592 It searches for required libraries in subdirectories of the package being
6593 built, and adds those to @code{RUNPATH} where needed. It also removes
6594 references to libraries left over from the build phase by
6595 @code{meson-for-build}, such as test dependencies, that aren't actually
6596 required for the program to run.
6598 @item glib-or-gtk-wrap
6599 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6600 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6602 @item glib-or-gtk-compile-schemas
6603 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
6604 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
6608 @defvr {Scheme Variable} linux-module-build-system
6609 @var{linux-module-build-system} allows building Linux kernel modules.
6611 @cindex build phases
6612 This build system is an extension of @var{gnu-build-system}, but with the
6613 following phases changed:
6618 This phase configures the environment so that the Linux kernel's Makefile
6619 can be used to build the external kernel module.
6622 This phase uses the Linux kernel's Makefile in order to build the external
6626 This phase uses the Linux kernel's Makefile in order to install the external
6630 It is possible and useful to specify the Linux kernel to use for building
6631 the module (in the "arguments" form of a package using the
6632 linux-module-build-system, use the key #:linux to specify it).
6635 @defvr {Scheme Variable} node-build-system
6636 This variable is exported by @code{(guix build-system node)}. It
6637 implements the build procedure used by @uref{http://nodejs.org,
6638 Node.js}, which implements an approximation of the @code{npm install}
6639 command, followed by an @code{npm test} command.
6641 Which Node.js package is used to interpret the @code{npm} commands can
6642 be specified with the @code{#:node} parameter which defaults to
6646 Lastly, for packages that do not need anything as sophisticated, a
6647 ``trivial'' build system is provided. It is trivial in the sense that
6648 it provides basically no support: it does not pull any implicit inputs,
6649 and does not have a notion of build phases.
6651 @defvr {Scheme Variable} trivial-build-system
6652 This variable is exported by @code{(guix build-system trivial)}.
6654 This build system requires a @code{#:builder} argument. This argument
6655 must be a Scheme expression that builds the package output(s)---as
6656 with @code{build-expression->derivation} (@pxref{Derivations,
6657 @code{build-expression->derivation}}).
6667 Conceptually, the @dfn{store} is the place where derivations that have
6668 been built successfully are stored---by default, @file{/gnu/store}.
6669 Sub-directories in the store are referred to as @dfn{store items} or
6670 sometimes @dfn{store paths}. The store has an associated database that
6671 contains information such as the store paths referred to by each store
6672 path, and the list of @emph{valid} store items---results of successful
6673 builds. This database resides in @file{@var{localstatedir}/guix/db},
6674 where @var{localstatedir} is the state directory specified @i{via}
6675 @option{--localstatedir} at configure time, usually @file{/var}.
6677 The store is @emph{always} accessed by the daemon on behalf of its clients
6678 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
6679 connect to the daemon over a Unix-domain socket, send requests to it,
6680 and read the result---these are remote procedure calls, or RPCs.
6683 Users must @emph{never} modify files under @file{/gnu/store} directly.
6684 This would lead to inconsistencies and break the immutability
6685 assumptions of Guix's functional model (@pxref{Introduction}).
6687 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
6688 how to check the integrity of the store and attempt recovery from
6689 accidental modifications.
6692 The @code{(guix store)} module provides procedures to connect to the
6693 daemon, and to perform RPCs. These are described below. By default,
6694 @code{open-connection}, and thus all the @command{guix} commands,
6695 connect to the local daemon or to the URI specified by the
6696 @code{GUIX_DAEMON_SOCKET} environment variable.
6698 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
6699 When set, the value of this variable should be a file name or a URI
6700 designating the daemon endpoint. When it is a file name, it denotes a
6701 Unix-domain socket to connect to. In addition to file names, the
6702 supported URI schemes are:
6707 These are for Unix-domain sockets.
6708 @code{file:///var/guix/daemon-socket/socket} is equivalent to
6709 @file{/var/guix/daemon-socket/socket}.
6712 @cindex daemon, remote access
6713 @cindex remote access to the daemon
6714 @cindex daemon, cluster setup
6715 @cindex clusters, daemon setup
6716 These URIs denote connections over TCP/IP, without encryption nor
6717 authentication of the remote host. The URI must specify the host name
6718 and optionally a port number (by default port 44146 is used):
6721 guix://master.guix.example.org:1234
6724 This setup is suitable on local networks, such as clusters, where only
6725 trusted nodes may connect to the build daemon at
6726 @code{master.guix.example.org}.
6728 The @code{--listen} option of @command{guix-daemon} can be used to
6729 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
6733 @cindex SSH access to build daemons
6734 These URIs allow you to connect to a remote daemon over
6735 SSH@footnote{This feature requires Guile-SSH (@pxref{Requirements}).}.
6736 A typical URL might look like this:
6739 ssh://charlie@@guix.example.org:22
6742 As for @command{guix copy}, the usual OpenSSH client configuration files
6743 are honored (@pxref{Invoking guix copy}).
6746 Additional URI schemes may be supported in the future.
6748 @c XXX: Remove this note when the protocol incurs fewer round trips
6749 @c and when (guix derivations) no longer relies on file system access.
6751 The ability to connect to remote build daemons is considered
6752 experimental as of @value{VERSION}. Please get in touch with us to
6753 share any problems or suggestions you may have (@pxref{Contributing}).
6757 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
6758 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
6759 @var{reserve-space?} is true, instruct it to reserve a little bit of
6760 extra space on the file system so that the garbage collector can still
6761 operate should the disk become full. Return a server object.
6763 @var{file} defaults to @code{%default-socket-path}, which is the normal
6764 location given the options that were passed to @command{configure}.
6767 @deffn {Scheme Procedure} close-connection @var{server}
6768 Close the connection to @var{server}.
6771 @defvr {Scheme Variable} current-build-output-port
6772 This variable is bound to a SRFI-39 parameter, which refers to the port
6773 where build and error logs sent by the daemon should be written.
6776 Procedures that make RPCs all take a server object as their first
6779 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
6780 @cindex invalid store items
6781 Return @code{#t} when @var{path} designates a valid store item and
6782 @code{#f} otherwise (an invalid item may exist on disk but still be
6783 invalid, for instance because it is the result of an aborted or failed
6786 A @code{&store-protocol-error} condition is raised if @var{path} is not
6787 prefixed by the store directory (@file{/gnu/store}).
6790 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
6791 Add @var{text} under file @var{name} in the store, and return its store
6792 path. @var{references} is the list of store paths referred to by the
6793 resulting store path.
6796 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
6798 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
6799 file names, or derivation/output pairs, using the specified
6800 @var{mode}---@code{(build-mode normal)} by default.
6803 Note that the @code{(guix monads)} module provides a monad as well as
6804 monadic versions of the above procedures, with the goal of making it
6805 more convenient to work with code that accesses the store (@pxref{The
6809 @i{This section is currently incomplete.}
6812 @section Derivations
6815 Low-level build actions and the environment in which they are performed
6816 are represented by @dfn{derivations}. A derivation contains the
6817 following pieces of information:
6821 The outputs of the derivation---derivations produce at least one file or
6822 directory in the store, but may produce more.
6825 @cindex build-time dependencies
6826 @cindex dependencies, build-time
6827 The inputs of the derivations---i.e., its build-time dependencies---which may
6828 be other derivations or plain files in the store (patches, build scripts,
6832 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
6835 The file name of a build script in the store, along with the arguments
6839 A list of environment variables to be defined.
6843 @cindex derivation path
6844 Derivations allow clients of the daemon to communicate build actions to
6845 the store. They exist in two forms: as an in-memory representation,
6846 both on the client- and daemon-side, and as files in the store whose
6847 name end in @code{.drv}---these files are referred to as @dfn{derivation
6848 paths}. Derivations paths can be passed to the @code{build-derivations}
6849 procedure to perform the build actions they prescribe (@pxref{The
6852 @cindex fixed-output derivations
6853 Operations such as file downloads and version-control checkouts for
6854 which the expected content hash is known in advance are modeled as
6855 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
6856 of a fixed-output derivation are independent of its inputs---e.g., a
6857 source code download produces the same result regardless of the download
6858 method and tools being used.
6861 @cindex run-time dependencies
6862 @cindex dependencies, run-time
6863 The outputs of derivations---i.e., the build results---have a set of
6864 @dfn{references}, as reported by the @code{references} RPC or the
6865 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
6866 are the set of run-time dependencies of the build results. References are a
6867 subset of the inputs of the derivation; this subset is automatically computed
6868 by the build daemon by scanning all the files in the outputs.
6870 The @code{(guix derivations)} module provides a representation of
6871 derivations as Scheme objects, along with procedures to create and
6872 otherwise manipulate derivations. The lowest-level primitive to create
6873 a derivation is the @code{derivation} procedure:
6875 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
6876 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6877 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
6878 [#:system (%current-system)] [#:references-graphs #f] @
6879 [#:allowed-references #f] [#:disallowed-references #f] @
6880 [#:leaked-env-vars #f] [#:local-build? #f] @
6881 [#:substitutable? #t] [#:properties '()]
6882 Build a derivation with the given arguments, and return the resulting
6883 @code{<derivation>} object.
6885 When @var{hash} and @var{hash-algo} are given, a
6886 @dfn{fixed-output derivation} is created---i.e., one whose result is
6887 known in advance, such as a file download. If, in addition,
6888 @var{recursive?} is true, then that fixed output may be an executable
6889 file or a directory and @var{hash} must be the hash of an archive
6890 containing this output.
6892 When @var{references-graphs} is true, it must be a list of file
6893 name/store path pairs. In that case, the reference graph of each store
6894 path is exported in the build environment in the corresponding file, in
6895 a simple text format.
6897 When @var{allowed-references} is true, it must be a list of store items
6898 or outputs that the derivation's output may refer to. Likewise,
6899 @var{disallowed-references}, if true, must be a list of things the
6900 outputs may @emph{not} refer to.
6902 When @var{leaked-env-vars} is true, it must be a list of strings
6903 denoting environment variables that are allowed to ``leak'' from the
6904 daemon's environment to the build environment. This is only applicable
6905 to fixed-output derivations---i.e., when @var{hash} is true. The main
6906 use is to allow variables such as @code{http_proxy} to be passed to
6907 derivations that download files.
6909 When @var{local-build?} is true, declare that the derivation is not a
6910 good candidate for offloading and should rather be built locally
6911 (@pxref{Daemon Offload Setup}). This is the case for small derivations
6912 where the costs of data transfers would outweigh the benefits.
6914 When @var{substitutable?} is false, declare that substitutes of the
6915 derivation's output should not be used (@pxref{Substitutes}). This is
6916 useful, for instance, when building packages that capture details of the
6917 host CPU instruction set.
6919 @var{properties} must be an association list describing ``properties'' of the
6920 derivation. It is kept as-is, uninterpreted, in the derivation.
6924 Here's an example with a shell script as its builder, assuming
6925 @var{store} is an open connection to the daemon, and @var{bash} points
6926 to a Bash executable in the store:
6929 (use-modules (guix utils)
6933 (let ((builder ; add the Bash script to the store
6934 (add-text-to-store store "my-builder.sh"
6935 "echo hello world > $out\n" '())))
6936 (derivation store "foo"
6937 bash `("-e" ,builder)
6938 #:inputs `((,bash) (,builder))
6939 #:env-vars '(("HOME" . "/homeless"))))
6940 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
6943 As can be guessed, this primitive is cumbersome to use directly. A
6944 better approach is to write build scripts in Scheme, of course! The
6945 best course of action for that is to write the build code as a
6946 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
6947 information, @pxref{G-Expressions}.
6949 Once upon a time, @code{gexp->derivation} did not exist and constructing
6950 derivations with build code written in Scheme was achieved with
6951 @code{build-expression->derivation}, documented below. This procedure
6952 is now deprecated in favor of the much nicer @code{gexp->derivation}.
6954 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
6955 @var{name} @var{exp} @
6956 [#:system (%current-system)] [#:inputs '()] @
6957 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
6958 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
6959 [#:references-graphs #f] [#:allowed-references #f] @
6960 [#:disallowed-references #f] @
6961 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
6962 Return a derivation that executes Scheme expression @var{exp} as a
6963 builder for derivation @var{name}. @var{inputs} must be a list of
6964 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
6965 @code{"out"} is assumed. @var{modules} is a list of names of Guile
6966 modules from the current search path to be copied in the store,
6967 compiled, and made available in the load path during the execution of
6968 @var{exp}---e.g., @code{((guix build utils) (guix build
6969 gnu-build-system))}.
6971 @var{exp} is evaluated in an environment where @code{%outputs} is bound
6972 to a list of output/path pairs, and where @code{%build-inputs} is bound
6973 to a list of string/output-path pairs made from @var{inputs}.
6974 Optionally, @var{env-vars} is a list of string pairs specifying the name
6975 and value of environment variables visible to the builder. The builder
6976 terminates by passing the result of @var{exp} to @code{exit}; thus, when
6977 @var{exp} returns @code{#f}, the build is considered to have failed.
6979 @var{exp} is built using @var{guile-for-build} (a derivation). When
6980 @var{guile-for-build} is omitted or is @code{#f}, the value of the
6981 @code{%guile-for-build} fluid is used instead.
6983 See the @code{derivation} procedure for the meaning of
6984 @var{references-graphs}, @var{allowed-references},
6985 @var{disallowed-references}, @var{local-build?}, and
6986 @var{substitutable?}.
6990 Here's an example of a single-output derivation that creates a directory
6991 containing one file:
6994 (let ((builder '(let ((out (assoc-ref %outputs "out")))
6995 (mkdir out) ; create /gnu/store/@dots{}-goo
6996 (call-with-output-file (string-append out "/test")
6998 (display '(hello guix) p))))))
6999 (build-expression->derivation store "goo" builder))
7001 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7005 @node The Store Monad
7006 @section The Store Monad
7010 The procedures that operate on the store described in the previous
7011 sections all take an open connection to the build daemon as their first
7012 argument. Although the underlying model is functional, they either have
7013 side effects or depend on the current state of the store.
7015 The former is inconvenient: the connection to the build daemon has to be
7016 carried around in all those functions, making it impossible to compose
7017 functions that do not take that parameter with functions that do. The
7018 latter can be problematic: since store operations have side effects
7019 and/or depend on external state, they have to be properly sequenced.
7021 @cindex monadic values
7022 @cindex monadic functions
7023 This is where the @code{(guix monads)} module comes in. This module
7024 provides a framework for working with @dfn{monads}, and a particularly
7025 useful monad for our uses, the @dfn{store monad}. Monads are a
7026 construct that allows two things: associating ``context'' with values
7027 (in our case, the context is the store), and building sequences of
7028 computations (here computations include accesses to the store). Values
7029 in a monad---values that carry this additional context---are called
7030 @dfn{monadic values}; procedures that return such values are called
7031 @dfn{monadic procedures}.
7033 Consider this ``normal'' procedure:
7036 (define (sh-symlink store)
7037 ;; Return a derivation that symlinks the 'bash' executable.
7038 (let* ((drv (package-derivation store bash))
7039 (out (derivation->output-path drv))
7040 (sh (string-append out "/bin/bash")))
7041 (build-expression->derivation store "sh"
7042 `(symlink ,sh %output))))
7045 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7046 as a monadic function:
7049 (define (sh-symlink)
7050 ;; Same, but return a monadic value.
7051 (mlet %store-monad ((drv (package->derivation bash)))
7052 (gexp->derivation "sh"
7053 #~(symlink (string-append #$drv "/bin/bash")
7057 There are several things to note in the second version: the @code{store}
7058 parameter is now implicit and is ``threaded'' in the calls to the
7059 @code{package->derivation} and @code{gexp->derivation} monadic
7060 procedures, and the monadic value returned by @code{package->derivation}
7061 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7063 As it turns out, the call to @code{package->derivation} can even be
7064 omitted since it will take place implicitly, as we will see later
7065 (@pxref{G-Expressions}):
7068 (define (sh-symlink)
7069 (gexp->derivation "sh"
7070 #~(symlink (string-append #$bash "/bin/bash")
7075 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7076 @c for the funny quote.
7077 Calling the monadic @code{sh-symlink} has no effect. As someone once
7078 said, ``you exit a monad like you exit a building on fire: by running''.
7079 So, to exit the monad and get the desired effect, one must use
7080 @code{run-with-store}:
7083 (run-with-store (open-connection) (sh-symlink))
7084 @result{} /gnu/store/...-sh-symlink
7087 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7088 new ``meta-commands'' to make it easier to deal with monadic procedures:
7089 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7090 to ``run'' a single monadic value through the store:
7093 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7094 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7097 The latter enters a recursive REPL, where all the return values are
7098 automatically run through the store:
7101 scheme@@(guile-user)> ,enter-store-monad
7102 store-monad@@(guile-user) [1]> (package->derivation hello)
7103 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7104 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7105 $3 = "/gnu/store/@dots{}-foo"
7106 store-monad@@(guile-user) [1]> ,q
7107 scheme@@(guile-user)>
7111 Note that non-monadic values cannot be returned in the
7112 @code{store-monad} REPL.
7114 The main syntactic forms to deal with monads in general are provided by
7115 the @code{(guix monads)} module and are described below.
7117 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7118 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7122 @deffn {Scheme Syntax} return @var{val}
7123 Return a monadic value that encapsulates @var{val}.
7126 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7127 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7128 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7129 referred to as ``bind'', but that name denotes an unrelated procedure in
7130 Guile. Thus we use this somewhat cryptic symbol inherited from the
7131 Haskell language.}. There can be one @var{mproc} or several of them, as
7136 (with-monad %state-monad
7138 (lambda (x) (return (+ 1 x)))
7139 (lambda (x) (return (* 2 x)))))
7143 @result{} some-state
7147 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7149 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7151 Bind the variables @var{var} to the monadic values @var{mval} in
7152 @var{body}, which is a sequence of expressions. As with the bind
7153 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7154 value ``contained'' in @var{mval} and making @var{var} refer to that
7155 raw, non-monadic value within the scope of the @var{body}. The form
7156 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7157 @var{val}, as per @code{let}. The binding operations occur in sequence
7158 from left to right. The last expression of @var{body} must be a monadic
7159 expression, and its result will become the result of the @code{mlet} or
7160 @code{mlet*} when run in the @var{monad}.
7162 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
7163 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
7166 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
7167 Bind @var{mexp} and the following monadic expressions in sequence,
7168 returning the result of the last expression. Every expression in the
7169 sequence must be a monadic expression.
7171 This is akin to @code{mlet}, except that the return values of the
7172 monadic expressions are ignored. In that sense, it is analogous to
7173 @code{begin}, but applied to monadic expressions.
7176 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
7177 When @var{condition} is true, evaluate the sequence of monadic
7178 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7179 @var{condition} is false, return @code{*unspecified*} in the current
7180 monad. Every expression in the sequence must be a monadic expression.
7183 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
7184 When @var{condition} is false, evaluate the sequence of monadic
7185 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
7186 @var{condition} is true, return @code{*unspecified*} in the current
7187 monad. Every expression in the sequence must be a monadic expression.
7191 The @code{(guix monads)} module provides the @dfn{state monad}, which
7192 allows an additional value---the state---to be @emph{threaded} through
7193 monadic procedure calls.
7195 @defvr {Scheme Variable} %state-monad
7196 The state monad. Procedures in the state monad can access and change
7197 the state that is threaded.
7199 Consider the example below. The @code{square} procedure returns a value
7200 in the state monad. It returns the square of its argument, but also
7201 increments the current state value:
7205 (mlet %state-monad ((count (current-state)))
7206 (mbegin %state-monad
7207 (set-current-state (+ 1 count))
7210 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
7215 When ``run'' through @var{%state-monad}, we obtain that additional state
7216 value, which is the number of @code{square} calls.
7219 @deffn {Monadic Procedure} current-state
7220 Return the current state as a monadic value.
7223 @deffn {Monadic Procedure} set-current-state @var{value}
7224 Set the current state to @var{value} and return the previous state as a
7228 @deffn {Monadic Procedure} state-push @var{value}
7229 Push @var{value} to the current state, which is assumed to be a list,
7230 and return the previous state as a monadic value.
7233 @deffn {Monadic Procedure} state-pop
7234 Pop a value from the current state and return it as a monadic value.
7235 The state is assumed to be a list.
7238 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
7239 Run monadic value @var{mval} starting with @var{state} as the initial
7240 state. Return two values: the resulting value, and the resulting state.
7243 The main interface to the store monad, provided by the @code{(guix
7244 store)} module, is as follows.
7246 @defvr {Scheme Variable} %store-monad
7247 The store monad---an alias for @var{%state-monad}.
7249 Values in the store monad encapsulate accesses to the store. When its
7250 effect is needed, a value of the store monad must be ``evaluated'' by
7251 passing it to the @code{run-with-store} procedure (see below.)
7254 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
7255 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
7256 open store connection.
7259 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
7260 Return as a monadic value the absolute file name in the store of the file
7261 containing @var{text}, a string. @var{references} is a list of store items that the
7262 resulting text file refers to; it defaults to the empty list.
7265 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
7266 Return as a monadic value the absolute file name in the store of the file
7267 containing @var{data}, a bytevector. @var{references} is a list of store
7268 items that the resulting binary file refers to; it defaults to the empty list.
7271 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
7272 [#:recursive? #t] [#:select? (const #t)]
7273 Return the name of @var{file} once interned in the store. Use
7274 @var{name} as its store name, or the basename of @var{file} if
7275 @var{name} is omitted.
7277 When @var{recursive?} is true, the contents of @var{file} are added
7278 recursively; if @var{file} designates a flat file and @var{recursive?}
7279 is true, its contents are added, and its permission bits are kept.
7281 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7282 @var{stat})} for each directory entry, where @var{file} is the entry's
7283 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7284 entries for which @var{select?} does not return true.
7286 The example below adds a file to the store, under two different names:
7289 (run-with-store (open-connection)
7290 (mlet %store-monad ((a (interned-file "README"))
7291 (b (interned-file "README" "LEGU-MIN")))
7292 (return (list a b))))
7294 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
7299 The @code{(guix packages)} module exports the following package-related
7302 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
7303 [#:system (%current-system)] [#:target #f] @
7306 value in the absolute file name of @var{file} within the @var{output}
7307 directory of @var{package}. When @var{file} is omitted, return the name
7308 of the @var{output} directory of @var{package}. When @var{target} is
7309 true, use it as a cross-compilation target triplet.
7312 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
7313 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
7314 @var{target} [@var{system}]
7315 Monadic version of @code{package-derivation} and
7316 @code{package-cross-derivation} (@pxref{Defining Packages}).
7321 @section G-Expressions
7323 @cindex G-expression
7324 @cindex build code quoting
7325 So we have ``derivations'', which represent a sequence of build actions
7326 to be performed to produce an item in the store (@pxref{Derivations}).
7327 These build actions are performed when asking the daemon to actually
7328 build the derivations; they are run by the daemon in a container
7329 (@pxref{Invoking guix-daemon}).
7331 @cindex strata of code
7332 It should come as no surprise that we like to write these build actions
7333 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
7334 code@footnote{The term @dfn{stratum} in this context was coined by
7335 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
7336 Kiselyov, who has written insightful
7337 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
7338 on this topic}, refers to this kind of code generation as
7339 @dfn{staging}.}: the ``host code''---code that defines packages, talks
7340 to the daemon, etc.---and the ``build code''---code that actually
7341 performs build actions, such as making directories, invoking
7342 @command{make}, etc.
7344 To describe a derivation and its build actions, one typically needs to
7345 embed build code inside host code. It boils down to manipulating build
7346 code as data, and the homoiconicity of Scheme---code has a direct
7347 representation as data---comes in handy for that. But we need more than
7348 the normal @code{quasiquote} mechanism in Scheme to construct build
7351 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
7352 S-expressions adapted to build expressions. G-expressions, or
7353 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
7354 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
7355 @code{#$}, and @code{#$@@}), which are comparable to
7356 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
7357 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
7358 GNU Guile Reference Manual}). However, there are major differences:
7362 Gexps are meant to be written to a file and run or manipulated by other
7366 When a high-level object such as a package or derivation is unquoted
7367 inside a gexp, the result is as if its output file name had been
7371 Gexps carry information about the packages or derivations they refer to,
7372 and these dependencies are automatically added as inputs to the build
7373 processes that use them.
7376 @cindex lowering, of high-level objects in gexps
7377 This mechanism is not limited to package and derivation
7378 objects: @dfn{compilers} able to ``lower'' other high-level objects to
7379 derivations or files in the store can be defined,
7380 such that these objects can also be inserted
7381 into gexps. For example, a useful type of high-level objects that can be
7382 inserted in a gexp is ``file-like objects'', which make it easy to
7383 add files to the store and to refer to them in
7384 derivations and such (see @code{local-file} and @code{plain-file}
7387 To illustrate the idea, here is an example of a gexp:
7394 (symlink (string-append #$coreutils "/bin/ls")
7398 This gexp can be passed to @code{gexp->derivation}; we obtain a
7399 derivation that builds a directory containing exactly one symlink to
7400 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
7403 (gexp->derivation "the-thing" build-exp)
7406 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
7407 substituted to the reference to the @var{coreutils} package in the
7408 actual build code, and @var{coreutils} is automatically made an input to
7409 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
7410 output)}) is replaced by a string containing the directory name of the
7411 output of the derivation.
7413 @cindex cross compilation
7414 In a cross-compilation context, it is useful to distinguish between
7415 references to the @emph{native} build of a package---that can run on the
7416 host---versus references to cross builds of a package. To that end, the
7417 @code{#+} plays the same role as @code{#$}, but is a reference to a
7418 native package build:
7421 (gexp->derivation "vi"
7424 (system* (string-append #+coreutils "/bin/ln")
7426 (string-append #$emacs "/bin/emacs")
7427 (string-append #$output "/bin/vi")))
7428 #:target "mips64el-linux-gnu")
7432 In the example above, the native build of @var{coreutils} is used, so
7433 that @command{ln} can actually run on the host; but then the
7434 cross-compiled build of @var{emacs} is referenced.
7436 @cindex imported modules, for gexps
7437 @findex with-imported-modules
7438 Another gexp feature is @dfn{imported modules}: sometimes you want to be
7439 able to use certain Guile modules from the ``host environment'' in the
7440 gexp, so those modules should be imported in the ``build environment''.
7441 The @code{with-imported-modules} form allows you to express that:
7444 (let ((build (with-imported-modules '((guix build utils))
7446 (use-modules (guix build utils))
7447 (mkdir-p (string-append #$output "/bin"))))))
7448 (gexp->derivation "empty-dir"
7451 (display "success!\n")
7456 In this example, the @code{(guix build utils)} module is automatically
7457 pulled into the isolated build environment of our gexp, such that
7458 @code{(use-modules (guix build utils))} works as expected.
7460 @cindex module closure
7461 @findex source-module-closure
7462 Usually you want the @emph{closure} of the module to be imported---i.e.,
7463 the module itself and all the modules it depends on---rather than just
7464 the module; failing to do that, attempts to use the module will fail
7465 because of missing dependent modules. The @code{source-module-closure}
7466 procedure computes the closure of a module by looking at its source file
7467 headers, which comes in handy in this case:
7470 (use-modules (guix modules)) ;for 'source-module-closure'
7472 (with-imported-modules (source-module-closure
7473 '((guix build utils)
7475 (gexp->derivation "something-with-vms"
7477 (use-modules (guix build utils)
7482 @cindex extensions, for gexps
7483 @findex with-extensions
7484 In the same vein, sometimes you want to import not just pure-Scheme
7485 modules, but also ``extensions'' such as Guile bindings to C libraries
7486 or other ``full-blown'' packages. Say you need the @code{guile-json}
7487 package available on the build side, here's how you would do it:
7490 (use-modules (gnu packages guile)) ;for 'guile-json'
7492 (with-extensions (list guile-json)
7493 (gexp->derivation "something-with-json"
7495 (use-modules (json))
7499 The syntactic form to construct gexps is summarized below.
7501 @deffn {Scheme Syntax} #~@var{exp}
7502 @deffnx {Scheme Syntax} (gexp @var{exp})
7503 Return a G-expression containing @var{exp}. @var{exp} may contain one
7504 or more of the following forms:
7508 @itemx (ungexp @var{obj})
7509 Introduce a reference to @var{obj}. @var{obj} may have one of the
7510 supported types, for example a package or a
7511 derivation, in which case the @code{ungexp} form is replaced by its
7512 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
7514 If @var{obj} is a list, it is traversed and references to supported
7515 objects are substituted similarly.
7517 If @var{obj} is another gexp, its contents are inserted and its
7518 dependencies are added to those of the containing gexp.
7520 If @var{obj} is another kind of object, it is inserted as is.
7522 @item #$@var{obj}:@var{output}
7523 @itemx (ungexp @var{obj} @var{output})
7524 This is like the form above, but referring explicitly to the
7525 @var{output} of @var{obj}---this is useful when @var{obj} produces
7526 multiple outputs (@pxref{Packages with Multiple Outputs}).
7529 @itemx #+@var{obj}:output
7530 @itemx (ungexp-native @var{obj})
7531 @itemx (ungexp-native @var{obj} @var{output})
7532 Same as @code{ungexp}, but produces a reference to the @emph{native}
7533 build of @var{obj} when used in a cross compilation context.
7535 @item #$output[:@var{output}]
7536 @itemx (ungexp output [@var{output}])
7537 Insert a reference to derivation output @var{output}, or to the main
7538 output when @var{output} is omitted.
7540 This only makes sense for gexps passed to @code{gexp->derivation}.
7543 @itemx (ungexp-splicing @var{lst})
7544 Like the above, but splices the contents of @var{lst} inside the
7548 @itemx (ungexp-native-splicing @var{lst})
7549 Like the above, but refers to native builds of the objects listed in
7554 G-expressions created by @code{gexp} or @code{#~} are run-time objects
7555 of the @code{gexp?} type (see below.)
7558 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
7559 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
7560 in their execution environment.
7562 Each item in @var{modules} can be the name of a module, such as
7563 @code{(guix build utils)}, or it can be a module name, followed by an
7564 arrow, followed by a file-like object:
7567 `((guix build utils)
7569 ((guix config) => ,(scheme-file "config.scm"
7570 #~(define-module @dots{}))))
7574 In the example above, the first two modules are taken from the search
7575 path, and the last one is created from the given file-like object.
7577 This form has @emph{lexical} scope: it has an effect on the gexps
7578 directly defined in @var{body}@dots{}, but not on those defined, say, in
7579 procedures called from @var{body}@dots{}.
7582 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
7583 Mark the gexps defined in @var{body}@dots{} as requiring
7584 @var{extensions} in their build and execution environment.
7585 @var{extensions} is typically a list of package objects such as those
7586 defined in the @code{(gnu packages guile)} module.
7588 Concretely, the packages listed in @var{extensions} are added to the
7589 load path while compiling imported modules in @var{body}@dots{}; they
7590 are also added to the load path of the gexp returned by
7594 @deffn {Scheme Procedure} gexp? @var{obj}
7595 Return @code{#t} if @var{obj} is a G-expression.
7598 G-expressions are meant to be written to disk, either as code building
7599 some derivation, or as plain files in the store. The monadic procedures
7600 below allow you to do that (@pxref{The Store Monad}, for more
7601 information about monads.)
7603 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
7604 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
7605 [#:hash #f] [#:hash-algo #f] @
7606 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7607 [#:module-path @var{%load-path}] @
7608 [#:effective-version "2.2"] @
7609 [#:references-graphs #f] [#:allowed-references #f] @
7610 [#:disallowed-references #f] @
7611 [#:leaked-env-vars #f] @
7612 [#:script-name (string-append @var{name} "-builder")] @
7613 [#:deprecation-warnings #f] @
7614 [#:local-build? #f] [#:substitutable? #t] @
7615 [#:properties '()] [#:guile-for-build #f]
7616 Return a derivation @var{name} that runs @var{exp} (a gexp) with
7617 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
7618 stored in a file called @var{script-name}. When @var{target} is true,
7619 it is used as the cross-compilation target triplet for packages referred
7622 @var{modules} is deprecated in favor of @code{with-imported-modules}.
7624 make @var{modules} available in the evaluation context of @var{exp};
7625 @var{modules} is a list of names of Guile modules searched in
7626 @var{module-path} to be copied in the store, compiled, and made available in
7627 the load path during the execution of @var{exp}---e.g., @code{((guix
7628 build utils) (guix build gnu-build-system))}.
7630 @var{effective-version} determines the string to use when adding extensions of
7631 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
7633 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
7636 When @var{references-graphs} is true, it must be a list of tuples of one of the
7640 (@var{file-name} @var{package})
7641 (@var{file-name} @var{package} @var{output})
7642 (@var{file-name} @var{derivation})
7643 (@var{file-name} @var{derivation} @var{output})
7644 (@var{file-name} @var{store-item})
7647 The right-hand-side of each element of @var{references-graphs} is automatically made
7648 an input of the build process of @var{exp}. In the build environment, each
7649 @var{file-name} contains the reference graph of the corresponding item, in a simple
7652 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
7653 In the latter case, the list denotes store items that the result is allowed to
7654 refer to. Any reference to another store item will lead to a build error.
7655 Similarly for @var{disallowed-references}, which can list items that must not be
7656 referenced by the outputs.
7658 @var{deprecation-warnings} determines whether to show deprecation warnings while
7659 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
7661 The other arguments are as for @code{derivation} (@pxref{Derivations}).
7664 @cindex file-like objects
7665 The @code{local-file}, @code{plain-file}, @code{computed-file},
7666 @code{program-file}, and @code{scheme-file} procedures below return
7667 @dfn{file-like objects}. That is, when unquoted in a G-expression,
7668 these objects lead to a file in the store. Consider this G-expression:
7671 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
7672 #$(local-file "/tmp/my-nscd.conf"))
7675 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
7676 to the store. Once expanded, for instance @i{via}
7677 @code{gexp->derivation}, the G-expression refers to that copy under
7678 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
7679 does not have any effect on what the G-expression does.
7680 @code{plain-file} can be used similarly; it differs in that the file
7681 content is directly passed as a string.
7683 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
7684 [#:recursive? #f] [#:select? (const #t)]
7685 Return an object representing local file @var{file} to add to the store; this
7686 object can be used in a gexp. If @var{file} is a relative file name, it is looked
7687 up relative to the source file where this form appears. @var{file} will be added to
7688 the store under @var{name}--by default the base name of @var{file}.
7690 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
7691 designates a flat file and @var{recursive?} is true, its contents are added, and its
7692 permission bits are kept.
7694 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
7695 @var{stat})} for each directory entry, where @var{file} is the entry's
7696 absolute file name and @var{stat} is the result of @code{lstat}; exclude
7697 entries for which @var{select?} does not return true.
7699 This is the declarative counterpart of the @code{interned-file} monadic
7700 procedure (@pxref{The Store Monad, @code{interned-file}}).
7703 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
7704 Return an object representing a text file called @var{name} with the given
7705 @var{content} (a string or a bytevector) to be added to the store.
7707 This is the declarative counterpart of @code{text-file}.
7710 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
7711 [#:options '(#:local-build? #t)]
7712 Return an object representing the store item @var{name}, a file or
7713 directory computed by @var{gexp}. @var{options}
7714 is a list of additional arguments to pass to @code{gexp->derivation}.
7716 This is the declarative counterpart of @code{gexp->derivation}.
7719 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
7720 [#:guile (default-guile)] [#:module-path %load-path] @
7721 [#:system (%current-system)] [#:target #f]
7722 Return an executable script @var{name} that runs @var{exp} using
7723 @var{guile}, with @var{exp}'s imported modules in its search path.
7724 Look up @var{exp}'s modules in @var{module-path}.
7726 The example below builds a script that simply invokes the @command{ls}
7730 (use-modules (guix gexp) (gnu packages base))
7732 (gexp->script "list-files"
7733 #~(execl #$(file-append coreutils "/bin/ls")
7737 When ``running'' it through the store (@pxref{The Store Monad,
7738 @code{run-with-store}}), we obtain a derivation that produces an
7739 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
7742 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
7744 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
7748 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
7749 [#:guile #f] [#:module-path %load-path]
7750 Return an object representing the executable store item @var{name} that
7751 runs @var{gexp}. @var{guile} is the Guile package used to execute that
7752 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
7754 This is the declarative counterpart of @code{gexp->script}.
7757 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
7758 [#:set-load-path? #t] [#:module-path %load-path] @
7760 [#:guile (default-guile)]
7761 Return a derivation that builds a file @var{name} containing @var{exp}.
7762 When @var{splice?} is true, @var{exp} is considered to be a list of
7763 expressions that will be spliced in the resulting file.
7765 When @var{set-load-path?} is true, emit code in the resulting file to
7766 set @code{%load-path} and @code{%load-compiled-path} to honor
7767 @var{exp}'s imported modules. Look up @var{exp}'s modules in
7770 The resulting file holds references to all the dependencies of @var{exp}
7771 or a subset thereof.
7774 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} [#:splice? #f]
7775 Return an object representing the Scheme file @var{name} that contains
7778 This is the declarative counterpart of @code{gexp->file}.
7781 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
7782 Return as a monadic value a derivation that builds a text file
7783 containing all of @var{text}. @var{text} may list, in addition to
7784 strings, objects of any type that can be used in a gexp: packages,
7785 derivations, local file objects, etc. The resulting store file holds
7786 references to all these.
7788 This variant should be preferred over @code{text-file} anytime the file
7789 to create will reference items from the store. This is typically the
7790 case when building a configuration file that embeds store file names,
7794 (define (profile.sh)
7795 ;; Return the name of a shell script in the store that
7796 ;; initializes the 'PATH' environment variable.
7797 (text-file* "profile.sh"
7798 "export PATH=" coreutils "/bin:"
7799 grep "/bin:" sed "/bin\n"))
7802 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
7803 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
7804 preventing them from being garbage-collected during its lifetime.
7807 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
7808 Return an object representing store file @var{name} containing
7809 @var{text}. @var{text} is a sequence of strings and file-like objects,
7813 (mixed-text-file "profile"
7814 "export PATH=" coreutils "/bin:" grep "/bin")
7817 This is the declarative counterpart of @code{text-file*}.
7820 @deffn {Scheme Procedure} file-union @var{name} @var{files}
7821 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
7822 Each item in @var{files} must be a two-element list where the first element is the
7823 file name to use in the new directory, and the second element is a gexp
7824 denoting the target file. Here's an example:
7828 `(("hosts" ,(plain-file "hosts"
7829 "127.0.0.1 localhost"))
7830 ("bashrc" ,(plain-file "bashrc"
7831 "alias ls='ls --color=auto'"))))
7834 This yields an @code{etc} directory containing these two files.
7837 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
7838 Return a directory that is the union of @var{things}, where @var{things} is a list of
7839 file-like objects denoting directories. For example:
7842 (directory-union "guile+emacs" (list guile emacs))
7845 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
7848 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
7849 Return a file-like object that expands to the concatenation of @var{obj}
7850 and @var{suffix}, where @var{obj} is a lowerable object and each
7851 @var{suffix} is a string.
7853 As an example, consider this gexp:
7856 (gexp->script "run-uname"
7857 #~(system* #$(file-append coreutils
7861 The same effect could be achieved with:
7864 (gexp->script "run-uname"
7865 #~(system* (string-append #$coreutils
7869 There is one difference though: in the @code{file-append} case, the
7870 resulting script contains the absolute file name as a string, whereas in
7871 the second case, the resulting script contains a @code{(string-append
7872 @dots{})} expression to construct the file name @emph{at run time}.
7876 Of course, in addition to gexps embedded in ``host'' code, there are
7877 also modules containing build tools. To make it clear that they are
7878 meant to be used in the build stratum, these modules are kept in the
7879 @code{(guix build @dots{})} name space.
7881 @cindex lowering, of high-level objects in gexps
7882 Internally, high-level objects are @dfn{lowered}, using their compiler,
7883 to either derivations or store items. For instance, lowering a package
7884 yields a derivation, and lowering a @code{plain-file} yields a store
7885 item. This is achieved using the @code{lower-object} monadic procedure.
7887 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
7889 Return as a value in @var{%store-monad} the derivation or store item
7890 corresponding to @var{obj} for @var{system}, cross-compiling for
7891 @var{target} if @var{target} is true. @var{obj} must be an object that
7892 has an associated gexp compiler, such as a @code{<package>}.
7895 @node Invoking guix repl
7896 @section Invoking @command{guix repl}
7898 @cindex REPL, read-eval-print loop
7899 The @command{guix repl} command spawns a Guile @dfn{read-eval-print loop}
7900 (REPL) for interactive programming (@pxref{Using Guile Interactively,,, guile,
7901 GNU Guile Reference Manual}). Compared to just launching the @command{guile}
7902 command, @command{guix repl} guarantees that all the Guix modules and all its
7903 dependencies are available in the search path. You can use it this way:
7907 scheme@@(guile-user)> ,use (gnu packages base)
7908 scheme@@(guile-user)> coreutils
7909 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
7913 In addition, @command{guix repl} implements a simple machine-readable REPL
7914 protocol for use by @code{(guix inferior)}, a facility to interact with
7915 @dfn{inferiors}, separate processes running a potentially different revision
7918 The available options are as follows:
7921 @item --type=@var{type}
7922 @itemx -t @var{type}
7923 Start a REPL of the given @var{TYPE}, which can be one of the following:
7927 This is default, and it spawns a standard full-featured Guile REPL.
7929 Spawn a REPL that uses the machine-readable protocol. This is the protocol
7930 that the @code{(guix inferior)} module speaks.
7933 @item --listen=@var{endpoint}
7934 By default, @command{guix repl} reads from standard input and writes to
7935 standard output. When this option is passed, it will instead listen for
7936 connections on @var{endpoint}. Here are examples of valid options:
7939 @item --listen=tcp:37146
7940 Accept connections on localhost on port 37146.
7942 @item --listen=unix:/tmp/socket
7943 Accept connections on the Unix-domain socket @file{/tmp/socket}.
7947 @c *********************************************************************
7951 This section describes Guix command-line utilities. Some of them are
7952 primarily targeted at developers and users who write new package
7953 definitions, while others are more generally useful. They complement
7954 the Scheme programming interface of Guix in a convenient way.
7957 * Invoking guix build:: Building packages from the command line.
7958 * Invoking guix edit:: Editing package definitions.
7959 * Invoking guix download:: Downloading a file and printing its hash.
7960 * Invoking guix hash:: Computing the cryptographic hash of a file.
7961 * Invoking guix import:: Importing package definitions.
7962 * Invoking guix refresh:: Updating package definitions.
7963 * Invoking guix lint:: Finding errors in package definitions.
7964 * Invoking guix size:: Profiling disk usage.
7965 * Invoking guix graph:: Visualizing the graph of packages.
7966 * Invoking guix publish:: Sharing substitutes.
7967 * Invoking guix challenge:: Challenging substitute servers.
7968 * Invoking guix copy:: Copying to and from a remote store.
7969 * Invoking guix container:: Process isolation.
7970 * Invoking guix weather:: Assessing substitute availability.
7971 * Invoking guix processes:: Listing client processes.
7974 @node Invoking guix build
7975 @section Invoking @command{guix build}
7977 @cindex package building
7978 @cindex @command{guix build}
7979 The @command{guix build} command builds packages or derivations and
7980 their dependencies, and prints the resulting store paths. Note that it
7981 does not modify the user's profile---this is the job of the
7982 @command{guix package} command (@pxref{Invoking guix package}). Thus,
7983 it is mainly useful for distribution developers.
7985 The general syntax is:
7988 guix build @var{options} @var{package-or-derivation}@dots{}
7991 As an example, the following command builds the latest versions of Emacs
7992 and of Guile, displays their build logs, and finally displays the
7993 resulting directories:
7996 guix build emacs guile
7999 Similarly, the following command builds all the available packages:
8002 guix build --quiet --keep-going \
8003 `guix package -A | cut -f1,2 --output-delimiter=@@`
8006 @var{package-or-derivation} may be either the name of a package found in
8007 the software distribution such as @code{coreutils} or
8008 @code{coreutils@@8.20}, or a derivation such as
8009 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8010 package with the corresponding name (and optionally version) is searched
8011 for among the GNU distribution modules (@pxref{Package Modules}).
8013 Alternatively, the @code{--expression} option may be used to specify a
8014 Scheme expression that evaluates to a package; this is useful when
8015 disambiguating among several same-named packages or package variants is
8018 There may be zero or more @var{options}. The available options are
8019 described in the subsections below.
8022 * Common Build Options:: Build options for most commands.
8023 * Package Transformation Options:: Creating variants of packages.
8024 * Additional Build Options:: Options specific to 'guix build'.
8025 * Debugging Build Failures:: Real life packaging experience.
8028 @node Common Build Options
8029 @subsection Common Build Options
8031 A number of options that control the build process are common to
8032 @command{guix build} and other commands that can spawn builds, such as
8033 @command{guix package} or @command{guix archive}. These are the
8038 @item --load-path=@var{directory}
8039 @itemx -L @var{directory}
8040 Add @var{directory} to the front of the package module search path
8041 (@pxref{Package Modules}).
8043 This allows users to define their own packages and make them visible to
8044 the command-line tools.
8048 Keep the build tree of failed builds. Thus, if a build fails, its build
8049 tree is kept under @file{/tmp}, in a directory whose name is shown at
8050 the end of the build log. This is useful when debugging build issues.
8051 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8054 This option implies @option{--no-offload}, and it has no effect when
8055 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8056 Store, the @code{GUIX_DAEMON_SOCKET} variable}).
8060 Keep going when some of the derivations fail to build; return only once
8061 all the builds have either completed or failed.
8063 The default behavior is to stop as soon as one of the specified
8064 derivations has failed.
8068 Do not build the derivations.
8070 @anchor{fallback-option}
8072 When substituting a pre-built binary fails, fall back to building
8073 packages locally (@pxref{Substitution Failure}).
8075 @item --substitute-urls=@var{urls}
8076 @anchor{client-substitute-urls}
8077 Consider @var{urls} the whitespace-separated list of substitute source
8078 URLs, overriding the default list of URLs of @command{guix-daemon}
8079 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
8081 This means that substitutes may be downloaded from @var{urls}, provided
8082 they are signed by a key authorized by the system administrator
8083 (@pxref{Substitutes}).
8085 When @var{urls} is the empty string, substitutes are effectively
8088 @item --no-substitutes
8089 Do not use substitutes for build products. That is, always build things
8090 locally instead of allowing downloads of pre-built binaries
8091 (@pxref{Substitutes}).
8094 Do not ``graft'' packages. In practice, this means that package updates
8095 available as grafts are not applied. @xref{Security Updates}, for more
8096 information on grafts.
8098 @item --rounds=@var{n}
8099 Build each derivation @var{n} times in a row, and raise an error if
8100 consecutive build results are not bit-for-bit identical.
8102 This is a useful way to detect non-deterministic builds processes.
8103 Non-deterministic build processes are a problem because they make it
8104 practically impossible for users to @emph{verify} whether third-party
8105 binaries are genuine. @xref{Invoking guix challenge}, for more.
8107 Note that, currently, the differing build results are not kept around,
8108 so you will have to manually investigate in case of an error---e.g., by
8109 stashing one of the build results with @code{guix archive --export}
8110 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
8114 Do not use offload builds to other machines (@pxref{Daemon Offload
8115 Setup}). That is, always build things locally instead of offloading
8116 builds to remote machines.
8118 @item --max-silent-time=@var{seconds}
8119 When the build or substitution process remains silent for more than
8120 @var{seconds}, terminate it and report a build failure.
8122 By default, the daemon's setting is honored (@pxref{Invoking
8123 guix-daemon, @code{--max-silent-time}}).
8125 @item --timeout=@var{seconds}
8126 Likewise, when the build or substitution process lasts for more than
8127 @var{seconds}, terminate it and report a build failure.
8129 By default, the daemon's setting is honored (@pxref{Invoking
8130 guix-daemon, @code{--timeout}}).
8132 @c Note: This option is actually not part of %standard-build-options but
8133 @c most programs honor it.
8134 @cindex verbosity, of the command-line tools
8135 @cindex build logs, verbosity
8136 @item -v @var{level}
8137 @itemx --verbosity=@var{level}
8138 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
8139 output is produced, 1 is for quiet output, and 2 shows all the build log
8140 output on standard error.
8142 @item --cores=@var{n}
8144 Allow the use of up to @var{n} CPU cores for the build. The special
8145 value @code{0} means to use as many CPU cores as available.
8147 @item --max-jobs=@var{n}
8149 Allow at most @var{n} build jobs in parallel. @xref{Invoking
8150 guix-daemon, @code{--max-jobs}}, for details about this option and the
8151 equivalent @command{guix-daemon} option.
8153 @item --debug=@var{level}
8154 Produce debugging output coming from the build daemon. @var{level} must be an
8155 integer between 0 and 5; higher means more verbose output. Setting a level of
8156 4 or more may be helpful when debugging setup issues with the build daemon.
8160 Behind the scenes, @command{guix build} is essentially an interface to
8161 the @code{package-derivation} procedure of the @code{(guix packages)}
8162 module, and to the @code{build-derivations} procedure of the @code{(guix
8163 derivations)} module.
8165 In addition to options explicitly passed on the command line,
8166 @command{guix build} and other @command{guix} commands that support
8167 building honor the @code{GUIX_BUILD_OPTIONS} environment variable.
8169 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
8170 Users can define this variable to a list of command line options that
8171 will automatically be used by @command{guix build} and other
8172 @command{guix} commands that can perform builds, as in the example
8176 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
8179 These options are parsed independently, and the result is appended to
8180 the parsed command-line options.
8184 @node Package Transformation Options
8185 @subsection Package Transformation Options
8187 @cindex package variants
8188 Another set of command-line options supported by @command{guix build}
8189 and also @command{guix package} are @dfn{package transformation
8190 options}. These are options that make it possible to define @dfn{package
8191 variants}---for instance, packages built from different source code.
8192 This is a convenient way to create customized packages on the fly
8193 without having to type in the definitions of package variants
8194 (@pxref{Defining Packages}).
8198 @item --with-source=@var{source}
8199 @itemx --with-source=@var{package}=@var{source}
8200 @itemx --with-source=@var{package}@@@var{version}=@var{source}
8201 Use @var{source} as the source of @var{package}, and @var{version} as
8203 @var{source} must be a file name or a URL, as for @command{guix
8204 download} (@pxref{Invoking guix download}).
8206 When @var{package} is omitted,
8207 it is taken to be the package name specified on the
8208 command line that matches the base of @var{source}---e.g.,
8209 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
8210 package is @code{guile}.
8212 Likewise, when @var{version} is omitted, the version string is inferred from
8213 @var{source}; in the previous example, it is @code{2.0.10}.
8215 This option allows users to try out versions of packages other than the
8216 one provided by the distribution. The example below downloads
8217 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
8218 the @code{ed} package:
8221 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
8224 As a developer, @code{--with-source} makes it easy to test release
8228 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
8231 @dots{} or to build from a checkout in a pristine environment:
8234 $ git clone git://git.sv.gnu.org/guix.git
8235 $ guix build guix --with-source=guix@@1.0=./guix
8238 @item --with-input=@var{package}=@var{replacement}
8239 Replace dependency on @var{package} by a dependency on
8240 @var{replacement}. @var{package} must be a package name, and
8241 @var{replacement} must be a package specification such as @code{guile}
8242 or @code{guile@@1.8}.
8244 For instance, the following command builds Guix, but replaces its
8245 dependency on the current stable version of Guile with a dependency on
8246 the legacy version of Guile, @code{guile@@2.0}:
8249 guix build --with-input=guile=guile@@2.0 guix
8252 This is a recursive, deep replacement. So in this example, both
8253 @code{guix} and its dependency @code{guile-json} (which also depends on
8254 @code{guile}) get rebuilt against @code{guile@@2.0}.
8256 This is implemented using the @code{package-input-rewriting} Scheme
8257 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
8259 @item --with-graft=@var{package}=@var{replacement}
8260 This is similar to @code{--with-input} but with an important difference:
8261 instead of rebuilding the whole dependency chain, @var{replacement} is
8262 built and then @dfn{grafted} onto the binaries that were initially
8263 referring to @var{package}. @xref{Security Updates}, for more
8264 information on grafts.
8266 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
8267 and all its dependencies, replacing references to the version of GnuTLS
8268 they currently refer to:
8271 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
8274 This has the advantage of being much faster than rebuilding everything.
8275 But there is a caveat: it works if and only if @var{package} and
8276 @var{replacement} are strictly compatible---for example, if they provide
8277 a library, the application binary interface (ABI) of those libraries
8278 must be compatible. If @var{replacement} is somehow incompatible with
8279 @var{package}, then the resulting package may be unusable. Use with
8282 @item --with-git-url=@var{package}=@var{url}
8283 @cindex Git, using the latest commit
8284 @cindex latest commit, building
8285 Build @var{package} from the latest commit of the @code{master} branch of the
8286 Git repository at @var{url}. Git sub-modules of the repository are fetched,
8289 For example, the following command builds the NumPy Python library against the
8290 latest commit of the master branch of Python itself:
8293 guix build python-numpy \
8294 --with-git-url=python=https://github.com/python/cpython
8297 This option can also be combined with @code{--with-branch} or
8298 @code{--with-commit} (see below).
8300 @cindex continuous integration
8301 Obviously, since it uses the latest commit of the given branch, the result of
8302 such a command varies over time. Nevertheless it is a convenient way to
8303 rebuild entire software stacks against the latest commit of one or more
8304 packages. This is particularly useful in the context of continuous
8307 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
8308 consecutive accesses to the same repository. You may want to clean it up once
8309 in a while to save disk space.
8311 @item --with-branch=@var{package}=@var{branch}
8312 Build @var{package} from the latest commit of @var{branch}. If the
8313 @code{source} field of @var{package} is an origin with the @code{git-fetch}
8314 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
8315 repository URL is taken from that @code{source}. Otherwise you have to use
8316 @code{--with-git-url} to specify the URL of the Git repository.
8318 For instance, the following command builds @code{guile-sqlite3} from the
8319 latest commit of its @code{master} branch, and then builds @code{guix} (which
8320 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
8321 specific @code{guile-sqlite3} build:
8324 guix build --with-branch=guile-sqlite3=master cuirass
8327 @item --with-commit=@var{package}=@var{commit}
8328 This is similar to @code{--with-branch}, except that it builds from
8329 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
8330 Git commit SHA1 identifier or a tag.
8333 @node Additional Build Options
8334 @subsection Additional Build Options
8336 The command-line options presented below are specific to @command{guix
8343 Build quietly, without displaying the build log; this is equivalent to
8344 @code{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
8345 (or similar) and can always be retrieved using the @option{--log-file} option.
8347 @item --file=@var{file}
8348 @itemx -f @var{file}
8349 Build the package, derivation, or other file-like object that the code within
8350 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
8352 As an example, @var{file} might contain a package definition like this
8353 (@pxref{Defining Packages}):
8356 @include package-hello.scm
8359 @item --expression=@var{expr}
8360 @itemx -e @var{expr}
8361 Build the package or derivation @var{expr} evaluates to.
8363 For example, @var{expr} may be @code{(@@ (gnu packages guile)
8364 guile-1.8)}, which unambiguously designates this specific variant of
8365 version 1.8 of Guile.
8367 Alternatively, @var{expr} may be a G-expression, in which case it is used
8368 as a build program passed to @code{gexp->derivation}
8369 (@pxref{G-Expressions}).
8371 Lastly, @var{expr} may refer to a zero-argument monadic procedure
8372 (@pxref{The Store Monad}). The procedure must return a derivation as a
8373 monadic value, which is then passed through @code{run-with-store}.
8377 Build the source derivations of the packages, rather than the packages
8380 For instance, @code{guix build -S gcc} returns something like
8381 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
8384 The returned source tarball is the result of applying any patches and
8385 code snippets specified in the package @code{origin} (@pxref{Defining
8388 Note that @command{guix build -S} compiles the sources only of the
8389 specified packages. They do not include the sources of statically
8390 linked dependencies and by themselves are insufficient for reproducing
8394 Fetch and return the source of @var{package-or-derivation} and all their
8395 dependencies, recursively. This is a handy way to obtain a local copy
8396 of all the source code needed to build @var{packages}, allowing you to
8397 eventually build them even without network access. It is an extension
8398 of the @code{--source} option and can accept one of the following
8399 optional argument values:
8403 This value causes the @code{--sources} option to behave in the same way
8404 as the @code{--source} option.
8407 Build the source derivations of all packages, including any source that
8408 might be listed as @code{inputs}. This is the default value.
8411 $ guix build --sources tzdata
8412 The following derivations will be built:
8413 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
8414 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8418 Build the source derivations of all packages, as well of all transitive
8419 inputs to the packages. This can be used e.g.@: to
8420 prefetch package source for later offline building.
8423 $ guix build --sources=transitive tzdata
8424 The following derivations will be built:
8425 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
8426 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
8427 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
8428 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
8429 /gnu/store/@dots{}-make-4.1.tar.xz.drv
8430 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
8436 @item --system=@var{system}
8437 @itemx -s @var{system}
8438 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
8439 the system type of the build host. The @command{guix build} command allows
8440 you to repeat this option several times, in which case it builds for all the
8441 specified systems; other commands ignore extraneous @option{-s} options.
8444 The @code{--system} flag is for @emph{native} compilation and must not
8445 be confused with cross-compilation. See @code{--target} below for
8446 information on cross-compilation.
8449 An example use of this is on Linux-based systems, which can emulate
8450 different personalities. For instance, passing
8451 @code{--system=i686-linux} on an @code{x86_64-linux} system or
8452 @code{--system=armhf-linux} on an @code{aarch64-linux} system allows you
8453 to build packages in a complete 32-bit environment.
8456 Building for an @code{armhf-linux} system is unconditionally enabled on
8457 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
8458 allow for this functionality, notably the ThunderX.
8461 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
8462 is enabled (@pxref{Virtualization Services,
8463 @code{qemu-binfmt-service-type}}), you can build for any system for
8464 which a QEMU @code{binfmt_misc} handler is installed.
8466 Builds for a system other than that of the machine you are using can
8467 also be offloaded to a remote machine of the right architecture.
8468 @xref{Daemon Offload Setup}, for more information on offloading.
8470 @item --target=@var{triplet}
8471 @cindex cross-compilation
8472 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
8473 as @code{"mips64el-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
8474 configuration triplets,, autoconf, Autoconf}).
8476 @anchor{build-check}
8478 @cindex determinism, checking
8479 @cindex reproducibility, checking
8480 Rebuild @var{package-or-derivation}, which are already available in the
8481 store, and raise an error if the build results are not bit-for-bit
8484 This mechanism allows you to check whether previously installed
8485 substitutes are genuine (@pxref{Substitutes}), or whether the build result
8486 of a package is deterministic. @xref{Invoking guix challenge}, for more
8487 background information and tools.
8489 When used in conjunction with @option{--keep-failed}, the differing
8490 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
8491 This makes it easy to look for differences between the two results.
8494 @cindex repairing store items
8495 @cindex corruption, recovering from
8496 Attempt to repair the specified store items, if they are corrupt, by
8497 re-downloading or rebuilding them.
8499 This operation is not atomic and thus restricted to @code{root}.
8503 Return the derivation paths, not the output paths, of the given
8506 @item --root=@var{file}
8507 @itemx -r @var{file}
8508 @cindex GC roots, adding
8509 @cindex garbage collector roots, adding
8510 Make @var{file} a symlink to the result, and register it as a garbage
8513 Consequently, the results of this @command{guix build} invocation are
8514 protected from garbage collection until @var{file} is removed. When
8515 that option is omitted, build results are eligible for garbage
8516 collection as soon as the build completes. @xref{Invoking guix gc}, for
8520 @cindex build logs, access
8521 Return the build log file names or URLs for the given
8522 @var{package-or-derivation}, or raise an error if build logs are
8525 This works regardless of how packages or derivations are specified. For
8526 instance, the following invocations are equivalent:
8529 guix build --log-file `guix build -d guile`
8530 guix build --log-file `guix build guile`
8531 guix build --log-file guile
8532 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
8535 If a log is unavailable locally, and unless @code{--no-substitutes} is
8536 passed, the command looks for a corresponding log on one of the
8537 substitute servers (as specified with @code{--substitute-urls}.)
8539 So for instance, imagine you want to see the build log of GDB on MIPS,
8540 but you are actually on an @code{x86_64} machine:
8543 $ guix build --log-file gdb -s mips64el-linux
8544 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
8547 You can freely access a huge library of build logs!
8550 @node Debugging Build Failures
8551 @subsection Debugging Build Failures
8553 @cindex build failures, debugging
8554 When defining a new package (@pxref{Defining Packages}), you will
8555 probably find yourself spending some time debugging and tweaking the
8556 build until it succeeds. To do that, you need to operate the build
8557 commands yourself in an environment as close as possible to the one the
8560 To that end, the first thing to do is to use the @option{--keep-failed}
8561 or @option{-K} option of @command{guix build}, which will keep the
8562 failed build tree in @file{/tmp} or whatever directory you specified as
8563 @code{TMPDIR} (@pxref{Invoking guix build, @code{--keep-failed}}).
8565 From there on, you can @command{cd} to the failed build tree and source
8566 the @file{environment-variables} file, which contains all the
8567 environment variable definitions that were in place when the build
8568 failed. So let's say you're debugging a build failure in package
8569 @code{foo}; a typical session would look like this:
8573 @dots{} @i{build fails}
8574 $ cd /tmp/guix-build-foo.drv-0
8575 $ source ./environment-variables
8579 Now, you can invoke commands as if you were the daemon (almost) and
8580 troubleshoot your build process.
8582 Sometimes it happens that, for example, a package's tests pass when you
8583 run them manually but they fail when the daemon runs them. This can
8584 happen because the daemon runs builds in containers where, unlike in our
8585 environment above, network access is missing, @file{/bin/sh} does not
8586 exist, etc. (@pxref{Build Environment Setup}).
8588 In such cases, you may need to run inspect the build process from within
8589 a container similar to the one the build daemon creates:
8594 $ cd /tmp/guix-build-foo.drv-0
8595 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
8596 [env]# source ./environment-variables
8600 Here, @command{guix environment -C} creates a container and spawns a new
8601 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
8602 strace gdb} part adds the @command{strace} and @command{gdb} commands to
8603 the container, which would may find handy while debugging. The
8604 @option{--no-grafts} option makes sure we get the exact same
8605 environment, with ungrafted packages (@pxref{Security Updates}, for more
8608 To get closer to a container like that used by the build daemon, we can
8609 remove @file{/bin/sh}:
8615 (Don't worry, this is harmless: this is all happening in the throw-away
8616 container created by @command{guix environment}.)
8618 The @command{strace} command is probably not in the search path, but we
8622 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
8625 In this way, not only you will have reproduced the environment variables
8626 the daemon uses, you will also be running the build process in a container
8627 similar to the one the daemon uses.
8630 @node Invoking guix edit
8631 @section Invoking @command{guix edit}
8633 @cindex @command{guix edit}
8634 @cindex package definition, editing
8635 So many packages, so many source files! The @command{guix edit} command
8636 facilitates the life of users and packagers by pointing their editor at
8637 the source file containing the definition of the specified packages.
8641 guix edit gcc@@4.9 vim
8645 launches the program specified in the @code{VISUAL} or in the
8646 @code{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
8649 If you are using a Guix Git checkout (@pxref{Building from Git}), or
8650 have created your own packages on @code{GUIX_PACKAGE_PATH}
8651 (@pxref{Package Modules}), you will be able to edit the package
8652 recipes. In other cases, you will be able to examine the read-only recipes
8653 for packages currently in the store.
8656 @node Invoking guix download
8657 @section Invoking @command{guix download}
8659 @cindex @command{guix download}
8660 @cindex downloading package sources
8661 When writing a package definition, developers typically need to download
8662 a source tarball, compute its SHA256 hash, and write that
8663 hash in the package definition (@pxref{Defining Packages}). The
8664 @command{guix download} tool helps with this task: it downloads a file
8665 from the given URI, adds it to the store, and prints both its file name
8666 in the store and its SHA256 hash.
8668 The fact that the downloaded file is added to the store saves bandwidth:
8669 when the developer eventually tries to build the newly defined package
8670 with @command{guix build}, the source tarball will not have to be
8671 downloaded again because it is already in the store. It is also a
8672 convenient way to temporarily stash files, which may be deleted
8673 eventually (@pxref{Invoking guix gc}).
8675 The @command{guix download} command supports the same URIs as used in
8676 package definitions. In particular, it supports @code{mirror://} URIs.
8677 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
8678 Guile bindings for GnuTLS are available in the user's environment; when
8679 they are not available, an error is raised. @xref{Guile Preparations,
8680 how to install the GnuTLS bindings for Guile,, gnutls-guile,
8681 GnuTLS-Guile}, for more information.
8683 @command{guix download} verifies HTTPS server certificates by loading
8684 the certificates of X.509 authorities from the directory pointed to by
8685 the @code{SSL_CERT_DIR} environment variable (@pxref{X.509
8686 Certificates}), unless @option{--no-check-certificate} is used.
8688 The following options are available:
8691 @item --format=@var{fmt}
8693 Write the hash in the format specified by @var{fmt}. For more
8694 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
8696 @item --no-check-certificate
8697 Do not validate the X.509 certificates of HTTPS servers.
8699 When using this option, you have @emph{absolutely no guarantee} that you
8700 are communicating with the authentic server responsible for the given
8701 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
8703 @item --output=@var{file}
8704 @itemx -o @var{file}
8705 Save the downloaded file to @var{file} instead of adding it to the
8709 @node Invoking guix hash
8710 @section Invoking @command{guix hash}
8712 @cindex @command{guix hash}
8713 The @command{guix hash} command computes the SHA256 hash of a file.
8714 It is primarily a convenience tool for anyone contributing to the
8715 distribution: it computes the cryptographic hash of a file, which can be
8716 used in the definition of a package (@pxref{Defining Packages}).
8718 The general syntax is:
8721 guix hash @var{option} @var{file}
8724 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
8725 hash of data read from standard input. @command{guix hash} has the
8730 @item --format=@var{fmt}
8732 Write the hash in the format specified by @var{fmt}.
8734 Supported formats: @code{nix-base32}, @code{base32}, @code{base16}
8735 (@code{hex} and @code{hexadecimal} can be used as well).
8737 If the @option{--format} option is not specified, @command{guix hash}
8738 will output the hash in @code{nix-base32}. This representation is used
8739 in the definitions of packages.
8743 Compute the hash on @var{file} recursively.
8745 In this case, the hash is computed on an archive containing @var{file},
8746 including its children if it is a directory. Some of the metadata of
8747 @var{file} is part of the archive; for instance, when @var{file} is a
8748 regular file, the hash is different depending on whether @var{file} is
8749 executable or not. Metadata such as time stamps has no impact on the
8750 hash (@pxref{Invoking guix archive}).
8751 @c FIXME: Replace xref above with xref to an ``Archive'' section when
8756 When combined with @option{--recursive}, exclude version control system
8757 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.)
8760 As an example, here is how you would compute the hash of a Git checkout,
8761 which is useful when using the @code{git-fetch} method (@pxref{origin
8765 $ git clone http://example.org/foo.git
8771 @node Invoking guix import
8772 @section Invoking @command{guix import}
8774 @cindex importing packages
8775 @cindex package import
8776 @cindex package conversion
8777 @cindex Invoking @command{guix import}
8778 The @command{guix import} command is useful for people who would like to
8779 add a package to the distribution with as little work as
8780 possible---a legitimate demand. The command knows of a few
8781 repositories from which it can ``import'' package metadata. The result
8782 is a package definition, or a template thereof, in the format we know
8783 (@pxref{Defining Packages}).
8785 The general syntax is:
8788 guix import @var{importer} @var{options}@dots{}
8791 @var{importer} specifies the source from which to import package
8792 metadata, and @var{options} specifies a package identifier and other
8793 options specific to @var{importer}.
8795 Some of the importers rely on the ability to run the @command{gpgv} command.
8796 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
8799 Currently, the available ``importers'' are:
8803 Import metadata for the given GNU package. This provides a template
8804 for the latest version of that GNU package, including the hash of its
8805 source tarball, and its canonical synopsis and description.
8807 Additional information such as the package dependencies and its
8808 license needs to be figured out manually.
8810 For example, the following command returns a package definition for
8814 guix import gnu hello
8817 Specific command-line options are:
8820 @item --key-download=@var{policy}
8821 As for @code{guix refresh}, specify the policy to handle missing OpenPGP
8822 keys when verifying the package signature. @xref{Invoking guix
8823 refresh, @code{--key-download}}.
8828 Import metadata from the @uref{https://pypi.python.org/, Python Package
8829 Index}. Information is taken from the JSON-formatted description
8830 available at @code{pypi.python.org} and usually includes all the relevant
8831 information, including package dependencies. For maximum efficiency, it
8832 is recommended to install the @command{unzip} utility, so that the
8833 importer can unzip Python wheels and gather data from them.
8835 The command below imports metadata for the @code{itsdangerous} Python
8839 guix import pypi itsdangerous
8845 Traverse the dependency graph of the given upstream package recursively
8846 and generate package expressions for all those packages that are not yet
8852 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
8853 is taken from the JSON-formatted description available at
8854 @code{rubygems.org} and includes most relevant information, including
8855 runtime dependencies. There are some caveats, however. The metadata
8856 doesn't distinguish between synopses and descriptions, so the same string
8857 is used for both fields. Additionally, the details of non-Ruby
8858 dependencies required to build native extensions is unavailable and left
8859 as an exercise to the packager.
8861 The command below imports metadata for the @code{rails} Ruby package:
8864 guix import gem rails
8870 Traverse the dependency graph of the given upstream package recursively
8871 and generate package expressions for all those packages that are not yet
8877 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
8878 Information is taken from the JSON-formatted metadata provided through
8879 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
8880 relevant information, such as module dependencies. License information
8881 should be checked closely. If Perl is available in the store, then the
8882 @code{corelist} utility will be used to filter core modules out of the
8883 list of dependencies.
8885 The command command below imports metadata for the @code{Acme::Boolean}
8889 guix import cpan Acme::Boolean
8894 @cindex Bioconductor
8895 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
8896 central repository for the @uref{https://r-project.org, GNU@tie{}R
8897 statistical and graphical environment}.
8899 Information is extracted from the @code{DESCRIPTION} file of the package.
8901 The command command below imports metadata for the @code{Cairo}
8905 guix import cran Cairo
8908 When @code{--recursive} is added, the importer will traverse the
8909 dependency graph of the given upstream package recursively and generate
8910 package expressions for all those packages that are not yet in Guix.
8912 When @code{--archive=bioconductor} is added, metadata is imported from
8913 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
8914 packages for for the analysis and comprehension of high-throughput
8915 genomic data in bioinformatics.
8917 Information is extracted from the @code{DESCRIPTION} file contained in the
8920 The command below imports metadata for the @code{GenomicRanges}
8924 guix import cran --archive=bioconductor GenomicRanges
8927 Finally, you can also import R packages that have not yet been published on
8928 CRAN or Bioconductor as long as they are in a git repository. Use
8929 @code{--archive=git} followed by the URL of the git repository:
8932 guix import cran --archive=git https://github.com/immunogenomics/harmony
8938 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
8939 comprehensive TeX archive network for TeX packages that are part of the
8940 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
8942 Information about the package is obtained through the XML API provided
8943 by CTAN, while the source code is downloaded from the SVN repository of
8944 the Tex Live project. This is done because the CTAN does not keep
8947 The command command below imports metadata for the @code{fontspec}
8951 guix import texlive fontspec
8954 When @code{--archive=DIRECTORY} is added, the source code is downloaded
8955 not from the @file{latex} sub-directory of the @file{texmf-dist/source}
8956 tree in the TeX Live SVN repository, but from the specified sibling
8957 directory under the same root.
8959 The command below imports metadata for the @code{ifxetex} package from
8960 CTAN while fetching the sources from the directory
8961 @file{texmf/source/generic}:
8964 guix import texlive --archive=generic ifxetex
8968 @cindex JSON, import
8969 Import package metadata from a local JSON file. Consider the following
8970 example package definition in JSON format:
8976 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
8977 "build-system": "gnu",
8978 "home-page": "https://www.gnu.org/software/hello/",
8979 "synopsis": "Hello, GNU world: An example GNU package",
8980 "description": "GNU Hello prints a greeting.",
8981 "license": "GPL-3.0+",
8982 "native-inputs": ["gettext"]
8986 The field names are the same as for the @code{<package>} record
8987 (@xref{Defining Packages}). References to other packages are provided
8988 as JSON lists of quoted package specification strings such as
8989 @code{guile} or @code{guile@@2.0}.
8991 The importer also supports a more explicit source definition using the
8992 common fields for @code{<origin>} records:
8998 "method": "url-fetch",
8999 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9001 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9008 The command below reads metadata from the JSON file @code{hello.json}
9009 and outputs a package expression:
9012 guix import json hello.json
9016 Import metadata from a local copy of the source of the
9017 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9018 relies on the @command{nix-instantiate} command of
9019 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9020 typically written in a mixture of Nix-language and Bash code. This
9021 command only imports the high-level package structure that is written in
9022 the Nix language. It normally includes all the basic fields of a
9025 When importing a GNU package, the synopsis and descriptions are replaced
9026 by their canonical upstream variant.
9028 Usually, you will first need to do:
9031 export NIX_REMOTE=daemon
9035 so that @command{nix-instantiate} does not try to open the Nix database.
9037 As an example, the command below imports the package definition of
9038 LibreOffice (more precisely, it imports the definition of the package
9039 bound to the @code{libreoffice} top-level attribute):
9042 guix import nix ~/path/to/nixpkgs libreoffice
9047 Import metadata from the Haskell community's central package archive
9048 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
9049 Cabal files and includes all the relevant information, including package
9052 Specific command-line options are:
9057 Read a Cabal file from standard input.
9058 @item --no-test-dependencies
9060 Do not include dependencies required only by the test suites.
9061 @item --cabal-environment=@var{alist}
9062 @itemx -e @var{alist}
9063 @var{alist} is a Scheme alist defining the environment in which the
9064 Cabal conditionals are evaluated. The accepted keys are: @code{os},
9065 @code{arch}, @code{impl} and a string representing the name of a flag.
9066 The value associated with a flag has to be either the symbol
9067 @code{true} or @code{false}. The value associated with other keys
9068 has to conform to the Cabal file format definition. The default value
9069 associated with the keys @code{os}, @code{arch} and @code{impl} is
9070 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
9073 Traverse the dependency graph of the given upstream package recursively
9074 and generate package expressions for all those packages that are not yet
9078 The command below imports metadata for the latest version of the
9079 @code{HTTP} Haskell package without including test dependencies and
9080 specifying the value of the flag @samp{network-uri} as @code{false}:
9083 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
9086 A specific package version may optionally be specified by following the
9087 package name by an at-sign and a version number as in the following example:
9090 guix import hackage mtl@@2.1.3.1
9095 The @code{stackage} importer is a wrapper around the @code{hackage} one.
9096 It takes a package name, looks up the package version included in a
9097 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
9098 release and uses the @code{hackage} importer to retrieve its metadata.
9099 Note that it is up to you to select an LTS release compatible with the
9100 GHC compiler used by Guix.
9102 Specific command-line options are:
9105 @item --no-test-dependencies
9107 Do not include dependencies required only by the test suites.
9108 @item --lts-version=@var{version}
9109 @itemx -l @var{version}
9110 @var{version} is the desired LTS release version. If omitted the latest
9114 Traverse the dependency graph of the given upstream package recursively
9115 and generate package expressions for all those packages that are not yet
9119 The command below imports metadata for the @code{HTTP} Haskell package
9120 included in the LTS Stackage release version 7.18:
9123 guix import stackage --lts-version=7.18 HTTP
9128 Import metadata from an Emacs Lisp Package Archive (ELPA) package
9129 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
9131 Specific command-line options are:
9134 @item --archive=@var{repo}
9135 @itemx -a @var{repo}
9136 @var{repo} identifies the archive repository from which to retrieve the
9137 information. Currently the supported repositories and their identifiers
9141 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
9142 identifier. This is the default.
9144 Packages from @code{elpa.gnu.org} are signed with one of the keys
9145 contained in the GnuPG keyring at
9146 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
9147 @code{emacs} package (@pxref{Package Installation, ELPA package
9148 signatures,, emacs, The GNU Emacs Manual}).
9151 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
9152 @code{melpa-stable} identifier.
9155 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
9161 Traverse the dependency graph of the given upstream package recursively
9162 and generate package expressions for all those packages that are not yet
9168 Import metadata from the crates.io Rust package repository
9169 @uref{https://crates.io, crates.io}, as in this example:
9172 guix import crate blake2-rfc
9175 The crate importer also allows you to specify a version string:
9178 guix import crate constant-time-eq@@0.1.0
9181 Additional options include:
9186 Traverse the dependency graph of the given upstream package recursively
9187 and generate package expressions for all those packages that are not yet
9194 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
9195 repository used by the OCaml community.
9198 The structure of the @command{guix import} code is modular. It would be
9199 useful to have more importers for other package formats, and your help
9200 is welcome here (@pxref{Contributing}).
9202 @node Invoking guix refresh
9203 @section Invoking @command{guix refresh}
9205 @cindex @command {guix refresh}
9206 The primary audience of the @command{guix refresh} command is developers
9207 of the GNU software distribution. By default, it reports any packages
9208 provided by the distribution that are outdated compared to the latest
9209 upstream version, like this:
9213 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
9214 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
9217 Alternately, one can specify packages to consider, in which case a
9218 warning is emitted for packages that lack an updater:
9221 $ guix refresh coreutils guile guile-ssh
9222 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
9223 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
9226 @command{guix refresh} browses the upstream repository of each package and determines
9227 the highest version number of the releases therein. The command
9228 knows how to update specific types of packages: GNU packages, ELPA
9229 packages, etc.---see the documentation for @option{--type} below. There
9230 are many packages, though, for which it lacks a method to determine
9231 whether a new upstream release is available. However, the mechanism is
9232 extensible, so feel free to get in touch with us to add a new method!
9237 Consider the packages specified, and all the packages upon which they depend.
9240 $ guix refresh --recursive coreutils
9241 gnu/packages/acl.scm:35:2: warning: no updater for acl
9242 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
9243 gnu/packages/xml.scm:68:2: warning: no updater for expat
9244 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
9250 Sometimes the upstream name differs from the package name used in Guix,
9251 and @command{guix refresh} needs a little help. Most updaters honor the
9252 @code{upstream-name} property in package definitions, which can be used
9256 (define-public network-manager
9258 (name "network-manager")
9260 (properties '((upstream-name . "NetworkManager")))))
9263 When passed @code{--update}, it modifies distribution source files to
9264 update the version numbers and source tarball hashes of those package
9265 recipes (@pxref{Defining Packages}). This is achieved by downloading
9266 each package's latest source tarball and its associated OpenPGP
9267 signature, authenticating the downloaded tarball against its signature
9268 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
9269 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
9272 key used to sign the tarball is missing from the user's keyring, an
9273 attempt is made to automatically retrieve it from a public key server;
9274 when this is successful, the key is added to the user's keyring; otherwise,
9275 @command{guix refresh} reports an error.
9277 The following options are supported:
9281 @item --expression=@var{expr}
9282 @itemx -e @var{expr}
9283 Consider the package @var{expr} evaluates to.
9285 This is useful to precisely refer to a package, as in this example:
9288 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
9291 This command lists the dependents of the ``final'' libc (essentially all
9296 Update distribution source files (package recipes) in place. This is
9297 usually run from a checkout of the Guix source tree (@pxref{Running
9298 Guix Before It Is Installed}):
9301 $ ./pre-inst-env guix refresh -s non-core -u
9304 @xref{Defining Packages}, for more information on package definitions.
9306 @item --select=[@var{subset}]
9307 @itemx -s @var{subset}
9308 Select all the packages in @var{subset}, one of @code{core} or
9311 The @code{core} subset refers to all the packages at the core of the
9312 distribution---i.e., packages that are used to build ``everything
9313 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
9314 changing one of these packages in the distribution entails a rebuild of
9315 all the others. Thus, such updates are an inconvenience to users in
9316 terms of build time or bandwidth used to achieve the upgrade.
9318 The @code{non-core} subset refers to the remaining packages. It is
9319 typically useful in cases where an update of the core packages would be
9322 @item --manifest=@var{file}
9323 @itemx -m @var{file}
9324 Select all the packages from the manifest in @var{file}. This is useful to
9325 check if any packages of the user manifest can be updated.
9327 @item --type=@var{updater}
9328 @itemx -t @var{updater}
9329 Select only packages handled by @var{updater} (may be a comma-separated
9330 list of updaters). Currently, @var{updater} may be one of:
9334 the updater for GNU packages;
9336 the updater for GNOME packages;
9338 the updater for KDE packages;
9340 the updater for X.org packages;
9342 the updater for packages hosted on kernel.org;
9344 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
9346 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
9348 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
9350 the updater for @uref{https://www.cpan.org/, CPAN} packages;
9352 the updater for @uref{https://pypi.python.org, PyPI} packages.
9354 the updater for @uref{https://rubygems.org, RubyGems} packages.
9356 the updater for @uref{https://github.com, GitHub} packages.
9358 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
9360 the updater for @uref{https://www.stackage.org, Stackage} packages.
9362 the updater for @uref{https://crates.io, Crates} packages.
9364 the updater for @uref{https://launchpad.net, Launchpad} packages.
9367 For instance, the following command only checks for updates of Emacs
9368 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
9371 $ guix refresh --type=elpa,cran
9372 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
9373 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
9378 In addition, @command{guix refresh} can be passed one or more package
9379 names, as in this example:
9382 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
9386 The command above specifically updates the @code{emacs} and
9387 @code{idutils} packages. The @code{--select} option would have no
9388 effect in this case.
9390 When considering whether to upgrade a package, it is sometimes
9391 convenient to know which packages would be affected by the upgrade and
9392 should be checked for compatibility. For this the following option may
9393 be used when passing @command{guix refresh} one or more package names:
9397 @item --list-updaters
9399 List available updaters and exit (see @option{--type} above.)
9401 For each updater, display the fraction of packages it covers; at the
9402 end, display the fraction of packages covered by all these updaters.
9404 @item --list-dependent
9406 List top-level dependent packages that would need to be rebuilt as a
9407 result of upgrading one or more packages.
9409 @xref{Invoking guix graph, the @code{reverse-package} type of
9410 @command{guix graph}}, for information on how to visualize the list of
9411 dependents of a package.
9415 Be aware that the @code{--list-dependent} option only
9416 @emph{approximates} the rebuilds that would be required as a result of
9417 an upgrade. More rebuilds might be required under some circumstances.
9420 $ guix refresh --list-dependent flex
9421 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
9422 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
9425 The command above lists a set of packages that could be built to check
9426 for compatibility with an upgraded @code{flex} package.
9430 @item --list-transitive
9431 List all the packages which one or more packages depend upon.
9434 $ guix refresh --list-transitive flex
9435 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
9436 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{}
9441 The command above lists a set of packages which, when changed, would cause
9442 @code{flex} to be rebuilt.
9444 The following options can be used to customize GnuPG operation:
9448 @item --gpg=@var{command}
9449 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
9450 for in @code{$PATH}.
9452 @item --keyring=@var{file}
9453 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
9454 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
9455 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
9456 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
9457 information on a tool to manipulate keybox files).
9459 When this option is omitted, @command{guix refresh} uses
9460 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
9461 signing keys. OpenPGP signatures are checked against keys from this keyring;
9462 missing keys are downloaded to this keyring as well (see
9463 @option{--key-download} below.)
9465 You can export keys from your default GPG keyring into a keybox file using
9466 commands like this one:
9469 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
9472 Likewise, you can fetch keys to a specific keybox file like this:
9475 gpg --no-default-keyring --keyring mykeyring.kbx \
9476 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
9479 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
9480 Privacy Guard}, for more information on GPG's @option{--keyring} option.
9482 @item --key-download=@var{policy}
9483 Handle missing OpenPGP keys according to @var{policy}, which may be one
9488 Always download missing OpenPGP keys from the key server, and add them
9489 to the user's GnuPG keyring.
9492 Never try to download missing OpenPGP keys. Instead just bail out.
9495 When a package signed with an unknown OpenPGP key is encountered, ask
9496 the user whether to download it or not. This is the default behavior.
9499 @item --key-server=@var{host}
9500 Use @var{host} as the OpenPGP key server when importing a public key.
9504 The @code{github} updater uses the
9505 @uref{https://developer.github.com/v3/, GitHub API} to query for new
9506 releases. When used repeatedly e.g.@: when refreshing all packages,
9507 GitHub will eventually refuse to answer any further API requests. By
9508 default 60 API requests per hour are allowed, and a full refresh on all
9509 GitHub packages in Guix requires more than this. Authentication with
9510 GitHub through the use of an API token alleviates these limits. To use
9511 an API token, set the environment variable @code{GUIX_GITHUB_TOKEN} to a
9512 token procured from @uref{https://github.com/settings/tokens} or
9516 @node Invoking guix lint
9517 @section Invoking @command{guix lint}
9519 @cindex @command{guix lint}
9520 @cindex package, checking for errors
9521 The @command{guix lint} command is meant to help package developers avoid
9522 common errors and use a consistent style. It runs a number of checks on
9523 a given set of packages in order to find common mistakes in their
9524 definitions. Available @dfn{checkers} include (see
9525 @code{--list-checkers} for a complete list):
9530 Validate certain typographical and stylistic rules about package
9531 descriptions and synopses.
9533 @item inputs-should-be-native
9534 Identify inputs that should most likely be native inputs.
9540 @itemx source-file-name
9541 Probe @code{home-page} and @code{source} URLs and report those that are
9542 invalid. Suggest a @code{mirror://} URL when applicable. If the
9543 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
9544 URL. Check that the source file name is meaningful, e.g.@: is not just a
9545 version number or ``git-checkout'', without a declared @code{file-name}
9546 (@pxref{origin Reference}).
9548 @item source-unstable-tarball
9549 Parse the @code{source} URL to determine if a tarball from GitHub is
9550 autogenerated or if it is a release tarball. Unfortunately GitHub's
9551 autogenerated tarballs are sometimes regenerated.
9554 @cindex Software Heritage, source code archive
9555 @cindex archival of source code, Software Heritage
9556 Checks whether the package's source code is archived at
9557 @uref{https://www.softwareheritage.org, Software Heritage}.
9559 When the source code that is not archived comes from a version-control system
9560 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
9561 ``save'' request so that it eventually archives it. This ensures that the
9562 source will remain available in the long term, and that Guix can fall back to
9563 Software Heritage should the source code disappear from its original host.
9564 The status of recent ``save'' requests can be
9565 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
9567 When source code is a tarball obtained with @code{url-fetch}, simply print a
9568 message when it is not archived. As of this writing, Software Heritage does
9569 not allow requests to save arbitrary tarballs; we are working on ways to
9570 ensure that non-VCS source code is also archived.
9573 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
9574 request rate per IP address}. When the limit is reached, @command{guix lint}
9575 prints a message and the @code{archival} checker stops doing anything until
9576 that limit has been reset.
9579 @cindex security vulnerabilities
9580 @cindex CVE, Common Vulnerabilities and Exposures
9581 Report known vulnerabilities found in the Common Vulnerabilities and
9582 Exposures (CVE) databases of the current and past year
9583 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
9586 To view information about a particular vulnerability, visit pages such as:
9590 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
9592 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
9596 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
9597 @code{CVE-2015-7554}.
9599 Package developers can specify in package recipes the
9600 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
9601 name and version of the package when they differ from the name or version
9602 that Guix uses, as in this example:
9608 ;; CPE calls this package "grub2".
9609 (properties '((cpe-name . "grub2")
9610 (cpe-version . "2.3"))))
9613 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
9614 Some entries in the CVE database do not specify which version of a
9615 package they apply to, and would thus ``stick around'' forever. Package
9616 developers who found CVE alerts and verified they can be ignored can
9617 declare them as in this example:
9623 ;; These CVEs no longer apply and can be safely ignored.
9624 (properties `((lint-hidden-cve . ("CVE-2011-0433"
9627 "CVE-2011-5244")))))
9631 Warn about obvious source code formatting issues: trailing white space,
9632 use of tabulations, etc.
9635 The general syntax is:
9638 guix lint @var{options} @var{package}@dots{}
9641 If no package is given on the command line, then all packages are checked.
9642 The @var{options} may be zero or more of the following:
9645 @item --list-checkers
9647 List and describe all the available checkers that will be run on packages
9652 Only enable the checkers specified in a comma-separated list using the
9653 names returned by @code{--list-checkers}.
9657 @node Invoking guix size
9658 @section Invoking @command{guix size}
9661 @cindex package size
9663 @cindex @command{guix size}
9664 The @command{guix size} command helps package developers profile the
9665 disk usage of packages. It is easy to overlook the impact of an
9666 additional dependency added to a package, or the impact of using a
9667 single output for a package that could easily be split (@pxref{Packages
9668 with Multiple Outputs}). Such are the typical issues that
9669 @command{guix size} can highlight.
9671 The command can be passed one or more package specifications
9672 such as @code{gcc@@4.8}
9673 or @code{guile:debug}, or a file name in the store. Consider this
9677 $ guix size coreutils
9678 store item total self
9679 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
9680 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
9681 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
9682 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
9683 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
9684 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
9685 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
9686 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
9691 The store items listed here constitute the @dfn{transitive closure} of
9692 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
9693 would be returned by:
9696 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
9699 Here the output shows three columns next to store items. The first column,
9700 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
9701 the store item---that is, its own size plus the size of all its
9702 dependencies. The next column, labeled ``self'', shows the size of the
9703 item itself. The last column shows the ratio of the size of the item
9704 itself to the space occupied by all the items listed here.
9706 In this example, we see that the closure of Coreutils weighs in at
9707 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
9708 libraries. (That libc and GCC's libraries represent a large fraction of
9709 the closure is not a problem @i{per se} because they are always available
9710 on the system anyway.)
9712 When the package(s) passed to @command{guix size} are available in the
9713 store@footnote{More precisely, @command{guix size} looks for the
9714 @emph{ungrafted} variant of the given package(s), as returned by
9715 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
9716 for information on grafts.}, @command{guix size} queries the daemon to determine its
9717 dependencies, and measures its size in the store, similar to @command{du
9718 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
9721 When the given packages are @emph{not} in the store, @command{guix size}
9722 reports information based on the available substitutes
9723 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
9724 store items that are not even on disk, only available remotely.
9726 You can also specify several package names:
9729 $ guix size coreutils grep sed bash
9730 store item total self
9731 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
9732 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
9733 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
9734 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
9740 In this example we see that the combination of the four packages takes
9741 102.3@tie{}MiB in total, which is much less than the sum of each closure
9742 since they have a lot of dependencies in common.
9744 The available options are:
9748 @item --substitute-urls=@var{urls}
9749 Use substitute information from @var{urls}.
9750 @xref{client-substitute-urls, the same option for @code{guix build}}.
9752 @item --sort=@var{key}
9753 Sort lines according to @var{key}, one of the following options:
9757 the size of each item (the default);
9759 the total size of the item's closure.
9762 @item --map-file=@var{file}
9763 Write a graphical map of disk usage in PNG format to @var{file}.
9765 For the example above, the map looks like this:
9767 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
9768 produced by @command{guix size}}
9770 This option requires that
9771 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
9772 installed and visible in Guile's module search path. When that is not
9773 the case, @command{guix size} fails as it tries to load it.
9775 @item --system=@var{system}
9776 @itemx -s @var{system}
9777 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
9781 @node Invoking guix graph
9782 @section Invoking @command{guix graph}
9785 @cindex @command{guix graph}
9786 @cindex package dependencies
9787 Packages and their dependencies form a @dfn{graph}, specifically a
9788 directed acyclic graph (DAG). It can quickly become difficult to have a
9789 mental model of the package DAG, so the @command{guix graph} command
9790 provides a visual representation of the DAG. By default,
9791 @command{guix graph} emits a DAG representation in the input format of
9792 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
9793 directly to the @command{dot} command of Graphviz. It can also emit an
9794 HTML page with embedded JavaScript code to display a ``chord diagram''
9795 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
9796 emit Cypher queries to construct a graph in a graph database supporting
9797 the @uref{https://www.opencypher.org/, openCypher} query language.
9798 The general syntax is:
9801 guix graph @var{options} @var{package}@dots{}
9804 For example, the following command generates a PDF file representing the
9805 package DAG for the GNU@tie{}Core Utilities, showing its build-time
9809 guix graph coreutils | dot -Tpdf > dag.pdf
9812 The output looks like this:
9814 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
9816 Nice little graph, no?
9818 But there is more than one graph! The one above is concise: it is the
9819 graph of package objects, omitting implicit inputs such as GCC, libc,
9820 grep, etc. It is often useful to have such a concise graph, but
9821 sometimes one may want to see more details. @command{guix graph} supports
9822 several types of graphs, allowing you to choose the level of detail:
9826 This is the default type used in the example above. It shows the DAG of
9827 package objects, excluding implicit dependencies. It is concise, but
9828 filters out many details.
9830 @item reverse-package
9831 This shows the @emph{reverse} DAG of packages. For example:
9834 guix graph --type=reverse-package ocaml
9837 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
9838 you are also interested in cases where OCaml is an implicit dependency, see
9839 @code{reverse-bag} below.)
9841 Note that for core packages this can yield huge graphs. If all you want
9842 is to know the number of packages that depend on a given package, use
9843 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
9844 @option{--list-dependent}}).
9847 This is the package DAG, @emph{including} implicit inputs.
9849 For instance, the following command:
9852 guix graph --type=bag-emerged coreutils | dot -Tpdf > dag.pdf
9855 ...@: yields this bigger graph:
9857 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
9859 At the bottom of the graph, we see all the implicit inputs of
9860 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
9862 Now, note that the dependencies of these implicit inputs---that is, the
9863 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
9864 here, for conciseness.
9867 Similar to @code{bag-emerged}, but this time including all the bootstrap
9870 @item bag-with-origins
9871 Similar to @code{bag}, but also showing origins and their dependencies.
9874 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
9875 it also takes implicit dependencies into account. For example:
9878 guix graph -t reverse-bag dune
9882 ...@: yields the graph of all packages that depend on Dune, directly or
9883 indirectly. Since Dune is an @emph{implicit} dependency of many packages
9884 @i{via} @code{dune-build-system}, this shows a large number of packages,
9885 whereas @code{reverse-package} would show very few if any.
9888 This is the most detailed representation: It shows the DAG of
9889 derivations (@pxref{Derivations}) and plain store items. Compared to
9890 the above representation, many additional nodes are visible, including
9891 build scripts, patches, Guile modules, etc.
9893 For this type of graph, it is also possible to pass a @file{.drv} file
9894 name instead of a package name, as in:
9897 guix graph -t derivation `guix system build -d my-config.scm`
9901 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
9902 For example, the following command shows the graph for the package
9903 module that defines the @code{guile} package:
9906 guix graph -t module guile | dot -Tpdf > module-graph.pdf
9910 All the types above correspond to @emph{build-time dependencies}. The
9911 following graph type represents the @emph{run-time dependencies}:
9915 This is the graph of @dfn{references} of a package output, as returned
9916 by @command{guix gc --references} (@pxref{Invoking guix gc}).
9918 If the given package output is not available in the store, @command{guix
9919 graph} attempts to obtain dependency information from substitutes.
9921 Here you can also pass a store file name instead of a package name. For
9922 example, the command below produces the reference graph of your profile
9923 (which can be big!):
9926 guix graph -t references `readlink -f ~/.guix-profile`
9930 This is the graph of the @dfn{referrers} of a store item, as returned by
9931 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
9933 This relies exclusively on local information from your store. For
9934 instance, let us suppose that the current Inkscape is available in 10
9935 profiles on your machine; @command{guix graph -t referrers inkscape}
9936 will show a graph rooted at Inkscape and with those 10 profiles linked
9939 It can help determine what is preventing a store item from being garbage
9944 The available options are the following:
9947 @item --type=@var{type}
9948 @itemx -t @var{type}
9949 Produce a graph output of @var{type}, where @var{type} must be one of
9950 the values listed above.
9953 List the supported graph types.
9955 @item --backend=@var{backend}
9956 @itemx -b @var{backend}
9957 Produce a graph using the selected @var{backend}.
9959 @item --list-backends
9960 List the supported graph backends.
9962 Currently, the available backends are Graphviz and d3.js.
9964 @item --expression=@var{expr}
9965 @itemx -e @var{expr}
9966 Consider the package @var{expr} evaluates to.
9968 This is useful to precisely refer to a package, as in this example:
9971 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
9974 @item --system=@var{system}
9975 @itemx -s @var{system}
9976 Display the graph for @var{system}---e.g., @code{i686-linux}.
9978 The package dependency graph is largely architecture-independent, but there
9979 are some architecture-dependent bits that this option allows you to visualize.
9982 On top of that, @command{guix graph} supports all the usual package
9983 transformation options (@pxref{Package Transformation Options}). This
9984 makes it easy to view the effect of a graph-rewriting transformation
9985 such as @option{--with-input}. For example, the command below outputs
9986 the graph of @code{git} once @code{openssl} has been replaced by
9987 @code{libressl} everywhere in the graph:
9990 guix graph git --with-input=openssl=libressl
9993 So many possibilities, so much fun!
9995 @node Invoking guix publish
9996 @section Invoking @command{guix publish}
9998 @cindex @command{guix publish}
9999 The purpose of @command{guix publish} is to enable users to easily share
10000 their store with others, who can then use it as a substitute server
10001 (@pxref{Substitutes}).
10003 When @command{guix publish} runs, it spawns an HTTP server which allows
10004 anyone with network access to obtain substitutes from it. This means
10005 that any machine running Guix can also act as if it were a build farm,
10006 since the HTTP interface is compatible with Cuirass, the software behind
10007 the @code{@value{SUBSTITUTE-SERVER}} build farm.
10009 For security, each substitute is signed, allowing recipients to check
10010 their authenticity and integrity (@pxref{Substitutes}). Because
10011 @command{guix publish} uses the signing key of the system, which is only
10012 readable by the system administrator, it must be started as root; the
10013 @code{--user} option makes it drop root privileges early on.
10015 The signing key pair must be generated before @command{guix publish} is
10016 launched, using @command{guix archive --generate-key} (@pxref{Invoking
10019 The general syntax is:
10022 guix publish @var{options}@dots{}
10025 Running @command{guix publish} without any additional arguments will
10026 spawn an HTTP server on port 8080:
10032 Once a publishing server has been authorized (@pxref{Invoking guix
10033 archive}), the daemon may download substitutes from it:
10036 guix-daemon --substitute-urls=http://example.org:8080
10039 By default, @command{guix publish} compresses archives on the fly as it
10040 serves them. This ``on-the-fly'' mode is convenient in that it requires
10041 no setup and is immediately available. However, when serving lots of
10042 clients, we recommend using the @option{--cache} option, which enables
10043 caching of the archives before they are sent to clients---see below for
10044 details. The @command{guix weather} command provides a handy way to
10045 check what a server provides (@pxref{Invoking guix weather}).
10047 As a bonus, @command{guix publish} also serves as a content-addressed
10048 mirror for source files referenced in @code{origin} records
10049 (@pxref{origin Reference}). For instance, assuming @command{guix
10050 publish} is running on @code{example.org}, the following URL returns the
10051 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
10052 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
10055 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
10058 Obviously, these URLs only work for files that are in the store; in
10059 other cases, they return 404 (``Not Found'').
10061 @cindex build logs, publication
10062 Build logs are available from @code{/log} URLs like:
10065 http://example.org/log/gwspk@dots{}-guile-2.2.3
10069 When @command{guix-daemon} is configured to save compressed build logs,
10070 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
10071 URLs return the compressed log as-is, with an appropriate
10072 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
10073 running @command{guix-daemon} with @code{--log-compression=gzip} since
10074 Web browsers can automatically decompress it, which is not the case with
10077 The following options are available:
10080 @item --port=@var{port}
10081 @itemx -p @var{port}
10082 Listen for HTTP requests on @var{port}.
10084 @item --listen=@var{host}
10085 Listen on the network interface for @var{host}. The default is to
10086 accept connections from any interface.
10088 @item --user=@var{user}
10089 @itemx -u @var{user}
10090 Change privileges to @var{user} as soon as possible---i.e., once the
10091 server socket is open and the signing key has been read.
10093 @item --compression[=@var{method}[:@var{level}]]
10094 @itemx -C [@var{method}[:@var{level}]]
10095 Compress data using the given @var{method} and @var{level}. @var{method} is
10096 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
10099 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
10100 to different compression levels: 1 is the fastest, and 9 is the best
10101 (CPU-intensive). The default is 3.
10103 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
10104 increase in CPU usage; see
10105 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
10108 Unless @option{--cache} is used, compression occurs on the fly and
10109 the compressed streams are not
10110 cached. Thus, to reduce load on the machine that runs @command{guix
10111 publish}, it may be a good idea to choose a low compression level, to
10112 run @command{guix publish} behind a caching proxy, or to use
10113 @option{--cache}. Using @option{--cache} has the advantage that it
10114 allows @command{guix publish} to add @code{Content-Length} HTTP header
10117 This option can be repeated, in which case every substitute gets compressed
10118 using all the selected methods, and all of them are advertised. This is
10119 useful when users may not support all the compression methods: they can select
10120 the one they support.
10122 @item --cache=@var{directory}
10123 @itemx -c @var{directory}
10124 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
10125 and only serve archives that are in cache.
10127 When this option is omitted, archives and meta-data are created
10128 on-the-fly. This can reduce the available bandwidth, especially when
10129 compression is enabled, since this may become CPU-bound. Another
10130 drawback of the default mode is that the length of archives is not known
10131 in advance, so @command{guix publish} does not add a
10132 @code{Content-Length} HTTP header to its responses, which in turn
10133 prevents clients from knowing the amount of data being downloaded.
10135 Conversely, when @option{--cache} is used, the first request for a store
10136 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
10137 background process to @dfn{bake} the archive---computing its
10138 @code{.narinfo} and compressing the archive, if needed. Once the
10139 archive is cached in @var{directory}, subsequent requests succeed and
10140 are served directly from the cache, which guarantees that clients get
10141 the best possible bandwidth.
10143 The ``baking'' process is performed by worker threads. By default, one
10144 thread per CPU core is created, but this can be customized. See
10145 @option{--workers} below.
10147 When @option{--ttl} is used, cached entries are automatically deleted
10148 when they have expired.
10150 @item --workers=@var{N}
10151 When @option{--cache} is used, request the allocation of @var{N} worker
10152 threads to ``bake'' archives.
10154 @item --ttl=@var{ttl}
10155 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
10156 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
10157 days, @code{1m} means 1 month, and so on.
10159 This allows the user's Guix to keep substitute information in cache for
10160 @var{ttl}. However, note that @code{guix publish} does not itself
10161 guarantee that the store items it provides will indeed remain available
10162 for as long as @var{ttl}.
10164 Additionally, when @option{--cache} is used, cached entries that have
10165 not been accessed for @var{ttl} and that no longer have a corresponding
10166 item in the store, may be deleted.
10168 @item --nar-path=@var{path}
10169 Use @var{path} as the prefix for the URLs of ``nar'' files
10170 (@pxref{Invoking guix archive, normalized archives}).
10172 By default, nars are served at a URL such as
10173 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
10174 change the @code{/nar} part to @var{path}.
10176 @item --public-key=@var{file}
10177 @itemx --private-key=@var{file}
10178 Use the specific @var{file}s as the public/private key pair used to sign
10179 the store items being published.
10181 The files must correspond to the same key pair (the private key is used
10182 for signing and the public key is merely advertised in the signature
10183 metadata). They must contain keys in the canonical s-expression format
10184 as produced by @command{guix archive --generate-key} (@pxref{Invoking
10185 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
10186 @file{/etc/guix/signing-key.sec} are used.
10188 @item --repl[=@var{port}]
10189 @itemx -r [@var{port}]
10190 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
10191 Reference Manual}) on @var{port} (37146 by default). This is used
10192 primarily for debugging a running @command{guix publish} server.
10195 Enabling @command{guix publish} on Guix System is a one-liner: just
10196 instantiate a @code{guix-publish-service-type} service in the @code{services} field
10197 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
10198 @code{guix-publish-service-type}}).
10200 If you are instead running Guix on a ``foreign distro'', follow these
10205 If your host distro uses the systemd init system:
10208 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
10209 /etc/systemd/system/
10210 # systemctl start guix-publish && systemctl enable guix-publish
10214 If your host distro uses the Upstart init system:
10217 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
10218 # start guix-publish
10222 Otherwise, proceed similarly with your distro's init system.
10225 @node Invoking guix challenge
10226 @section Invoking @command{guix challenge}
10228 @cindex reproducible builds
10229 @cindex verifiable builds
10230 @cindex @command{guix challenge}
10232 Do the binaries provided by this server really correspond to the source
10233 code it claims to build? Is a package build process deterministic?
10234 These are the questions the @command{guix challenge} command attempts to
10237 The former is obviously an important question: Before using a substitute
10238 server (@pxref{Substitutes}), one had better @emph{verify} that it
10239 provides the right binaries, and thus @emph{challenge} it. The latter
10240 is what enables the former: If package builds are deterministic, then
10241 independent builds of the package should yield the exact same result,
10242 bit for bit; if a server provides a binary different from the one
10243 obtained locally, it may be either corrupt or malicious.
10245 We know that the hash that shows up in @file{/gnu/store} file names is
10246 the hash of all the inputs of the process that built the file or
10247 directory---compilers, libraries, build scripts,
10248 etc. (@pxref{Introduction}). Assuming deterministic build processes,
10249 one store file name should map to exactly one build output.
10250 @command{guix challenge} checks whether there is, indeed, a single
10251 mapping by comparing the build outputs of several independent builds of
10252 any given store item.
10254 The command output looks like this:
10257 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
10258 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
10259 updating list of substitutes from 'https://guix.example.org'... 100.0%
10260 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
10261 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10262 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
10263 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
10264 /gnu/store/@dots{}-git-2.5.0 contents differ:
10265 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
10266 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
10267 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
10268 /gnu/store/@dots{}-pius-2.1.1 contents differ:
10269 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10270 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
10271 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
10275 6,406 store items were analyzed:
10276 - 4,749 (74.1%) were identical
10277 - 525 (8.2%) differed
10278 - 1,132 (17.7%) were inconclusive
10282 In this example, @command{guix challenge} first scans the store to
10283 determine the set of locally-built derivations---as opposed to store
10284 items that were downloaded from a substitute server---and then queries
10285 all the substitute servers. It then reports those store items for which
10286 the servers obtained a result different from the local build.
10288 @cindex non-determinism, in package builds
10289 As an example, @code{guix.example.org} always gets a different answer.
10290 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
10291 case of Git. This might indicate that the build process of Git is
10292 non-deterministic, meaning that its output varies as a function of
10293 various things that Guix does not fully control, in spite of building
10294 packages in isolated environments (@pxref{Features}). Most common
10295 sources of non-determinism include the addition of timestamps in build
10296 results, the inclusion of random numbers, and directory listings sorted
10297 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
10300 To find out what is wrong with this Git binary, we can do something along
10301 these lines (@pxref{Invoking guix archive}):
10304 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0 \
10305 | guix archive -x /tmp/git
10306 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
10309 This command shows the difference between the files resulting from the
10310 local build, and the files resulting from the build on
10311 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
10312 diffutils, Comparing and Merging Files}). The @command{diff} command
10313 works great for text files. When binary files differ, a better option
10314 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
10315 visualize differences for all kinds of files.
10317 Once you have done that work, you can tell whether the differences are due
10318 to a non-deterministic build process or to a malicious server. We try
10319 hard to remove sources of non-determinism in packages to make it easier
10320 to verify substitutes, but of course, this is a process that
10321 involves not just Guix, but a large part of the free software community.
10322 In the meantime, @command{guix challenge} is one tool to help address
10325 If you are writing packages for Guix, you are encouraged to check
10326 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
10327 same build result as you did with:
10330 $ guix challenge @var{package}
10334 where @var{package} is a package specification such as
10335 @code{guile@@2.0} or @code{glibc:debug}.
10337 The general syntax is:
10340 guix challenge @var{options} [@var{packages}@dots{}]
10343 When a difference is found between the hash of a locally-built item and
10344 that of a server-provided substitute, or among substitutes provided by
10345 different servers, the command displays it as in the example above and
10346 its exit code is 2 (other non-zero exit codes denote other kinds of
10349 The one option that matters is:
10353 @item --substitute-urls=@var{urls}
10354 Consider @var{urls} the whitespace-separated list of substitute source
10355 URLs to compare to.
10359 Show details about matches (identical contents) in addition to
10360 information about mismatches.
10364 @node Invoking guix copy
10365 @section Invoking @command{guix copy}
10367 @cindex copy, of store items, over SSH
10368 @cindex SSH, copy of store items
10369 @cindex sharing store items across machines
10370 @cindex transferring store items across machines
10371 The @command{guix copy} command copies items from the store of one
10372 machine to that of another machine over a secure shell (SSH)
10373 connection@footnote{This command is available only when Guile-SSH was
10374 found. @xref{Requirements}, for details.}. For example, the following
10375 command copies the @code{coreutils} package, the user's profile, and all
10376 their dependencies over to @var{host}, logged in as @var{user}:
10379 guix copy --to=@var{user}@@@var{host} \
10380 coreutils `readlink -f ~/.guix-profile`
10383 If some of the items to be copied are already present on @var{host},
10384 they are not actually sent.
10386 The command below retrieves @code{libreoffice} and @code{gimp} from
10387 @var{host}, assuming they are available there:
10390 guix copy --from=@var{host} libreoffice gimp
10393 The SSH connection is established using the Guile-SSH client, which is
10394 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
10395 @file{~/.ssh/config}, and uses the SSH agent for authentication.
10397 The key used to sign items that are sent must be accepted by the remote
10398 machine. Likewise, the key used by the remote machine to sign items you
10399 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
10400 own daemon. @xref{Invoking guix archive}, for more information about
10401 store item authentication.
10403 The general syntax is:
10406 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
10409 You must always specify one of the following options:
10412 @item --to=@var{spec}
10413 @itemx --from=@var{spec}
10414 Specify the host to send to or receive from. @var{spec} must be an SSH
10415 spec such as @code{example.org}, @code{charlie@@example.org}, or
10416 @code{charlie@@example.org:2222}.
10419 The @var{items} can be either package names, such as @code{gimp}, or
10420 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
10422 When specifying the name of a package to send, it is first built if
10423 needed, unless @option{--dry-run} was specified. Common build options
10424 are supported (@pxref{Common Build Options}).
10427 @node Invoking guix container
10428 @section Invoking @command{guix container}
10430 @cindex @command{guix container}
10432 As of version @value{VERSION}, this tool is experimental. The interface
10433 is subject to radical change in the future.
10436 The purpose of @command{guix container} is to manipulate processes
10437 running within an isolated environment, commonly known as a
10438 ``container'', typically created by the @command{guix environment}
10439 (@pxref{Invoking guix environment}) and @command{guix system container}
10440 (@pxref{Invoking guix system}) commands.
10442 The general syntax is:
10445 guix container @var{action} @var{options}@dots{}
10448 @var{action} specifies the operation to perform with a container, and
10449 @var{options} specifies the context-specific arguments for the action.
10451 The following actions are available:
10455 Execute a command within the context of a running container.
10460 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
10463 @var{pid} specifies the process ID of the running container.
10464 @var{program} specifies an executable file name within the root file
10465 system of the container. @var{arguments} are the additional options that
10466 will be passed to @var{program}.
10468 The following command launches an interactive login shell inside a
10469 Guix system container, started by @command{guix system container}, and whose
10470 process ID is 9001:
10473 guix container exec 9001 /run/current-system/profile/bin/bash --login
10476 Note that the @var{pid} cannot be the parent process of a container. It
10477 must be PID 1 of the container or one of its child processes.
10481 @node Invoking guix weather
10482 @section Invoking @command{guix weather}
10484 Occasionally you're grumpy because substitutes are lacking and you end
10485 up building packages by yourself (@pxref{Substitutes}). The
10486 @command{guix weather} command reports on substitute availability on the
10487 specified servers so you can have an idea of whether you'll be grumpy
10488 today. It can sometimes be useful info as a user, but it is primarily
10489 useful to people running @command{guix publish} (@pxref{Invoking guix
10492 @cindex statistics, for substitutes
10493 @cindex availability of substitutes
10494 @cindex substitute availability
10495 @cindex weather, substitute availability
10496 Here's a sample run:
10499 $ guix weather --substitute-urls=https://guix.example.org
10500 computing 5,872 package derivations for x86_64-linux...
10501 looking for 6,128 store items on https://guix.example.org..
10502 updating list of substitutes from 'https://guix.example.org'... 100.0%
10503 https://guix.example.org
10504 43.4% substitutes available (2,658 out of 6,128)
10505 7,032.5 MiB of nars (compressed)
10506 19,824.2 MiB on disk (uncompressed)
10507 0.030 seconds per request (182.9 seconds in total)
10508 33.5 requests per second
10510 9.8% (342 out of 3,470) of the missing items are queued
10512 x86_64-linux: 518 (59.7%)
10513 i686-linux: 221 (25.5%)
10514 aarch64-linux: 128 (14.8%)
10515 build rate: 23.41 builds per hour
10516 x86_64-linux: 11.16 builds per hour
10517 i686-linux: 6.03 builds per hour
10518 aarch64-linux: 6.41 builds per hour
10521 @cindex continuous integration, statistics
10522 As you can see, it reports the fraction of all the packages for which
10523 substitutes are available on the server---regardless of whether
10524 substitutes are enabled, and regardless of whether this server's signing
10525 key is authorized. It also reports the size of the compressed archives
10526 (``nars'') provided by the server, the size the corresponding store
10527 items occupy in the store (assuming deduplication is turned off), and
10528 the server's throughput. The second part gives continuous integration
10529 (CI) statistics, if the server supports it. In addition, using the
10530 @option{--coverage} option, @command{guix weather} can list ``important''
10531 package substitutes missing on the server (see below).
10533 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
10534 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
10535 challenge}, it ignores signatures on those substitutes, which is
10536 innocuous since the command only gathers statistics and cannot install
10539 The general syntax is:
10542 guix weather @var{options}@dots{} [@var{packages}@dots{}]
10545 When @var{packages} is omitted, @command{guix weather} checks the availability
10546 of substitutes for @emph{all} the packages, or for those specified with
10547 @option{--manifest}; otherwise it only considers the specified packages. It
10548 is also possible to query specific system types with @option{--system}. The
10549 available options are listed below.
10552 @item --substitute-urls=@var{urls}
10553 @var{urls} is the space-separated list of substitute server URLs to
10554 query. When this option is omitted, the default set of substitute
10555 servers is queried.
10557 @item --system=@var{system}
10558 @itemx -s @var{system}
10559 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
10560 option can be repeated, in which case @command{guix weather} will query
10561 substitutes for several system types.
10563 @item --manifest=@var{file}
10564 Instead of querying substitutes for all the packages, only ask for those
10565 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
10566 with the @code{-m} option of @command{guix package} (@pxref{Invoking
10569 @item --coverage[=@var{count}]
10570 @itemx -c [@var{count}]
10571 Report on substitute coverage for packages: list packages with at least
10572 @var{count} dependents (zero by default) for which substitutes are
10573 unavailable. Dependent packages themselves are not listed: if @var{b} depends
10574 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
10575 @var{b} usually lacks substitutes as well. The result looks like this:
10578 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
10579 computing 8,983 package derivations for x86_64-linux...
10580 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
10581 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
10582 @value{SUBSTITUTE-URL}
10583 64.7% substitutes available (6,047 out of 9,343)
10585 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
10586 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
10587 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
10588 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
10592 What this example shows is that @code{kcoreaddons} and presumably the 58
10593 packages that depend on it have no substitutes at @code{ci.guix.info};
10594 likewise for @code{qgpgme} and the 46 packages that depend on it.
10596 If you are a Guix developer, or if you are taking care of this build farm,
10597 you'll probably want to have a closer look at these packages: they may simply
10601 @node Invoking guix processes
10602 @section Invoking @command{guix processes}
10604 The @command{guix processes} command can be useful to developers and system
10605 administrators, especially on multi-user machines and on build farms: it lists
10606 the current sessions (connections to the daemon), as well as information about
10607 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
10608 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
10609 listed.}. Here's an example of the information it returns:
10612 $ sudo guix processes
10615 ClientCommand: guix environment --ad-hoc python
10619 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
10623 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10624 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
10625 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
10626 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
10627 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
10628 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
10629 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
10632 In this example we see that @command{guix-daemon} has three clients:
10633 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
10634 integration tool; their process identifier (PID) is given by the
10635 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
10636 @command{guix-daemon} sub-process of this particular session.
10638 The @code{LockHeld} fields show which store items are currently locked by this
10639 session, which corresponds to store items being built or substituted (the
10640 @code{LockHeld} field is not displayed when @command{guix processes} is not
10641 running as root.) Last, by looking at the @code{ChildProcess} field, we
10642 understand that these three builds are being offloaded (@pxref{Daemon Offload
10645 The output is in Recutils format so we can use the handy @command{recsel}
10646 command to select sessions of interest (@pxref{Selection Expressions,,,
10647 recutils, GNU recutils manual}). As an example, the command shows the command
10648 line and PID of the client that triggered the build of a Perl package:
10651 $ sudo guix processes | \
10652 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
10654 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
10657 @node System Configuration
10658 @chapter System Configuration
10660 @cindex system configuration
10661 Guix System supports a consistent whole-system configuration
10662 mechanism. By that we mean that all aspects of the global system
10663 configuration---such as the available system services, timezone and
10664 locale settings, user accounts---are declared in a single place. Such
10665 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
10667 One of the advantages of putting all the system configuration under the
10668 control of Guix is that it supports transactional system upgrades, and
10669 makes it possible to roll back to a previous system instantiation,
10670 should something go wrong with the new one (@pxref{Features}). Another
10671 advantage is that it makes it easy to replicate the exact same configuration
10672 across different machines, or at different points in time, without
10673 having to resort to additional administration tools layered on top of
10674 the own tools of the system.
10675 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
10677 This section describes this mechanism. First we focus on the system
10678 administrator's viewpoint---explaining how the system is configured and
10679 instantiated. Then we show how this mechanism can be extended, for
10680 instance to support new system services.
10683 * Using the Configuration System:: Customizing your GNU system.
10684 * operating-system Reference:: Detail of operating-system declarations.
10685 * File Systems:: Configuring file system mounts.
10686 * Mapped Devices:: Block device extra processing.
10687 * User Accounts:: Specifying user accounts.
10688 * Keyboard Layout:: How the system interprets key strokes.
10689 * Locales:: Language and cultural convention settings.
10690 * Services:: Specifying system services.
10691 * Setuid Programs:: Programs running with root privileges.
10692 * X.509 Certificates:: Authenticating HTTPS servers.
10693 * Name Service Switch:: Configuring libc's name service switch.
10694 * Initial RAM Disk:: Linux-Libre bootstrapping.
10695 * Bootloader Configuration:: Configuring the boot loader.
10696 * Invoking guix system:: Instantiating a system configuration.
10697 * Invoking guix deploy:: Deploying a system configuration to a remote host.
10698 * Running Guix in a VM:: How to run Guix System in a virtual machine.
10699 * Defining Services:: Adding new service definitions.
10702 @node Using the Configuration System
10703 @section Using the Configuration System
10705 The operating system is configured by providing an
10706 @code{operating-system} declaration in a file that can then be passed to
10707 the @command{guix system} command (@pxref{Invoking guix system}). A
10708 simple setup, with the default system services, the default Linux-Libre
10709 kernel, initial RAM disk, and boot loader looks like this:
10711 @findex operating-system
10713 @include os-config-bare-bones.texi
10716 This example should be self-describing. Some of the fields defined
10717 above, such as @code{host-name} and @code{bootloader}, are mandatory.
10718 Others, such as @code{packages} and @code{services}, can be omitted, in
10719 which case they get a default value.
10721 Below we discuss the effect of some of the most important fields
10722 (@pxref{operating-system Reference}, for details about all the available
10723 fields), and how to @dfn{instantiate} the operating system using
10724 @command{guix system}.
10726 @unnumberedsubsec Bootloader
10728 @cindex legacy boot, on Intel machines
10729 @cindex BIOS boot, on Intel machines
10732 The @code{bootloader} field describes the method that will be used to boot
10733 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
10734 mode, as in the example above. However, more recent machines rely instead on
10735 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
10736 the @code{bootloader} field should contain something along these lines:
10739 (bootloader-configuration
10740 (bootloader grub-efi-bootloader)
10741 (target "/boot/efi"))
10744 @xref{Bootloader Configuration}, for more information on the available
10745 configuration options.
10747 @unnumberedsubsec Globally-Visible Packages
10749 @vindex %base-packages
10750 The @code{packages} field lists packages that will be globally visible
10751 on the system, for all user accounts---i.e., in every user's @code{PATH}
10752 environment variable---in addition to the per-user profiles
10753 (@pxref{Invoking guix package}). The @code{%base-packages} variable
10754 provides all the tools one would expect for basic user and administrator
10755 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
10756 the GNU Zile lightweight text editor, @command{find}, @command{grep},
10757 etc. The example above adds GNU@tie{}Screen to those,
10758 taken from the @code{(gnu packages screen)}
10759 module (@pxref{Package Modules}). The
10760 @code{(list package output)} syntax can be used to add a specific output
10764 (use-modules (gnu packages))
10765 (use-modules (gnu packages dns))
10769 (packages (cons (list bind "utils")
10773 @findex specification->package
10774 Referring to packages by variable name, like @code{bind} above, has
10775 the advantage of being unambiguous; it also allows typos and such to be
10776 diagnosed right away as ``unbound variables''. The downside is that one
10777 needs to know which module defines which package, and to augment the
10778 @code{use-package-modules} line accordingly. To avoid that, one can use
10779 the @code{specification->package} procedure of the @code{(gnu packages)}
10780 module, which returns the best package for a given name or name and
10784 (use-modules (gnu packages))
10788 (packages (append (map specification->package
10789 '("tcpdump" "htop" "gnupg@@2.0"))
10793 @unnumberedsubsec System Services
10796 @vindex %base-services
10797 The @code{services} field lists @dfn{system services} to be made
10798 available when the system starts (@pxref{Services}).
10799 The @code{operating-system} declaration above specifies that, in
10800 addition to the basic services, we want the OpenSSH secure shell
10801 daemon listening on port 2222 (@pxref{Networking Services,
10802 @code{openssh-service-type}}). Under the hood,
10803 @code{openssh-service-type} arranges so that @command{sshd} is started with the
10804 right command-line options, possibly with supporting configuration files
10805 generated as needed (@pxref{Defining Services}).
10807 @cindex customization, of services
10808 @findex modify-services
10809 Occasionally, instead of using the base services as is, you will want to
10810 customize them. To do this, use @code{modify-services} (@pxref{Service
10811 Reference, @code{modify-services}}) to modify the list.
10813 For example, suppose you want to modify @code{guix-daemon} and Mingetty
10814 (the console log-in) in the @code{%base-services} list (@pxref{Base
10815 Services, @code{%base-services}}). To do that, you can write the
10816 following in your operating system declaration:
10819 (define %my-services
10820 ;; My very own list of services.
10821 (modify-services %base-services
10822 (guix-service-type config =>
10823 (guix-configuration
10825 (use-substitutes? #f)
10826 (extra-options '("--gc-keep-derivations"))))
10827 (mingetty-service-type config =>
10828 (mingetty-configuration
10829 (inherit config)))))
10833 (services %my-services))
10836 This changes the configuration---i.e., the service parameters---of the
10837 @code{guix-service-type} instance, and that of all the
10838 @code{mingetty-service-type} instances in the @code{%base-services} list.
10839 Observe how this is accomplished: first, we arrange for the original
10840 configuration to be bound to the identifier @code{config} in the
10841 @var{body}, and then we write the @var{body} so that it evaluates to the
10842 desired configuration. In particular, notice how we use @code{inherit}
10843 to create a new configuration which has the same values as the old
10844 configuration, but with a few modifications.
10846 @cindex encrypted disk
10847 The configuration for a typical ``desktop'' usage, with an encrypted
10848 root partition, the X11 display
10849 server, GNOME and Xfce (users can choose which of these desktop
10850 environments to use at the log-in screen by pressing @kbd{F1}), network
10851 management, power management, and more, would look like this:
10854 @include os-config-desktop.texi
10857 A graphical system with a choice of lightweight window managers
10858 instead of full-blown desktop environments would look like this:
10861 @include os-config-lightweight-desktop.texi
10864 This example refers to the @file{/boot/efi} file system by its UUID,
10865 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
10866 as returned by the @command{blkid} command.
10868 @xref{Desktop Services}, for the exact list of services provided by
10869 @code{%desktop-services}. @xref{X.509 Certificates}, for background
10870 information about the @code{nss-certs} package that is used here.
10872 Again, @code{%desktop-services} is just a list of service objects. If
10873 you want to remove services from there, you can do so using the
10874 procedures for list filtering (@pxref{SRFI-1 Filtering and
10875 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
10876 following expression returns a list that contains all the services in
10877 @code{%desktop-services} minus the Avahi service:
10880 (remove (lambda (service)
10881 (eq? (service-kind service) avahi-service-type))
10885 @unnumberedsubsec Instantiating the System
10887 Assuming the @code{operating-system} declaration
10888 is stored in the @file{my-system-config.scm}
10889 file, the @command{guix system reconfigure my-system-config.scm} command
10890 instantiates that configuration, and makes it the default GRUB boot
10891 entry (@pxref{Invoking guix system}).
10893 The normal way to change the system configuration is by updating this
10894 file and re-running @command{guix system reconfigure}. One should never
10895 have to touch files in @file{/etc} or to run commands that modify the
10896 system state such as @command{useradd} or @command{grub-install}. In
10897 fact, you must avoid that since that would not only void your warranty
10898 but also prevent you from rolling back to previous versions of your
10899 system, should you ever need to.
10901 @cindex roll-back, of the operating system
10902 Speaking of roll-back, each time you run @command{guix system
10903 reconfigure}, a new @dfn{generation} of the system is created---without
10904 modifying or deleting previous generations. Old system generations get
10905 an entry in the bootloader boot menu, allowing you to boot them in case
10906 something went wrong with the latest generation. Reassuring, no? The
10907 @command{guix system list-generations} command lists the system
10908 generations available on disk. It is also possible to roll back the
10909 system via the commands @command{guix system roll-back} and
10910 @command{guix system switch-generation}.
10912 Although the @command{guix system reconfigure} command will not modify
10913 previous generations, you must take care when the current generation is not
10914 the latest (e.g., after invoking @command{guix system roll-back}), since
10915 the operation might overwrite a later generation (@pxref{Invoking guix
10918 @unnumberedsubsec The Programming Interface
10920 At the Scheme level, the bulk of an @code{operating-system} declaration
10921 is instantiated with the following monadic procedure (@pxref{The Store
10924 @deffn {Monadic Procedure} operating-system-derivation os
10925 Return a derivation that builds @var{os}, an @code{operating-system}
10926 object (@pxref{Derivations}).
10928 The output of the derivation is a single directory that refers to all
10929 the packages, configuration files, and other supporting files needed to
10930 instantiate @var{os}.
10933 This procedure is provided by the @code{(gnu system)} module. Along
10934 with @code{(gnu services)} (@pxref{Services}), this module contains the
10935 guts of Guix System. Make sure to visit it!
10938 @node operating-system Reference
10939 @section @code{operating-system} Reference
10941 This section summarizes all the options available in
10942 @code{operating-system} declarations (@pxref{Using the Configuration
10945 @deftp {Data Type} operating-system
10946 This is the data type representing an operating system configuration.
10947 By that, we mean all the global system configuration, not per-user
10948 configuration (@pxref{Using the Configuration System}).
10951 @item @code{kernel} (default: @var{linux-libre})
10952 The package object of the operating system kernel to use@footnote{Currently
10953 only the Linux-libre kernel is supported. In the future, it will be
10954 possible to use the GNU@tie{}Hurd.}.
10956 @item @code{kernel-arguments} (default: @code{'("quiet")})
10957 List of strings or gexps representing additional arguments to pass on
10958 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
10960 @item @code{bootloader}
10961 The system bootloader configuration object. @xref{Bootloader Configuration}.
10964 This is the label (a string) as it appears in the bootloader's menu entry.
10965 The default label includes the kernel name and version.
10967 @item @code{keyboard-layout} (default: @code{#f})
10968 This field specifies the keyboard layout to use in the console. It can be
10969 either @code{#f}, in which case the default keyboard layout is used (usually
10970 US English), or a @code{<keyboard-layout>} record.
10972 This keyboard layout is in effect as soon as the kernel has booted. For
10973 instance, it is the keyboard layout in effect when you type a passphrase if
10974 your root file system is on a @code{luks-device-mapping} mapped device
10975 (@pxref{Mapped Devices}).
10978 This does @emph{not} specify the keyboard layout used by the bootloader, nor
10979 that used by the graphical display server. @xref{Bootloader Configuration},
10980 for information on how to specify the bootloader's keyboard layout. @xref{X
10981 Window}, for information on how to specify the keyboard layout used by the X
10985 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
10987 @cindex initial RAM disk
10988 The list of Linux kernel modules that need to be available in the
10989 initial RAM disk. @xref{Initial RAM Disk}.
10991 @item @code{initrd} (default: @code{base-initrd})
10992 A procedure that returns an initial RAM disk for the Linux
10993 kernel. This field is provided to support low-level customization and
10994 should rarely be needed for casual use. @xref{Initial RAM Disk}.
10996 @item @code{firmware} (default: @code{%base-firmware})
10998 List of firmware packages loadable by the operating system kernel.
11000 The default includes firmware needed for Atheros- and Broadcom-based
11001 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
11002 respectively). @xref{Hardware Considerations}, for more info on
11003 supported hardware.
11005 @item @code{host-name}
11008 @item @code{hosts-file}
11010 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
11011 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
11012 Reference Manual}). The default is a file with entries for
11013 @code{localhost} and @var{host-name}.
11015 @item @code{mapped-devices} (default: @code{'()})
11016 A list of mapped devices. @xref{Mapped Devices}.
11018 @item @code{file-systems}
11019 A list of file systems. @xref{File Systems}.
11021 @item @code{swap-devices} (default: @code{'()})
11022 @cindex swap devices
11023 A list of strings identifying devices or files to be used for ``swap
11024 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
11025 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
11026 It is possible to specify a swap file in a file system on a mapped
11027 device, provided that the necessary device mapping and file system are
11028 also specified. @xref{Mapped Devices} and @ref{File Systems}.
11030 @item @code{users} (default: @code{%base-user-accounts})
11031 @itemx @code{groups} (default: @code{%base-groups})
11032 List of user accounts and groups. @xref{User Accounts}.
11034 If the @code{users} list lacks a user account with UID@tie{}0, a
11035 ``root'' account with UID@tie{}0 is automatically added.
11037 @item @code{skeletons} (default: @code{(default-skeletons)})
11038 A list target file name/file-like object tuples (@pxref{G-Expressions,
11039 file-like objects}). These are the skeleton files that will be added to
11040 the home directory of newly-created user accounts.
11042 For instance, a valid value may look like this:
11045 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
11046 (".guile" ,(plain-file "guile"
11047 "(use-modules (ice-9 readline))
11048 (activate-readline)")))
11051 @item @code{issue} (default: @code{%default-issue})
11052 A string denoting the contents of the @file{/etc/issue} file, which is
11053 displayed when users log in on a text console.
11055 @item @code{packages} (default: @code{%base-packages})
11056 The set of packages installed in the global profile, which is accessible
11057 at @file{/run/current-system/profile}.
11059 The default set includes core utilities and it is good practice to
11060 install non-core utilities in user profiles (@pxref{Invoking guix
11063 @item @code{timezone}
11064 A timezone identifying string---e.g., @code{"Europe/Paris"}.
11066 You can run the @command{tzselect} command to find out which timezone
11067 string corresponds to your region. Choosing an invalid timezone name
11068 causes @command{guix system} to fail.
11070 @item @code{locale} (default: @code{"en_US.utf8"})
11071 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
11072 Library Reference Manual}). @xref{Locales}, for more information.
11074 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
11075 The list of locale definitions to be compiled and that may be used at
11076 run time. @xref{Locales}.
11078 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
11079 The list of GNU@tie{}libc packages whose locale data and tools are used
11080 to build the locale definitions. @xref{Locales}, for compatibility
11081 considerations that justify this option.
11083 @item @code{name-service-switch} (default: @code{%default-nss})
11084 Configuration of the libc name service switch (NSS)---a
11085 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
11088 @item @code{services} (default: @code{%base-services})
11089 A list of service objects denoting system services. @xref{Services}.
11091 @cindex essential services
11092 @item @code{essential-services} (default: ...)
11093 The list of ``essential services''---i.e., things like instances of
11094 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
11095 Reference}), which are derived from the operating system definition itself.
11096 As a user you should @emph{never} need to touch this field.
11098 @item @code{pam-services} (default: @code{(base-pam-services)})
11100 @cindex pluggable authentication modules
11101 Linux @dfn{pluggable authentication module} (PAM) services.
11102 @c FIXME: Add xref to PAM services section.
11104 @item @code{setuid-programs} (default: @var{%setuid-programs})
11105 List of string-valued G-expressions denoting setuid programs.
11106 @xref{Setuid Programs}.
11108 @item @code{sudoers-file} (default: @var{%sudoers-specification})
11109 @cindex sudoers file
11110 The contents of the @file{/etc/sudoers} file as a file-like object
11111 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
11113 This file specifies which users can use the @command{sudo} command, what
11114 they are allowed to do, and what privileges they may gain. The default
11115 is that only @code{root} and members of the @code{wheel} group may use
11120 @deffn {Scheme Syntax} this-operating-system
11121 When used in the @emph{lexical scope} of an operating system field definition,
11122 this identifier resolves to the operating system being defined.
11124 The example below shows how to refer to the operating system being defined in
11125 the definition of the @code{label} field:
11128 (use-modules (gnu) (guix))
11132 (label (package-full-name
11133 (operating-system-kernel this-operating-system))))
11136 It is an error to refer to @code{this-operating-system} outside an operating
11143 @section File Systems
11145 The list of file systems to be mounted is specified in the
11146 @code{file-systems} field of the operating system declaration
11147 (@pxref{Using the Configuration System}). Each file system is declared
11148 using the @code{file-system} form, like this:
11152 (mount-point "/home")
11153 (device "/dev/sda3")
11157 As usual, some of the fields are mandatory---those shown in the example
11158 above---while others can be omitted. These are described below.
11160 @deftp {Data Type} file-system
11161 Objects of this type represent file systems to be mounted. They
11162 contain the following members:
11166 This is a string specifying the type of the file system---e.g.,
11169 @item @code{mount-point}
11170 This designates the place where the file system is to be mounted.
11172 @item @code{device}
11173 This names the ``source'' of the file system. It can be one of three
11174 things: a file system label, a file system UUID, or the name of a
11175 @file{/dev} node. Labels and UUIDs offer a way to refer to file
11176 systems without having to hard-code their actual device
11177 name@footnote{Note that, while it is tempting to use
11178 @file{/dev/disk/by-uuid} and similar device names to achieve the same
11179 result, this is not recommended: These special device nodes are created
11180 by the udev daemon and may be unavailable at the time the device is
11183 @findex file-system-label
11184 File system labels are created using the @code{file-system-label}
11185 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
11186 plain strings. Here's an example of a file system referred to by its
11187 label, as shown by the @command{e2label} command:
11191 (mount-point "/home")
11193 (device (file-system-label "my-home")))
11197 UUIDs are converted from their string representation (as shown by the
11198 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
11199 @code{uuid} form expects 16-byte UUIDs as defined in
11200 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
11201 form of UUID used by the ext2 family of file systems and others, but it
11202 is different from ``UUIDs'' found in FAT file systems, for instance.},
11207 (mount-point "/home")
11209 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
11212 When the source of a file system is a mapped device (@pxref{Mapped
11213 Devices}), its @code{device} field @emph{must} refer to the mapped
11214 device name---e.g., @file{"/dev/mapper/root-partition"}.
11215 This is required so that
11216 the system knows that mounting the file system depends on having the
11217 corresponding device mapping established.
11219 @item @code{flags} (default: @code{'()})
11220 This is a list of symbols denoting mount flags. Recognized flags
11221 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
11222 access to special files), @code{no-suid} (ignore setuid and setgid
11223 bits), @code{no-atime} (do not update file access times), and @code{no-exec}
11224 (disallow program execution). @xref{Mount-Unmount-Remount,,, libc, The GNU C
11225 Library Reference Manual}, for more information on these flags.
11227 @item @code{options} (default: @code{#f})
11228 This is either @code{#f}, or a string denoting mount options passed to the
11229 file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C Library
11230 Reference Manual}, for details and run @command{man 8 mount} for options for
11231 various file systems.
11233 @item @code{mount?} (default: @code{#t})
11234 This value indicates whether to automatically mount the file system when
11235 the system is brought up. When set to @code{#f}, the file system gets
11236 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
11237 is not automatically mounted.
11239 @item @code{needed-for-boot?} (default: @code{#f})
11240 This Boolean value indicates whether the file system is needed when
11241 booting. If that is true, then the file system is mounted when the
11242 initial RAM disk (initrd) is loaded. This is always the case, for
11243 instance, for the root file system.
11245 @item @code{check?} (default: @code{#t})
11246 This Boolean indicates whether the file system needs to be checked for
11247 errors before being mounted.
11249 @item @code{create-mount-point?} (default: @code{#f})
11250 When true, the mount point is created if it does not exist yet.
11252 @item @code{dependencies} (default: @code{'()})
11253 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
11254 representing file systems that must be mounted or mapped devices that
11255 must be opened before (and unmounted or closed after) this one.
11257 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
11258 a dependency of @file{/sys/fs/cgroup/cpu} and
11259 @file{/sys/fs/cgroup/memory}.
11261 Another example is a file system that depends on a mapped device, for
11262 example for an encrypted partition (@pxref{Mapped Devices}).
11266 The @code{(gnu system file-systems)} exports the following useful
11269 @defvr {Scheme Variable} %base-file-systems
11270 These are essential file systems that are required on normal systems,
11271 such as @var{%pseudo-terminal-file-system} and @var{%immutable-store} (see
11272 below.) Operating system declarations should always contain at least
11276 @defvr {Scheme Variable} %pseudo-terminal-file-system
11277 This is the file system to be mounted as @file{/dev/pts}. It supports
11278 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
11279 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
11280 Manual}). Pseudo-terminals are used by terminal emulators such as
11284 @defvr {Scheme Variable} %shared-memory-file-system
11285 This file system is mounted as @file{/dev/shm} and is used to support
11286 memory sharing across processes (@pxref{Memory-mapped I/O,
11287 @code{shm_open},, libc, The GNU C Library Reference Manual}).
11290 @defvr {Scheme Variable} %immutable-store
11291 This file system performs a read-only ``bind mount'' of
11292 @file{/gnu/store}, making it read-only for all the users including
11293 @code{root}. This prevents against accidental modification by software
11294 running as @code{root} or by system administrators.
11296 The daemon itself is still able to write to the store: it remounts it
11297 read-write in its own ``name space.''
11300 @defvr {Scheme Variable} %binary-format-file-system
11301 The @code{binfmt_misc} file system, which allows handling of arbitrary
11302 executable file types to be delegated to user space. This requires the
11303 @code{binfmt.ko} kernel module to be loaded.
11306 @defvr {Scheme Variable} %fuse-control-file-system
11307 The @code{fusectl} file system, which allows unprivileged users to mount
11308 and unmount user-space FUSE file systems. This requires the
11309 @code{fuse.ko} kernel module to be loaded.
11312 @node Mapped Devices
11313 @section Mapped Devices
11315 @cindex device mapping
11316 @cindex mapped devices
11317 The Linux kernel has a notion of @dfn{device mapping}: a block device,
11318 such as a hard disk partition, can be @dfn{mapped} into another device,
11319 usually in @code{/dev/mapper/},
11320 with additional processing over the data that flows through
11321 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
11322 concept of a ``mapped device'' and that of a file system: both boil down
11323 to @emph{translating} input/output operations made on a file to
11324 operations on its backing store. Thus, the Hurd implements mapped
11325 devices, like file systems, using the generic @dfn{translator} mechanism
11326 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
11327 typical example is encryption device mapping: all writes to the mapped
11328 device are encrypted, and all reads are deciphered, transparently.
11329 Guix extends this notion by considering any device or set of devices that
11330 are @dfn{transformed} in some way to create a new device; for instance,
11331 RAID devices are obtained by @dfn{assembling} several other devices, such
11332 as hard disks or partitions, into a new one that behaves as one partition.
11333 Other examples, not yet implemented, are LVM logical volumes.
11335 Mapped devices are declared using the @code{mapped-device} form,
11336 defined as follows; for examples, see below.
11338 @deftp {Data Type} mapped-device
11339 Objects of this type represent device mappings that will be made when
11340 the system boots up.
11344 This is either a string specifying the name of the block device to be mapped,
11345 such as @code{"/dev/sda3"}, or a list of such strings when several devices
11346 need to be assembled for creating a new one.
11349 This string specifies the name of the resulting mapped device. For
11350 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
11351 specifying @code{"my-partition"} leads to the creation of
11352 the @code{"/dev/mapper/my-partition"} device.
11353 For RAID devices of type @code{raid-device-mapping}, the full device name
11354 such as @code{"/dev/md0"} needs to be given.
11357 This must be a @code{mapped-device-kind} object, which specifies how
11358 @var{source} is mapped to @var{target}.
11362 @defvr {Scheme Variable} luks-device-mapping
11363 This defines LUKS block device encryption using the @command{cryptsetup}
11364 command from the package with the same name. It relies on the
11365 @code{dm-crypt} Linux kernel module.
11368 @defvr {Scheme Variable} raid-device-mapping
11369 This defines a RAID device, which is assembled using the @code{mdadm}
11370 command from the package with the same name. It requires a Linux kernel
11371 module for the appropriate RAID level to be loaded, such as @code{raid456}
11372 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
11375 @cindex disk encryption
11377 The following example specifies a mapping from @file{/dev/sda3} to
11378 @file{/dev/mapper/home} using LUKS---the
11379 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
11380 standard mechanism for disk encryption.
11381 The @file{/dev/mapper/home}
11382 device can then be used as the @code{device} of a @code{file-system}
11383 declaration (@pxref{File Systems}).
11387 (source "/dev/sda3")
11389 (type luks-device-mapping))
11392 Alternatively, to become independent of device numbering, one may obtain
11393 the LUKS UUID (@dfn{unique identifier}) of the source device by a
11397 cryptsetup luksUUID /dev/sda3
11400 and use it as follows:
11404 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
11406 (type luks-device-mapping))
11409 @cindex swap encryption
11410 It is also desirable to encrypt swap space, since swap space may contain
11411 sensitive data. One way to accomplish that is to use a swap file in a
11412 file system on a device mapped via LUKS encryption. In this way, the
11413 swap file is encrypted because the entire device is encrypted.
11414 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
11416 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
11417 may be declared as follows:
11421 (source (list "/dev/sda1" "/dev/sdb1"))
11422 (target "/dev/md0")
11423 (type raid-device-mapping))
11426 The @file{/dev/md0} device can then be used as the @code{device} of a
11427 @code{file-system} declaration (@pxref{File Systems}).
11428 Note that the RAID level need not be given; it is chosen during the
11429 initial creation and formatting of the RAID device and is determined
11430 automatically later.
11433 @node User Accounts
11434 @section User Accounts
11438 @cindex user accounts
11439 User accounts and groups are entirely managed through the
11440 @code{operating-system} declaration. They are specified with the
11441 @code{user-account} and @code{user-group} forms:
11447 (supplementary-groups '("wheel" ;allow use of sudo, etc.
11448 "audio" ;sound card
11449 "video" ;video devices such as webcams
11450 "cdrom")) ;the good ol' CD-ROM
11451 (comment "Bob's sister")
11452 (home-directory "/home/alice"))
11455 When booting or upon completion of @command{guix system reconfigure},
11456 the system ensures that only the user accounts and groups specified in
11457 the @code{operating-system} declaration exist, and with the specified
11458 properties. Thus, account or group creations or modifications made by
11459 directly invoking commands such as @command{useradd} are lost upon
11460 reconfiguration or reboot. This ensures that the system remains exactly
11463 @deftp {Data Type} user-account
11464 Objects of this type represent user accounts. The following members may
11469 The name of the user account.
11473 This is the name (a string) or identifier (a number) of the user group
11474 this account belongs to.
11476 @item @code{supplementary-groups} (default: @code{'()})
11477 Optionally, this can be defined as a list of group names that this
11478 account belongs to.
11480 @item @code{uid} (default: @code{#f})
11481 This is the user ID for this account (a number), or @code{#f}. In the
11482 latter case, a number is automatically chosen by the system when the
11483 account is created.
11485 @item @code{comment} (default: @code{""})
11486 A comment about the account, such as the account owner's full name.
11488 @item @code{home-directory}
11489 This is the name of the home directory for the account.
11491 @item @code{create-home-directory?} (default: @code{#t})
11492 Indicates whether the home directory of this account should be created
11493 if it does not exist yet.
11495 @item @code{shell} (default: Bash)
11496 This is a G-expression denoting the file name of a program to be used as
11497 the shell (@pxref{G-Expressions}).
11499 @item @code{system?} (default: @code{#f})
11500 This Boolean value indicates whether the account is a ``system''
11501 account. System accounts are sometimes treated specially; for instance,
11502 graphical login managers do not list them.
11504 @anchor{user-account-password}
11505 @cindex password, for user accounts
11506 @item @code{password} (default: @code{#f})
11507 You would normally leave this field to @code{#f}, initialize user
11508 passwords as @code{root} with the @command{passwd} command, and then let
11509 users change it with @command{passwd}. Passwords set with
11510 @command{passwd} are of course preserved across reboot and
11513 If you @emph{do} want to set an initial password for an account, then
11514 this field must contain the encrypted password, as a string. You can use the
11515 @code{crypt} procedure for this purpose:
11522 ;; Specify a SHA-512-hashed initial password.
11523 (password (crypt "InitialPassword!" "$6$abc")))
11527 The hash of this initial password will be available in a file in
11528 @file{/gnu/store}, readable by all the users, so this method must be used with
11532 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
11533 more information on password encryption, and @ref{Encryption,,, guile, GNU
11534 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
11540 User group declarations are even simpler:
11543 (user-group (name "students"))
11546 @deftp {Data Type} user-group
11547 This type is for, well, user groups. There are just a few fields:
11551 The name of the group.
11553 @item @code{id} (default: @code{#f})
11554 The group identifier (a number). If @code{#f}, a new number is
11555 automatically allocated when the group is created.
11557 @item @code{system?} (default: @code{#f})
11558 This Boolean value indicates whether the group is a ``system'' group.
11559 System groups have low numerical IDs.
11561 @item @code{password} (default: @code{#f})
11562 What, user groups can have a password? Well, apparently yes. Unless
11563 @code{#f}, this field specifies the password of the group.
11568 For convenience, a variable lists all the basic user groups one may
11571 @defvr {Scheme Variable} %base-groups
11572 This is the list of basic user groups that users and/or packages expect
11573 to be present on the system. This includes groups such as ``root'',
11574 ``wheel'', and ``users'', as well as groups used to control access to
11575 specific devices such as ``audio'', ``disk'', and ``cdrom''.
11578 @defvr {Scheme Variable} %base-user-accounts
11579 This is the list of basic system accounts that programs may expect to
11580 find on a GNU/Linux system, such as the ``nobody'' account.
11582 Note that the ``root'' account is not included here. It is a
11583 special-case and is automatically added whether or not it is specified.
11586 @node Keyboard Layout
11587 @section Keyboard Layout
11589 @cindex keyboard layout
11591 To specify what each key of your keyboard does, you need to tell the operating
11592 system what @dfn{keyboard layout} you want to use. The default, when nothing
11593 is specified, is the US English QWERTY layout for 105-key PC keyboards.
11594 However, German speakers will usually prefer the German QWERTZ layout, French
11595 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
11596 or bépo, and they might even want to further customize the effect of some of
11597 the keys. This section explains how to get that done.
11599 @cindex keyboard layout, definition
11600 There are three components that will want to know about your keyboard layout:
11604 The @emph{bootloader} may want to know what keyboard layout you want to use
11605 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
11606 you want, for instance, to make sure that you can type the passphrase of your
11607 encrypted root partition using the right layout.
11610 The @emph{operating system kernel}, Linux, will need that so that the console
11611 is properly configured (@pxref{operating-system Reference,
11612 @code{keyboard-layout}}).
11615 The @emph{graphical display server}, usually Xorg, also has its own idea of
11616 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
11619 Guix allows you to configure all three separately but, fortunately, it allows
11620 you to share the same keyboard layout for all three components.
11622 @cindex XKB, keyboard layouts
11623 Keyboard layouts are represented by records created by the
11624 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
11625 the X Keyboard extension (XKB), each layout has four attributes: a name (often
11626 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
11627 optional variant name, an optional keyboard model name, and a possibly empty
11628 list of additional options. In most cases the layout name is all you care
11629 about. Here are a few example:
11632 ;; The German QWERTZ layout. Here we assume a standard
11633 ;; "pc105" keyboard model.
11634 (keyboard-layout "de")
11636 ;; The bépo variant of the French layout.
11637 (keyboard-layout "fr" "bepo")
11639 ;; The Catalan layout.
11640 (keyboard-layout "es" "cat")
11642 ;; The Latin American Spanish layout. In addition, the
11643 ;; "Caps Lock" key is used as an additional "Ctrl" key,
11644 ;; and the "Menu" key is used as a "Compose" key to enter
11645 ;; accented letters.
11646 (keyboard-layout "latam"
11647 #:options '("ctrl:nocaps" "compose:menu"))
11649 ;; The Russian layout for a ThinkPad keyboard.
11650 (keyboard-layout "ru" #:model "thinkpad")
11652 ;; The "US international" layout, which is the US layout plus
11653 ;; dead keys to enter accented characters. This is for an
11654 ;; Apple MacBook keyboard.
11655 (keyboard-layout "us" "intl" #:model "macbook78")
11658 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
11659 for a complete list of supported layouts, variants, and models.
11661 @cindex keyboard layout, configuration
11662 Let's say you want your system to use the Turkish keyboard layout throughout
11663 your system---bootloader, console, and Xorg. Here's what your system
11664 configuration would look like:
11666 @findex set-xorg-configuration
11668 ;; Using the Turkish layout for the bootloader, the console,
11673 (keyboard-layout (keyboard-layout "tr")) ;for the console
11674 (bootloader (bootloader-configuration
11675 (bootloader grub-efi-bootloader)
11676 (target "/boot/efi")
11677 (keyboard-layout keyboard-layout))) ;for GRUB
11678 (services (cons (set-xorg-configuration
11679 (xorg-configuration ;for Xorg
11680 (keyboard-layout keyboard-layout)))
11681 %desktop-services)))
11684 In the example above, for GRUB and for Xorg, we just refer to the
11685 @code{keyboard-layout} field defined above, but we could just as well refer to
11686 a different layout. The @code{set-xorg-configuration} procedure communicates
11687 the desired Xorg configuration to the graphical log-in manager, by default
11690 We've discussed how to specify the @emph{default} keyboard layout of your
11691 system when it starts, but you can also adjust it at run time:
11695 If you're using GNOME, its settings panel has a ``Region & Language'' entry
11696 where you can select one or more keyboard layouts.
11699 Under Xorg, the @command{setxkbmap} command (from the same-named package)
11700 allows you to change the current layout. For example, this is how you would
11701 change the layout to US Dvorak:
11704 setxkbmap us dvorak
11708 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
11709 console. However, note that @code{loadkeys} does @emph{not} use the XKB
11710 keyboard layout categorization described above. The command below loads the
11711 French bépo layout:
11722 A @dfn{locale} defines cultural conventions for a particular language
11723 and region of the world (@pxref{Locales,,, libc, The GNU C Library
11724 Reference Manual}). Each locale has a name that typically has the form
11725 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
11726 @code{fr_LU.utf8} designates the locale for the French language, with
11727 cultural conventions from Luxembourg, and using the UTF-8 encoding.
11729 @cindex locale definition
11730 Usually, you will want to specify the default locale for the machine
11731 using the @code{locale} field of the @code{operating-system} declaration
11732 (@pxref{operating-system Reference, @code{locale}}).
11734 The selected locale is automatically added to the @dfn{locale
11735 definitions} known to the system if needed, with its codeset inferred
11736 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
11737 @code{UTF-8} codeset. Additional locale definitions can be specified in
11738 the @code{locale-definitions} slot of @code{operating-system}---this is
11739 useful, for instance, if the codeset could not be inferred from the
11740 locale name. The default set of locale definitions includes some widely
11741 used locales, but not all the available locales, in order to save space.
11743 For instance, to add the North Frisian locale for Germany, the value of
11747 (cons (locale-definition
11748 (name "fy_DE.utf8") (source "fy_DE"))
11749 %default-locale-definitions)
11752 Likewise, to save space, one might want @code{locale-definitions} to
11753 list only the locales that are actually used, as in:
11756 (list (locale-definition
11757 (name "ja_JP.eucjp") (source "ja_JP")
11758 (charset "EUC-JP")))
11762 The compiled locale definitions are available at
11763 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
11764 version, which is the default location where the GNU@tie{}libc provided
11765 by Guix looks for locale data. This can be overridden using the
11766 @code{LOCPATH} environment variable (@pxref{locales-and-locpath,
11767 @code{LOCPATH} and locale packages}).
11769 The @code{locale-definition} form is provided by the @code{(gnu system
11770 locale)} module. Details are given below.
11772 @deftp {Data Type} locale-definition
11773 This is the data type of a locale definition.
11778 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
11779 Reference Manual}, for more information on locale names.
11781 @item @code{source}
11782 The name of the source for that locale. This is typically the
11783 @code{@var{language}_@var{territory}} part of the locale name.
11785 @item @code{charset} (default: @code{"UTF-8"})
11786 The ``character set'' or ``code set'' for that locale,
11787 @uref{https://www.iana.org/assignments/character-sets, as defined by
11793 @defvr {Scheme Variable} %default-locale-definitions
11794 A list of commonly used UTF-8 locales, used as the default
11795 value of the @code{locale-definitions} field of @code{operating-system}
11798 @cindex locale name
11799 @cindex normalized codeset in locale names
11800 These locale definitions use the @dfn{normalized codeset} for the part
11801 that follows the dot in the name (@pxref{Using gettextized software,
11802 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
11803 instance it has @code{uk_UA.utf8} but @emph{not}, say,
11804 @code{uk_UA.UTF-8}.
11807 @subsection Locale Data Compatibility Considerations
11809 @cindex incompatibility, of locale data
11810 @code{operating-system} declarations provide a @code{locale-libcs} field
11811 to specify the GNU@tie{}libc packages that are used to compile locale
11812 declarations (@pxref{operating-system Reference}). ``Why would I
11813 care?'', you may ask. Well, it turns out that the binary format of
11814 locale data is occasionally incompatible from one libc version to
11817 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
11818 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
11819 For instance, a program linked against libc version 2.21 is unable to
11820 read locale data produced with libc 2.22; worse, that program
11821 @emph{aborts} instead of simply ignoring the incompatible locale
11822 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
11823 the incompatible locale data, which is already an improvement.}.
11824 Similarly, a program linked against libc 2.22 can read most, but not
11825 all, of the locale data from libc 2.21 (specifically, @code{LC_COLLATE}
11826 data is incompatible); thus calls to @code{setlocale} may fail, but
11827 programs will not abort.
11829 The ``problem'' with Guix is that users have a lot of freedom: They can
11830 choose whether and when to upgrade software in their profiles, and might
11831 be using a libc version different from the one the system administrator
11832 used to build the system-wide locale data.
11834 Fortunately, unprivileged users can also install their own locale data
11835 and define @var{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
11836 @code{GUIX_LOCPATH} and locale packages}).
11838 Still, it is best if the system-wide locale data at
11839 @file{/run/current-system/locale} is built for all the libc versions
11840 actually in use on the system, so that all the programs can access
11841 it---this is especially crucial on a multi-user system. To do that, the
11842 administrator can specify several libc packages in the
11843 @code{locale-libcs} field of @code{operating-system}:
11846 (use-package-modules base)
11850 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
11853 This example would lead to a system containing locale definitions for
11854 both libc 2.21 and the current version of libc in
11855 @file{/run/current-system/locale}.
11861 @cindex system services
11862 An important part of preparing an @code{operating-system} declaration is
11863 listing @dfn{system services} and their configuration (@pxref{Using the
11864 Configuration System}). System services are typically daemons launched
11865 when the system boots, or other actions needed at that time---e.g.,
11866 configuring network access.
11868 Guix has a broad definition of ``service'' (@pxref{Service
11869 Composition}), but many services are managed by the GNU@tie{}Shepherd
11870 (@pxref{Shepherd Services}). On a running system, the @command{herd}
11871 command allows you to list the available services, show their status,
11872 start and stop them, or do other specific operations (@pxref{Jump
11873 Start,,, shepherd, The GNU Shepherd Manual}). For example:
11879 The above command, run as @code{root}, lists the currently defined
11880 services. The @command{herd doc} command shows a synopsis of the given
11881 service and its associated actions:
11885 Run libc's name service cache daemon (nscd).
11887 # herd doc nscd action invalidate
11888 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
11891 The @command{start}, @command{stop}, and @command{restart} sub-commands
11892 have the effect you would expect. For instance, the commands below stop
11893 the nscd service and restart the Xorg display server:
11897 Service nscd has been stopped.
11898 # herd restart xorg-server
11899 Service xorg-server has been stopped.
11900 Service xorg-server has been started.
11903 The following sections document the available services, starting with
11904 the core services, that may be used in an @code{operating-system}
11908 * Base Services:: Essential system services.
11909 * Scheduled Job Execution:: The mcron service.
11910 * Log Rotation:: The rottlog service.
11911 * Networking Services:: Network setup, SSH daemon, etc.
11912 * X Window:: Graphical display.
11913 * Printing Services:: Local and remote printer support.
11914 * Desktop Services:: D-Bus and desktop services.
11915 * Sound Services:: ALSA and Pulseaudio services.
11916 * Database Services:: SQL databases, key-value stores, etc.
11917 * Mail Services:: IMAP, POP3, SMTP, and all that.
11918 * Messaging Services:: Messaging services.
11919 * Telephony Services:: Telephony services.
11920 * Monitoring Services:: Monitoring services.
11921 * Kerberos Services:: Kerberos services.
11922 * LDAP Services:: LDAP services.
11923 * Web Services:: Web servers.
11924 * Certificate Services:: TLS certificates via Let's Encrypt.
11925 * DNS Services:: DNS daemons.
11926 * VPN Services:: VPN daemons.
11927 * Network File System:: NFS related services.
11928 * Continuous Integration:: The Cuirass service.
11929 * Power Management Services:: Extending battery life.
11930 * Audio Services:: The MPD.
11931 * Virtualization Services:: Virtualization services.
11932 * Version Control Services:: Providing remote access to Git repositories.
11933 * Game Services:: Game servers.
11934 * Guix Services:: Services relating specifically to Guix.
11935 * Miscellaneous Services:: Other services.
11938 @node Base Services
11939 @subsection Base Services
11941 The @code{(gnu services base)} module provides definitions for the basic
11942 services that one expects from the system. The services exported by
11943 this module are listed below.
11945 @defvr {Scheme Variable} %base-services
11946 This variable contains a list of basic services (@pxref{Service Types
11947 and Services}, for more information on service objects) one would
11948 expect from the system: a login service (mingetty) on each tty, syslogd,
11949 the libc name service cache daemon (nscd), the udev device manager, and
11952 This is the default value of the @code{services} field of
11953 @code{operating-system} declarations. Usually, when customizing a
11954 system, you will want to append services to @code{%base-services}, like
11958 (append (list (service avahi-service-type)
11959 (service openssh-service-type))
11964 @defvr {Scheme Variable} special-files-service-type
11965 This is the service that sets up ``special files'' such as
11966 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
11968 The value associated with @code{special-files-service-type} services
11969 must be a list of tuples where the first element is the ``special file''
11970 and the second element is its target. By default it is:
11972 @cindex @file{/bin/sh}
11973 @cindex @file{sh}, in @file{/bin}
11975 `(("/bin/sh" ,(file-append bash "/bin/sh")))
11978 @cindex @file{/usr/bin/env}
11979 @cindex @file{env}, in @file{/usr/bin}
11980 If you want to add, say, @code{/usr/bin/env} to your system, you can
11984 `(("/bin/sh" ,(file-append bash "/bin/sh"))
11985 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
11988 Since this is part of @code{%base-services}, you can use
11989 @code{modify-services} to customize the set of special files
11990 (@pxref{Service Reference, @code{modify-services}}). But the simple way
11991 to add a special file is @i{via} the @code{extra-special-file} procedure
11995 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
11996 Use @var{target} as the ``special file'' @var{file}.
11998 For example, adding the following lines to the @code{services} field of
11999 your operating system declaration leads to a @file{/usr/bin/env}
12003 (extra-special-file "/usr/bin/env"
12004 (file-append coreutils "/bin/env"))
12008 @deffn {Scheme Procedure} host-name-service @var{name}
12009 Return a service that sets the host name to @var{name}.
12012 @deffn {Scheme Procedure} login-service @var{config}
12013 Return a service to run login according to @var{config}, a
12014 @code{<login-configuration>} object, which specifies the message of the day,
12015 among other things.
12018 @deftp {Data Type} login-configuration
12019 This is the data type representing the configuration of login.
12024 @cindex message of the day
12025 A file-like object containing the ``message of the day''.
12027 @item @code{allow-empty-passwords?} (default: @code{#t})
12028 Allow empty passwords by default so that first-time users can log in when
12029 the 'root' account has just been created.
12034 @deffn {Scheme Procedure} mingetty-service @var{config}
12035 Return a service to run mingetty according to @var{config}, a
12036 @code{<mingetty-configuration>} object, which specifies the tty to run, among
12040 @deftp {Data Type} mingetty-configuration
12041 This is the data type representing the configuration of Mingetty, which
12042 provides the default implementation of virtual console log-in.
12047 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
12049 @item @code{auto-login} (default: @code{#f})
12050 When true, this field must be a string denoting the user name under
12051 which the system automatically logs in. When it is @code{#f}, a
12052 user name and password must be entered to log in.
12054 @item @code{login-program} (default: @code{#f})
12055 This must be either @code{#f}, in which case the default log-in program
12056 is used (@command{login} from the Shadow tool suite), or a gexp denoting
12057 the name of the log-in program.
12059 @item @code{login-pause?} (default: @code{#f})
12060 When set to @code{#t} in conjunction with @var{auto-login}, the user
12061 will have to press a key before the log-in shell is launched.
12063 @item @code{mingetty} (default: @var{mingetty})
12064 The Mingetty package to use.
12069 @deffn {Scheme Procedure} agetty-service @var{config}
12070 Return a service to run agetty according to @var{config}, an
12071 @code{<agetty-configuration>} object, which specifies the tty to run,
12072 among other things.
12075 @deftp {Data Type} agetty-configuration
12076 This is the data type representing the configuration of agetty, which
12077 implements virtual and serial console log-in. See the @code{agetty(8)}
12078 man page for more information.
12083 The name of the console this agetty runs on, as a string---e.g.,
12084 @code{"ttyS0"}. This argument is optional, it will default to
12085 a reasonable default serial port used by the kernel Linux.
12087 For this, if there is a value for an option @code{agetty.tty} in the kernel
12088 command line, agetty will extract the device name of the serial port
12089 from it and use that.
12091 If not and if there is a value for an option @code{console} with a tty in
12092 the Linux command line, agetty will extract the device name of the
12093 serial port from it and use that.
12095 In both cases, agetty will leave the other serial device settings
12096 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
12099 @item @code{baud-rate} (default: @code{#f})
12100 A string containing a comma-separated list of one or more baud rates, in
12103 @item @code{term} (default: @code{#f})
12104 A string containing the value used for the @code{TERM} environment
12107 @item @code{eight-bits?} (default: @code{#f})
12108 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
12111 @item @code{auto-login} (default: @code{#f})
12112 When passed a login name, as a string, the specified user will be logged
12113 in automatically without prompting for their login name or password.
12115 @item @code{no-reset?} (default: @code{#f})
12116 When @code{#t}, don't reset terminal cflags (control modes).
12118 @item @code{host} (default: @code{#f})
12119 This accepts a string containing the "login_host", which will be written
12120 into the @file{/var/run/utmpx} file.
12122 @item @code{remote?} (default: @code{#f})
12123 When set to @code{#t} in conjunction with @var{host}, this will add an
12124 @code{-r} fakehost option to the command line of the login program
12125 specified in @var{login-program}.
12127 @item @code{flow-control?} (default: @code{#f})
12128 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
12130 @item @code{no-issue?} (default: @code{#f})
12131 When set to @code{#t}, the contents of the @file{/etc/issue} file will
12132 not be displayed before presenting the login prompt.
12134 @item @code{init-string} (default: @code{#f})
12135 This accepts a string that will be sent to the tty or modem before
12136 sending anything else. It can be used to initialize a modem.
12138 @item @code{no-clear?} (default: @code{#f})
12139 When set to @code{#t}, agetty will not clear the screen before showing
12142 @item @code{login-program} (default: (file-append shadow "/bin/login"))
12143 This must be either a gexp denoting the name of a log-in program, or
12144 unset, in which case the default value is the @command{login} from the
12147 @item @code{local-line} (default: @code{#f})
12148 Control the CLOCAL line flag. This accepts one of three symbols as
12149 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
12150 the default value chosen by agetty is @code{'auto}.
12152 @item @code{extract-baud?} (default: @code{#f})
12153 When set to @code{#t}, instruct agetty to try to extract the baud rate
12154 from the status messages produced by certain types of modems.
12156 @item @code{skip-login?} (default: @code{#f})
12157 When set to @code{#t}, do not prompt the user for a login name. This
12158 can be used with @var{login-program} field to use non-standard login
12161 @item @code{no-newline?} (default: @code{#f})
12162 When set to @code{#t}, do not print a newline before printing the
12163 @file{/etc/issue} file.
12165 @c Is this dangerous only when used with login-program, or always?
12166 @item @code{login-options} (default: @code{#f})
12167 This option accepts a string containing options that are passed to the
12168 login program. When used with the @var{login-program}, be aware that a
12169 malicious user could try to enter a login name containing embedded
12170 options that could be parsed by the login program.
12172 @item @code{login-pause} (default: @code{#f})
12173 When set to @code{#t}, wait for any key before showing the login prompt.
12174 This can be used in conjunction with @var{auto-login} to save memory by
12175 lazily spawning shells.
12177 @item @code{chroot} (default: @code{#f})
12178 Change root to the specified directory. This option accepts a directory
12181 @item @code{hangup?} (default: @code{#f})
12182 Use the Linux system call @code{vhangup} to do a virtual hangup of the
12183 specified terminal.
12185 @item @code{keep-baud?} (default: @code{#f})
12186 When set to @code{#t}, try to keep the existing baud rate. The baud
12187 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
12190 @item @code{timeout} (default: @code{#f})
12191 When set to an integer value, terminate if no user name could be read
12192 within @var{timeout} seconds.
12194 @item @code{detect-case?} (default: @code{#f})
12195 When set to @code{#t}, turn on support for detecting an uppercase-only
12196 terminal. This setting will detect a login name containing only
12197 uppercase letters as indicating an uppercase-only terminal and turn on
12198 some upper-to-lower case conversions. Note that this will not support
12199 Unicode characters.
12201 @item @code{wait-cr?} (default: @code{#f})
12202 When set to @code{#t}, wait for the user or modem to send a
12203 carriage-return or linefeed character before displaying
12204 @file{/etc/issue} or login prompt. This is typically used with the
12205 @var{init-string} option.
12207 @item @code{no-hints?} (default: @code{#f})
12208 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
12211 @item @code{no-hostname?} (default: @code{#f})
12212 By default, the hostname is printed. When this option is set to
12213 @code{#t}, no hostname will be shown at all.
12215 @item @code{long-hostname?} (default: @code{#f})
12216 By default, the hostname is only printed until the first dot. When this
12217 option is set to @code{#t}, the fully qualified hostname by
12218 @code{gethostname} or @code{getaddrinfo} is shown.
12220 @item @code{erase-characters} (default: @code{#f})
12221 This option accepts a string of additional characters that should be
12222 interpreted as backspace when the user types their login name.
12224 @item @code{kill-characters} (default: @code{#f})
12225 This option accepts a string that should be interpreted to mean "ignore
12226 all previous characters" (also called a "kill" character) when the user
12227 types their login name.
12229 @item @code{chdir} (default: @code{#f})
12230 This option accepts, as a string, a directory path that will be changed
12233 @item @code{delay} (default: @code{#f})
12234 This options accepts, as an integer, the number of seconds to sleep
12235 before opening the tty and displaying the login prompt.
12237 @item @code{nice} (default: @code{#f})
12238 This option accepts, as an integer, the nice value with which to run the
12239 @command{login} program.
12241 @item @code{extra-options} (default: @code{'()})
12242 This option provides an "escape hatch" for the user to provide arbitrary
12243 command-line arguments to @command{agetty} as a list of strings.
12248 @deffn {Scheme Procedure} kmscon-service-type @var{config}
12249 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
12250 according to @var{config}, a @code{<kmscon-configuration>} object, which
12251 specifies the tty to run, among other things.
12254 @deftp {Data Type} kmscon-configuration
12255 This is the data type representing the configuration of Kmscon, which
12256 implements virtual console log-in.
12260 @item @code{virtual-terminal}
12261 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
12263 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
12264 A gexp denoting the name of the log-in program. The default log-in program is
12265 @command{login} from the Shadow tool suite.
12267 @item @code{login-arguments} (default: @code{'("-p")})
12268 A list of arguments to pass to @command{login}.
12270 @item @code{auto-login} (default: @code{#f})
12271 When passed a login name, as a string, the specified user will be logged
12272 in automatically without prompting for their login name or password.
12274 @item @code{hardware-acceleration?} (default: #f)
12275 Whether to use hardware acceleration.
12277 @item @code{kmscon} (default: @var{kmscon})
12278 The Kmscon package to use.
12283 @cindex name service cache daemon
12285 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
12286 [#:name-services '()]
12287 Return a service that runs the libc name service cache daemon (nscd) with the
12288 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
12289 Service Switch}, for an example.
12291 For convenience, the Shepherd service for nscd provides the following actions:
12295 @cindex cache invalidation, nscd
12296 @cindex nscd, cache invalidation
12297 This invalidate the given cache. For instance, running:
12300 herd invalidate nscd hosts
12304 invalidates the host name lookup cache of nscd.
12307 Running @command{herd statistics nscd} displays information about nscd usage
12313 @defvr {Scheme Variable} %nscd-default-configuration
12314 This is the default @code{<nscd-configuration>} value (see below) used
12315 by @code{nscd-service}. It uses the caches defined by
12316 @var{%nscd-default-caches}; see below.
12319 @deftp {Data Type} nscd-configuration
12320 This is the data type representing the name service cache daemon (nscd)
12325 @item @code{name-services} (default: @code{'()})
12326 List of packages denoting @dfn{name services} that must be visible to
12327 the nscd---e.g., @code{(list @var{nss-mdns})}.
12329 @item @code{glibc} (default: @var{glibc})
12330 Package object denoting the GNU C Library providing the @command{nscd}
12333 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
12334 Name of the nscd log file. This is where debugging output goes when
12335 @code{debug-level} is strictly positive.
12337 @item @code{debug-level} (default: @code{0})
12338 Integer denoting the debugging levels. Higher numbers mean that more
12339 debugging output is logged.
12341 @item @code{caches} (default: @var{%nscd-default-caches})
12342 List of @code{<nscd-cache>} objects denoting things to be cached; see
12348 @deftp {Data Type} nscd-cache
12349 Data type representing a cache database of nscd and its parameters.
12353 @item @code{database}
12354 This is a symbol representing the name of the database to be cached.
12355 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
12356 @code{services}, which designate the corresponding NSS database
12357 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
12359 @item @code{positive-time-to-live}
12360 @itemx @code{negative-time-to-live} (default: @code{20})
12361 A number representing the number of seconds during which a positive or
12362 negative lookup result remains in cache.
12364 @item @code{check-files?} (default: @code{#t})
12365 Whether to check for updates of the files corresponding to
12368 For instance, when @var{database} is @code{hosts}, setting this flag
12369 instructs nscd to check for updates in @file{/etc/hosts} and to take
12372 @item @code{persistent?} (default: @code{#t})
12373 Whether the cache should be stored persistently on disk.
12375 @item @code{shared?} (default: @code{#t})
12376 Whether the cache should be shared among users.
12378 @item @code{max-database-size} (default: 32@tie{}MiB)
12379 Maximum size in bytes of the database cache.
12381 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
12382 @c settings, so leave them out.
12387 @defvr {Scheme Variable} %nscd-default-caches
12388 List of @code{<nscd-cache>} objects used by default by
12389 @code{nscd-configuration} (see above).
12391 It enables persistent and aggressive caching of service and host name
12392 lookups. The latter provides better host name lookup performance,
12393 resilience in the face of unreliable name servers, and also better
12394 privacy---often the result of host name lookups is in local cache, so
12395 external name servers do not even need to be queried.
12398 @anchor{syslog-configuration-type}
12401 @deftp {Data Type} syslog-configuration
12402 This data type represents the configuration of the syslog daemon.
12405 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
12406 The syslog daemon to use.
12408 @item @code{config-file} (default: @code{%default-syslog.conf})
12409 The syslog configuration file to use.
12414 @anchor{syslog-service}
12416 @deffn {Scheme Procedure} syslog-service @var{config}
12417 Return a service that runs a syslog daemon according to @var{config}.
12419 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
12420 information on the configuration file syntax.
12423 @defvr {Scheme Variable} guix-service-type
12424 This is the type of the service that runs the build daemon,
12425 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
12426 @code{guix-configuration} record as described below.
12429 @anchor{guix-configuration-type}
12430 @deftp {Data Type} guix-configuration
12431 This data type represents the configuration of the Guix build daemon.
12432 @xref{Invoking guix-daemon}, for more information.
12435 @item @code{guix} (default: @var{guix})
12436 The Guix package to use.
12438 @item @code{build-group} (default: @code{"guixbuild"})
12439 Name of the group for build user accounts.
12441 @item @code{build-accounts} (default: @code{10})
12442 Number of build user accounts to create.
12444 @item @code{authorize-key?} (default: @code{#t})
12445 @cindex substitutes, authorization thereof
12446 Whether to authorize the substitute keys listed in
12447 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
12448 (@pxref{Substitutes}).
12450 @vindex %default-authorized-guix-keys
12451 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
12452 The list of authorized key files for archive imports, as a list of
12453 string-valued gexps (@pxref{Invoking guix archive}). By default, it
12454 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
12456 @item @code{use-substitutes?} (default: @code{#t})
12457 Whether to use substitutes.
12459 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
12460 The list of URLs where to look for substitutes by default.
12462 @item @code{max-silent-time} (default: @code{0})
12463 @itemx @code{timeout} (default: @code{0})
12464 The number of seconds of silence and the number of seconds of activity,
12465 respectively, after which a build process times out. A value of zero
12466 disables the timeout.
12468 @item @code{log-compression} (default: @code{'bzip2})
12469 The type of compression used for build logs---one of @code{gzip},
12470 @code{bzip2}, or @code{none}.
12472 @item @code{extra-options} (default: @code{'()})
12473 List of extra command-line options for @command{guix-daemon}.
12475 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
12476 File where @command{guix-daemon}'s standard output and standard error
12479 @item @code{http-proxy} (default: @code{#f})
12480 The HTTP proxy used for downloading fixed-output derivations and
12483 @item @code{tmpdir} (default: @code{#f})
12484 A directory path where the @command{guix-daemon} will perform builds.
12489 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
12490 Run @var{udev}, which populates the @file{/dev} directory dynamically.
12491 udev rules can be provided as a list of files through the @var{rules}
12492 variable. The procedures @code{udev-rule} and @code{file->udev-rule} from
12493 @code{(gnu services base)} simplify the creation of such rule files.
12496 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
12497 Return a udev-rule file named @var{file-name} containing the rules
12498 defined by the @var{contents} literal.
12500 In the following example, a rule for a USB device is defined to be
12501 stored in the file @file{90-usb-thing.rules}. The rule runs a script
12502 upon detecting a USB device with a given product identifier.
12505 (define %example-udev-rule
12507 "90-usb-thing.rules"
12508 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
12509 "ATTR@{product@}==\"Example\", "
12510 "RUN+=\"/path/to/script\"")))
12513 The @command{herd rules udev} command, as root, returns the name of the
12514 directory containing all the active udev rules.
12517 Here we show how the default @var{udev-service} can be extended with it.
12523 (modify-services %desktop-services
12524 (udev-service-type config =>
12525 (udev-configuration (inherit config)
12526 (rules (append (udev-configuration-rules config)
12527 (list %example-udev-rule))))))))
12530 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
12531 Return a udev file named @var{file-name} containing the rules defined
12532 within @var{file}, a file-like object.
12534 The following example showcases how we can use an existing rule file.
12537 (use-modules (guix download) ;for url-fetch
12538 (guix packages) ;for origin
12541 (define %android-udev-rules
12543 "51-android-udev.rules"
12544 (let ((version "20170910"))
12547 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
12548 "android-udev-rules/" version "/51-android.rules"))
12550 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
12554 Additionally, Guix package definitions can be included in @var{rules} in
12555 order to extend the udev rules with the definitions found under their
12556 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
12557 @var{file->udev-rule} example, we could have used the
12558 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
12559 packages android)} module.
12561 The following example shows how to use the @var{android-udev-rules}
12562 package so that the Android tool @command{adb} can detect devices
12563 without root privileges. It also details how to create the
12564 @code{adbusers} group, which is required for the proper functioning of
12565 the rules defined within the @var{android-udev-rules} package. To
12566 create such a group, we must define it both as part of the
12567 @var{supplementary-groups} of our @var{user-account} declaration, as
12568 well as in the @var{groups} field of the @var{operating-system} record.
12571 (use-modules (gnu packages android) ;for android-udev-rules
12572 (gnu system shadow) ;for user-group
12577 (users (cons (user-acount
12579 (supplementary-groups
12580 '("adbusers" ;for adb
12581 "wheel" "netdev" "audio" "video")))))
12583 (groups (cons (user-group (system? #t) (name "adbusers"))
12589 (modify-services %desktop-services
12592 (udev-configuration (inherit config)
12593 (rules (cons android-udev-rules
12594 (udev-configuration-rules config))))))))
12597 @defvr {Scheme Variable} urandom-seed-service-type
12598 Save some entropy in @var{%random-seed-file} to seed @file{/dev/urandom}
12599 when rebooting. It also tries to seed @file{/dev/urandom} from
12600 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
12604 @defvr {Scheme Variable} %random-seed-file
12605 This is the name of the file where some random bytes are saved by
12606 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
12607 It defaults to @file{/var/lib/random-seed}.
12612 @defvr {Scheme Variable} gpm-service-type
12613 This is the type of the service that runs GPM, the @dfn{general-purpose
12614 mouse daemon}, which provides mouse support to the Linux console. GPM
12615 allows users to use the mouse in the console, notably to select, copy,
12618 The value for services of this type must be a @code{gpm-configuration}
12619 (see below). This service is not part of @code{%base-services}.
12622 @deftp {Data Type} gpm-configuration
12623 Data type representing the configuration of GPM.
12626 @item @code{options} (default: @code{%default-gpm-options})
12627 Command-line options passed to @command{gpm}. The default set of
12628 options instruct @command{gpm} to listen to mouse events on
12629 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
12632 @item @code{gpm} (default: @code{gpm})
12633 The GPM package to use.
12638 @anchor{guix-publish-service-type}
12639 @deffn {Scheme Variable} guix-publish-service-type
12640 This is the service type for @command{guix publish} (@pxref{Invoking
12641 guix publish}). Its value must be a @code{guix-publish-configuration}
12642 object, as described below.
12644 This assumes that @file{/etc/guix} already contains a signing key pair as
12645 created by @command{guix archive --generate-key} (@pxref{Invoking guix
12646 archive}). If that is not the case, the service will fail to start.
12649 @deftp {Data Type} guix-publish-configuration
12650 Data type representing the configuration of the @code{guix publish}
12654 @item @code{guix} (default: @code{guix})
12655 The Guix package to use.
12657 @item @code{port} (default: @code{80})
12658 The TCP port to listen for connections.
12660 @item @code{host} (default: @code{"localhost"})
12661 The host (and thus, network interface) to listen to. Use
12662 @code{"0.0.0.0"} to listen on all the network interfaces.
12664 @item @code{compression} (default: @code{'(("gzip" 3))})
12665 This is a list of compression method/level tuple used when compressing
12666 substitutes. For example, to compress all substitutes with @emph{both} lzip
12667 at level 7 and gzip at level 9, write:
12670 '(("lzip" 7) ("gzip" 9))
12673 Level 9 achieves the best compression ratio at the expense of increased CPU
12674 usage, whereas level 1 achieves fast compression.
12676 An empty list disables compression altogether.
12678 @item @code{nar-path} (default: @code{"nar"})
12679 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
12680 publish, @code{--nar-path}}, for details.
12682 @item @code{cache} (default: @code{#f})
12683 When it is @code{#f}, disable caching and instead generate archives on
12684 demand. Otherwise, this should be the name of a directory---e.g.,
12685 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
12686 archives and meta-data ready to be sent. @xref{Invoking guix publish,
12687 @option{--cache}}, for more information on the tradeoffs involved.
12689 @item @code{workers} (default: @code{#f})
12690 When it is an integer, this is the number of worker threads used for
12691 caching; when @code{#f}, the number of processors is used.
12692 @xref{Invoking guix publish, @option{--workers}}, for more information.
12694 @item @code{ttl} (default: @code{#f})
12695 When it is an integer, this denotes the @dfn{time-to-live} in seconds
12696 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
12697 for more information.
12701 @anchor{rngd-service}
12702 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
12703 [#:device "/dev/hwrng"]
12704 Return a service that runs the @command{rngd} program from @var{rng-tools}
12705 to add @var{device} to the kernel's entropy pool. The service will fail if
12706 @var{device} does not exist.
12709 @anchor{pam-limits-service}
12710 @cindex session limits
12715 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
12717 Return a service that installs a configuration file for the
12718 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
12719 @code{pam_limits} module}. The procedure optionally takes a list of
12720 @code{pam-limits-entry} values, which can be used to specify
12721 @code{ulimit} limits and nice priority limits to user sessions.
12723 The following limits definition sets two hard and soft limits for all
12724 login sessions of users in the @code{realtime} group:
12727 (pam-limits-service
12729 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
12730 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
12733 The first entry increases the maximum realtime priority for
12734 non-privileged processes; the second entry lifts any restriction of the
12735 maximum address space that can be locked in memory. These settings are
12736 commonly used for real-time audio systems.
12739 @node Scheduled Job Execution
12740 @subsection Scheduled Job Execution
12744 @cindex scheduling jobs
12745 The @code{(gnu services mcron)} module provides an interface to
12746 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
12747 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
12748 Unix @command{cron} daemon; the main difference is that it is
12749 implemented in Guile Scheme, which provides a lot of flexibility when
12750 specifying the scheduling of jobs and their actions.
12752 The example below defines an operating system that runs the
12753 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
12754 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
12755 well as the @command{mkid} command on behalf of an unprivileged user
12756 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
12757 gexps to introduce job definitions that are passed to mcron
12758 (@pxref{G-Expressions}).
12761 (use-modules (guix) (gnu) (gnu services mcron))
12762 (use-package-modules base idutils)
12764 (define updatedb-job
12765 ;; Run 'updatedb' at 3AM every day. Here we write the
12766 ;; job's action as a Scheme procedure.
12767 #~(job '(next-hour '(3))
12769 (execl (string-append #$findutils "/bin/updatedb")
12771 "--prunepaths=/tmp /var/tmp /gnu/store"))))
12773 (define garbage-collector-job
12774 ;; Collect garbage 5 minutes after midnight every day.
12775 ;; The job's action is a shell command.
12776 #~(job "5 0 * * *" ;Vixie cron syntax
12779 (define idutils-job
12780 ;; Update the index database as user "charlie" at 12:15PM
12781 ;; and 19:15PM. This runs from the user's home directory.
12782 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
12783 (string-append #$idutils "/bin/mkid src")
12788 (services (cons (service mcron-service-type
12789 (mcron-configuration
12790 (jobs (list garbage-collector-job
12796 For more complex jobs defined in Scheme where you need control over the top
12797 level, for instance to introduce a @code{use-modules} form, you can move your
12798 code to a separate program using the @code{program-file} procedure of the
12799 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
12803 (define %battery-alert-job
12804 ;; Beep when the battery percentage falls below %MIN-LEVEL.
12806 '(next-minute (range 0 60 1))
12808 "battery-alert.scm"
12809 (with-imported-modules (source-module-closure
12810 '((guix build utils)))
12812 (define %min-level 20)
12813 (use-modules (guix build utils)
12816 (ice-9 textual-ports)
12818 (setenv "LC_ALL" "C") ;ensure English output
12819 (and-let* ((input-pipe (open-pipe*
12821 #$(file-append acpi "/bin/acpi")))
12822 (output (get-string-all input-pipe))
12823 (m (string-match "Discharging, ([0-9]+)%" output))
12824 (level (string->number (match:substring m 1)))
12825 ((< level %min-level)))
12826 (format #t "warning: Battery level is low (~a%)~%" level)
12827 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
12830 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
12831 for more information on mcron job specifications. Below is the
12832 reference of the mcron service.
12834 On a running system, you can use the @code{schedule} action of the service to
12835 visualize the mcron jobs that will be executed next:
12838 # herd schedule mcron
12842 The example above lists the next five tasks that will be executed, but you can
12843 also specify the number of tasks to display:
12846 # herd schedule mcron 10
12849 @defvr {Scheme Variable} mcron-service-type
12850 This is the type of the @code{mcron} service, whose value is an
12851 @code{mcron-configuration} object.
12853 This service type can be the target of a service extension that provides
12854 it additional job specifications (@pxref{Service Composition}). In
12855 other words, it is possible to define services that provide additional
12859 @deftp {Data Type} mcron-configuration
12860 Data type representing the configuration of mcron.
12863 @item @code{mcron} (default: @var{mcron})
12864 The mcron package to use.
12867 This is a list of gexps (@pxref{G-Expressions}), where each gexp
12868 corresponds to an mcron job specification (@pxref{Syntax, mcron job
12869 specifications,, mcron, GNU@tie{}mcron}).
12875 @subsection Log Rotation
12878 @cindex log rotation
12880 Log files such as those found in @file{/var/log} tend to grow endlessly,
12881 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
12882 their contents in separate files, possibly compressed. The @code{(gnu
12883 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
12884 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
12886 The example below defines an operating system that provides log rotation
12887 with the default settings, for commonly encountered log files.
12890 (use-modules (guix) (gnu))
12891 (use-service-modules admin mcron)
12892 (use-package-modules base idutils)
12896 (services (cons (service rottlog-service-type)
12900 @defvr {Scheme Variable} rottlog-service-type
12901 This is the type of the Rottlog service, whose value is a
12902 @code{rottlog-configuration} object.
12904 Other services can extend this one with new @code{log-rotation} objects
12905 (see below), thereby augmenting the set of files to be rotated.
12907 This service type can define mcron jobs (@pxref{Scheduled Job
12908 Execution}) to run the rottlog service.
12911 @deftp {Data Type} rottlog-configuration
12912 Data type representing the configuration of rottlog.
12915 @item @code{rottlog} (default: @code{rottlog})
12916 The Rottlog package to use.
12918 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
12919 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
12920 rottlog, GNU Rot[t]log Manual}).
12922 @item @code{rotations} (default: @code{%default-rotations})
12923 A list of @code{log-rotation} objects as defined below.
12926 This is a list of gexps where each gexp corresponds to an mcron job
12927 specification (@pxref{Scheduled Job Execution}).
12931 @deftp {Data Type} log-rotation
12932 Data type representing the rotation of a group of log files.
12934 Taking an example from the Rottlog manual (@pxref{Period Related File
12935 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
12941 (files '("/var/log/apache/*"))
12942 (options '("storedir apache-archives"
12948 The list of fields is as follows:
12951 @item @code{frequency} (default: @code{'weekly})
12952 The log rotation frequency, a symbol.
12955 The list of files or file glob patterns to rotate.
12957 @item @code{options} (default: @code{'()})
12958 The list of rottlog options for this rotation (@pxref{Configuration
12959 parameters,,, rottlog, GNU Rot[t]lg Manual}).
12961 @item @code{post-rotate} (default: @code{#f})
12962 Either @code{#f} or a gexp to execute once the rotation has completed.
12966 @defvr {Scheme Variable} %default-rotations
12967 Specifies weekly rotation of @var{%rotated-files} and of
12968 @file{/var/log/guix-daemon.log}.
12971 @defvr {Scheme Variable} %rotated-files
12972 The list of syslog-controlled files to be rotated. By default it is:
12973 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
12974 "/var/log/maillog")}.
12977 @node Networking Services
12978 @subsection Networking Services
12980 The @code{(gnu services networking)} module provides services to configure
12981 the network interface.
12983 @cindex DHCP, networking service
12984 @defvr {Scheme Variable} dhcp-client-service-type
12985 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
12986 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
12987 is the DHCP client package to use, @code{isc-dhcp} by default.
12990 @deffn {Scheme Procedure} dhcpd-service-type
12991 This type defines a service that runs a DHCP daemon. To create a
12992 service of this type, you must supply a @code{<dhcpd-configuration>}.
12996 (service dhcpd-service-type
12997 (dhcpd-configuration
12998 (config-file (local-file "my-dhcpd.conf"))
12999 (interfaces '("enp0s25"))))
13003 @deftp {Data Type} dhcpd-configuration
13005 @item @code{package} (default: @code{isc-dhcp})
13006 The package that provides the DHCP daemon. This package is expected to
13007 provide the daemon at @file{sbin/dhcpd} relative to its output
13008 directory. The default package is the
13009 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
13010 @item @code{config-file} (default: @code{#f})
13011 The configuration file to use. This is required. It will be passed to
13012 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
13013 object (@pxref{G-Expressions, file-like objects}). See @code{man
13014 dhcpd.conf} for details on the configuration file syntax.
13015 @item @code{version} (default: @code{"4"})
13016 The DHCP version to use. The ISC DHCP server supports the values ``4'',
13017 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
13018 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
13020 @item @code{run-directory} (default: @code{"/run/dhcpd"})
13021 The run directory to use. At service activation time, this directory
13022 will be created if it does not exist.
13023 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
13024 The PID file to use. This corresponds to the @code{-pf} option of
13025 @code{dhcpd}. See @code{man dhcpd} for details.
13026 @item @code{interfaces} (default: @code{'()})
13027 The names of the network interfaces on which dhcpd should listen for
13028 broadcasts. If this list is not empty, then its elements (which must be
13029 strings) will be appended to the @code{dhcpd} invocation when starting
13030 the daemon. It may not be necessary to explicitly specify any
13031 interfaces here; see @code{man dhcpd} for details.
13035 @defvr {Scheme Variable} static-networking-service-type
13036 This is the type for statically-configured network interfaces.
13037 @c TODO Document <static-networking> data structures.
13040 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
13041 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
13042 [#:requirement @code{'(udev)}]
13043 Return a service that starts @var{interface} with address @var{ip}. If
13044 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
13045 it must be a string specifying the default network gateway. @var{requirement}
13046 can be used to declare a dependency on another service before configuring the
13049 This procedure can be called several times, one for each network
13050 interface of interest. Behind the scenes what it does is extend
13051 @code{static-networking-service-type} with additional network interfaces
13057 (static-networking-service "eno1" "192.168.1.82"
13058 #:gateway "192.168.1.2"
13059 #:name-servers '("192.168.1.2"))
13066 @cindex network management
13067 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
13068 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
13069 management daemon that aims to simplify wired and wireless networking.
13071 This service adds the @var{wicd} package to the global profile, providing
13072 several commands to interact with the daemon and configure networking:
13073 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
13074 and @command{wicd-curses} user interfaces.
13077 @cindex ModemManager
13079 @defvr {Scheme Variable} modem-manager-service-type
13080 This is the service type for the
13081 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
13082 service. The value for this service type is a
13083 @code{modem-manager-configuration} record.
13085 This service is part of @code{%desktop-services} (@pxref{Desktop
13089 @deftp {Data Type} modem-manager-configuration
13090 Data type representing the configuration of ModemManager.
13093 @item @code{modem-manager} (default: @code{modem-manager})
13094 The ModemManager package to use.
13099 @cindex USB_ModeSwitch
13100 @cindex Modeswitching
13102 @defvr {Scheme Variable} usb-modeswitch-service-type
13103 This is the service type for the
13104 @uref{http://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
13105 value for this service type is a @code{usb-modeswitch-configuration} record.
13107 When plugged in, some USB modems (and other USB devices) initially present
13108 themselves as a read-only storage medium and not as a modem. They need to be
13109 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
13110 installs udev rules to automatically modeswitch these devices when they are
13113 This service is part of @code{%desktop-services} (@pxref{Desktop
13117 @deftp {Data Type} usb-modeswitch-configuration
13118 Data type representing the configuration of USB_ModeSwitch.
13121 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
13122 The USB_ModeSwitch package providing the binaries for modeswitching.
13124 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
13125 The package providing the device data and udev rules file used by
13128 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
13129 Which config file to use for the USB_ModeSwitch dispatcher. By default the
13130 config file shipped with USB_ModeSwitch is used which disables logging to
13131 @file{/var/log} among other default settings. If set to @code{#f}, no config
13137 @cindex NetworkManager
13139 @defvr {Scheme Variable} network-manager-service-type
13140 This is the service type for the
13141 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
13142 service. The value for this service type is a
13143 @code{network-manager-configuration} record.
13145 This service is part of @code{%desktop-services} (@pxref{Desktop
13149 @deftp {Data Type} network-manager-configuration
13150 Data type representing the configuration of NetworkManager.
13153 @item @code{network-manager} (default: @code{network-manager})
13154 The NetworkManager package to use.
13156 @item @code{dns} (default: @code{"default"})
13157 Processing mode for DNS, which affects how NetworkManager uses the
13158 @code{resolv.conf} configuration file.
13162 NetworkManager will update @code{resolv.conf} to reflect the nameservers
13163 provided by currently active connections.
13166 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
13167 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
13168 then update @code{resolv.conf} to point to the local nameserver.
13170 With this setting, you can share your network connection. For example when
13171 you want to share your network connection to another laptop @i{via} an
13172 Ethernet cable, you can open @command{nm-connection-editor} and configure the
13173 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
13174 and reestablish the connection (or reboot).
13176 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
13177 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
13178 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
13179 browser on your host system, or connect to the VM @i{via} SSH
13180 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
13181 host-to-guest connection, run this command once:
13184 nmcli connection add type tun \
13185 connection.interface-name tap0 \
13186 tun.mode tap tun.owner $(id -u) \
13187 ipv4.method shared \
13188 ipv4.addresses 172.28.112.1/24
13191 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
13192 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
13193 @command{qemu-system-...}.
13196 NetworkManager will not modify @code{resolv.conf}.
13199 @item @code{vpn-plugins} (default: @code{'()})
13200 This is the list of available plugins for virtual private networks
13201 (VPNs). An example of this is the @code{network-manager-openvpn}
13202 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
13208 @deffn {Scheme Variable} connman-service-type
13209 This is the service type to run @url{https://01.org/connman,Connman},
13210 a network connection manager.
13212 Its value must be an
13213 @code{connman-configuration} record as in this example:
13216 (service connman-service-type
13217 (connman-configuration
13218 (disable-vpn? #t)))
13221 See below for details about @code{connman-configuration}.
13224 @deftp {Data Type} connman-configuration
13225 Data Type representing the configuration of connman.
13228 @item @code{connman} (default: @var{connman})
13229 The connman package to use.
13231 @item @code{disable-vpn?} (default: @code{#f})
13232 When true, disable connman's vpn plugin.
13236 @cindex WPA Supplicant
13237 @defvr {Scheme Variable} wpa-supplicant-service-type
13238 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
13239 supplicant}, an authentication daemon required to authenticate against
13240 encrypted WiFi or ethernet networks.
13243 @deftp {Data Type} wpa-supplicant-configuration
13244 Data type representing the configuration of WPA Supplicant.
13246 It takes the following parameters:
13249 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
13250 The WPA Supplicant package to use.
13252 @item @code{dbus?} (default: @code{#t})
13253 Whether to listen for requests on D-Bus.
13255 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
13256 Where to store the PID file.
13258 @item @code{interface} (default: @code{#f})
13259 If this is set, it must specify the name of a network interface that
13260 WPA supplicant will control.
13262 @item @code{config-file} (default: @code{#f})
13263 Optional configuration file to use.
13265 @item @code{extra-options} (default: @code{'()})
13266 List of additional command-line arguments to pass to the daemon.
13271 @defvr {Scheme Variable} iptables-service-type
13272 This is the service type to set up an iptables configuration. iptables is a
13273 packet filtering framework supported by the Linux kernel. This service
13274 supports configuring iptables for both IPv4 and IPv6. A simple example
13275 configuration rejecting all incoming connections except those to the ssh port
13279 (service iptables-service-type
13280 (iptables-configuration
13281 (ipv4-rules (plain-file "iptables.rules" "*filter
13285 -A INPUT -p tcp --dport 22 -j ACCEPT
13286 -A INPUT -j REJECT --reject-with icmp-port-unreachable
13289 (ipv6-rules (plain-file "ip6tables.rules" "*filter
13293 -A INPUT -p tcp --dport 22 -j ACCEPT
13294 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
13300 @deftp {Data Type} iptables-configuration
13301 The data type representing the configuration of iptables.
13304 @item @code{iptables} (default: @code{iptables})
13305 The iptables package that provides @code{iptables-restore} and
13306 @code{ip6tables-restore}.
13307 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
13308 The iptables rules to use. It will be passed to @code{iptables-restore}.
13309 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13311 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
13312 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
13313 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
13319 @defvr {Scheme Variable} nftables-service-type
13320 This is the service type to set up a nftables configuration. nftables is a
13321 netfilter project that aims to replace the existing iptables, ip6tables,
13322 arptables and ebtables framework. It provides a new packet filtering
13323 framework, a new user-space utility @command{nft}, and a compatibility layer
13324 for iptables. This service comes with a default ruleset
13325 @code{%default-nftables-ruleset} that rejecting all incomming connections
13326 except those to the ssh port 22. To use it, simply write:
13329 (service nftables-service-type)
13333 @deftp {Data Type} nftables-configuration
13334 The data type representing the configuration of nftables.
13337 @item @code{package} (default: @code{nftables})
13338 The nftables package that provides @command{nft}.
13339 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
13340 The nftables ruleset to use. This may be any ``file-like'' object
13341 (@pxref{G-Expressions, file-like objects}).
13345 @cindex NTP (Network Time Protocol), service
13346 @cindex ntpd, service for the Network Time Protocol daemon
13347 @cindex real time clock
13348 @defvr {Scheme Variable} ntp-service-type
13349 This is the type of the service running the @uref{http://www.ntp.org,
13350 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
13351 system clock synchronized with that of the specified NTP servers.
13353 The value of this service is an @code{ntpd-configuration} object, as described
13357 @deftp {Data Type} ntp-configuration
13358 This is the data type for the NTP service configuration.
13361 @item @code{servers} (default: @code{%ntp-servers})
13362 This is the list of servers (@code{<ntp-server>} records) with which
13363 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
13366 @item @code{allow-large-adjustment?} (default: @code{#t})
13367 This determines whether @command{ntpd} is allowed to make an initial
13368 adjustment of more than 1,000 seconds.
13370 @item @code{ntp} (default: @code{ntp})
13371 The NTP package to use.
13375 @defvr {Scheme Variable} %ntp-servers
13376 List of host names used as the default NTP servers. These are servers of the
13377 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
13380 @deftp {Data Type} ntp-server
13381 The data type representing the configuration of a NTP server.
13384 @item @code{type} (default: @code{'server})
13385 The type of the NTP server, given as a symbol. One of @code{'pool},
13386 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
13388 @item @code{address}
13389 The address of the server, as a string.
13391 @item @code{options}
13392 NTPD options to use with that specific server, given as a list of option names
13393 and/or of option names and values tuples. The following example define a server
13394 to use with the options @option{iburst} and @option{prefer}, as well as
13395 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
13400 (address "some.ntp.server.org")
13401 (options `(iburst (version 3) (maxpoll 16) prefer))))
13407 @deffn {Scheme Procedure} openntpd-service-type
13408 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
13409 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
13410 clock synchronized with that of the given servers.
13414 openntpd-service-type
13415 (openntpd-configuration
13416 (listen-on '("127.0.0.1" "::1"))
13417 (sensor '("udcf0 correction 70000"))
13418 (constraint-from '("www.gnu.org"))
13419 (constraints-from '("https://www.google.com/"))
13420 (allow-large-adjustment? #t)))
13425 @defvr {Scheme Variable} %openntpd-servers
13426 This variable is a list of the server addresses defined in
13427 @var{%ntp-servers}.
13430 @deftp {Data Type} openntpd-configuration
13432 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
13433 The openntpd executable to use.
13434 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
13435 A list of local IP addresses or hostnames the ntpd daemon should listen on.
13436 @item @code{query-from} (default: @code{'()})
13437 A list of local IP address the ntpd daemon should use for outgoing queries.
13438 @item @code{sensor} (default: @code{'()})
13439 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
13440 will listen to each sensor that actually exists and ignore non-existent ones.
13441 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
13443 @item @code{server} (default: @code{'()})
13444 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
13445 @item @code{servers} (default: @var{%openntp-servers})
13446 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
13447 @item @code{constraint-from} (default: @code{'()})
13448 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
13449 This time information is not used for precision but acts as an authenticated
13450 constraint, thereby reducing the impact of unauthenticated NTP
13451 man-in-the-middle attacks.
13452 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
13454 @item @code{constraints-from} (default: @code{'()})
13455 As with constraint from, specify a list of URLs, IP addresses or hostnames of
13456 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
13457 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
13458 @item @code{allow-large-adjustment?} (default: @code{#f})
13459 Determines if @code{ntpd} is allowed to make an initial adjustment of more
13465 @deffn {Scheme variable} inetd-service-type
13466 This service runs the @command{inetd} (@pxref{inetd invocation,,,
13467 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
13468 connections on internet sockets, and lazily starts the specified server
13469 program when a connection is made on one of these sockets.
13471 The value of this service is an @code{inetd-configuration} object. The
13472 following example configures the @command{inetd} daemon to provide the
13473 built-in @command{echo} service, as well as an smtp service which
13474 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
13475 gateway @code{hostname}:
13480 (inetd-configuration
13484 (socket-type 'stream)
13491 (socket-type 'stream)
13495 (program (file-append openssh "/bin/ssh"))
13497 '("ssh" "-qT" "-i" "/path/to/ssh_key"
13498 "-W" "smtp-server:25" "user@@hostname")))))))
13501 See below for more details about @code{inetd-configuration}.
13504 @deftp {Data Type} inetd-configuration
13505 Data type representing the configuration of @command{inetd}.
13508 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
13509 The @command{inetd} executable to use.
13511 @item @code{entries} (default: @code{'()})
13512 A list of @command{inetd} service entries. Each entry should be created
13513 by the @code{inetd-entry} constructor.
13517 @deftp {Data Type} inetd-entry
13518 Data type representing an entry in the @command{inetd} configuration.
13519 Each entry corresponds to a socket where @command{inetd} will listen for
13523 @item @code{node} (default: @code{#f})
13524 Optional string, a comma-separated list of local addresses
13525 @command{inetd} should use when listening for this service.
13526 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
13527 description of all options.
13529 A string, the name must correspond to an entry in @code{/etc/services}.
13530 @item @code{socket-type}
13531 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
13533 @item @code{protocol}
13534 A string, must correspond to an entry in @code{/etc/protocols}.
13535 @item @code{wait?} (default: @code{#t})
13536 Whether @command{inetd} should wait for the server to exit before
13537 listening to new service requests.
13539 A string containing the user (and, optionally, group) name of the user
13540 as whom the server should run. The group name can be specified in a
13541 suffix, separated by a colon or period, i.e.@: @code{"user"},
13542 @code{"user:group"} or @code{"user.group"}.
13543 @item @code{program} (default: @code{"internal"})
13544 The server program which will serve the requests, or @code{"internal"}
13545 if @command{inetd} should use a built-in service.
13546 @item @code{arguments} (default: @code{'()})
13547 A list strings or file-like objects, which are the server program's
13548 arguments, starting with the zeroth argument, i.e.@: the name of the
13549 program itself. For @command{inetd}'s internal services, this entry
13550 must be @code{'()} or @code{'("internal")}.
13553 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
13554 detailed discussion of each configuration field.
13558 @defvr {Scheme Variable} tor-service-type
13559 This is the type for a service that runs the @uref{https://torproject.org,
13560 Tor} anonymous networking daemon. The service is configured using a
13561 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
13562 @code{tor} unprivileged user, which is a member of the @code{tor} group.
13566 @deftp {Data Type} tor-configuration
13568 @item @code{tor} (default: @code{tor})
13569 The package that provides the Tor daemon. This package is expected to provide
13570 the daemon at @file{bin/tor} relative to its output directory. The default
13571 package is the @uref{https://www.torproject.org, Tor Project's}
13574 @item @code{config-file} (default: @code{(plain-file "empty" "")})
13575 The configuration file to use. It will be appended to a default configuration
13576 file, and the final configuration file will be passed to @code{tor} via its
13577 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
13578 file-like objects}). See @code{man tor} for details on the configuration file
13581 @item @code{hidden-services} (default: @code{'()})
13582 The list of @code{<hidden-service>} records to use. For any hidden service
13583 you include in this list, appropriate configuration to enable the hidden
13584 service will be automatically added to the default configuration file. You
13585 may conveniently create @code{<hidden-service>} records using the
13586 @code{tor-hidden-service} procedure described below.
13588 @item @code{socks-socket-type} (default: @code{'tcp})
13589 The default socket type that Tor should use for its SOCKS socket. This must
13590 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
13591 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
13592 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
13593 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
13596 If you want to customize the SOCKS socket in more detail, leave
13597 @code{socks-socket-type} at its default value of @code{'tcp} and use
13598 @code{config-file} to override the default by providing your own
13599 @code{SocksPort} option.
13603 @cindex hidden service
13604 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
13605 Define a new Tor @dfn{hidden service} called @var{name} and implementing
13606 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
13609 '((22 "127.0.0.1:22")
13610 (80 "127.0.0.1:8080"))
13613 In this example, port 22 of the hidden service is mapped to local port 22, and
13614 port 80 is mapped to local port 8080.
13616 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
13617 the @file{hostname} file contains the @code{.onion} host name for the hidden
13620 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
13621 project's documentation} for more information.
13624 The @code{(gnu services rsync)} module provides the following services:
13626 You might want an rsync daemon if you have files that you want available
13627 so anyone (or just yourself) can download existing files or upload new
13630 @deffn {Scheme Variable} rsync-service-type
13631 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
13632 The value for this service type is a
13633 @command{rsync-configuration} record as in this example:
13636 (service rsync-service-type)
13639 See below for details about @code{rsync-configuration}.
13642 @deftp {Data Type} rsync-configuration
13643 Data type representing the configuration for @code{rsync-service}.
13646 @item @code{package} (default: @var{rsync})
13647 @code{rsync} package to use.
13649 @item @code{port-number} (default: @code{873})
13650 TCP port on which @command{rsync} listens for incoming connections. If port
13651 is less than @code{1024} @command{rsync} needs to be started as the
13652 @code{root} user and group.
13654 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
13655 Name of the file where @command{rsync} writes its PID.
13657 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
13658 Name of the file where @command{rsync} writes its lock file.
13660 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
13661 Name of the file where @command{rsync} writes its log file.
13663 @item @code{use-chroot?} (default: @var{#t})
13664 Whether to use chroot for @command{rsync} shared directory.
13666 @item @code{share-path} (default: @file{/srv/rsync})
13667 Location of the @command{rsync} shared directory.
13669 @item @code{share-comment} (default: @code{"Rsync share"})
13670 Comment of the @command{rsync} shared directory.
13672 @item @code{read-only?} (default: @var{#f})
13673 Read-write permissions to shared directory.
13675 @item @code{timeout} (default: @code{300})
13676 I/O timeout in seconds.
13678 @item @code{user} (default: @var{"root"})
13679 Owner of the @code{rsync} process.
13681 @item @code{group} (default: @var{"root"})
13682 Group of the @code{rsync} process.
13684 @item @code{uid} (default: @var{"rsyncd"})
13685 User name or user ID that file transfers to and from that module should take
13686 place as when the daemon was run as @code{root}.
13688 @item @code{gid} (default: @var{"rsyncd"})
13689 Group name or group ID that will be used when accessing the module.
13694 Furthermore, @code{(gnu services ssh)} provides the following services.
13698 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
13699 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
13700 [#:allow-empty-passwords? #f] [#:root-login? #f] @
13701 [#:syslog-output? #t] [#:x11-forwarding? #t] @
13702 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
13703 [#:public-key-authentication? #t] [#:initialize? #t]
13704 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
13705 @var{host-key} must designate a file containing the host key, and readable
13708 When @var{daemonic?} is true, @command{lshd} will detach from the
13709 controlling terminal and log its output to syslogd, unless one sets
13710 @var{syslog-output?} to false. Obviously, it also makes lsh-service
13711 depend on existence of syslogd service. When @var{pid-file?} is true,
13712 @command{lshd} writes its PID to the file called @var{pid-file}.
13714 When @var{initialize?} is true, automatically create the seed and host key
13715 upon service activation if they do not exist yet. This may take long and
13716 require interaction.
13718 When @var{initialize?} is false, it is up to the user to initialize the
13719 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
13720 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
13721 basics,,, lsh, LSH Manual}).
13723 When @var{interfaces} is empty, lshd listens for connections on all the
13724 network interfaces; otherwise, @var{interfaces} must be a list of host names
13727 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
13728 passwords, and @var{root-login?} specifies whether to accept log-ins as
13731 The other options should be self-descriptive.
13736 @deffn {Scheme Variable} openssh-service-type
13737 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
13738 shell daemon, @command{sshd}. Its value must be an
13739 @code{openssh-configuration} record as in this example:
13742 (service openssh-service-type
13743 (openssh-configuration
13744 (x11-forwarding? #t)
13745 (permit-root-login 'without-password)
13747 `(("alice" ,(local-file "alice.pub"))
13748 ("bob" ,(local-file "bob.pub"))))))
13751 See below for details about @code{openssh-configuration}.
13753 This service can be extended with extra authorized keys, as in this
13757 (service-extension openssh-service-type
13758 (const `(("charlie"
13759 ,(local-file "charlie.pub")))))
13763 @deftp {Data Type} openssh-configuration
13764 This is the configuration record for OpenSSH's @command{sshd}.
13767 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
13768 Name of the file where @command{sshd} writes its PID.
13770 @item @code{port-number} (default: @code{22})
13771 TCP port on which @command{sshd} listens for incoming connections.
13773 @item @code{permit-root-login} (default: @code{#f})
13774 This field determines whether and when to allow logins as root. If
13775 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
13776 If it's the symbol @code{'without-password}, then root logins are
13777 permitted but not with password-based authentication.
13779 @item @code{allow-empty-passwords?} (default: @code{#f})
13780 When true, users with empty passwords may log in. When false, they may
13783 @item @code{password-authentication?} (default: @code{#t})
13784 When true, users may log in with their password. When false, they have
13785 other authentication methods.
13787 @item @code{public-key-authentication?} (default: @code{#t})
13788 When true, users may log in using public key authentication. When
13789 false, users have to use other authentication method.
13791 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
13792 This is used only by protocol version 2.
13794 @item @code{x11-forwarding?} (default: @code{#f})
13795 When true, forwarding of X11 graphical client connections is
13796 enabled---in other words, @command{ssh} options @option{-X} and
13797 @option{-Y} will work.
13799 @item @code{allow-agent-forwarding?} (default: @code{#t})
13800 Whether to allow agent forwarding.
13802 @item @code{allow-tcp-forwarding?} (default: @code{#t})
13803 Whether to allow TCP forwarding.
13805 @item @code{gateway-ports?} (default: @code{#f})
13806 Whether to allow gateway ports.
13808 @item @code{challenge-response-authentication?} (default: @code{#f})
13809 Specifies whether challenge response authentication is allowed (e.g.@: via
13812 @item @code{use-pam?} (default: @code{#t})
13813 Enables the Pluggable Authentication Module interface. If set to
13814 @code{#t}, this will enable PAM authentication using
13815 @code{challenge-response-authentication?} and
13816 @code{password-authentication?}, in addition to PAM account and session
13817 module processing for all authentication types.
13819 Because PAM challenge response authentication usually serves an
13820 equivalent role to password authentication, you should disable either
13821 @code{challenge-response-authentication?} or
13822 @code{password-authentication?}.
13824 @item @code{print-last-log?} (default: @code{#t})
13825 Specifies whether @command{sshd} should print the date and time of the
13826 last user login when a user logs in interactively.
13828 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
13829 Configures external subsystems (e.g.@: file transfer daemon).
13831 This is a list of two-element lists, each of which containing the
13832 subsystem name and a command (with optional arguments) to execute upon
13835 The command @command{internal-sftp} implements an in-process SFTP
13836 server. Alternately, one can specify the @command{sftp-server} command:
13838 (service openssh-service-type
13839 (openssh-configuration
13841 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
13844 @item @code{accepted-environment} (default: @code{'()})
13845 List of strings describing which environment variables may be exported.
13847 Each string gets on its own line. See the @code{AcceptEnv} option in
13848 @code{man sshd_config}.
13850 This example allows ssh-clients to export the @code{COLORTERM} variable.
13851 It is set by terminal emulators, which support colors. You can use it in
13852 your shell's ressource file to enable colors for the prompt and commands
13853 if this variable is set.
13856 (service openssh-service-type
13857 (openssh-configuration
13858 (accepted-environment '("COLORTERM"))))
13861 @item @code{authorized-keys} (default: @code{'()})
13862 @cindex authorized keys, SSH
13863 @cindex SSH authorized keys
13864 This is the list of authorized keys. Each element of the list is a user
13865 name followed by one or more file-like objects that represent SSH public
13869 (openssh-configuration
13871 `(("rekado" ,(local-file "rekado.pub"))
13872 ("chris" ,(local-file "chris.pub"))
13873 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
13877 registers the specified public keys for user accounts @code{rekado},
13878 @code{chris}, and @code{root}.
13880 Additional authorized keys can be specified @i{via}
13881 @code{service-extension}.
13883 Note that this does @emph{not} interfere with the use of
13884 @file{~/.ssh/authorized_keys}.
13886 @item @code{log-level} (default: @code{'info})
13887 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
13888 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
13889 page for @file{sshd_config} for the full list of level names.
13891 @item @code{extra-content} (default: @code{""})
13892 This field can be used to append arbitrary text to the configuration file. It
13893 is especially useful for elaborate configurations that cannot be expressed
13894 otherwise. This configuration, for example, would generally disable root
13895 logins, but permit them from one specific IP address:
13898 (openssh-configuration
13900 Match Address 192.168.0.1
13901 PermitRootLogin yes"))
13907 @deffn {Scheme Procedure} dropbear-service [@var{config}]
13908 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
13909 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
13912 For example, to specify a Dropbear service listening on port 1234, add
13913 this call to the operating system's @code{services} field:
13916 (dropbear-service (dropbear-configuration
13917 (port-number 1234)))
13921 @deftp {Data Type} dropbear-configuration
13922 This data type represents the configuration of a Dropbear SSH daemon.
13925 @item @code{dropbear} (default: @var{dropbear})
13926 The Dropbear package to use.
13928 @item @code{port-number} (default: 22)
13929 The TCP port where the daemon waits for incoming connections.
13931 @item @code{syslog-output?} (default: @code{#t})
13932 Whether to enable syslog output.
13934 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
13935 File name of the daemon's PID file.
13937 @item @code{root-login?} (default: @code{#f})
13938 Whether to allow @code{root} logins.
13940 @item @code{allow-empty-passwords?} (default: @code{#f})
13941 Whether to allow empty passwords.
13943 @item @code{password-authentication?} (default: @code{#t})
13944 Whether to enable password-based authentication.
13948 @defvr {Scheme Variable} %facebook-host-aliases
13949 This variable contains a string for use in @file{/etc/hosts}
13950 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
13951 line contains a entry that maps a known server name of the Facebook
13952 on-line service---e.g., @code{www.facebook.com}---to the local
13953 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
13955 This variable is typically used in the @code{hosts-file} field of an
13956 @code{operating-system} declaration (@pxref{operating-system Reference,
13957 @file{/etc/hosts}}):
13960 (use-modules (gnu) (guix))
13963 (host-name "mymachine")
13966 ;; Create a /etc/hosts file with aliases for "localhost"
13967 ;; and "mymachine", as well as for Facebook servers.
13968 (plain-file "hosts"
13969 (string-append (local-host-aliases host-name)
13970 %facebook-host-aliases))))
13973 This mechanism can prevent programs running locally, such as Web
13974 browsers, from accessing Facebook.
13977 The @code{(gnu services avahi)} provides the following definition.
13979 @defvr {Scheme Variable} avahi-service-type
13980 This is the service that runs @command{avahi-daemon}, a system-wide
13981 mDNS/DNS-SD responder that allows for service discovery and
13982 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
13983 Its value must be a @code{zero-configuration} record---see below.
13985 This service extends the name service cache daemon (nscd) so that it can
13986 resolve @code{.local} host names using
13987 @uref{http://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
13988 Service Switch}, for information on host name resolution.
13990 Additionally, add the @var{avahi} package to the system profile so that
13991 commands such as @command{avahi-browse} are directly usable.
13994 @deftp {Data Type} avahi-configuration
13995 Data type representation the configuration for Avahi.
13999 @item @code{host-name} (default: @code{#f})
14000 If different from @code{#f}, use that as the host name to
14001 publish for this machine; otherwise, use the machine's actual host name.
14003 @item @code{publish?} (default: @code{#t})
14004 When true, allow host names and services to be published (broadcast) over the
14007 @item @code{publish-workstation?} (default: @code{#t})
14008 When true, @command{avahi-daemon} publishes the machine's host name and IP
14009 address via mDNS on the local network. To view the host names published on
14010 your local network, you can run:
14013 avahi-browse _workstation._tcp
14016 @item @code{wide-area?} (default: @code{#f})
14017 When true, DNS-SD over unicast DNS is enabled.
14019 @item @code{ipv4?} (default: @code{#t})
14020 @itemx @code{ipv6?} (default: @code{#t})
14021 These fields determine whether to use IPv4/IPv6 sockets.
14023 @item @code{domains-to-browse} (default: @code{'()})
14024 This is a list of domains to browse.
14028 @deffn {Scheme Variable} openvswitch-service-type
14029 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
14030 service, whose value should be an @code{openvswitch-configuration}
14034 @deftp {Data Type} openvswitch-configuration
14035 Data type representing the configuration of Open vSwitch, a multilayer
14036 virtual switch which is designed to enable massive network automation
14037 through programmatic extension.
14040 @item @code{package} (default: @var{openvswitch})
14041 Package object of the Open vSwitch.
14046 @defvr {Scheme Variable} pagekite-service-type
14047 This is the service type for the @uref{https://pagekite.net, PageKite} service,
14048 a tunneling solution for making localhost servers publicly visible, even from
14049 behind NAT or restrictive firewalls. The value for this service type is a
14050 @code{pagekite-configuration} record.
14052 Here's an example exposing the local HTTP and SSH daemons:
14055 (service pagekite-service-type
14056 (pagekite-configuration
14057 (kites '("http:@@kitename:localhost:80:@@kitesecret"
14058 "raw/22:@@kitename:localhost:22:@@kitesecret"))
14059 (extra-file "/etc/pagekite.rc")))
14063 @deftp {Data Type} pagekite-configuration
14064 Data type representing the configuration of PageKite.
14067 @item @code{package} (default: @var{pagekite})
14068 Package object of PageKite.
14070 @item @code{kitename} (default: @code{#f})
14071 PageKite name for authenticating to the frontend server.
14073 @item @code{kitesecret} (default: @code{#f})
14074 Shared secret for authenticating to the frontend server. You should probably
14075 put this inside @code{extra-file} instead.
14077 @item @code{frontend} (default: @code{#f})
14078 Connect to the named PageKite frontend server instead of the
14079 @uref{https://pagekite.net,,pagekite.net} service.
14081 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
14082 List of service kites to use. Exposes HTTP on port 80 by default. The format
14083 is @code{proto:kitename:host:port:secret}.
14085 @item @code{extra-file} (default: @code{#f})
14086 Extra configuration file to read, which you are expected to create manually.
14087 Use this to add additional options and manage shared secrets out-of-band.
14093 @subsection X Window
14096 @cindex X Window System
14097 @cindex login manager
14098 Support for the X Window graphical display system---specifically
14099 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
14100 there is no @code{xorg-service} procedure. Instead, the X server is
14101 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
14104 @cindex GNOME, login manager
14105 GDM of course allows users to log in into window managers and desktop
14106 environments other than GNOME; for those using GNOME, GDM is required for
14107 features such as automatic screen locking.
14109 @cindex window manager
14110 To use X11, you must install at least one @dfn{window manager}---for
14111 example the @code{windowmaker} or @code{openbox} packages---preferably
14112 by adding it to the @code{packages} field of your operating system
14113 definition (@pxref{operating-system Reference, system-wide packages}).
14115 @defvr {Scheme Variable} gdm-service-type
14116 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
14117 Desktop Manager} (GDM), a program that manages graphical display servers and
14118 handles graphical user logins. Its value must be a @code{gdm-configuration}
14121 @cindex session types (X11)
14122 @cindex X11 session types
14123 GDM looks for @dfn{session types} described by the @file{.desktop} files in
14124 @file{/run/current-system/profile/share/xsessions} and allows users to choose
14125 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
14126 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
14127 set of packages automatically makes them available at the log-in screen.
14129 In addition, @file{~/.xsession} files are honored. When available,
14130 @file{~/.xsession} must be an executable that starts a window manager
14131 and/or other X clients.
14134 @deftp {Data Type} gdm-configuration
14136 @item @code{auto-login?} (default: @code{#f})
14137 @itemx @code{default-user} (default: @code{#f})
14138 When @code{auto-login?} is false, GDM presents a log-in screen.
14140 When @code{auto-login?} is true, GDM logs in directly as
14141 @code{default-user}.
14143 @item @code{debug?} (default: @code{#f})
14144 When true, GDM writes debug messages to its log.
14146 @item @code{gnome-shell-assets} (default: ...)
14147 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
14149 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
14150 Configuration of the Xorg graphical server.
14152 @item @code{xsession} (default: @code{(xinitrc)})
14153 Script to run before starting a X session.
14155 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
14156 File name of the @code{dbus-daemon} executable.
14158 @item @code{gdm} (default: @code{gdm})
14159 The GDM package to use.
14163 @defvr {Scheme Variable} slim-service-type
14164 This is the type for the SLiM graphical login manager for X11.
14166 Like GDM, SLiM looks for session types described by @file{.desktop} files and
14167 allows users to choose a session from the log-in screen using @kbd{F1}. It
14168 also honors @file{~/.xsession} files.
14170 Unlike GDM, SLiM does not spawn the user session on a different VT after
14171 logging in, which means that you can only start one graphical session. If you
14172 want to be able to run multiple graphical sessions at the same time you have
14173 to add multiple SLiM services to your system services. The following example
14174 shows how to replace the default GDM service with two SLiM services on tty7
14178 (use-modules (gnu services)
14179 (gnu services desktop)
14180 (gnu services xorg)
14181 (srfi srfi-1)) ;for 'remove'
14185 (services (cons* (service slim-service-type (slim-configuration
14188 (service slim-service-type (slim-configuration
14191 (remove (lambda (service)
14192 (eq? (service-kind service) gdm-service-type))
14193 %desktop-services))))
14198 @deftp {Data Type} slim-configuration
14199 Data type representing the configuration of @code{slim-service-type}.
14202 @item @code{allow-empty-passwords?} (default: @code{#t})
14203 Whether to allow logins with empty passwords.
14205 @item @code{auto-login?} (default: @code{#f})
14206 @itemx @code{default-user} (default: @code{""})
14207 When @code{auto-login?} is false, SLiM presents a log-in screen.
14209 When @code{auto-login?} is true, SLiM logs in directly as
14210 @code{default-user}.
14212 @item @code{theme} (default: @code{%default-slim-theme})
14213 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
14214 The graphical theme to use and its name.
14216 @item @code{auto-login-session} (default: @code{#f})
14217 If true, this must be the name of the executable to start as the default
14218 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
14220 If false, a session described by one of the available @file{.desktop}
14221 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
14225 You must install at least one window manager in the system profile or in
14226 your user profile. Failing to do that, if @code{auto-login-session} is
14227 false, you will be unable to log in.
14230 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14231 Configuration of the Xorg graphical server.
14233 @item @code{display} (default @code{":0"})
14234 The display on which to start the Xorg graphical server.
14236 @item @code{vt} (default @code{"vt7"})
14237 The VT on which to start the Xorg graphical server.
14239 @item @code{xauth} (default: @code{xauth})
14240 The XAuth package to use.
14242 @item @code{shepherd} (default: @code{shepherd})
14243 The Shepherd package used when invoking @command{halt} and
14246 @item @code{sessreg} (default: @code{sessreg})
14247 The sessreg package used in order to register the session.
14249 @item @code{slim} (default: @code{slim})
14250 The SLiM package to use.
14254 @defvr {Scheme Variable} %default-theme
14255 @defvrx {Scheme Variable} %default-theme-name
14256 The default SLiM theme and its name.
14260 @deftp {Data Type} sddm-configuration
14261 This is the data type representing the sddm service configuration.
14264 @item @code{display-server} (default: "x11")
14265 Select display server to use for the greeter. Valid values are "x11"
14268 @item @code{numlock} (default: "on")
14269 Valid values are "on", "off" or "none".
14271 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
14272 Command to run when halting.
14274 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
14275 Command to run when rebooting.
14277 @item @code{theme} (default "maldives")
14278 Theme to use. Default themes provided by SDDM are "elarun" or "maldives".
14280 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
14281 Directory to look for themes.
14283 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
14284 Directory to look for faces.
14286 @item @code{default-path} (default "/run/current-system/profile/bin")
14287 Default PATH to use.
14289 @item @code{minimum-uid} (default: 1000)
14290 Minimum UID displayed in SDDM and allowed for log-in.
14292 @item @code{maximum-uid} (default: 2000)
14293 Maximum UID to display in SDDM.
14295 @item @code{remember-last-user?} (default #t)
14296 Remember last user.
14298 @item @code{remember-last-session?} (default #t)
14299 Remember last session.
14301 @item @code{hide-users} (default "")
14302 Usernames to hide from SDDM greeter.
14304 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
14305 Users with shells listed will be hidden from the SDDM greeter.
14307 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
14308 Script to run before starting a wayland session.
14310 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
14311 Directory to look for desktop files starting wayland sessions.
14313 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
14314 Configuration of the Xorg graphical server.
14316 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
14319 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
14322 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
14323 Script to run after starting xorg-server.
14325 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
14326 Script to run before stopping xorg-server.
14328 @item @code{xsession-command} (default: @code{xinitrc})
14329 Script to run before starting a X session.
14331 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
14332 Directory to look for desktop files starting X sessions.
14334 @item @code{minimum-vt} (default: 7)
14337 @item @code{auto-login-user} (default "")
14338 User to use for auto-login.
14340 @item @code{auto-login-session} (default "")
14341 Desktop file to use for auto-login.
14343 @item @code{relogin?} (default #f)
14344 Relogin after logout.
14349 @cindex login manager
14351 @defvr {Scheme Variable} sddm-service-type
14352 This is the type of the service to run the
14353 @uref{https://github.com/sddm/sddm,SSDM display manager}. Its value
14354 must be a @code{sddm-configuration} record (see below).
14356 Here's an example use:
14359 (service sddm-service-type
14360 (sddm-configuration
14361 (auto-login-user "alice")
14362 (auto-login-session "xfce.desktop")))
14366 @deftp {Data Type} sddm-configuration
14367 This data type represents the configuration of the SDDM login manager.
14368 The available fields are:
14371 @item @code{sddm} (default: @code{sddm})
14372 The SDDM package to use.
14374 @item @code{display-server} (default: @code{"x11"})
14375 This must be either @code{"x11"} or @code{"wayland"}.
14377 @c FIXME: Add more fields.
14379 @item @code{auto-login-user} (default: @code{""})
14380 If non-empty, this is the user account under which to log in
14383 @item @code{auto-login-session} (default: @code{""})
14384 If non-empty, this is the @file{.desktop} file name to use as the
14385 auto-login session.
14389 @cindex Xorg, configuration
14390 @deftp {Data Type} xorg-configuration
14391 This data type represents the configuration of the Xorg graphical display
14392 server. Note that there is not Xorg service; instead, the X server is started
14393 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
14394 of these display managers aggregates an @code{xorg-configuration} record.
14397 @item @code{modules} (default: @code{%default-xorg-modules})
14398 This is a list of @dfn{module packages} loaded by the Xorg
14399 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
14401 @item @code{fonts} (default: @code{%default-xorg-fonts})
14402 This is a list of font directories to add to the server's @dfn{font path}.
14404 @item @code{drivers} (default: @code{'()})
14405 This must be either the empty list, in which case Xorg chooses a graphics
14406 driver automatically, or a list of driver names that will be tried in this
14407 order---e.g., @code{("modesetting" "vesa")}.
14409 @item @code{resolutions} (default: @code{'()})
14410 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
14411 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
14414 @cindex keyboard layout, for Xorg
14415 @cindex keymap, for Xorg
14416 @item @code{keyboard-layout} (default: @code{#f})
14417 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
14418 English (``qwerty'') for a 105-key PC keyboard.
14420 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
14421 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
14422 information on how to specify the keyboard layout.
14424 @item @code{extra-config} (default: @code{'()})
14425 This is a list of strings or objects appended to the configuration file. It
14426 is used to pass extra text to be added verbatim to the configuration file.
14428 @item @code{server} (default: @code{xorg-server})
14429 This is the package providing the Xorg server.
14431 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
14432 This is the list of command-line arguments to pass to the X server. The
14433 default is @code{-nolisten tcp}.
14437 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
14438 [@var{login-manager-service-type}]
14439 Tell the log-in manager (of type @var{login-manager-service-type}) to use
14440 @var{config}, an @code{<xorg-configuration>} record.
14442 Since the Xorg configuration is embedded in the log-in manager's
14443 configuration---e.g., @code{gdm-configuration}---this procedure provides a
14444 shorthand to set the Xorg configuration.
14447 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
14448 Return a @code{startx} script in which the modules, fonts, etc. specified
14449 in @var{config}, are available. The result should be used in place of
14452 Usually the X server is started by a login manager.
14456 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
14457 Add @var{package}, a package for a screen locker or screen saver whose
14458 command is @var{program}, to the set of setuid programs and add a PAM entry
14459 for it. For example:
14462 (screen-locker-service xlockmore "xlock")
14465 makes the good ol' XlockMore usable.
14469 @node Printing Services
14470 @subsection Printing Services
14472 @cindex printer support with CUPS
14473 The @code{(gnu services cups)} module provides a Guix service definition
14474 for the CUPS printing service. To add printer support to a Guix
14475 system, add a @code{cups-service} to the operating system definition:
14477 @deffn {Scheme Variable} cups-service-type
14478 The service type for the CUPS print server. Its value should be a valid
14479 CUPS configuration (see below). To use the default settings, simply
14482 (service cups-service-type)
14486 The CUPS configuration controls the basic things about your CUPS
14487 installation: what interfaces it listens on, what to do if a print job
14488 fails, how much logging to do, and so on. To actually add a printer,
14489 you have to visit the @url{http://localhost:631} URL, or use a tool such
14490 as GNOME's printer configuration services. By default, configuring a
14491 CUPS service will generate a self-signed certificate if needed, for
14492 secure connections to the print server.
14494 Suppose you want to enable the Web interface of CUPS and also add
14495 support for Epson printers @i{via} the @code{escpr} package and for HP
14496 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
14497 like this (you need to use the @code{(gnu packages cups)} module):
14500 (service cups-service-type
14501 (cups-configuration
14502 (web-interface? #t)
14504 (list cups-filters escpr hplip-minimal))))
14507 Note: If you wish to use the Qt5 based GUI which comes with the hplip
14508 package then it is suggested that you install the @code{hplip} package,
14509 either in your OS configuration file or as your user.
14511 The available configuration parameters follow. Each parameter
14512 definition is preceded by its type; for example, @samp{string-list foo}
14513 indicates that the @code{foo} parameter should be specified as a list of
14514 strings. There is also a way to specify the configuration as a string,
14515 if you have an old @code{cupsd.conf} file that you want to port over
14516 from some other system; see the end for more details.
14518 @c The following documentation was initially generated by
14519 @c (generate-documentation) in (gnu services cups). Manually maintained
14520 @c documentation is better, so we shouldn't hesitate to edit below as
14521 @c needed. However if the change you want to make to this documentation
14522 @c can be done in an automated way, it's probably easier to change
14523 @c (generate-documentation) than to make it below and have to deal with
14524 @c the churn as CUPS updates.
14527 Available @code{cups-configuration} fields are:
14529 @deftypevr {@code{cups-configuration} parameter} package cups
14533 @deftypevr {@code{cups-configuration} parameter} package-list extensions
14534 Drivers and other extensions to the CUPS package.
14537 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
14538 Configuration of where to write logs, what directories to use for print
14539 spools, and related privileged configuration parameters.
14541 Available @code{files-configuration} fields are:
14543 @deftypevr {@code{files-configuration} parameter} log-location access-log
14544 Defines the access log filename. Specifying a blank filename disables
14545 access log generation. The value @code{stderr} causes log entries to be
14546 sent to the standard error file when the scheduler is running in the
14547 foreground, or to the system log daemon when run in the background. The
14548 value @code{syslog} causes log entries to be sent to the system log
14549 daemon. The server name may be included in filenames using the string
14550 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
14552 Defaults to @samp{"/var/log/cups/access_log"}.
14555 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
14556 Where CUPS should cache data.
14558 Defaults to @samp{"/var/cache/cups"}.
14561 @deftypevr {@code{files-configuration} parameter} string config-file-perm
14562 Specifies the permissions for all configuration files that the scheduler
14565 Note that the permissions for the printers.conf file are currently
14566 masked to only allow access from the scheduler user (typically root).
14567 This is done because printer device URIs sometimes contain sensitive
14568 authentication information that should not be generally known on the
14569 system. There is no way to disable this security feature.
14571 Defaults to @samp{"0640"}.
14574 @deftypevr {@code{files-configuration} parameter} log-location error-log
14575 Defines the error log filename. Specifying a blank filename disables
14576 error log generation. The value @code{stderr} causes log entries to be
14577 sent to the standard error file when the scheduler is running in the
14578 foreground, or to the system log daemon when run in the background. The
14579 value @code{syslog} causes log entries to be sent to the system log
14580 daemon. The server name may be included in filenames using the string
14581 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
14583 Defaults to @samp{"/var/log/cups/error_log"}.
14586 @deftypevr {@code{files-configuration} parameter} string fatal-errors
14587 Specifies which errors are fatal, causing the scheduler to exit. The
14592 No errors are fatal.
14595 All of the errors below are fatal.
14598 Browsing initialization errors are fatal, for example failed connections
14599 to the DNS-SD daemon.
14602 Configuration file syntax errors are fatal.
14605 Listen or Port errors are fatal, except for IPv6 failures on the
14606 loopback or @code{any} addresses.
14609 Log file creation or write errors are fatal.
14612 Bad startup file permissions are fatal, for example shared TLS
14613 certificate and key files with world-read permissions.
14616 Defaults to @samp{"all -browse"}.
14619 @deftypevr {@code{files-configuration} parameter} boolean file-device?
14620 Specifies whether the file pseudo-device can be used for new printer
14621 queues. The URI @uref{file:///dev/null} is always allowed.
14623 Defaults to @samp{#f}.
14626 @deftypevr {@code{files-configuration} parameter} string group
14627 Specifies the group name or ID that will be used when executing external
14630 Defaults to @samp{"lp"}.
14633 @deftypevr {@code{files-configuration} parameter} string log-file-perm
14634 Specifies the permissions for all log files that the scheduler writes.
14636 Defaults to @samp{"0644"}.
14639 @deftypevr {@code{files-configuration} parameter} log-location page-log
14640 Defines the page log filename. Specifying a blank filename disables
14641 page log generation. The value @code{stderr} causes log entries to be
14642 sent to the standard error file when the scheduler is running in the
14643 foreground, or to the system log daemon when run in the background. The
14644 value @code{syslog} causes log entries to be sent to the system log
14645 daemon. The server name may be included in filenames using the string
14646 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
14648 Defaults to @samp{"/var/log/cups/page_log"}.
14651 @deftypevr {@code{files-configuration} parameter} string remote-root
14652 Specifies the username that is associated with unauthenticated accesses
14653 by clients claiming to be the root user. The default is @code{remroot}.
14655 Defaults to @samp{"remroot"}.
14658 @deftypevr {@code{files-configuration} parameter} file-name request-root
14659 Specifies the directory that contains print jobs and other HTTP request
14662 Defaults to @samp{"/var/spool/cups"}.
14665 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
14666 Specifies the level of security sandboxing that is applied to print
14667 filters, backends, and other child processes of the scheduler; either
14668 @code{relaxed} or @code{strict}. This directive is currently only
14669 used/supported on macOS.
14671 Defaults to @samp{strict}.
14674 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
14675 Specifies the location of TLS certificates and private keys. CUPS will
14676 look for public and private keys in this directory: a @code{.crt} files
14677 for PEM-encoded certificates and corresponding @code{.key} files for
14678 PEM-encoded private keys.
14680 Defaults to @samp{"/etc/cups/ssl"}.
14683 @deftypevr {@code{files-configuration} parameter} file-name server-root
14684 Specifies the directory containing the server configuration files.
14686 Defaults to @samp{"/etc/cups"}.
14689 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
14690 Specifies whether the scheduler calls fsync(2) after writing
14691 configuration or state files.
14693 Defaults to @samp{#f}.
14696 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
14697 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
14700 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
14701 Specifies the directory where temporary files are stored.
14703 Defaults to @samp{"/var/spool/cups/tmp"}.
14706 @deftypevr {@code{files-configuration} parameter} string user
14707 Specifies the user name or ID that is used when running external
14710 Defaults to @samp{"lp"}.
14713 @deftypevr {@code{files-configuration} parameter} string set-env
14714 Set the specified environment variable to be passed to child processes.
14716 Defaults to @samp{"variable value"}.
14720 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
14721 Specifies the logging level for the AccessLog file. The @code{config}
14722 level logs when printers and classes are added, deleted, or modified and
14723 when configuration files are accessed or updated. The @code{actions}
14724 level logs when print jobs are submitted, held, released, modified, or
14725 canceled, and any of the conditions for @code{config}. The @code{all}
14726 level logs all requests.
14728 Defaults to @samp{actions}.
14731 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
14732 Specifies whether to purge job history data automatically when it is no
14733 longer required for quotas.
14735 Defaults to @samp{#f}.
14738 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
14739 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
14740 For example, @samp{"_cups" "_print"} will tell network clients that both
14741 CUPS sharing and IPP Everywhere are supported.
14743 Defaults to @samp{"_cups"}.
14746 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
14747 Specifies which protocols to use for local printer sharing.
14749 Defaults to @samp{dnssd}.
14752 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
14753 Specifies whether the CUPS web interface is advertised.
14755 Defaults to @samp{#f}.
14758 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
14759 Specifies whether shared printers are advertised.
14761 Defaults to @samp{#f}.
14764 @deftypevr {@code{cups-configuration} parameter} string classification
14765 Specifies the security classification of the server. Any valid banner
14766 name can be used, including "classified", "confidential", "secret",
14767 "topsecret", and "unclassified", or the banner can be omitted to disable
14768 secure printing functions.
14770 Defaults to @samp{""}.
14773 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
14774 Specifies whether users may override the classification (cover page) of
14775 individual print jobs using the @code{job-sheets} option.
14777 Defaults to @samp{#f}.
14780 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
14781 Specifies the default type of authentication to use.
14783 Defaults to @samp{Basic}.
14786 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
14787 Specifies whether encryption will be used for authenticated requests.
14789 Defaults to @samp{Required}.
14792 @deftypevr {@code{cups-configuration} parameter} string default-language
14793 Specifies the default language to use for text and web content.
14795 Defaults to @samp{"en"}.
14798 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
14799 Specifies the default paper size for new print queues. @samp{"Auto"}
14800 uses a locale-specific default, while @samp{"None"} specifies there is
14801 no default paper size. Specific size names are typically
14802 @samp{"Letter"} or @samp{"A4"}.
14804 Defaults to @samp{"Auto"}.
14807 @deftypevr {@code{cups-configuration} parameter} string default-policy
14808 Specifies the default access policy to use.
14810 Defaults to @samp{"default"}.
14813 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
14814 Specifies whether local printers are shared by default.
14816 Defaults to @samp{#t}.
14819 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
14820 Specifies the delay for updating of configuration and state files, in
14821 seconds. A value of 0 causes the update to happen as soon as possible,
14822 typically within a few milliseconds.
14824 Defaults to @samp{30}.
14827 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
14828 Specifies what to do when an error occurs. Possible values are
14829 @code{abort-job}, which will discard the failed print job;
14830 @code{retry-job}, which will retry the job at a later time;
14831 @code{retry-current-job}, which retries the failed job immediately; and
14832 @code{stop-printer}, which stops the printer.
14834 Defaults to @samp{stop-printer}.
14837 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
14838 Specifies the maximum cost of filters that are run concurrently, which
14839 can be used to minimize disk, memory, and CPU resource problems. A
14840 limit of 0 disables filter limiting. An average print to a
14841 non-PostScript printer needs a filter limit of about 200. A PostScript
14842 printer needs about half that (100). Setting the limit below these
14843 thresholds will effectively limit the scheduler to printing a single job
14846 Defaults to @samp{0}.
14849 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
14850 Specifies the scheduling priority of filters that are run to print a
14851 job. The nice value ranges from 0, the highest priority, to 19, the
14854 Defaults to @samp{0}.
14857 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
14858 Specifies whether to do reverse lookups on connecting clients. The
14859 @code{double} setting causes @code{cupsd} to verify that the hostname
14860 resolved from the address matches one of the addresses returned for that
14861 hostname. Double lookups also prevent clients with unregistered
14862 addresses from connecting to your server. Only set this option to
14863 @code{#t} or @code{double} if absolutely required.
14865 Defaults to @samp{#f}.
14868 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
14869 Specifies the number of seconds to wait before killing the filters and
14870 backend associated with a canceled or held job.
14872 Defaults to @samp{30}.
14875 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
14876 Specifies the interval between retries of jobs in seconds. This is
14877 typically used for fax queues but can also be used with normal print
14878 queues whose error policy is @code{retry-job} or
14879 @code{retry-current-job}.
14881 Defaults to @samp{30}.
14884 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
14885 Specifies the number of retries that are done for jobs. This is
14886 typically used for fax queues but can also be used with normal print
14887 queues whose error policy is @code{retry-job} or
14888 @code{retry-current-job}.
14890 Defaults to @samp{5}.
14893 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
14894 Specifies whether to support HTTP keep-alive connections.
14896 Defaults to @samp{#t}.
14899 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
14900 Specifies how long an idle client connection remains open, in seconds.
14902 Defaults to @samp{30}.
14905 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
14906 Specifies the maximum size of print files, IPP requests, and HTML form
14907 data. A limit of 0 disables the limit check.
14909 Defaults to @samp{0}.
14912 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
14913 Listens on the specified interfaces for connections. Valid values are
14914 of the form @var{address}:@var{port}, where @var{address} is either an
14915 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
14916 indicate all addresses. Values can also be file names of local UNIX
14917 domain sockets. The Listen directive is similar to the Port directive
14918 but allows you to restrict access to specific interfaces or networks.
14921 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
14922 Specifies the number of pending connections that will be allowed. This
14923 normally only affects very busy servers that have reached the MaxClients
14924 limit, but can also be triggered by large numbers of simultaneous
14925 connections. When the limit is reached, the operating system will
14926 refuse additional connections until the scheduler can accept the pending
14929 Defaults to @samp{128}.
14932 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
14933 Specifies a set of additional access controls.
14935 Available @code{location-access-controls} fields are:
14937 @deftypevr {@code{location-access-controls} parameter} file-name path
14938 Specifies the URI path to which the access control applies.
14941 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
14942 Access controls for all access to this path, in the same format as the
14943 @code{access-controls} of @code{operation-access-control}.
14945 Defaults to @samp{()}.
14948 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
14949 Access controls for method-specific access to this path.
14951 Defaults to @samp{()}.
14953 Available @code{method-access-controls} fields are:
14955 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
14956 If @code{#t}, apply access controls to all methods except the listed
14957 methods. Otherwise apply to only the listed methods.
14959 Defaults to @samp{#f}.
14962 @deftypevr {@code{method-access-controls} parameter} method-list methods
14963 Methods to which this access control applies.
14965 Defaults to @samp{()}.
14968 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
14969 Access control directives, as a list of strings. Each string should be
14970 one directive, such as "Order allow,deny".
14972 Defaults to @samp{()}.
14977 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
14978 Specifies the number of debugging messages that are retained for logging
14979 if an error occurs in a print job. Debug messages are logged regardless
14980 of the LogLevel setting.
14982 Defaults to @samp{100}.
14985 @deftypevr {@code{cups-configuration} parameter} log-level log-level
14986 Specifies the level of logging for the ErrorLog file. The value
14987 @code{none} stops all logging while @code{debug2} logs everything.
14989 Defaults to @samp{info}.
14992 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
14993 Specifies the format of the date and time in the log files. The value
14994 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
14996 Defaults to @samp{standard}.
14999 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
15000 Specifies the maximum number of simultaneous clients that are allowed by
15003 Defaults to @samp{100}.
15006 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
15007 Specifies the maximum number of simultaneous clients that are allowed
15008 from a single address.
15010 Defaults to @samp{100}.
15013 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
15014 Specifies the maximum number of copies that a user can print of each
15017 Defaults to @samp{9999}.
15020 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
15021 Specifies the maximum time a job may remain in the @code{indefinite}
15022 hold state before it is canceled. A value of 0 disables cancellation of
15025 Defaults to @samp{0}.
15028 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
15029 Specifies the maximum number of simultaneous jobs that are allowed. Set
15030 to 0 to allow an unlimited number of jobs.
15032 Defaults to @samp{500}.
15035 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
15036 Specifies the maximum number of simultaneous jobs that are allowed per
15037 printer. A value of 0 allows up to MaxJobs jobs per printer.
15039 Defaults to @samp{0}.
15042 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
15043 Specifies the maximum number of simultaneous jobs that are allowed per
15044 user. A value of 0 allows up to MaxJobs jobs per user.
15046 Defaults to @samp{0}.
15049 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
15050 Specifies the maximum time a job may take to print before it is
15051 canceled, in seconds. Set to 0 to disable cancellation of "stuck" jobs.
15053 Defaults to @samp{10800}.
15056 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
15057 Specifies the maximum size of the log files before they are rotated, in
15058 bytes. The value 0 disables log rotation.
15060 Defaults to @samp{1048576}.
15063 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
15064 Specifies the maximum amount of time to allow between files in a
15065 multiple file print job, in seconds.
15067 Defaults to @samp{300}.
15070 @deftypevr {@code{cups-configuration} parameter} string page-log-format
15071 Specifies the format of PageLog lines. Sequences beginning with percent
15072 (@samp{%}) characters are replaced with the corresponding information,
15073 while all other characters are copied literally. The following percent
15074 sequences are recognized:
15078 insert a single percent character
15081 insert the value of the specified IPP attribute
15084 insert the number of copies for the current page
15087 insert the current page number
15090 insert the current date and time in common log format
15096 insert the printer name
15099 insert the username
15102 A value of the empty string disables page logging. The string @code{%p
15103 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
15104 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
15107 Defaults to @samp{""}.
15110 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
15111 Passes the specified environment variable(s) to child processes; a list
15114 Defaults to @samp{()}.
15117 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
15118 Specifies named access control policies.
15120 Available @code{policy-configuration} fields are:
15122 @deftypevr {@code{policy-configuration} parameter} string name
15123 Name of the policy.
15126 @deftypevr {@code{policy-configuration} parameter} string job-private-access
15127 Specifies an access list for a job's private values. @code{@@ACL} maps
15128 to the printer's requesting-user-name-allowed or
15129 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15130 owner. @code{@@SYSTEM} maps to the groups listed for the
15131 @code{system-group} field of the @code{files-config} configuration,
15132 which is reified into the @code{cups-files.conf(5)} file. Other
15133 possible elements of the access list include specific user names, and
15134 @code{@@@var{group}} to indicate members of a specific group. The
15135 access list may also be simply @code{all} or @code{default}.
15137 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15140 @deftypevr {@code{policy-configuration} parameter} string job-private-values
15141 Specifies the list of job values to make private, or @code{all},
15142 @code{default}, or @code{none}.
15144 Defaults to @samp{"job-name job-originating-host-name
15145 job-originating-user-name phone"}.
15148 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
15149 Specifies an access list for a subscription's private values.
15150 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
15151 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
15152 owner. @code{@@SYSTEM} maps to the groups listed for the
15153 @code{system-group} field of the @code{files-config} configuration,
15154 which is reified into the @code{cups-files.conf(5)} file. Other
15155 possible elements of the access list include specific user names, and
15156 @code{@@@var{group}} to indicate members of a specific group. The
15157 access list may also be simply @code{all} or @code{default}.
15159 Defaults to @samp{"@@OWNER @@SYSTEM"}.
15162 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
15163 Specifies the list of job values to make private, or @code{all},
15164 @code{default}, or @code{none}.
15166 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
15167 notify-subscriber-user-name notify-user-data"}.
15170 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
15171 Access control by IPP operation.
15173 Defaults to @samp{()}.
15177 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
15178 Specifies whether job files (documents) are preserved after a job is
15179 printed. If a numeric value is specified, job files are preserved for
15180 the indicated number of seconds after printing. Otherwise a boolean
15181 value applies indefinitely.
15183 Defaults to @samp{86400}.
15186 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
15187 Specifies whether the job history is preserved after a job is printed.
15188 If a numeric value is specified, the job history is preserved for the
15189 indicated number of seconds after printing. If @code{#t}, the job
15190 history is preserved until the MaxJobs limit is reached.
15192 Defaults to @samp{#t}.
15195 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
15196 Specifies the amount of time to wait for job completion before
15197 restarting the scheduler.
15199 Defaults to @samp{30}.
15202 @deftypevr {@code{cups-configuration} parameter} string rip-cache
15203 Specifies the maximum amount of memory to use when converting documents
15204 into bitmaps for a printer.
15206 Defaults to @samp{"128m"}.
15209 @deftypevr {@code{cups-configuration} parameter} string server-admin
15210 Specifies the email address of the server administrator.
15212 Defaults to @samp{"root@@localhost.localdomain"}.
15215 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
15216 The ServerAlias directive is used for HTTP Host header validation when
15217 clients connect to the scheduler from external interfaces. Using the
15218 special name @code{*} can expose your system to known browser-based DNS
15219 rebinding attacks, even when accessing sites through a firewall. If the
15220 auto-discovery of alternate names does not work, we recommend listing
15221 each alternate name with a ServerAlias directive instead of using
15224 Defaults to @samp{*}.
15227 @deftypevr {@code{cups-configuration} parameter} string server-name
15228 Specifies the fully-qualified host name of the server.
15230 Defaults to @samp{"localhost"}.
15233 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
15234 Specifies what information is included in the Server header of HTTP
15235 responses. @code{None} disables the Server header. @code{ProductOnly}
15236 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
15237 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
15238 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
15239 the output of the @code{uname} command. @code{Full} reports @code{CUPS
15240 2.0.0 (@var{uname}) IPP/2.0}.
15242 Defaults to @samp{Minimal}.
15245 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
15246 Listens on the specified interfaces for encrypted connections. Valid
15247 values are of the form @var{address}:@var{port}, where @var{address} is
15248 either an IPv6 address enclosed in brackets, an IPv4 address, or
15249 @code{*} to indicate all addresses.
15251 Defaults to @samp{()}.
15254 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
15255 Sets encryption options. By default, CUPS only supports encryption
15256 using TLS v1.0 or higher using known secure cipher suites. Security is
15257 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
15258 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
15259 suites, which are required for some older clients. The @code{AllowSSL3} option
15260 enables SSL v3.0, which is required for some older clients that do not support
15261 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
15262 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
15263 protocol version to TLS v1.1.
15265 Defaults to @samp{()}.
15268 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
15269 Specifies whether the scheduler requires clients to strictly adhere to
15270 the IPP specifications.
15272 Defaults to @samp{#f}.
15275 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
15276 Specifies the HTTP request timeout, in seconds.
15278 Defaults to @samp{300}.
15282 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
15283 Specifies whether the web interface is enabled.
15285 Defaults to @samp{#f}.
15288 At this point you're probably thinking ``oh dear, Guix manual, I like
15289 you but you can stop already with the configuration options''. Indeed.
15290 However, one more point: it could be that you have an existing
15291 @code{cupsd.conf} that you want to use. In that case, you can pass an
15292 @code{opaque-cups-configuration} as the configuration of a
15293 @code{cups-service-type}.
15295 Available @code{opaque-cups-configuration} fields are:
15297 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
15301 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
15302 The contents of the @code{cupsd.conf}, as a string.
15305 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
15306 The contents of the @code{cups-files.conf} file, as a string.
15309 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
15310 strings of the same name, you could instantiate a CUPS service like
15314 (service cups-service-type
15315 (opaque-cups-configuration
15316 (cupsd.conf cupsd.conf)
15317 (cups-files.conf cups-files.conf)))
15321 @node Desktop Services
15322 @subsection Desktop Services
15324 The @code{(gnu services desktop)} module provides services that are
15325 usually useful in the context of a ``desktop'' setup---that is, on a
15326 machine running a graphical display server, possibly with graphical user
15327 interfaces, etc. It also defines services that provide specific desktop
15328 environments like GNOME, Xfce or MATE.
15330 To simplify things, the module defines a variable containing the set of
15331 services that users typically expect on a machine with a graphical
15332 environment and networking:
15334 @defvr {Scheme Variable} %desktop-services
15335 This is a list of services that builds upon @code{%base-services} and
15336 adds or adjusts services for a typical ``desktop'' setup.
15338 In particular, it adds a graphical login manager (@pxref{X Window,
15339 @code{gdm-service-type}}), screen lockers, a network management tool
15340 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
15341 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
15342 energy and color management services, the @code{elogind} login and seat
15343 manager, the Polkit privilege service, the GeoClue location service, the
15344 AccountsService daemon that allows authorized users change system passwords,
15345 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
15346 name service switch service configured to be able to use @code{nss-mdns}
15347 (@pxref{Name Service Switch, mDNS}).
15350 The @code{%desktop-services} variable can be used as the @code{services}
15351 field of an @code{operating-system} declaration (@pxref{operating-system
15352 Reference, @code{services}}).
15354 Additionally, the @code{gnome-desktop-service-type},
15355 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
15356 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
15357 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
15358 services like the backlight adjustment helpers and the power management
15359 utilities are added to the system, extending @code{polkit} and @code{dbus}
15360 appropriately, allowing GNOME to operate with elevated privileges on a
15361 limited number of special-purpose system interfaces. Additionally,
15362 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
15363 metapackage to the system profile. Likewise, adding the Xfce service
15364 not only adds the @code{xfce} metapackage to the system profile, but it
15365 also gives the Thunar file manager the ability to open a ``root-mode''
15366 file management window, if the user authenticates using the
15367 administrator's password via the standard polkit graphical interface.
15368 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
15369 appropriately, allowing MATE to operate with elevated privileges on a
15370 limited number of special-purpose system interfaces. Additionally,
15371 adding a service of type @code{mate-desktop-service-type} adds the MATE
15372 metapackage to the system profile. ``Adding Enlightenment'' means that
15373 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
15374 are set as setuid, allowing Enlightenment's screen locker and other
15375 functionality to work as expetected.
15377 The desktop environments in Guix use the Xorg display server by
15378 default. If you'd like to use the newer display server protocol
15379 called Wayland, you need to use the @code{sddm-service} instead of
15380 GDM as the graphical login manager. You should then
15381 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
15382 also try starting GNOME on Wayland manually from a TTY with the
15383 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
15384 gnome-session``. Currently only GNOME has support for Wayland.
15386 @defvr {Scheme Variable} gnome-desktop-service-type
15387 This is the type of the service that adds the @uref{https://www.gnome.org,
15388 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
15389 object (see below.)
15391 This service adds the @code{gnome} package to the system profile, and extends
15392 polkit with the actions from @code{gnome-settings-daemon}.
15395 @deftp {Data Type} gnome-desktop-configuration
15396 Configuration record for the GNOME desktop environment.
15399 @item @code{gnome} (default: @code{gnome})
15400 The GNOME package to use.
15404 @defvr {Scheme Variable} xfce-desktop-service-type
15405 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
15406 desktop environment. Its value is an @code{xfce-desktop-configuration} object
15409 This service adds the @code{xfce} package to the system profile, and
15410 extends polkit with the ability for @code{thunar} to manipulate the file
15411 system as root from within a user session, after the user has authenticated
15412 with the administrator's password.
15415 @deftp {Data Type} xfce-desktop-configuration
15416 Configuration record for the Xfce desktop environment.
15419 @item @code{xfce} (default: @code{xfce})
15420 The Xfce package to use.
15424 @deffn {Scheme Variable} mate-desktop-service-type
15425 This is the type of the service that runs the @uref{https://mate-desktop.org/,
15426 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
15427 object (see below.)
15429 This service adds the @code{mate} package to the system
15430 profile, and extends polkit with the actions from
15431 @code{mate-settings-daemon}.
15434 @deftp {Data Type} mate-desktop-configuration
15435 Configuration record for the MATE desktop environment.
15438 @item @code{mate} (default: @code{mate})
15439 The MATE package to use.
15443 @deffn {Scheme Variable} enlightenment-desktop-service-type
15444 Return a service that adds the @code{enlightenment} package to the system
15445 profile, and extends dbus with actions from @code{efl}.
15448 @deftp {Data Type} enlightenment-desktop-service-configuration
15450 @item @code{enlightenment} (default: @code{enlightenment})
15451 The enlightenment package to use.
15455 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
15456 the default @code{%desktop-services} variable doesn't include any of
15457 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
15458 @code{%desktop-services} in the @code{services} field of your
15459 @code{operating-system}:
15462 (use-modules (gnu))
15463 (use-service-modules desktop)
15466 ;; cons* adds items to the list given as its last argument.
15467 (services (cons* (service gnome-desktop-service-type)
15468 (service xfce-desktop-service)
15469 %desktop-services))
15473 These desktop environments will then be available as options in the
15474 graphical login window.
15476 The actual service definitions included in @code{%desktop-services} and
15477 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
15478 are described below.
15480 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
15481 Return a service that runs the ``system bus'', using @var{dbus}, with
15482 support for @var{services}.
15484 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
15485 facility. Its system bus is used to allow system services to communicate
15486 and to be notified of system-wide events.
15488 @var{services} must be a list of packages that provide an
15489 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
15490 and policy files. For example, to allow avahi-daemon to use the system bus,
15491 @var{services} must be equal to @code{(list avahi)}.
15494 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
15495 Return a service that runs the @code{elogind} login and
15496 seat management daemon. @uref{https://github.com/elogind/elogind,
15497 Elogind} exposes a D-Bus interface that can be used to know which users
15498 are logged in, know what kind of sessions they have open, suspend the
15499 system, inhibit system suspend, reboot the system, and other tasks.
15501 Elogind handles most system-level power events for a computer, for
15502 example suspending the system when a lid is closed, or shutting it down
15503 when the power button is pressed.
15505 The @var{config} keyword argument specifies the configuration for
15506 elogind, and should be the result of an @code{(elogind-configuration
15507 (@var{parameter} @var{value})...)} invocation. Available parameters and
15508 their default values are:
15511 @item kill-user-processes?
15513 @item kill-only-users
15515 @item kill-exclude-users
15517 @item inhibit-delay-max-seconds
15519 @item handle-power-key
15521 @item handle-suspend-key
15523 @item handle-hibernate-key
15525 @item handle-lid-switch
15527 @item handle-lid-switch-docked
15529 @item power-key-ignore-inhibited?
15531 @item suspend-key-ignore-inhibited?
15533 @item hibernate-key-ignore-inhibited?
15535 @item lid-switch-ignore-inhibited?
15537 @item holdoff-timeout-seconds
15541 @item idle-action-seconds
15543 @item runtime-directory-size-percent
15545 @item runtime-directory-size
15549 @item suspend-state
15550 @code{("mem" "standby" "freeze")}
15553 @item hibernate-state
15555 @item hibernate-mode
15556 @code{("platform" "shutdown")}
15557 @item hybrid-sleep-state
15559 @item hybrid-sleep-mode
15560 @code{("suspend" "platform" "shutdown")}
15564 @deffn {Scheme Procedure} accountsservice-service @
15565 [#:accountsservice @var{accountsservice}]
15566 Return a service that runs AccountsService, a system service that can
15567 list available accounts, change their passwords, and so on.
15568 AccountsService integrates with PolicyKit to enable unprivileged users
15569 to acquire the capability to modify their system configuration.
15570 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
15571 accountsservice web site} for more information.
15573 The @var{accountsservice} keyword argument is the @code{accountsservice}
15574 package to expose as a service.
15577 @deffn {Scheme Procedure} polkit-service @
15578 [#:polkit @var{polkit}]
15579 Return a service that runs the
15580 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
15581 management service}, which allows system administrators to grant access to
15582 privileged operations in a structured way. By querying the Polkit service, a
15583 privileged system component can know when it should grant additional
15584 capabilities to ordinary users. For example, an ordinary user can be granted
15585 the capability to suspend the system if the user is logged in locally.
15588 @defvr {Scheme Variable} upower-service-type
15589 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
15590 system-wide monitor for power consumption and battery levels, with the given
15591 configuration settings.
15593 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
15594 notably used by GNOME.
15597 @deftp {Data Type} upower-configuration
15598 Data type representation the configuration for UPower.
15602 @item @code{upower} (default: @var{upower})
15603 Package to use for @code{upower}.
15605 @item @code{watts-up-pro?} (default: @code{#f})
15606 Enable the Watts Up Pro device.
15608 @item @code{poll-batteries?} (default: @code{#t})
15609 Enable polling the kernel for battery level changes.
15611 @item @code{ignore-lid?} (default: @code{#f})
15612 Ignore the lid state, this can be useful if it's incorrect on a device.
15614 @item @code{use-percentage-for-policy?} (default: @code{#f})
15615 Whether battery percentage based policy should be used. The default is to use
15616 the time left, change to @code{#t} to use the percentage.
15618 @item @code{percentage-low} (default: @code{10})
15619 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15620 at which the battery is considered low.
15622 @item @code{percentage-critical} (default: @code{3})
15623 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15624 at which the battery is considered critical.
15626 @item @code{percentage-action} (default: @code{2})
15627 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
15628 at which action will be taken.
15630 @item @code{time-low} (default: @code{1200})
15631 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15632 seconds at which the battery is considered low.
15634 @item @code{time-critical} (default: @code{300})
15635 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15636 seconds at which the battery is considered critical.
15638 @item @code{time-action} (default: @code{120})
15639 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
15640 seconds at which action will be taken.
15642 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
15643 The action taken when @code{percentage-action} or @code{time-action} is
15644 reached (depending on the configuration of @code{use-percentage-for-policy?}).
15646 Possible values are:
15656 @code{'hybrid-sleep}.
15662 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
15663 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
15664 UDisks}, a @dfn{disk management} daemon that provides user interfaces with
15665 notifications and ways to mount/unmount disks. Programs that talk to UDisks
15666 include the @command{udisksctl} command, part of UDisks, and GNOME Disks.
15669 @deffn {Scheme Variable} colord-service-type
15670 This is the type of the service that runs @command{colord}, a system
15671 service with a D-Bus
15672 interface to manage the color profiles of input and output devices such as
15673 screens and scanners. It is notably used by the GNOME Color Manager graphical
15674 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
15675 site} for more information.
15678 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
15679 Return a configuration allowing an application to access GeoClue
15680 location data. @var{name} is the Desktop ID of the application, without
15681 the @code{.desktop} part. If @var{allowed?} is true, the application
15682 will have access to location information by default. The boolean
15683 @var{system?} value indicates whether an application is a system component
15684 or not. Finally @var{users} is a list of UIDs of all users for which
15685 this application is allowed location info access. An empty users list
15686 means that all users are allowed.
15689 @defvr {Scheme Variable} %standard-geoclue-applications
15690 The standard list of well-known GeoClue application configurations,
15691 granting authority to the GNOME date-and-time utility to ask for the
15692 current location in order to set the time zone, and allowing the
15693 IceCat and Epiphany web browsers to request location information.
15694 IceCat and Epiphany both query the user before allowing a web page to
15695 know the user's location.
15698 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
15699 [#:whitelist '()] @
15700 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
15701 [#:submit-data? #f]
15702 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
15703 [#:submission-nick "geoclue"] @
15704 [#:applications %standard-geoclue-applications]
15705 Return a service that runs the GeoClue location service. This service
15706 provides a D-Bus interface to allow applications to request access to a
15707 user's physical location, and optionally to add information to online
15708 location databases. See
15709 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
15710 web site} for more information.
15713 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
15714 [@w{#:auto-enable? #f}]
15715 Return a service that runs the @command{bluetoothd} daemon, which
15716 manages all the Bluetooth devices and provides a number of D-Bus
15717 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
15718 powered automatically at boot, which can be useful when using a
15719 bluetooth keyboard or mouse.
15721 Users need to be in the @code{lp} group to access the D-Bus service.
15724 @node Sound Services
15725 @subsection Sound Services
15727 @cindex sound support
15729 @cindex PulseAudio, sound support
15731 The @code{(gnu services sound)} module provides a service to configure the
15732 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
15733 preferred ALSA output driver.
15735 @deffn {Scheme Variable} alsa-service-type
15736 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
15737 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
15738 configuration file. The value for this type is a @command{alsa-configuration}
15739 record as in this example:
15742 (service alsa-service-type)
15745 See below for details about @code{alsa-configuration}.
15748 @deftp {Data Type} alsa-configuration
15749 Data type representing the configuration for @code{alsa-service}.
15752 @item @code{alsa-plugins} (default: @var{alsa-plugins})
15753 @code{alsa-plugins} package to use.
15755 @item @code{pulseaudio?} (default: @var{#t})
15756 Whether ALSA applications should transparently be made to use the
15757 @uref{http://www.pulseaudio.org/, PulseAudio} sound server.
15759 Using PulseAudio allows you to run several sound-producing applications
15760 at the same time and to individual control them @i{via}
15761 @command{pavucontrol}, among other things.
15763 @item @code{extra-options} (default: @var{""})
15764 String to append to the @file{/etc/asound.conf} file.
15769 Individual users who want to override the system configuration of ALSA can do
15770 it with the @file{~/.asoundrc} file:
15773 # In guix, we have to specify the absolute path for plugins.
15775 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
15778 # Routing ALSA to jack:
15779 # <http://jackaudio.org/faq/routing_alsa.html>.
15783 0 system:playback_1
15784 1 system:playback_2
15801 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
15805 @node Database Services
15806 @subsection Database Services
15810 The @code{(gnu services databases)} module provides the following services.
15812 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
15813 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
15814 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
15815 Return a service that runs @var{postgresql}, the PostgreSQL database
15818 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
15819 creates a database cluster with @var{locale} as the default
15820 locale, stored in @var{data-directory}. It then listens on @var{port}.
15822 @cindex postgresql extension-packages
15823 Additional extensions are loaded from packages listed in
15824 @var{extension-packages}. Extensions are available at runtime. For instance,
15825 to create a geographic database using the @code{postgis} extension, a user can
15826 configure the postgresql-service as in this example:
15830 (use-package-modules databases geo)
15834 ;; postgresql is required to run `psql' but postgis is not required for
15835 ;; proper operation.
15836 (packages (cons* postgresql %base-packages))
15839 (postgresql-service #:extension-packages (list postgis))
15843 Then the extension becomes visible and you can initialise an empty geographic
15844 database in this way:
15848 > create database postgistest;
15849 > \connect postgistest;
15850 > create extension postgis;
15851 > create extension postgis_topology;
15854 There is no need to add this field for contrib extensions such as hstore or
15855 dblink as they are already loadable by postgresql. This field is only
15856 required to add extensions provided by other packages.
15859 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
15860 Return a service that runs @command{mysqld}, the MySQL or MariaDB
15863 The optional @var{config} argument specifies the configuration for
15864 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
15867 @deftp {Data Type} mysql-configuration
15868 Data type representing the configuration of @var{mysql-service}.
15871 @item @code{mysql} (default: @var{mariadb})
15872 Package object of the MySQL database server, can be either @var{mariadb}
15875 For MySQL, a temporary root password will be displayed at activation time.
15876 For MariaDB, the root password is empty.
15878 @item @code{port} (default: @code{3306})
15879 TCP port on which the database server listens for incoming connections.
15883 @defvr {Scheme Variable} memcached-service-type
15884 This is the service type for the @uref{https://memcached.org/,
15885 Memcached} service, which provides a distributed in memory cache. The
15886 value for the service type is a @code{memcached-configuration} object.
15890 (service memcached-service-type)
15893 @deftp {Data Type} memcached-configuration
15894 Data type representing the configuration of memcached.
15897 @item @code{memcached} (default: @code{memcached})
15898 The Memcached package to use.
15900 @item @code{interfaces} (default: @code{'("0.0.0.0")})
15901 Network interfaces on which to listen.
15903 @item @code{tcp-port} (default: @code{11211})
15904 Port on which to accept connections on,
15906 @item @code{udp-port} (default: @code{11211})
15907 Port on which to accept UDP connections on, a value of 0 will disable
15908 listening on a UDP socket.
15910 @item @code{additional-options} (default: @code{'()})
15911 Additional command line options to pass to @code{memcached}.
15915 @defvr {Scheme Variable} mongodb-service-type
15916 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
15917 The value for the service type is a @code{mongodb-configuration} object.
15921 (service mongodb-service-type)
15924 @deftp {Data Type} mongodb-configuration
15925 Data type representing the configuration of mongodb.
15928 @item @code{mongodb} (default: @code{mongodb})
15929 The MongoDB package to use.
15931 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
15932 The configuration file for MongoDB.
15934 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
15935 This value is used to create the directory, so that it exists and is
15936 owned by the mongodb user. It should match the data-directory which
15937 MongoDB is configured to use through the configuration file.
15941 @defvr {Scheme Variable} redis-service-type
15942 This is the service type for the @uref{https://redis.io/, Redis}
15943 key/value store, whose value is a @code{redis-configuration} object.
15946 @deftp {Data Type} redis-configuration
15947 Data type representing the configuration of redis.
15950 @item @code{redis} (default: @code{redis})
15951 The Redis package to use.
15953 @item @code{bind} (default: @code{"127.0.0.1"})
15954 Network interface on which to listen.
15956 @item @code{port} (default: @code{6379})
15957 Port on which to accept connections on, a value of 0 will disable
15958 listening on a TCP socket.
15960 @item @code{working-directory} (default: @code{"/var/lib/redis"})
15961 Directory in which to store the database and related files.
15965 @node Mail Services
15966 @subsection Mail Services
15970 The @code{(gnu services mail)} module provides Guix service definitions
15971 for email services: IMAP, POP3, and LMTP servers, as well as mail
15972 transport agents (MTAs). Lots of acronyms! These services are detailed
15973 in the subsections below.
15975 @subsubheading Dovecot Service
15977 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
15978 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
15981 By default, Dovecot does not need much configuration; the default
15982 configuration object created by @code{(dovecot-configuration)} will
15983 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
15984 certificate will be generated for TLS-protected connections, though
15985 Dovecot will also listen on cleartext ports by default. There are a
15986 number of options, though, which mail administrators might need to change,
15987 and as is the case with other services, Guix allows the system
15988 administrator to specify these parameters via a uniform Scheme interface.
15990 For example, to specify that mail is located at @code{maildir~/.mail},
15991 one would instantiate the Dovecot service like this:
15994 (dovecot-service #:config
15995 (dovecot-configuration
15996 (mail-location "maildir:~/.mail")))
15999 The available configuration parameters follow. Each parameter
16000 definition is preceded by its type; for example, @samp{string-list foo}
16001 indicates that the @code{foo} parameter should be specified as a list of
16002 strings. There is also a way to specify the configuration as a string,
16003 if you have an old @code{dovecot.conf} file that you want to port over
16004 from some other system; see the end for more details.
16006 @c The following documentation was initially generated by
16007 @c (generate-documentation) in (gnu services mail). Manually maintained
16008 @c documentation is better, so we shouldn't hesitate to edit below as
16009 @c needed. However if the change you want to make to this documentation
16010 @c can be done in an automated way, it's probably easier to change
16011 @c (generate-documentation) than to make it below and have to deal with
16012 @c the churn as dovecot updates.
16014 Available @code{dovecot-configuration} fields are:
16016 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
16017 The dovecot package.
16020 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
16021 A list of IPs or hosts where to listen for connections. @samp{*}
16022 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
16023 interfaces. If you want to specify non-default ports or anything more
16024 complex, customize the address and port fields of the
16025 @samp{inet-listener} of the specific services you are interested in.
16028 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
16029 List of protocols we want to serve. Available protocols include
16030 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
16032 Available @code{protocol-configuration} fields are:
16034 @deftypevr {@code{protocol-configuration} parameter} string name
16035 The name of the protocol.
16038 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
16039 UNIX socket path to the master authentication server to find users.
16040 This is used by imap (for shared users) and lda.
16041 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16044 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
16045 Space separated list of plugins to load.
16048 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
16049 Maximum number of IMAP connections allowed for a user from each IP
16050 address. NOTE: The username is compared case-sensitively.
16051 Defaults to @samp{10}.
16056 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
16057 List of services to enable. Available services include @samp{imap},
16058 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
16061 Available @code{service-configuration} fields are:
16063 @deftypevr {@code{service-configuration} parameter} string kind
16064 The service kind. Valid values include @code{director},
16065 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
16066 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
16067 @code{tcpwrap}, @code{quota-warning}, or anything else.
16070 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
16071 Listeners for the service. A listener is either a
16072 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
16073 an @code{inet-listener-configuration}.
16074 Defaults to @samp{()}.
16076 Available @code{unix-listener-configuration} fields are:
16078 @deftypevr {@code{unix-listener-configuration} parameter} string path
16079 Path to the file, relative to @code{base-dir} field. This is also used as
16083 @deftypevr {@code{unix-listener-configuration} parameter} string mode
16084 The access mode for the socket.
16085 Defaults to @samp{"0600"}.
16088 @deftypevr {@code{unix-listener-configuration} parameter} string user
16089 The user to own the socket.
16090 Defaults to @samp{""}.
16093 @deftypevr {@code{unix-listener-configuration} parameter} string group
16094 The group to own the socket.
16095 Defaults to @samp{""}.
16099 Available @code{fifo-listener-configuration} fields are:
16101 @deftypevr {@code{fifo-listener-configuration} parameter} string path
16102 Path to the file, relative to @code{base-dir} field. This is also used as
16106 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
16107 The access mode for the socket.
16108 Defaults to @samp{"0600"}.
16111 @deftypevr {@code{fifo-listener-configuration} parameter} string user
16112 The user to own the socket.
16113 Defaults to @samp{""}.
16116 @deftypevr {@code{fifo-listener-configuration} parameter} string group
16117 The group to own the socket.
16118 Defaults to @samp{""}.
16122 Available @code{inet-listener-configuration} fields are:
16124 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
16125 The protocol to listen for.
16128 @deftypevr {@code{inet-listener-configuration} parameter} string address
16129 The address on which to listen, or empty for all addresses.
16130 Defaults to @samp{""}.
16133 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
16134 The port on which to listen.
16137 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
16138 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
16140 Defaults to @samp{#t}.
16145 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
16146 Maximum number of simultaneous client connections per process. Once
16147 this number of connections is received, the next incoming connection
16148 will prompt Dovecot to spawn another process. If set to 0,
16149 @code{default-client-limit} is used instead.
16151 Defaults to @samp{0}.
16155 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
16156 Number of connections to handle before starting a new process.
16157 Typically the only useful values are 0 (unlimited) or 1. 1 is more
16158 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
16159 Defaults to @samp{1}.
16163 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
16164 Maximum number of processes that can exist for this service. If set to
16165 0, @code{default-process-limit} is used instead.
16167 Defaults to @samp{0}.
16171 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
16172 Number of processes to always keep waiting for more connections.
16173 Defaults to @samp{0}.
16176 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
16177 If you set @samp{service-count 0}, you probably need to grow
16179 Defaults to @samp{256000000}.
16184 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
16185 Dict configuration, as created by the @code{dict-configuration}
16188 Available @code{dict-configuration} fields are:
16190 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
16191 A list of key-value pairs that this dict should hold.
16192 Defaults to @samp{()}.
16197 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
16198 A list of passdb configurations, each one created by the
16199 @code{passdb-configuration} constructor.
16201 Available @code{passdb-configuration} fields are:
16203 @deftypevr {@code{passdb-configuration} parameter} string driver
16204 The driver that the passdb should use. Valid values include
16205 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
16207 Defaults to @samp{"pam"}.
16210 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
16211 Space separated list of arguments to the passdb driver.
16212 Defaults to @samp{""}.
16217 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
16218 List of userdb configurations, each one created by the
16219 @code{userdb-configuration} constructor.
16221 Available @code{userdb-configuration} fields are:
16223 @deftypevr {@code{userdb-configuration} parameter} string driver
16224 The driver that the userdb should use. Valid values include
16225 @samp{passwd} and @samp{static}.
16226 Defaults to @samp{"passwd"}.
16229 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
16230 Space separated list of arguments to the userdb driver.
16231 Defaults to @samp{""}.
16234 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
16235 Override fields from passwd.
16236 Defaults to @samp{()}.
16241 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
16242 Plug-in configuration, created by the @code{plugin-configuration}
16246 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
16247 List of namespaces. Each item in the list is created by the
16248 @code{namespace-configuration} constructor.
16250 Available @code{namespace-configuration} fields are:
16252 @deftypevr {@code{namespace-configuration} parameter} string name
16253 Name for this namespace.
16256 @deftypevr {@code{namespace-configuration} parameter} string type
16257 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
16258 Defaults to @samp{"private"}.
16261 @deftypevr {@code{namespace-configuration} parameter} string separator
16262 Hierarchy separator to use. You should use the same separator for
16263 all namespaces or some clients get confused. @samp{/} is usually a good
16264 one. The default however depends on the underlying mail storage
16266 Defaults to @samp{""}.
16269 @deftypevr {@code{namespace-configuration} parameter} string prefix
16270 Prefix required to access this namespace. This needs to be
16271 different for all namespaces. For example @samp{Public/}.
16272 Defaults to @samp{""}.
16275 @deftypevr {@code{namespace-configuration} parameter} string location
16276 Physical location of the mailbox. This is in the same format as
16277 mail_location, which is also the default for it.
16278 Defaults to @samp{""}.
16281 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
16282 There can be only one INBOX, and this setting defines which
16284 Defaults to @samp{#f}.
16287 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
16288 If namespace is hidden, it's not advertised to clients via NAMESPACE
16289 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
16290 useful when converting from another server with different namespaces
16291 which you want to deprecate but still keep working. For example you can
16292 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
16294 Defaults to @samp{#f}.
16297 @deftypevr {@code{namespace-configuration} parameter} boolean list?
16298 Show the mailboxes under this namespace with the LIST command. This
16299 makes the namespace visible for clients that do not support the NAMESPACE
16300 extension. The special @code{children} value lists child mailboxes, but
16301 hides the namespace prefix.
16302 Defaults to @samp{#t}.
16305 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
16306 Namespace handles its own subscriptions. If set to @code{#f}, the
16307 parent namespace handles them. The empty prefix should always have this
16309 Defaults to @samp{#t}.
16312 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
16313 List of predefined mailboxes in this namespace.
16314 Defaults to @samp{()}.
16316 Available @code{mailbox-configuration} fields are:
16318 @deftypevr {@code{mailbox-configuration} parameter} string name
16319 Name for this mailbox.
16322 @deftypevr {@code{mailbox-configuration} parameter} string auto
16323 @samp{create} will automatically create this mailbox.
16324 @samp{subscribe} will both create and subscribe to the mailbox.
16325 Defaults to @samp{"no"}.
16328 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
16329 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
16330 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
16331 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
16332 Defaults to @samp{()}.
16339 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
16340 Base directory where to store runtime data.
16341 Defaults to @samp{"/var/run/dovecot/"}.
16344 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
16345 Greeting message for clients.
16346 Defaults to @samp{"Dovecot ready."}.
16349 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
16350 List of trusted network ranges. Connections from these IPs are
16351 allowed to override their IP addresses and ports (for logging and for
16352 authentication checks). @samp{disable-plaintext-auth} is also ignored
16353 for these networks. Typically you would specify your IMAP proxy servers
16355 Defaults to @samp{()}.
16358 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
16359 List of login access check sockets (e.g.@: tcpwrap).
16360 Defaults to @samp{()}.
16363 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
16364 Show more verbose process titles (in ps). Currently shows user name
16365 and IP address. Useful for seeing who is actually using the IMAP
16366 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
16368 Defaults to @samp{#f}.
16371 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
16372 Should all processes be killed when Dovecot master process shuts down.
16373 Setting this to @code{#f} means that Dovecot can be upgraded without
16374 forcing existing client connections to close (although that could also
16375 be a problem if the upgrade is e.g.@: due to a security fix).
16376 Defaults to @samp{#t}.
16379 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
16380 If non-zero, run mail commands via this many connections to doveadm
16381 server, instead of running them directly in the same process.
16382 Defaults to @samp{0}.
16385 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
16386 UNIX socket or host:port used for connecting to doveadm server.
16387 Defaults to @samp{"doveadm-server"}.
16390 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
16391 List of environment variables that are preserved on Dovecot startup
16392 and passed down to all of its child processes. You can also give
16393 key=value pairs to always set specific settings.
16396 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
16397 Disable LOGIN command and all other plaintext authentications unless
16398 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
16399 matches the local IP (i.e.@: you're connecting from the same computer),
16400 the connection is considered secure and plaintext authentication is
16401 allowed. See also ssl=required setting.
16402 Defaults to @samp{#t}.
16405 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
16406 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
16407 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
16408 for caching to be used.
16409 Defaults to @samp{0}.
16412 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
16413 Time to live for cached data. After TTL expires the cached record
16414 is no longer used, *except* if the main database lookup returns internal
16415 failure. We also try to handle password changes automatically: If
16416 user's previous authentication was successful, but this one wasn't, the
16417 cache isn't used. For now this works only with plaintext
16419 Defaults to @samp{"1 hour"}.
16422 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
16423 TTL for negative hits (user not found, password mismatch).
16424 0 disables caching them completely.
16425 Defaults to @samp{"1 hour"}.
16428 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
16429 List of realms for SASL authentication mechanisms that need them.
16430 You can leave it empty if you don't want to support multiple realms.
16431 Many clients simply use the first one listed here, so keep the default
16433 Defaults to @samp{()}.
16436 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
16437 Default realm/domain to use if none was specified. This is used for
16438 both SASL realms and appending @@domain to username in plaintext
16440 Defaults to @samp{""}.
16443 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
16444 List of allowed characters in username. If the user-given username
16445 contains a character not listed in here, the login automatically fails.
16446 This is just an extra check to make sure user can't exploit any
16447 potential quote escaping vulnerabilities with SQL/LDAP databases. If
16448 you want to allow all characters, set this value to empty.
16449 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
16452 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
16453 Username character translations before it's looked up from
16454 databases. The value contains series of from -> to characters. For
16455 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
16456 translated to @samp{@@}.
16457 Defaults to @samp{""}.
16460 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
16461 Username formatting before it's looked up from databases. You can
16462 use the standard variables here, e.g.@: %Lu would lowercase the username,
16463 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
16464 change the @samp{@@} into @samp{-AT-}. This translation is done after
16465 @samp{auth-username-translation} changes.
16466 Defaults to @samp{"%Lu"}.
16469 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
16470 If you want to allow master users to log in by specifying the master
16471 username within the normal username string (i.e.@: not using SASL
16472 mechanism's support for it), you can specify the separator character
16473 here. The format is then <username><separator><master username>.
16474 UW-IMAP uses @samp{*} as the separator, so that could be a good
16476 Defaults to @samp{""}.
16479 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
16480 Username to use for users logging in with ANONYMOUS SASL
16482 Defaults to @samp{"anonymous"}.
16485 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
16486 Maximum number of dovecot-auth worker processes. They're used to
16487 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
16488 They're automatically created and destroyed as needed.
16489 Defaults to @samp{30}.
16492 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
16493 Host name to use in GSSAPI principal names. The default is to use
16494 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
16495 allow all keytab entries.
16496 Defaults to @samp{""}.
16499 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
16500 Kerberos keytab to use for the GSSAPI mechanism. Will use the
16501 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
16502 need to change the auth service to run as root to be able to read this
16504 Defaults to @samp{""}.
16507 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
16508 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
16509 and @samp{ntlm-auth} helper.
16510 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
16511 Defaults to @samp{#f}.
16514 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
16515 Path for Samba's @samp{ntlm-auth} helper binary.
16516 Defaults to @samp{"/usr/bin/ntlm_auth"}.
16519 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
16520 Time to delay before replying to failed authentications.
16521 Defaults to @samp{"2 secs"}.
16524 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
16525 Require a valid SSL client certificate or the authentication
16527 Defaults to @samp{#f}.
16530 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
16531 Take the username from client's SSL certificate, using
16532 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
16534 Defaults to @samp{#f}.
16537 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
16538 List of wanted authentication mechanisms. Supported mechanisms are:
16539 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
16540 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
16541 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
16542 @samp{disable-plaintext-auth} setting.
16545 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
16546 List of IPs or hostnames to all director servers, including ourself.
16547 Ports can be specified as ip:port. The default port is the same as what
16548 director service's @samp{inet-listener} is using.
16549 Defaults to @samp{()}.
16552 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
16553 List of IPs or hostnames to all backend mail servers. Ranges are
16554 allowed too, like 10.0.0.10-10.0.0.30.
16555 Defaults to @samp{()}.
16558 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
16559 How long to redirect users to a specific server after it no longer
16560 has any connections.
16561 Defaults to @samp{"15 min"}.
16564 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
16565 How the username is translated before being hashed. Useful values
16566 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
16567 are shared within domain.
16568 Defaults to @samp{"%Lu"}.
16571 @deftypevr {@code{dovecot-configuration} parameter} string log-path
16572 Log file to use for error messages. @samp{syslog} logs to syslog,
16573 @samp{/dev/stderr} logs to stderr.
16574 Defaults to @samp{"syslog"}.
16577 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
16578 Log file to use for informational messages. Defaults to
16580 Defaults to @samp{""}.
16583 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
16584 Log file to use for debug messages. Defaults to
16585 @samp{info-log-path}.
16586 Defaults to @samp{""}.
16589 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
16590 Syslog facility to use if you're logging to syslog. Usually if you
16591 don't want to use @samp{mail}, you'll use local0..local7. Also other
16592 standard facilities are supported.
16593 Defaults to @samp{"mail"}.
16596 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
16597 Log unsuccessful authentication attempts and the reasons why they
16599 Defaults to @samp{#f}.
16602 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
16603 In case of password mismatches, log the attempted password. Valid
16604 values are no, plain and sha1. sha1 can be useful for detecting brute
16605 force password attempts vs. user simply trying the same password over
16606 and over again. You can also truncate the value to n chars by appending
16607 ":n" (e.g.@: sha1:6).
16608 Defaults to @samp{"no"}.
16611 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
16612 Even more verbose logging for debugging purposes. Shows for example
16614 Defaults to @samp{#f}.
16617 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
16618 In case of password mismatches, log the passwords and used scheme so
16619 the problem can be debugged. Enabling this also enables
16621 Defaults to @samp{#f}.
16624 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
16625 Enable mail process debugging. This can help you figure out why
16626 Dovecot isn't finding your mails.
16627 Defaults to @samp{#f}.
16630 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
16631 Show protocol level SSL errors.
16632 Defaults to @samp{#f}.
16635 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
16636 Prefix for each line written to log file. % codes are in
16637 strftime(3) format.
16638 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
16641 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
16642 List of elements we want to log. The elements which have a
16643 non-empty variable value are joined together to form a comma-separated
16647 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
16648 Login log format. %s contains @samp{login-log-format-elements}
16649 string, %$ contains the data we want to log.
16650 Defaults to @samp{"%$: %s"}.
16653 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
16654 Log prefix for mail processes. See doc/wiki/Variables.txt for list
16655 of possible variables you can use.
16656 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
16659 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
16660 Format to use for logging mail deliveries. You can use variables:
16663 Delivery status message (e.g.@: @samp{saved to INBOX})
16675 Defaults to @samp{"msgid=%m: %$"}.
16678 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
16679 Location for users' mailboxes. The default is empty, which means
16680 that Dovecot tries to find the mailboxes automatically. This won't work
16681 if the user doesn't yet have any mail, so you should explicitly tell
16682 Dovecot the full location.
16684 If you're using mbox, giving a path to the INBOX
16685 file (e.g.@: /var/mail/%u) isn't enough. You'll also need to tell Dovecot
16686 where the other mailboxes are kept. This is called the "root mail
16687 directory", and it must be the first path given in the
16688 @samp{mail-location} setting.
16690 There are a few special variables you can use, eg.:
16696 user part in user@@domain, same as %u if there's no domain
16698 domain part in user@@domain, empty if there's no domain
16703 See doc/wiki/Variables.txt for full list. Some examples:
16705 @item maildir:~/Maildir
16706 @item mbox:~/mail:INBOX=/var/mail/%u
16707 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
16709 Defaults to @samp{""}.
16712 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
16713 System user and group used to access mails. If you use multiple,
16714 userdb can override these by returning uid or gid fields. You can use
16715 either numbers or names. <doc/wiki/UserIds.txt>.
16716 Defaults to @samp{""}.
16719 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
16721 Defaults to @samp{""}.
16724 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
16725 Group to enable temporarily for privileged operations. Currently
16726 this is used only with INBOX when either its initial creation or
16727 dotlocking fails. Typically this is set to "mail" to give access to
16729 Defaults to @samp{""}.
16732 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
16733 Grant access to these supplementary groups for mail processes.
16734 Typically these are used to set up access to shared mailboxes. Note
16735 that it may be dangerous to set these if users can create
16736 symlinks (e.g.@: if "mail" group is set here, ln -s /var/mail ~/mail/var
16737 could allow a user to delete others' mailboxes, or ln -s
16738 /secret/shared/box ~/mail/mybox would allow reading it).
16739 Defaults to @samp{""}.
16742 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
16743 Allow full file system access to clients. There's no access checks
16744 other than what the operating system does for the active UID/GID. It
16745 works with both maildir and mboxes, allowing you to prefix mailboxes
16746 names with e.g.@: /path/ or ~user/.
16747 Defaults to @samp{#f}.
16750 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
16751 Don't use mmap() at all. This is required if you store indexes to
16752 shared file systems (NFS or clustered file system).
16753 Defaults to @samp{#f}.
16756 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
16757 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
16758 supports @samp{O_EXCL} since version 3, so this should be safe to use
16759 nowadays by default.
16760 Defaults to @samp{#t}.
16763 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
16764 When to use fsync() or fdatasync() calls:
16767 Whenever necessary to avoid losing important data
16769 Useful with e.g.@: NFS when write()s are delayed
16771 Never use it (best performance, but crashes can lose data).
16773 Defaults to @samp{"optimized"}.
16776 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
16777 Mail storage exists in NFS. Set this to yes to make Dovecot flush
16778 NFS caches whenever needed. If you're using only a single mail server
16780 Defaults to @samp{#f}.
16783 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
16784 Mail index files also exist in NFS. Setting this to yes requires
16785 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
16786 Defaults to @samp{#f}.
16789 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
16790 Locking method for index files. Alternatives are fcntl, flock and
16791 dotlock. Dotlocking uses some tricks which may create more disk I/O
16792 than other locking methods. NFS users: flock doesn't work, remember to
16793 change @samp{mmap-disable}.
16794 Defaults to @samp{"fcntl"}.
16797 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
16798 Directory in which LDA/LMTP temporarily stores incoming mails >128
16800 Defaults to @samp{"/tmp"}.
16803 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
16804 Valid UID range for users. This is mostly to make sure that users can't
16805 log in as daemons or other system users. Note that denying root logins is
16806 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
16808 Defaults to @samp{500}.
16811 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
16813 Defaults to @samp{0}.
16816 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
16817 Valid GID range for users. Users having non-valid GID as primary group ID
16818 aren't allowed to log in. If user belongs to supplementary groups with
16819 non-valid GIDs, those groups are not set.
16820 Defaults to @samp{1}.
16823 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
16825 Defaults to @samp{0}.
16828 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
16829 Maximum allowed length for mail keyword name. It's only forced when
16830 trying to create new keywords.
16831 Defaults to @samp{50}.
16834 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
16835 List of directories under which chrooting is allowed for mail
16836 processes (i.e.@: /var/mail will allow chrooting to /var/mail/foo/bar
16837 too). This setting doesn't affect @samp{login-chroot}
16838 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
16839 "/./" in home dirs are ignored. WARNING: Never add directories here
16840 which local users can modify, that may lead to root exploit. Usually
16841 this should be done only if you don't allow shell access for users.
16842 <doc/wiki/Chrooting.txt>.
16843 Defaults to @samp{()}.
16846 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
16847 Default chroot directory for mail processes. This can be overridden
16848 for specific users in user database by giving /./ in user's home
16849 directory (e.g.@: /home/./user chroots into /home). Note that usually
16850 there is no real need to do chrooting, Dovecot doesn't allow users to
16851 access files outside their mail directory anyway. If your home
16852 directories are prefixed with the chroot directory, append "/."@: to
16853 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
16854 Defaults to @samp{""}.
16857 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
16858 UNIX socket path to master authentication server to find users.
16859 This is used by imap (for shared users) and lda.
16860 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
16863 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
16864 Directory where to look up mail plugins.
16865 Defaults to @samp{"/usr/lib/dovecot"}.
16868 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
16869 List of plugins to load for all services. Plugins specific to IMAP,
16870 LDA, etc.@: are added to this list in their own .conf files.
16871 Defaults to @samp{()}.
16874 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
16875 The minimum number of mails in a mailbox before updates are done to
16876 cache file. This allows optimizing Dovecot's behavior to do less disk
16877 writes at the cost of more disk reads.
16878 Defaults to @samp{0}.
16881 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
16882 When IDLE command is running, mailbox is checked once in a while to
16883 see if there are any new mails or other changes. This setting defines
16884 the minimum time to wait between those checks. Dovecot can also use
16885 dnotify, inotify and kqueue to find out immediately when changes
16887 Defaults to @samp{"30 secs"}.
16890 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
16891 Save mails with CR+LF instead of plain LF. This makes sending those
16892 mails take less CPU, especially with sendfile() syscall with Linux and
16893 FreeBSD. But it also creates a bit more disk I/O which may just make it
16894 slower. Also note that if other software reads the mboxes/maildirs,
16895 they may handle the extra CRs wrong and cause problems.
16896 Defaults to @samp{#f}.
16899 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
16900 By default LIST command returns all entries in maildir beginning
16901 with a dot. Enabling this option makes Dovecot return only entries
16902 which are directories. This is done by stat()ing each entry, so it
16903 causes more disk I/O.
16904 (For systems setting struct @samp{dirent->d_type} this check is free
16905 and it's done always regardless of this setting).
16906 Defaults to @samp{#f}.
16909 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
16910 When copying a message, do it with hard links whenever possible.
16911 This makes the performance much better, and it's unlikely to have any
16913 Defaults to @samp{#t}.
16916 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
16917 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
16918 directory only when its mtime changes unexpectedly or when we can't find
16919 the mail otherwise.
16920 Defaults to @samp{#f}.
16923 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
16924 Which locking methods to use for locking mbox. There are four
16929 Create <mailbox>.lock file. This is the oldest and most NFS-safe
16930 solution. If you want to use /var/mail/ like directory, the users will
16931 need write access to that directory.
16933 Same as dotlock, but if it fails because of permissions or because there
16934 isn't enough disk space, just skip it.
16936 Use this if possible. Works with NFS too if lockd is used.
16938 May not exist in all systems. Doesn't work with NFS.
16940 May not exist in all systems. Doesn't work with NFS.
16943 You can use multiple locking methods; if you do the order they're declared
16944 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
16945 locking methods as well. Some operating systems don't allow using some of
16946 them simultaneously.
16949 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
16953 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
16954 Maximum time to wait for lock (all of them) before aborting.
16955 Defaults to @samp{"5 mins"}.
16958 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
16959 If dotlock exists but the mailbox isn't modified in any way,
16960 override the lock file after this much time.
16961 Defaults to @samp{"2 mins"}.
16964 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
16965 When mbox changes unexpectedly we have to fully read it to find out
16966 what changed. If the mbox is large this can take a long time. Since
16967 the change is usually just a newly appended mail, it'd be faster to
16968 simply read the new mails. If this setting is enabled, Dovecot does
16969 this but still safely fallbacks to re-reading the whole mbox file
16970 whenever something in mbox isn't how it's expected to be. The only real
16971 downside to this setting is that if some other MUA changes message
16972 flags, Dovecot doesn't notice it immediately. Note that a full sync is
16973 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
16974 Defaults to @samp{#t}.
16977 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
16978 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
16979 EXAMINE, EXPUNGE or CHECK commands. If this is set,
16980 @samp{mbox-dirty-syncs} is ignored.
16981 Defaults to @samp{#f}.
16984 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
16985 Delay writing mbox headers until doing a full write sync (EXPUNGE
16986 and CHECK commands and when closing the mailbox). This is especially
16987 useful for POP3 where clients often delete all mails. The downside is
16988 that our changes aren't immediately visible to other MUAs.
16989 Defaults to @samp{#t}.
16992 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
16993 If mbox size is smaller than this (e.g.@: 100k), don't write index
16994 files. If an index file already exists it's still read, just not
16996 Defaults to @samp{0}.
16999 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
17000 Maximum dbox file size until it's rotated.
17001 Defaults to @samp{10000000}.
17004 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
17005 Maximum dbox file age until it's rotated. Typically in days. Day
17006 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
17008 Defaults to @samp{"1d"}.
17011 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
17012 When creating new mdbox files, immediately preallocate their size to
17013 @samp{mdbox-rotate-size}. This setting currently works only in Linux
17014 with some file systems (ext4, xfs).
17015 Defaults to @samp{#f}.
17018 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
17019 sdbox and mdbox support saving mail attachments to external files,
17020 which also allows single instance storage for them. Other backends
17021 don't support this for now.
17023 WARNING: This feature hasn't been tested much yet. Use at your own risk.
17025 Directory root where to store mail attachments. Disabled, if empty.
17026 Defaults to @samp{""}.
17029 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
17030 Attachments smaller than this aren't saved externally. It's also
17031 possible to write a plugin to disable saving specific attachments
17033 Defaults to @samp{128000}.
17036 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
17037 File system backend to use for saving attachments:
17040 No SiS done by Dovecot (but this might help FS's own deduplication)
17042 SiS with immediate byte-by-byte comparison during saving
17043 @item sis-queue posix
17044 SiS with delayed comparison and deduplication.
17046 Defaults to @samp{"sis posix"}.
17049 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
17050 Hash format to use in attachment filenames. You can add any text and
17051 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
17052 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
17053 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
17054 Defaults to @samp{"%@{sha1@}"}.
17057 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
17059 Defaults to @samp{100}.
17062 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
17064 Defaults to @samp{1000}.
17067 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
17068 Default VSZ (virtual memory size) limit for service processes.
17069 This is mainly intended to catch and kill processes that leak memory
17070 before they eat up everything.
17071 Defaults to @samp{256000000}.
17074 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
17075 Login user is internally used by login processes. This is the most
17076 untrusted user in Dovecot system. It shouldn't have access to anything
17078 Defaults to @samp{"dovenull"}.
17081 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
17082 Internal user is used by unprivileged processes. It should be
17083 separate from login user, so that login processes can't disturb other
17085 Defaults to @samp{"dovecot"}.
17088 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
17089 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
17090 Defaults to @samp{"required"}.
17093 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
17094 PEM encoded X.509 SSL/TLS certificate (public key).
17095 Defaults to @samp{"</etc/dovecot/default.pem"}.
17098 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
17099 PEM encoded SSL/TLS private key. The key is opened before
17100 dropping root privileges, so keep the key file unreadable by anyone but
17102 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
17105 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
17106 If key file is password protected, give the password here.
17107 Alternatively give it when starting dovecot with -p parameter. Since
17108 this file is often world-readable, you may want to place this setting
17109 instead to a different.
17110 Defaults to @samp{""}.
17113 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
17114 PEM encoded trusted certificate authority. Set this only if you
17115 intend to use @samp{ssl-verify-client-cert? #t}. The file should
17116 contain the CA certificate(s) followed by the matching
17117 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
17118 Defaults to @samp{""}.
17121 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
17122 Require that CRL check succeeds for client certificates.
17123 Defaults to @samp{#t}.
17126 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
17127 Request client to send a certificate. If you also want to require
17128 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
17129 Defaults to @samp{#f}.
17132 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
17133 Which field from certificate to use for username. commonName and
17134 x500UniqueIdentifier are the usual choices. You'll also need to set
17135 @samp{auth-ssl-username-from-cert? #t}.
17136 Defaults to @samp{"commonName"}.
17139 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
17140 Minimum SSL protocol version to accept.
17141 Defaults to @samp{"TLSv1"}.
17144 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
17145 SSL ciphers to use.
17146 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
17149 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
17150 SSL crypto device to use, for valid values run "openssl engine".
17151 Defaults to @samp{""}.
17154 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
17155 Address to use when sending rejection mails.
17156 %d expands to recipient domain.
17157 Defaults to @samp{"postmaster@@%d"}.
17160 @deftypevr {@code{dovecot-configuration} parameter} string hostname
17161 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
17162 and in LMTP replies. Default is the system's real hostname@@domain.
17163 Defaults to @samp{""}.
17166 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
17167 If user is over quota, return with temporary failure instead of
17169 Defaults to @samp{#f}.
17172 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
17173 Binary to use for sending mails.
17174 Defaults to @samp{"/usr/sbin/sendmail"}.
17177 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
17178 If non-empty, send mails via this SMTP host[:port] instead of
17180 Defaults to @samp{""}.
17183 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
17184 Subject: header to use for rejection mails. You can use the same
17185 variables as for @samp{rejection-reason} below.
17186 Defaults to @samp{"Rejected: %s"}.
17189 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
17190 Human readable error message for rejection mails. You can use
17203 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
17206 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
17207 Delimiter character between local-part and detail in email
17209 Defaults to @samp{"+"}.
17212 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
17213 Header where the original recipient address (SMTP's RCPT TO:
17214 address) is taken from if not available elsewhere. With dovecot-lda -a
17215 parameter overrides this. A commonly used header for this is
17217 Defaults to @samp{""}.
17220 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
17221 Should saving a mail to a nonexistent mailbox automatically create
17223 Defaults to @samp{#f}.
17226 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
17227 Should automatically created mailboxes be also automatically
17229 Defaults to @samp{#f}.
17232 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
17233 Maximum IMAP command line length. Some clients generate very long
17234 command lines with huge mailboxes, so you may need to raise this if you
17235 get "Too long argument" or "IMAP command line too large" errors
17237 Defaults to @samp{64000}.
17240 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
17241 IMAP logout format string:
17244 total number of bytes read from client
17246 total number of bytes sent to client.
17248 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
17249 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@}"}.
17252 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
17253 Override the IMAP CAPABILITY response. If the value begins with '+',
17254 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
17255 Defaults to @samp{""}.
17258 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
17259 How long to wait between "OK Still here" notifications when client
17261 Defaults to @samp{"2 mins"}.
17264 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
17265 ID field names and values to send to clients. Using * as the value
17266 makes Dovecot use the default value. The following fields have default
17267 values currently: name, version, os, os-version, support-url,
17269 Defaults to @samp{""}.
17272 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
17273 ID fields sent by client to log. * means everything.
17274 Defaults to @samp{""}.
17277 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
17278 Workarounds for various client bugs:
17281 @item delay-newmail
17282 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
17283 CHECK commands. Some clients ignore them otherwise, for example OSX
17284 Mail (<v2.1). Outlook Express breaks more badly though, without this it
17285 may show user "Message no longer in server" errors. Note that OE6
17286 still breaks even with this workaround if synchronization is set to
17289 @item tb-extra-mailbox-sep
17290 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
17291 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
17292 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
17294 @item tb-lsub-flags
17295 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
17296 This makes Thunderbird realize they aren't selectable and show them
17297 greyed out, instead of only later giving "not selectable" popup error.
17299 Defaults to @samp{()}.
17302 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
17303 Host allowed in URLAUTH URLs sent by client. "*" allows all.
17304 Defaults to @samp{""}.
17308 Whew! Lots of configuration options. The nice thing about it though is
17309 that Guix has a complete interface to Dovecot's configuration
17310 language. This allows not only a nice way to declare configurations,
17311 but also offers reflective capabilities as well: users can write code to
17312 inspect and transform configurations from within Scheme.
17314 However, it could be that you just want to get a @code{dovecot.conf} up
17315 and running. In that case, you can pass an
17316 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
17317 @code{dovecot-service}. As its name indicates, an opaque configuration
17318 does not have easy reflective capabilities.
17320 Available @code{opaque-dovecot-configuration} fields are:
17322 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
17323 The dovecot package.
17326 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
17327 The contents of the @code{dovecot.conf}, as a string.
17330 For example, if your @code{dovecot.conf} is just the empty string, you
17331 could instantiate a dovecot service like this:
17334 (dovecot-service #:config
17335 (opaque-dovecot-configuration
17339 @subsubheading OpenSMTPD Service
17341 @deffn {Scheme Variable} opensmtpd-service-type
17342 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
17343 service, whose value should be an @code{opensmtpd-configuration} object
17344 as in this example:
17347 (service opensmtpd-service-type
17348 (opensmtpd-configuration
17349 (config-file (local-file "./my-smtpd.conf"))))
17353 @deftp {Data Type} opensmtpd-configuration
17354 Data type representing the configuration of opensmtpd.
17357 @item @code{package} (default: @var{opensmtpd})
17358 Package object of the OpenSMTPD SMTP server.
17360 @item @code{config-file} (default: @code{%default-opensmtpd-file})
17361 File-like object of the OpenSMTPD configuration file to use. By default
17362 it listens on the loopback network interface, and allows for mail from
17363 users and daemons on the local machine, as well as permitting email to
17364 remote servers. Run @command{man smtpd.conf} for more information.
17369 @subsubheading Exim Service
17371 @cindex mail transfer agent (MTA)
17372 @cindex MTA (mail transfer agent)
17375 @deffn {Scheme Variable} exim-service-type
17376 This is the type of the @uref{https://exim.org, Exim} mail transfer
17377 agent (MTA), whose value should be an @code{exim-configuration} object
17378 as in this example:
17381 (service exim-service-type
17382 (exim-configuration
17383 (config-file (local-file "./my-exim.conf"))))
17387 In order to use an @code{exim-service-type} service you must also have a
17388 @code{mail-aliases-service-type} service present in your
17389 @code{operating-system} (even if it has no aliases).
17391 @deftp {Data Type} exim-configuration
17392 Data type representing the configuration of exim.
17395 @item @code{package} (default: @var{exim})
17396 Package object of the Exim server.
17398 @item @code{config-file} (default: @code{#f})
17399 File-like object of the Exim configuration file to use. If its value is
17400 @code{#f} then use the default configuration file from the package
17401 provided in @code{package}. The resulting configuration file is loaded
17402 after setting the @code{exim_user} and @code{exim_group} configuration
17408 @subsubheading Getmail service
17413 @deffn {Scheme Variable} getmail-service-type
17414 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
17415 mail retriever, whose value should be an @code{getmail-configuration}.
17418 Available @code{getmail-configuration} fields are:
17420 @deftypevr {@code{getmail-configuration} parameter} symbol name
17421 A symbol to identify the getmail service.
17423 Defaults to @samp{"unset"}.
17427 @deftypevr {@code{getmail-configuration} parameter} package package
17428 The getmail package to use.
17432 @deftypevr {@code{getmail-configuration} parameter} string user
17433 The user to run getmail as.
17435 Defaults to @samp{"getmail"}.
17439 @deftypevr {@code{getmail-configuration} parameter} string group
17440 The group to run getmail as.
17442 Defaults to @samp{"getmail"}.
17446 @deftypevr {@code{getmail-configuration} parameter} string directory
17447 The getmail directory to use.
17449 Defaults to @samp{"/var/lib/getmail/default"}.
17453 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
17454 The getmail configuration file to use.
17456 Available @code{getmail-configuration-file} fields are:
17458 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
17459 What mail account to retrieve mail from, and how to access that account.
17461 Available @code{getmail-retriever-configuration} fields are:
17463 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
17464 The type of mail retriever to use. Valid values include @samp{passwd}
17467 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
17471 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
17472 Space separated list of arguments to the userdb driver.
17474 Defaults to @samp{unset}.
17478 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
17479 Space separated list of arguments to the userdb driver.
17481 Defaults to @samp{unset}.
17485 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
17486 Space separated list of arguments to the userdb driver.
17488 Defaults to @samp{#f}.
17492 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
17493 Override fields from passwd.
17495 Defaults to @samp{""}.
17499 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
17500 Override fields from passwd.
17502 Defaults to @samp{()}.
17506 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
17507 PEM-formatted key file to use for the TLS negotiation
17509 Defaults to @samp{""}.
17513 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
17514 PEM-formatted certificate file to use for the TLS negotiation
17516 Defaults to @samp{""}.
17520 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
17521 CA certificates to use
17523 Defaults to @samp{""}.
17527 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
17528 Extra retriever parameters
17530 Defaults to @samp{()}.
17536 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
17537 What to do with retrieved messages.
17539 Available @code{getmail-destination-configuration} fields are:
17541 @deftypevr {@code{getmail-destination-configuration} parameter} string type
17542 The type of mail destination. Valid values include @samp{Maildir},
17543 @samp{Mboxrd} and @samp{MDA_external}.
17545 Defaults to @samp{unset}.
17549 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
17550 The path option for the mail destination. The behaviour depends on the
17553 Defaults to @samp{""}.
17557 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
17558 Extra destination parameters
17560 Defaults to @samp{()}.
17566 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
17569 Available @code{getmail-options-configuration} fields are:
17571 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
17572 If set to @samp{0}, getmail will only print warnings and errors. A
17573 value of @samp{1} means that messages will be printed about retrieving
17574 and deleting messages. If set to @samp{2}, getmail will print messages
17575 about each of it's actions.
17577 Defaults to @samp{1}.
17581 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
17582 If true, getmail will retrieve all available messages. Otherwise it
17583 will only retrieve messages it hasn't seen previously.
17585 Defaults to @samp{#t}.
17589 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
17590 If set to true, messages will be deleted from the server after
17591 retrieving and successfully delivering them. Otherwise, messages will
17592 be left on the server.
17594 Defaults to @samp{#f}.
17598 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
17599 Getmail will delete messages this number of days after seeing them, if
17600 they have been delivered. This means messages will be left on the
17601 server this number of days after delivering them. A value of @samp{0}
17602 disabled this feature.
17604 Defaults to @samp{0}.
17608 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
17609 Delete messages larger than this of bytes after retrieving them, even if
17610 the delete and delete-after options are disabled. A value of @samp{0}
17611 disables this feature.
17613 Defaults to @samp{0}.
17617 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
17618 Retrieve messages totalling up to this number of bytes before closing
17619 the session with the server. A value of @samp{0} disables this feature.
17621 Defaults to @samp{0}.
17625 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
17626 Don't retrieve messages larger than this number of bytes. A value of
17627 @samp{0} disables this feature.
17629 Defaults to @samp{0}.
17633 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
17634 If true, getmail will add a Delivered-To header to messages.
17636 Defaults to @samp{#t}.
17640 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
17641 If set, getmail adds a Received header to the messages.
17643 Defaults to @samp{#t}.
17647 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
17648 Getmail will record a log of its actions to the named file. A value of
17649 @samp{""} disables this feature.
17651 Defaults to @samp{""}.
17655 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
17656 If true, getmail will record a log of its actions using the system
17659 Defaults to @samp{#t}.
17663 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
17664 If true, getmail will log information about messages not retrieved and
17665 the reason for not retrieving them, as well as starting and ending
17668 Defaults to @samp{#t}.
17672 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
17673 Extra options to include.
17675 Defaults to @samp{()}.
17683 @deftypevr {@code{getmail-configuration} parameter} list idle
17684 A list of mailboxes that getmail should wait on the server for new mail
17685 notifications. This depends on the server supporting the IDLE
17688 Defaults to @samp{()}.
17692 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
17693 Environment variables to set for getmail.
17695 Defaults to @samp{()}.
17699 @subsubheading Mail Aliases Service
17701 @cindex email aliases
17702 @cindex aliases, for email addresses
17704 @deffn {Scheme Variable} mail-aliases-service-type
17705 This is the type of the service which provides @code{/etc/aliases},
17706 specifying how to deliver mail to users on this system.
17709 (service mail-aliases-service-type
17710 '(("postmaster" "bob")
17711 ("bob" "bob@@example.com" "bob@@example2.com")))
17715 The configuration for a @code{mail-aliases-service-type} service is an
17716 association list denoting how to deliver mail that comes to this
17717 system. Each entry is of the form @code{(alias addresses ...)}, with
17718 @code{alias} specifying the local alias and @code{addresses} specifying
17719 where to deliver this user's mail.
17721 The aliases aren't required to exist as users on the local system. In
17722 the above example, there doesn't need to be a @code{postmaster} entry in
17723 the @code{operating-system}'s @code{user-accounts} in order to deliver
17724 the @code{postmaster} mail to @code{bob} (which subsequently would
17725 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
17727 @subsubheading GNU Mailutils IMAP4 Daemon
17728 @cindex GNU Mailutils IMAP4 Daemon
17730 @deffn {Scheme Variable} imap4d-service-type
17731 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
17732 mailutils, GNU Mailutils Manual}), whose value should be an
17733 @code{imap4d-configuration} object as in this example:
17736 (service imap4d-service-type
17737 (imap4d-configuration
17738 (config-file (local-file "imap4d.conf"))))
17742 @deftp {Data Type} imap4d-configuration
17743 Data type representing the configuration of @command{imap4d}.
17746 @item @code{package} (default: @code{mailutils})
17747 The package that provides @command{imap4d}.
17749 @item @code{config-file} (default: @code{%default-imap4d-config-file})
17750 File-like object of the configuration file to use, by default it will listen
17751 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
17752 Mailutils Manual}, for details.
17757 @node Messaging Services
17758 @subsection Messaging Services
17763 The @code{(gnu services messaging)} module provides Guix service
17764 definitions for messaging services: currently only Prosody is supported.
17766 @subsubheading Prosody Service
17768 @deffn {Scheme Variable} prosody-service-type
17769 This is the type for the @uref{https://prosody.im, Prosody XMPP
17770 communication server}. Its value must be a @code{prosody-configuration}
17771 record as in this example:
17774 (service prosody-service-type
17775 (prosody-configuration
17776 (modules-enabled (cons "groups" "mam" %default-modules-enabled))
17779 (int-component-configuration
17780 (hostname "conference.example.net")
17782 (mod-muc (mod-muc-configuration)))))
17785 (virtualhost-configuration
17786 (domain "example.net"))))))
17789 See below for details about @code{prosody-configuration}.
17793 By default, Prosody does not need much configuration. Only one
17794 @code{virtualhosts} field is needed: it specifies the domain you wish
17797 You can perform various sanity checks on the generated configuration
17798 with the @code{prosodyctl check} command.
17800 Prosodyctl will also help you to import certificates from the
17801 @code{letsencrypt} directory so that the @code{prosody} user can access
17802 them. See @url{https://prosody.im/doc/letsencrypt}.
17805 prosodyctl --root cert import /etc/letsencrypt/live
17808 The available configuration parameters follow. Each parameter
17809 definition is preceded by its type; for example, @samp{string-list foo}
17810 indicates that the @code{foo} parameter should be specified as a list of
17811 strings. Types starting with @code{maybe-} denote parameters that won't
17812 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
17814 There is also a way to specify the configuration as a string, if you
17815 have an old @code{prosody.cfg.lua} file that you want to port over from
17816 some other system; see the end for more details.
17818 The @code{file-object} type designates either a file-like object
17819 (@pxref{G-Expressions, file-like objects}) or a file name.
17821 @c The following documentation was initially generated by
17822 @c (generate-documentation) in (gnu services messaging). Manually maintained
17823 @c documentation is better, so we shouldn't hesitate to edit below as
17824 @c needed. However if the change you want to make to this documentation
17825 @c can be done in an automated way, it's probably easier to change
17826 @c (generate-documentation) than to make it below and have to deal with
17827 @c the churn as Prosody updates.
17829 Available @code{prosody-configuration} fields are:
17831 @deftypevr {@code{prosody-configuration} parameter} package prosody
17832 The Prosody package.
17835 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
17836 Location of the Prosody data storage directory. See
17837 @url{https://prosody.im/doc/configure}.
17838 Defaults to @samp{"/var/lib/prosody"}.
17841 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
17842 Additional plugin directories. They are searched in all the specified
17843 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
17844 Defaults to @samp{()}.
17847 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
17848 Every virtual host and component needs a certificate so that clients and
17849 servers can securely verify its identity. Prosody will automatically load
17850 certificates/keys from the directory specified here.
17851 Defaults to @samp{"/etc/prosody/certs"}.
17854 @deftypevr {@code{prosody-configuration} parameter} string-list admins
17855 This is a list of accounts that are admins for the server. Note that you
17856 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
17857 @url{https://prosody.im/doc/creating_accounts}.
17858 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
17859 Defaults to @samp{()}.
17862 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
17863 Enable use of libevent for better performance under high load. See
17864 @url{https://prosody.im/doc/libevent}.
17865 Defaults to @samp{#f}.
17868 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
17869 This is the list of modules Prosody will load on startup. It looks for
17870 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
17871 Documentation on modules can be found at:
17872 @url{https://prosody.im/doc/modules}.
17873 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
17876 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
17877 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
17878 should you want to disable them then add them to this list.
17879 Defaults to @samp{()}.
17882 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
17883 Path to a text file where the shared groups are defined. If this path is
17884 empty then @samp{mod_groups} does nothing. See
17885 @url{https://prosody.im/doc/modules/mod_groups}.
17886 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
17889 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
17890 Disable account creation by default, for security. See
17891 @url{https://prosody.im/doc/creating_accounts}.
17892 Defaults to @samp{#f}.
17895 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
17896 These are the SSL/TLS-related settings. Most of them are disabled so to
17897 use Prosody's defaults. If you do not completely understand these options, do
17898 not add them to your config, it is easy to lower the security of your server
17899 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
17901 Available @code{ssl-configuration} fields are:
17903 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
17904 This determines what handshake to use.
17907 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
17908 Path to your private key file.
17911 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
17912 Path to your certificate file.
17915 @deftypevr {@code{ssl-configuration} parameter} file-object capath
17916 Path to directory containing root certificates that you wish Prosody to
17917 trust when verifying the certificates of remote servers.
17918 Defaults to @samp{"/etc/ssl/certs"}.
17921 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
17922 Path to a file containing root certificates that you wish Prosody to trust.
17923 Similar to @code{capath} but with all certificates concatenated together.
17926 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
17927 A list of verification options (these mostly map to OpenSSL's
17928 @code{set_verify()} flags).
17931 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
17932 A list of general options relating to SSL/TLS. These map to OpenSSL's
17933 @code{set_options()}. For a full list of options available in LuaSec, see the
17937 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
17938 How long a chain of certificate authorities to check when looking for a
17939 trusted root certificate.
17942 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
17943 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
17944 clients, and in what order.
17947 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
17948 A path to a file containing parameters for Diffie-Hellman key exchange. You
17949 can create such a file with:
17950 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
17953 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
17954 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
17955 @samp{"secp384r1"}.
17958 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
17959 A list of "extra" verification options.
17962 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
17963 Password for encrypted private keys.
17968 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
17969 Whether to force all client-to-server connections to be encrypted or not.
17970 See @url{https://prosody.im/doc/modules/mod_tls}.
17971 Defaults to @samp{#f}.
17974 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
17975 Set of mechanisms that will never be offered. See
17976 @url{https://prosody.im/doc/modules/mod_saslauth}.
17977 Defaults to @samp{("DIGEST-MD5")}.
17980 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
17981 Whether to force all server-to-server connections to be encrypted or not.
17982 See @url{https://prosody.im/doc/modules/mod_tls}.
17983 Defaults to @samp{#f}.
17986 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
17987 Whether to require encryption and certificate authentication. This
17988 provides ideal security, but requires servers you communicate with to support
17989 encryption AND present valid, trusted certificates. See
17990 @url{https://prosody.im/doc/s2s#security}.
17991 Defaults to @samp{#f}.
17994 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
17995 Many servers don't support encryption or have invalid or self-signed
17996 certificates. You can list domains here that will not be required to
17997 authenticate using certificates. They will be authenticated using DNS. See
17998 @url{https://prosody.im/doc/s2s#security}.
17999 Defaults to @samp{()}.
18002 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
18003 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
18004 valid certificates for some domains by specifying a list here. See
18005 @url{https://prosody.im/doc/s2s#security}.
18006 Defaults to @samp{()}.
18009 @deftypevr {@code{prosody-configuration} parameter} string authentication
18010 Select the authentication backend to use. The default provider stores
18011 passwords in plaintext and uses Prosody's configured data storage to store the
18012 authentication data. If you do not trust your server please see
18013 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
18014 about using the hashed backend. See also
18015 @url{https://prosody.im/doc/authentication}
18016 Defaults to @samp{"internal_plain"}.
18019 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
18020 Set logging options. Advanced logging configuration is not yet supported
18021 by the Prosody service. See @url{https://prosody.im/doc/logging}.
18022 Defaults to @samp{"*syslog"}.
18025 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
18026 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
18027 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
18030 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
18031 Maximum allowed size of the HTTP body (in bytes).
18034 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
18035 Some modules expose their own URL in various ways. This URL is built
18036 from the protocol, host and port used. If Prosody sits behind a proxy, the
18037 public URL will be @code{http-external-url} instead. See
18038 @url{https://prosody.im/doc/http#external_url}.
18041 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
18042 A host in Prosody is a domain on which user accounts can be created. For
18043 example if you want your users to have addresses like
18044 @samp{"john.smith@@example.com"} then you need to add a host
18045 @samp{"example.com"}. All options in this list will apply only to this host.
18047 Note: the name "virtual" host is used in configuration to avoid confusion with
18048 the actual physical host that Prosody is installed on. A single Prosody
18049 instance can serve many domains, each one defined as a VirtualHost entry in
18050 Prosody's configuration. Conversely a server that hosts a single domain would
18051 have just one VirtualHost entry.
18053 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
18055 Available @code{virtualhost-configuration} fields are:
18057 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:
18058 @deftypevr {@code{virtualhost-configuration} parameter} string domain
18059 Domain you wish Prosody to serve.
18064 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
18065 Components are extra services on a server which are available to clients,
18066 usually on a subdomain of the main server (such as
18067 @samp{"mycomponent.example.com"}). Example components might be chatroom
18068 servers, user directories, or gateways to other protocols.
18070 Internal components are implemented with Prosody-specific plugins. To add an
18071 internal component, you simply fill the hostname field, and the plugin you wish
18072 to use for the component.
18074 See @url{https://prosody.im/doc/components}.
18075 Defaults to @samp{()}.
18077 Available @code{int-component-configuration} fields are:
18079 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:
18080 @deftypevr {@code{int-component-configuration} parameter} string hostname
18081 Hostname of the component.
18084 @deftypevr {@code{int-component-configuration} parameter} string plugin
18085 Plugin you wish to use for the component.
18088 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
18089 Multi-user chat (MUC) is Prosody's module for allowing you to create
18090 hosted chatrooms/conferences for XMPP users.
18092 General information on setting up and using multi-user chatrooms can be found
18093 in the "Chatrooms" documentation (@url{https://prosody.im/doc/chatrooms}),
18094 which you should read if you are new to XMPP chatrooms.
18096 See also @url{https://prosody.im/doc/modules/mod_muc}.
18098 Available @code{mod-muc-configuration} fields are:
18100 @deftypevr {@code{mod-muc-configuration} parameter} string name
18101 The name to return in service discovery responses.
18102 Defaults to @samp{"Prosody Chatrooms"}.
18105 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
18106 If @samp{#t}, this will only allow admins to create new chatrooms.
18107 Otherwise anyone can create a room. The value @samp{"local"} restricts room
18108 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
18109 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
18110 restricts to service administrators only.
18111 Defaults to @samp{#f}.
18114 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
18115 Maximum number of history messages that will be sent to the member that has
18116 just joined the room.
18117 Defaults to @samp{20}.
18124 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
18125 External components use XEP-0114, which most standalone components
18126 support. To add an external component, you simply fill the hostname field. See
18127 @url{https://prosody.im/doc/components}.
18128 Defaults to @samp{()}.
18130 Available @code{ext-component-configuration} fields are:
18132 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:
18133 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
18134 Password which the component will use to log in.
18137 @deftypevr {@code{ext-component-configuration} parameter} string hostname
18138 Hostname of the component.
18143 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
18144 Port(s) Prosody listens on for component connections.
18145 Defaults to @samp{(5347)}.
18148 @deftypevr {@code{prosody-configuration} parameter} string component-interface
18149 Interface Prosody listens on for component connections.
18150 Defaults to @samp{"127.0.0.1"}.
18153 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
18154 Raw content that will be added to the configuration file.
18157 It could be that you just want to get a @code{prosody.cfg.lua}
18158 up and running. In that case, you can pass an
18159 @code{opaque-prosody-configuration} record as the value of
18160 @code{prosody-service-type}. As its name indicates, an opaque configuration
18161 does not have easy reflective capabilities.
18162 Available @code{opaque-prosody-configuration} fields are:
18164 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
18165 The prosody package.
18168 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
18169 The contents of the @code{prosody.cfg.lua} to use.
18172 For example, if your @code{prosody.cfg.lua} is just the empty
18173 string, you could instantiate a prosody service like this:
18176 (service prosody-service-type
18177 (opaque-prosody-configuration
18178 (prosody.cfg.lua "")))
18181 @c end of Prosody auto-generated documentation
18183 @subsubheading BitlBee Service
18185 @cindex IRC (Internet Relay Chat)
18186 @cindex IRC gateway
18187 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
18188 interface to a variety of messaging protocols such as XMPP.
18190 @defvr {Scheme Variable} bitlbee-service-type
18191 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
18192 gateway daemon. Its value is a @code{bitlbee-configuration} (see
18195 To have BitlBee listen on port 6667 on localhost, add this line to your
18199 (service bitlbee-service-type)
18203 @deftp {Data Type} bitlbee-configuration
18204 This is the configuration for BitlBee, with the following fields:
18207 @item @code{interface} (default: @code{"127.0.0.1"})
18208 @itemx @code{port} (default: @code{6667})
18209 Listen on the network interface corresponding to the IP address
18210 specified in @var{interface}, on @var{port}.
18212 When @var{interface} is @code{127.0.0.1}, only local clients can
18213 connect; when it is @code{0.0.0.0}, connections can come from any
18214 networking interface.
18216 @item @code{package} (default: @code{bitlbee})
18217 The BitlBee package to use.
18219 @item @code{plugins} (default: @code{'()})
18220 List of plugin packages to use---e.g., @code{bitlbee-discord}.
18222 @item @code{extra-settings} (default: @code{""})
18223 Configuration snippet added as-is to the BitlBee configuration file.
18227 @subsubheading Quassel Service
18229 @cindex IRC (Internet Relay Chat)
18230 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
18231 meaning that one or more clients can attach to and detach from the
18234 @defvr {Scheme Variable} quassel-service-type
18235 This is the service type for the @url{https://quassel-irc.org/,Quassel}
18236 IRC backend daemon. Its value is a @code{quassel-configuration}
18240 @deftp {Data Type} quassel-configuration
18241 This is the configuration for Quassel, with the following fields:
18244 @item @code{quassel} (default: @code{quassel})
18245 The Quassel package to use.
18247 @item @code{interface} (default: @code{"::,0.0.0.0"})
18248 @item @code{port} (default: @code{4242})
18249 Listen on the network interface(s) corresponding to the IPv4 or IPv6
18250 interfaces specified in the comma delimited @var{interface}, on
18253 @item @code{loglevel} (default: @code{"Info"})
18254 The level of logging desired. Accepted values are Debug, Info, Warning
18259 @node Telephony Services
18260 @subsection Telephony Services
18262 @cindex Murmur (VoIP server)
18263 @cindex VoIP server
18264 This section describes how to set up and run a Murmur server. Murmur is
18265 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
18268 @deftp {Data Type} murmur-configuration
18269 The service type for the Murmur server. An example configuration can
18273 (service murmur-service-type
18274 (murmur-configuration
18276 "Welcome to this Mumble server running on Guix!")
18277 (cert-required? #t) ;disallow text password logins
18278 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
18279 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
18282 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
18283 password with the command that is printed during the activation phase.
18285 It is recommended to register a normal Mumble user account
18286 and grant it admin or moderator rights.
18287 You can use the @code{mumble} client to
18288 login as new normal user, register yourself, and log out.
18289 For the next step login with the name @code{SuperUser} use
18290 the @code{SuperUser} password that you set previously,
18291 and grant your newly registered mumble user administrator or moderator
18292 rights and create some channels.
18294 Available @code{murmur-configuration} fields are:
18297 @item @code{package} (default: @code{mumble})
18298 Package that contains @code{bin/murmurd}.
18300 @item @code{user} (default: @code{"murmur"})
18301 User who will run the Murmur server.
18303 @item @code{group} (default: @code{"murmur"})
18304 Group of the user who will run the murmur server.
18306 @item @code{port} (default: @code{64738})
18307 Port on which the server will listen.
18309 @item @code{welcome-text} (default: @code{""})
18310 Welcome text sent to clients when they connect.
18312 @item @code{server-password} (default: @code{""})
18313 Password the clients have to enter in order to connect.
18315 @item @code{max-users} (default: @code{100})
18316 Maximum of users that can be connected to the server at once.
18318 @item @code{max-user-bandwidth} (default: @code{#f})
18319 Maximum voice traffic a user can send per second.
18321 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
18322 File name of the sqlite database.
18323 The service's user will become the owner of the directory.
18325 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
18326 File name of the log file.
18327 The service's user will become the owner of the directory.
18329 @item @code{autoban-attempts} (default: @code{10})
18330 Maximum number of logins a user can make in @code{autoban-timeframe}
18331 without getting auto banned for @code{autoban-time}.
18333 @item @code{autoban-timeframe} (default: @code{120})
18334 Timeframe for autoban in seconds.
18336 @item @code{autoban-time} (default: @code{300})
18337 Amount of time in seconds for which a client gets banned
18338 when violating the autoban limits.
18340 @item @code{opus-threshold} (default: @code{100})
18341 Percentage of clients that need to support opus
18342 before switching over to opus audio codec.
18344 @item @code{channel-nesting-limit} (default: @code{10})
18345 How deep channels can be nested at maximum.
18347 @item @code{channelname-regex} (default: @code{#f})
18348 A string in form of a Qt regular expression that channel names must conform to.
18350 @item @code{username-regex} (default: @code{#f})
18351 A string in form of a Qt regular expression that user names must conform to.
18353 @item @code{text-message-length} (default: @code{5000})
18354 Maximum size in bytes that a user can send in one text chat message.
18356 @item @code{image-message-length} (default: @code{(* 128 1024)})
18357 Maximum size in bytes that a user can send in one image message.
18359 @item @code{cert-required?} (default: @code{#f})
18360 If it is set to @code{#t} clients that use weak password authentication
18361 will not be accepted. Users must have completed the certificate wizard to join.
18363 @item @code{remember-channel?} (default: @code{#f})
18364 Should murmur remember the last channel each user was in when they disconnected
18365 and put them into the remembered channel when they rejoin.
18367 @item @code{allow-html?} (default: @code{#f})
18368 Should html be allowed in text messages, user comments, and channel descriptions.
18370 @item @code{allow-ping?} (default: @code{#f})
18371 Setting to true exposes the current user count, the maximum user count, and
18372 the server's maximum bandwidth per client to unauthenticated users. In the
18373 Mumble client, this information is shown in the Connect dialog.
18375 Disabling this setting will prevent public listing of the server.
18377 @item @code{bonjour?} (default: @code{#f})
18378 Should the server advertise itself in the local network through the bonjour protocol.
18380 @item @code{send-version?} (default: @code{#f})
18381 Should the murmur server version be exposed in ping requests.
18383 @item @code{log-days} (default: @code{31})
18384 Murmur also stores logs in the database, which are accessible via RPC.
18385 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
18386 or -1 to disable logging to the database.
18388 @item @code{obfuscate-ips?} (default: @code{#t})
18389 Should logged ips be obfuscated to protect the privacy of users.
18391 @item @code{ssl-cert} (default: @code{#f})
18392 File name of the SSL/TLS certificate used for encrypted connections.
18395 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
18397 @item @code{ssl-key} (default: @code{#f})
18398 Filepath to the ssl private key used for encrypted connections.
18400 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
18403 @item @code{ssl-dh-params} (default: @code{#f})
18404 File name of a PEM-encoded file with Diffie-Hellman parameters
18405 for the SSL/TLS encryption. Alternatively you set it to
18406 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
18407 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
18409 @item @code{ssl-ciphers} (default: @code{#f})
18410 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
18413 This option is specified using
18414 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
18415 OpenSSL cipher list notation}.
18417 It is recommended that you try your cipher string using 'openssl ciphers <string>'
18418 before setting it here, to get a feel for which cipher suites you will get.
18419 After setting this option, it is recommend that you inspect your Murmur log
18420 to ensure that Murmur is using the cipher suites that you expected it to.
18422 Note: Changing this option may impact the backwards compatibility of your
18423 Murmur server, and can remove the ability for older Mumble clients to be able
18426 @item @code{public-registration} (default: @code{#f})
18427 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
18429 You can optionally register your server in the public server list that the
18430 @code{mumble} client shows on startup.
18431 You cannot register your server if you have set a @code{server-password},
18432 or set @code{allow-ping} to @code{#f}.
18434 It might take a few hours until it shows up in the public list.
18436 @item @code{file} (default: @code{#f})
18437 Optional alternative override for this configuration.
18441 @deftp {Data Type} murmur-public-registration-configuration
18442 Configuration for public registration of a murmur service.
18446 This is a display name for your server. Not to be confused with the hostname.
18448 @item @code{password}
18449 A password to identify your registration.
18450 Subsequent updates will need the same password. Don't lose your password.
18453 This should be a @code{http://} or @code{https://} link to your web
18456 @item @code{hostname} (default: @code{#f})
18457 By default your server will be listed by its IP address.
18458 If it is set your server will be linked by this host name instead.
18464 @node Monitoring Services
18465 @subsection Monitoring Services
18467 @subsubheading Tailon Service
18469 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
18470 viewing and searching log files.
18472 The following example will configure the service with default values.
18473 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
18476 (service tailon-service-type)
18479 The following example customises more of the Tailon configuration,
18480 adding @command{sed} to the list of allowed commands.
18483 (service tailon-service-type
18484 (tailon-configuration
18486 (tailon-configuration-file
18487 (allowed-commands '("tail" "grep" "awk" "sed"))))))
18491 @deftp {Data Type} tailon-configuration
18492 Data type representing the configuration of Tailon.
18493 This type has the following parameters:
18496 @item @code{config-file} (default: @code{(tailon-configuration-file)})
18497 The configuration file to use for Tailon. This can be set to a
18498 @dfn{tailon-configuration-file} record value, or any gexp
18499 (@pxref{G-Expressions}).
18501 For example, to instead use a local file, the @code{local-file} function
18505 (service tailon-service-type
18506 (tailon-configuration
18507 (config-file (local-file "./my-tailon.conf"))))
18510 @item @code{package} (default: @code{tailon})
18511 The tailon package to use.
18516 @deftp {Data Type} tailon-configuration-file
18517 Data type representing the configuration options for Tailon.
18518 This type has the following parameters:
18521 @item @code{files} (default: @code{(list "/var/log")})
18522 List of files to display. The list can include strings for a single file
18523 or directory, or a list, where the first item is the name of a
18524 subsection, and the remaining items are the files or directories in that
18527 @item @code{bind} (default: @code{"localhost:8080"})
18528 Address and port to which Tailon should bind on.
18530 @item @code{relative-root} (default: @code{#f})
18531 URL path to use for Tailon, set to @code{#f} to not use a path.
18533 @item @code{allow-transfers?} (default: @code{#t})
18534 Allow downloading the log files in the web interface.
18536 @item @code{follow-names?} (default: @code{#t})
18537 Allow tailing of not-yet existent files.
18539 @item @code{tail-lines} (default: @code{200})
18540 Number of lines to read initially from each file.
18542 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
18543 Commands to allow running. By default, @code{sed} is disabled.
18545 @item @code{debug?} (default: @code{#f})
18546 Set @code{debug?} to @code{#t} to show debug messages.
18548 @item @code{wrap-lines} (default: @code{#t})
18549 Initial line wrapping state in the web interface. Set to @code{#t} to
18550 initially wrap lines (the default), or to @code{#f} to initially not
18553 @item @code{http-auth} (default: @code{#f})
18554 HTTP authentication type to use. Set to @code{#f} to disable
18555 authentication (the default). Supported values are @code{"digest"} or
18558 @item @code{users} (default: @code{#f})
18559 If HTTP authentication is enabled (see @code{http-auth}), access will be
18560 restricted to the credentials provided here. To configure users, use a
18561 list of pairs, where the first element of the pair is the username, and
18562 the 2nd element of the pair is the password.
18565 (tailon-configuration-file
18566 (http-auth "basic")
18567 (users '(("user1" . "password1")
18568 ("user2" . "password2"))))
18575 @subsubheading Darkstat Service
18577 Darkstat is a packet sniffer that captures network traffic, calculates
18578 statistics about usage, and serves reports over HTTP.
18580 @defvar {Scheme Variable} darkstat-service-type
18581 This is the service type for the
18582 @uref{https://unix4lyfe.org/darkstat/, darkstat}
18583 service, its value must be a @code{darkstat-configuration} record as in
18587 (service darkstat-service-type
18588 (darkstat-configuration
18589 (interface "eno1")))
18593 @deftp {Data Type} darkstat-configuration
18594 Data type representing the configuration of @command{darkstat}.
18597 @item @code{package} (default: @code{darkstat})
18598 The darkstat package to use.
18600 @item @code{interface}
18601 Capture traffic on the specified network interface.
18603 @item @code{port} (default: @code{"667"})
18604 Bind the web interface to the specified port.
18606 @item @code{bind-address} (default: @code{"127.0.0.1"})
18607 Bind the web interface to the specified address.
18609 @item @code{base} (default: @code{"/"})
18610 Specify the path of the base URL. This can be useful if
18611 @command{darkstat} is accessed via a reverse proxy.
18616 @subsubheading Prometheus Node Exporter Service
18618 @cindex prometheus-node-exporter
18619 The Prometheus ``node exporter'' makes hardware and operating system statistics
18620 provided by the Linux kernel available for the Prometheus monitoring system.
18621 This service should be deployed on all physical nodes and virtual machines,
18622 where monitoring these statistics is desirable.
18624 @defvar {Scheme variable} prometheus-node-exporter-service-type
18625 This is the service type for the
18626 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
18627 service, its value must be a @code{prometheus-node-exporter-configuration}
18628 record as in this example:
18631 (service prometheus-node-exporter-service-type
18632 (prometheus-node-exporter-configuration
18633 (web-listen-address ":9100")))
18637 @deftp {Data Type} prometheus-node-exporter-configuration
18638 Data type representing the configuration of @command{node_exporter}.
18641 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
18642 The prometheus-node-exporter package to use.
18644 @item @code{web-listen-address} (default: @code{":9100"})
18645 Bind the web interface to the specified address.
18650 @subsubheading Zabbix server
18651 @cindex zabbix zabbix-server
18652 Zabbix provides monitoring metrics, among others network utilization, CPU load
18653 and disk space consumption:
18656 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
18657 @item Auto-discovery of servers and network devices and interfaces.
18658 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
18659 @item Distributed monitoring with centralized web administration.
18660 @item Native high performance agents.
18661 @item SLA, and ITIL KPI metrics on reporting.
18662 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
18663 @item Remote command execution through Zabbix proxies.
18666 @c %start of fragment
18668 Available @code{zabbix-server-configuration} fields are:
18670 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
18671 The zabbix-server package.
18675 @deftypevr {@code{zabbix-server-configuration} parameter} string user
18676 User who will run the Zabbix server.
18678 Defaults to @samp{"zabbix"}.
18682 @deftypevr {@code{zabbix-server-configuration} parameter} group group
18683 Group who will run the Zabbix server.
18685 Defaults to @samp{"zabbix"}.
18689 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
18690 Database host name.
18692 Defaults to @samp{"127.0.0.1"}.
18696 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
18699 Defaults to @samp{"zabbix"}.
18703 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
18706 Defaults to @samp{"zabbix"}.
18710 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
18711 Database password. Please, use @code{include-files} with
18712 @code{DBPassword=SECRET} inside a specified file instead.
18714 Defaults to @samp{""}.
18718 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
18721 Defaults to @samp{5432}.
18725 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
18726 Specifies where log messages are written to:
18730 @code{system} - syslog.
18733 @code{file} - file specified with @code{log-file} parameter.
18736 @code{console} - standard output.
18740 Defaults to @samp{""}.
18744 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
18745 Log file name for @code{log-type} @code{file} parameter.
18747 Defaults to @samp{"/var/log/zabbix/server.log"}.
18751 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
18754 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
18758 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
18759 The location of certificate authority (CA) files for SSL server
18760 certificate verification.
18762 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
18766 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
18767 Location of SSL client certificates.
18769 Defaults to @samp{"/etc/ssl/certs"}.
18773 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
18774 Extra options will be appended to Zabbix server configuration file.
18776 Defaults to @samp{""}.
18780 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
18781 You may include individual files or all files in a directory in the
18782 configuration file.
18784 Defaults to @samp{()}.
18788 @c %end of fragment
18790 @subsubheading Zabbix agent
18791 @cindex zabbix zabbix-agent
18793 Zabbix agent gathers information for Zabbix server.
18795 @c %start of fragment
18797 Available @code{zabbix-agent-configuration} fields are:
18799 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
18800 The zabbix-agent package.
18804 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
18805 User who will run the Zabbix agent.
18807 Defaults to @samp{"zabbix"}.
18811 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
18812 Group who will run the Zabbix agent.
18814 Defaults to @samp{"zabbix"}.
18818 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
18819 Unique, case sensitive hostname which is required for active checks and
18820 must match hostname as configured on the server.
18822 Defaults to @samp{"Zabbix server"}.
18826 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
18827 Specifies where log messages are written to:
18831 @code{system} - syslog.
18834 @code{file} - file specified with @code{log-file} parameter.
18837 @code{console} - standard output.
18841 Defaults to @samp{""}.
18845 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
18846 Log file name for @code{log-type} @code{file} parameter.
18848 Defaults to @samp{"/var/log/zabbix/agent.log"}.
18852 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
18855 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
18859 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
18860 List of IP addresses, optionally in CIDR notation, or hostnames of
18861 Zabbix servers and Zabbix proxies. Incoming connections will be
18862 accepted only from the hosts listed here.
18864 Defaults to @samp{("127.0.0.1")}.
18868 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
18869 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
18870 proxies for active checks. If port is not specified, default port is
18871 used. If this parameter is not specified, active checks are disabled.
18873 Defaults to @samp{("127.0.0.1")}.
18877 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
18878 Extra options will be appended to Zabbix server configuration file.
18880 Defaults to @samp{""}.
18884 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
18885 You may include individual files or all files in a directory in the
18886 configuration file.
18888 Defaults to @samp{()}.
18892 @c %end of fragment
18894 @subsubheading Zabbix front-end
18895 @cindex zabbix zabbix-front-end
18897 This service provides a WEB interface to Zabbix server.
18899 @c %start of fragment
18901 Available @code{zabbix-front-end-configuration} fields are:
18903 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
18904 NGINX configuration.
18908 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
18909 Database host name.
18911 Defaults to @samp{"localhost"}.
18915 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
18918 Defaults to @samp{5432}.
18922 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
18925 Defaults to @samp{"zabbix"}.
18929 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
18932 Defaults to @samp{"zabbix"}.
18936 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
18937 Database password. Please, use @code{db-secret-file} instead.
18939 Defaults to @samp{""}.
18943 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
18944 Secret file which will be appended to @file{zabbix.conf.php} file. This
18945 file contains credentials for use by Zabbix front-end. You are expected
18946 to create it manually.
18948 Defaults to @samp{""}.
18952 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
18953 Zabbix server hostname.
18955 Defaults to @samp{"localhost"}.
18959 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
18960 Zabbix server port.
18962 Defaults to @samp{10051}.
18967 @c %end of fragment
18969 @node Kerberos Services
18970 @subsection Kerberos Services
18973 The @code{(gnu services kerberos)} module provides services relating to
18974 the authentication protocol @dfn{Kerberos}.
18976 @subsubheading Krb5 Service
18978 Programs using a Kerberos client library normally
18979 expect a configuration file in @file{/etc/krb5.conf}.
18980 This service generates such a file from a definition provided in the
18981 operating system declaration.
18982 It does not cause any daemon to be started.
18984 No ``keytab'' files are provided by this service---you must explicitly create them.
18985 This service is known to work with the MIT client library, @code{mit-krb5}.
18986 Other implementations have not been tested.
18988 @defvr {Scheme Variable} krb5-service-type
18989 A service type for Kerberos 5 clients.
18993 Here is an example of its use:
18995 (service krb5-service-type
18996 (krb5-configuration
18997 (default-realm "EXAMPLE.COM")
18998 (allow-weak-crypto? #t)
19001 (name "EXAMPLE.COM")
19002 (admin-server "groucho.example.com")
19003 (kdc "karl.example.com"))
19006 (admin-server "kerb-admin.argrx.edu")
19007 (kdc "keys.argrx.edu"))))))
19011 This example provides a Kerberos@tie{}5 client configuration which:
19013 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
19014 of which have distinct administration servers and key distribution centers;
19015 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
19016 specified by clients;
19017 @item Accepts services which only support encryption types known to be weak.
19020 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
19021 Only the most commonly used ones are described here.
19022 For a full list, and more detailed explanation of each, see the MIT
19023 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
19027 @deftp {Data Type} krb5-realm
19028 @cindex realm, kerberos
19031 This field is a string identifying the name of the realm.
19032 A common convention is to use the fully qualified DNS name of your organization,
19033 converted to upper case.
19035 @item @code{admin-server}
19036 This field is a string identifying the host where the administration server is
19040 This field is a string identifying the key distribution center
19045 @deftp {Data Type} krb5-configuration
19048 @item @code{allow-weak-crypto?} (default: @code{#f})
19049 If this flag is @code{#t} then services which only offer encryption algorithms
19050 known to be weak will be accepted.
19052 @item @code{default-realm} (default: @code{#f})
19053 This field should be a string identifying the default Kerberos
19054 realm for the client.
19055 You should set this field to the name of your Kerberos realm.
19056 If this value is @code{#f}
19057 then a realm must be specified with every Kerberos principal when invoking programs
19058 such as @command{kinit}.
19060 @item @code{realms}
19061 This should be a non-empty list of @code{krb5-realm} objects, which clients may
19063 Normally, one of them will have a @code{name} field matching the @code{default-realm}
19069 @subsubheading PAM krb5 Service
19072 The @code{pam-krb5} service allows for login authentication and password
19073 management via Kerberos.
19074 You will need this service if you want PAM enabled applications to authenticate
19075 users using Kerberos.
19077 @defvr {Scheme Variable} pam-krb5-service-type
19078 A service type for the Kerberos 5 PAM module.
19081 @deftp {Data Type} pam-krb5-configuration
19082 Data type representing the configuration of the Kerberos 5 PAM module.
19083 This type has the following parameters:
19085 @item @code{pam-krb5} (default: @code{pam-krb5})
19086 The pam-krb5 package to use.
19088 @item @code{minimum-uid} (default: @code{1000})
19089 The smallest user ID for which Kerberos authentications should be attempted.
19090 Local accounts with lower values will silently fail to authenticate.
19095 @node LDAP Services
19096 @subsection LDAP Services
19098 @cindex nslcd, LDAP service
19100 The @code{(gnu services authentication)} module provides the
19101 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
19102 server. In addition to configuring the service itself, you may want to add
19103 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
19104 Switch} for detailed information.
19106 Here is a simple operating system declaration with a default configuration of
19107 the @code{nslcd-service-type} and a Name Service Switch configuration that
19108 consults the @code{ldap} name service last:
19111 (use-service-modules authentication)
19112 (use-modules (gnu system nss))
19118 (service nslcd-service-type)
19119 (service dhcp-client-service-type)
19121 (name-service-switch
19122 (let ((services (list (name-service (name "db"))
19123 (name-service (name "files"))
19124 (name-service (name "ldap")))))
19125 (name-service-switch
19126 (inherit %mdns-host-lookup-nss)
19127 (password services)
19130 (netgroup services)
19131 (gshadow services)))))
19134 @c %start of generated documentation for nslcd-configuration
19136 Available @code{nslcd-configuration} fields are:
19138 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
19139 The @code{nss-pam-ldapd} package to use.
19143 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
19144 The number of threads to start that can handle requests and perform LDAP
19145 queries. Each thread opens a separate connection to the LDAP server.
19146 The default is to start 5 threads.
19148 Defaults to @samp{disabled}.
19152 @deftypevr {@code{nslcd-configuration} parameter} string uid
19153 This specifies the user id with which the daemon should be run.
19155 Defaults to @samp{"nslcd"}.
19159 @deftypevr {@code{nslcd-configuration} parameter} string gid
19160 This specifies the group id with which the daemon should be run.
19162 Defaults to @samp{"nslcd"}.
19166 @deftypevr {@code{nslcd-configuration} parameter} log-option log
19167 This option controls the way logging is done via a list containing
19168 SCHEME and LEVEL. The SCHEME argument may either be the symbols "none"
19169 or "syslog", or an absolute file name. The LEVEL argument is optional
19170 and specifies the log level. The log level may be one of the following
19171 symbols: "crit", "error", "warning", "notice", "info" or "debug". All
19172 messages with the specified log level or higher are logged.
19174 Defaults to @samp{("/var/log/nslcd" info)}.
19178 @deftypevr {@code{nslcd-configuration} parameter} list uri
19179 The list of LDAP server URIs. Normally, only the first server will be
19180 used with the following servers as fall-back.
19182 Defaults to @samp{("ldap://localhost:389/")}.
19186 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
19187 The version of the LDAP protocol to use. The default is to use the
19188 maximum version supported by the LDAP library.
19190 Defaults to @samp{disabled}.
19194 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
19195 Specifies the distinguished name with which to bind to the directory
19196 server for lookups. The default is to bind anonymously.
19198 Defaults to @samp{disabled}.
19202 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
19203 Specifies the credentials with which to bind. This option is only
19204 applicable when used with binddn.
19206 Defaults to @samp{disabled}.
19210 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
19211 Specifies the distinguished name to use when the root user tries to
19212 modify a user's password using the PAM module.
19214 Defaults to @samp{disabled}.
19218 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
19219 Specifies the credentials with which to bind if the root user tries to
19220 change a user's password. This option is only applicable when used with
19223 Defaults to @samp{disabled}.
19227 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
19228 Specifies the SASL mechanism to be used when performing SASL
19231 Defaults to @samp{disabled}.
19235 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
19236 Specifies the SASL realm to be used when performing SASL authentication.
19238 Defaults to @samp{disabled}.
19242 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
19243 Specifies the authentication identity to be used when performing SASL
19246 Defaults to @samp{disabled}.
19250 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
19251 Specifies the authorization identity to be used when performing SASL
19254 Defaults to @samp{disabled}.
19258 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
19259 Determines whether the LDAP server host name should be canonicalised. If
19260 this is enabled the LDAP library will do a reverse host name lookup. By
19261 default, it is left up to the LDAP library whether this check is
19264 Defaults to @samp{disabled}.
19268 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
19269 Set the name for the GSS-API Kerberos credentials cache.
19271 Defaults to @samp{disabled}.
19275 @deftypevr {@code{nslcd-configuration} parameter} string base
19276 The directory search base.
19278 Defaults to @samp{"dc=example,dc=com"}.
19282 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
19283 Specifies the search scope (subtree, onelevel, base or children). The
19284 default scope is subtree; base scope is almost never useful for name
19285 service lookups; children scope is not supported on all servers.
19287 Defaults to @samp{(subtree)}.
19291 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
19292 Specifies the policy for dereferencing aliases. The default policy is
19293 to never dereference aliases.
19295 Defaults to @samp{disabled}.
19299 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
19300 Specifies whether automatic referral chasing should be enabled. The
19301 default behaviour is to chase referrals.
19303 Defaults to @samp{disabled}.
19307 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
19308 This option allows for custom attributes to be looked up instead of the
19309 default RFC 2307 attributes. It is a list of maps, each consisting of
19310 the name of a map, the RFC 2307 attribute to match and the query
19311 expression for the attribute as it is available in the directory.
19313 Defaults to @samp{()}.
19317 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
19318 A list of filters consisting of the name of a map to which the filter
19319 applies and an LDAP search filter expression.
19321 Defaults to @samp{()}.
19325 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
19326 Specifies the time limit in seconds to use when connecting to the
19327 directory server. The default value is 10 seconds.
19329 Defaults to @samp{disabled}.
19333 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
19334 Specifies the time limit (in seconds) to wait for a response from the
19335 LDAP server. A value of zero, which is the default, is to wait
19336 indefinitely for searches to be completed.
19338 Defaults to @samp{disabled}.
19342 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
19343 Specifies the period if inactivity (in seconds) after which the con‐
19344 nection to the LDAP server will be closed. The default is not to time
19347 Defaults to @samp{disabled}.
19351 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
19352 Specifies the number of seconds to sleep when connecting to all LDAP
19353 servers fails. By default one second is waited between the first
19354 failure and the first retry.
19356 Defaults to @samp{disabled}.
19360 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
19361 Specifies the time after which the LDAP server is considered to be
19362 permanently unavailable. Once this time is reached retries will be done
19363 only once per this time period. The default value is 10 seconds.
19365 Defaults to @samp{disabled}.
19369 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
19370 Specifies whether to use SSL/TLS or not (the default is not to). If
19371 'start-tls is specified then StartTLS is used rather than raw LDAP over
19374 Defaults to @samp{disabled}.
19378 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
19379 Specifies what checks to perform on a server-supplied certificate. The
19380 meaning of the values is described in the ldap.conf(5) manual page.
19382 Defaults to @samp{disabled}.
19386 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
19387 Specifies the directory containing X.509 certificates for peer authen‐
19388 tication. This parameter is ignored when using GnuTLS.
19390 Defaults to @samp{disabled}.
19394 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
19395 Specifies the path to the X.509 certificate for peer authentication.
19397 Defaults to @samp{disabled}.
19401 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
19402 Specifies the path to an entropy source. This parameter is ignored when
19405 Defaults to @samp{disabled}.
19409 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
19410 Specifies the ciphers to use for TLS as a string.
19412 Defaults to @samp{disabled}.
19416 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
19417 Specifies the path to the file containing the local certificate for
19418 client TLS authentication.
19420 Defaults to @samp{disabled}.
19424 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
19425 Specifies the path to the file containing the private key for client TLS
19428 Defaults to @samp{disabled}.
19432 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
19433 Set this to a number greater than 0 to request paged results from the
19434 LDAP server in accordance with RFC2696. The default (0) is to not
19435 request paged results.
19437 Defaults to @samp{disabled}.
19441 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
19442 This option prevents group membership lookups through LDAP for the
19443 specified users. Alternatively, the value 'all-local may be used. With
19444 that value nslcd builds a full list of non-LDAP users on startup.
19446 Defaults to @samp{disabled}.
19450 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
19451 This option ensures that LDAP users with a numeric user id lower than
19452 the specified value are ignored.
19454 Defaults to @samp{disabled}.
19458 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
19459 This option specifies an offset that is added to all LDAP numeric user
19460 ids. This can be used to avoid user id collisions with local users.
19462 Defaults to @samp{disabled}.
19466 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
19467 This option specifies an offset that is added to all LDAP numeric group
19468 ids. This can be used to avoid user id collisions with local groups.
19470 Defaults to @samp{disabled}.
19474 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
19475 If this option is set, the member attribute of a group may point to
19476 another group. Members of nested groups are also returned in the higher
19477 level group and parent groups are returned when finding groups for a
19478 specific user. The default is not to perform extra searches for nested
19481 Defaults to @samp{disabled}.
19485 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
19486 If this option is set, the group member list is not retrieved when
19487 looking up groups. Lookups for finding which groups a user belongs to
19488 will remain functional so the user will likely still get the correct
19489 groups assigned on login.
19491 Defaults to @samp{disabled}.
19495 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
19496 If this option is set, functions which cause all user/group entries to
19497 be loaded from the directory will not succeed in doing so. This can
19498 dramatically reduce LDAP server load in situations where there are a
19499 great number of users and/or groups. This option is not recommended for
19500 most configurations.
19502 Defaults to @samp{disabled}.
19506 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
19507 This option can be used to specify how user and group names are verified
19508 within the system. This pattern is used to check all user and group
19509 names that are requested and returned from LDAP.
19511 Defaults to @samp{disabled}.
19515 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
19516 This specifies whether or not to perform searches using case-insensitive
19517 matching. Enabling this could open up the system to authorization
19518 bypass vulnerabilities and introduce nscd cache poisoning
19519 vulnerabilities which allow denial of service.
19521 Defaults to @samp{disabled}.
19525 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
19526 This option specifies whether password policy controls are requested and
19527 handled from the LDAP server when performing user authentication.
19529 Defaults to @samp{disabled}.
19533 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
19534 By default nslcd performs an LDAP search with the user's credentials
19535 after BIND (authentication) to ensure that the BIND operation was
19536 successful. The default search is a simple check to see if the user's
19537 DN exists. A search filter can be specified that will be used instead.
19538 It should return at least one entry.
19540 Defaults to @samp{disabled}.
19544 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
19545 This option allows flexible fine tuning of the authorisation check that
19546 should be performed. The search filter specified is executed and if any
19547 entries match, access is granted, otherwise access is denied.
19549 Defaults to @samp{disabled}.
19553 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
19554 If this option is set password modification using pam_ldap will be
19555 denied and the specified message will be presented to the user instead.
19556 The message can be used to direct the user to an alternative means of
19557 changing their password.
19559 Defaults to @samp{disabled}.
19563 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
19564 List of pam service names for which LDAP authentication should suffice.
19566 Defaults to @samp{()}.
19570 @c %end of generated documentation for nslcd-configuration
19574 @subsection Web Services
19579 The @code{(gnu services web)} module provides the Apache HTTP Server,
19580 the nginx web server, and also a fastcgi wrapper daemon.
19582 @subsubheading Apache HTTP Server
19584 @deffn {Scheme Variable} httpd-service-type
19585 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
19586 (@dfn{httpd}). The value for this service type is a
19587 @code{httpd-configuration} record.
19589 A simple example configuration is given below.
19592 (service httpd-service-type
19593 (httpd-configuration
19596 (server-name "www.example.com")
19597 (document-root "/srv/http/www.example.com")))))
19600 Other services can also extend the @code{httpd-service-type} to add to
19604 (simple-service 'www.example.com-server httpd-service-type
19608 (list (string-join '("ServerName www.example.com"
19609 "DocumentRoot /srv/http/www.example.com")
19614 The details for the @code{httpd-configuration}, @code{httpd-module},
19615 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
19618 @deffn {Data Type} httpd-configuration
19619 This data type represents the configuration for the httpd service.
19622 @item @code{package} (default: @code{httpd})
19623 The httpd package to use.
19625 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19626 The pid file used by the shepherd-service.
19628 @item @code{config} (default: @code{(httpd-config-file)})
19629 The configuration file to use with the httpd service. The default value
19630 is a @code{httpd-config-file} record, but this can also be a different
19631 G-expression that generates a file, for example a @code{plain-file}. A
19632 file outside of the store can also be specified through a string.
19637 @deffn {Data Type} httpd-module
19638 This data type represents a module for the httpd service.
19642 The name of the module.
19645 The file for the module. This can be relative to the httpd package being
19646 used, the absolute location of a file, or a G-expression for a file
19647 within the store, for example @code{(file-append mod-wsgi
19648 "/modules/mod_wsgi.so")}.
19653 @defvr {Scheme Variable} %default-httpd-modules
19654 A default list of @code{httpd-module} objects.
19657 @deffn {Data Type} httpd-config-file
19658 This data type represents a configuration file for the httpd service.
19661 @item @code{modules} (default: @code{%default-httpd-modules})
19662 The modules to load. Additional modules can be added here, or loaded by
19663 additional configuration.
19665 For example, in order to handle requests for PHP files, you can use Apache’s
19666 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
19669 (service httpd-service-type
19670 (httpd-configuration
19675 (name "proxy_module")
19676 (file "modules/mod_proxy.so"))
19678 (name "proxy_fcgi_module")
19679 (file "modules/mod_proxy_fcgi.so"))
19680 %default-httpd-modules))
19681 (extra-config (list "\
19682 <FilesMatch \\.php$>
19683 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
19684 </FilesMatch>"))))))
19685 (service php-fpm-service-type
19686 (php-fpm-configuration
19687 (socket "/var/run/php-fpm.sock")
19688 (socket-group "httpd")))
19691 @item @code{server-root} (default: @code{httpd})
19692 The @code{ServerRoot} in the configuration file, defaults to the httpd
19693 package. Directives including @code{Include} and @code{LoadModule} are
19694 taken as relative to the server root.
19696 @item @code{server-name} (default: @code{#f})
19697 The @code{ServerName} in the configuration file, used to specify the
19698 request scheme, hostname and port that the server uses to identify
19701 This doesn't need to be set in the server config, and can be specifyed
19702 in virtual hosts. The default is @code{#f} to not specify a
19705 @item @code{document-root} (default: @code{"/srv/http"})
19706 The @code{DocumentRoot} from which files will be served.
19708 @item @code{listen} (default: @code{'("80")})
19709 The list of values for the @code{Listen} directives in the config
19710 file. The value should be a list of strings, when each string can
19711 specify the port number to listen on, and optionally the IP address and
19714 @item @code{pid-file} (default: @code{"/var/run/httpd"})
19715 The @code{PidFile} to use. This should match the @code{pid-file} set in
19716 the @code{httpd-configuration} so that the Shepherd service is
19717 configured correctly.
19719 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
19720 The @code{ErrorLog} to which the server will log errors.
19722 @item @code{user} (default: @code{"httpd"})
19723 The @code{User} which the server will answer requests as.
19725 @item @code{group} (default: @code{"httpd"})
19726 The @code{Group} which the server will answer requests as.
19728 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
19729 A flat list of strings and G-expressions which will be added to the end
19730 of the configuration file.
19732 Any values which the service is extended with will be appended to this
19738 @deffn {Data Type} httpd-virtualhost
19739 This data type represents a virtualhost configuration block for the httpd service.
19741 These should be added to the extra-config for the httpd-service.
19744 (simple-service 'www.example.com-server httpd-service-type
19748 (list (string-join '("ServerName www.example.com"
19749 "DocumentRoot /srv/http/www.example.com")
19754 @item @code{addresses-and-ports}
19755 The addresses and ports for the @code{VirtualHost} directive.
19757 @item @code{contents}
19758 The contents of the @code{VirtualHost} directive, this should be a list
19759 of strings and G-expressions.
19764 @subsubheading NGINX
19766 @deffn {Scheme Variable} nginx-service-type
19767 Service type for the @uref{https://nginx.org/,NGinx} web server. The
19768 value for this service type is a @code{<nginx-configuration>} record.
19770 A simple example configuration is given below.
19773 (service nginx-service-type
19774 (nginx-configuration
19776 (list (nginx-server-configuration
19777 (server-name '("www.example.com"))
19778 (root "/srv/http/www.example.com"))))))
19781 In addition to adding server blocks to the service configuration
19782 directly, this service can be extended by other services to add server
19783 blocks, as in this example:
19786 (simple-service 'my-extra-server nginx-service-type
19787 (list (nginx-server-configuration
19788 (root "/srv/http/extra-website")
19789 (try-files (list "$uri" "$uri/index.html")))))
19793 At startup, @command{nginx} has not yet read its configuration file, so
19794 it uses a default file to log error messages. If it fails to load its
19795 configuration file, that is where error messages are logged. After the
19796 configuration file is loaded, the default error log file changes as per
19797 configuration. In our case, startup error messages can be found in
19798 @file{/var/run/nginx/logs/error.log}, and after configuration in
19799 @file{/var/log/nginx/error.log}. The second location can be changed
19800 with the @var{log-directory} configuration option.
19802 @deffn {Data Type} nginx-configuration
19803 This data type represents the configuration for NGinx. Some
19804 configuration can be done through this and the other provided record
19805 types, or alternatively, a config file can be provided.
19808 @item @code{nginx} (default: @code{nginx})
19809 The nginx package to use.
19811 @item @code{log-directory} (default: @code{"/var/log/nginx"})
19812 The directory to which NGinx will write log files.
19814 @item @code{run-directory} (default: @code{"/var/run/nginx"})
19815 The directory in which NGinx will create a pid file, and write temporary
19818 @item @code{server-blocks} (default: @code{'()})
19819 A list of @dfn{server blocks} to create in the generated configuration
19820 file, the elements should be of type
19821 @code{<nginx-server-configuration>}.
19823 The following example would setup NGinx to serve @code{www.example.com}
19824 from the @code{/srv/http/www.example.com} directory, without using
19827 (service nginx-service-type
19828 (nginx-configuration
19830 (list (nginx-server-configuration
19831 (server-name '("www.example.com"))
19832 (root "/srv/http/www.example.com"))))))
19835 @item @code{upstream-blocks} (default: @code{'()})
19836 A list of @dfn{upstream blocks} to create in the generated configuration
19837 file, the elements should be of type
19838 @code{<nginx-upstream-configuration>}.
19840 Configuring upstreams through the @code{upstream-blocks} can be useful
19841 when combined with @code{locations} in the
19842 @code{<nginx-server-configuration>} records. The following example
19843 creates a server configuration with one location configuration, that
19844 will proxy requests to a upstream configuration, which will handle
19845 requests with two servers.
19850 (nginx-configuration
19852 (list (nginx-server-configuration
19853 (server-name '("www.example.com"))
19854 (root "/srv/http/www.example.com")
19857 (nginx-location-configuration
19859 (body '("proxy_pass http://server-proxy;"))))))))
19861 (list (nginx-upstream-configuration
19862 (name "server-proxy")
19863 (servers (list "server1.example.com"
19864 "server2.example.com")))))))
19867 @item @code{file} (default: @code{#f})
19868 If a configuration @var{file} is provided, this will be used, rather than
19869 generating a configuration file from the provided @code{log-directory},
19870 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
19871 proper operation, these arguments should match what is in @var{file} to ensure
19872 that the directories are created when the service is activated.
19874 This can be useful if you have an existing configuration file, or it's
19875 not possible to do what is required through the other parts of the
19876 nginx-configuration record.
19878 @item @code{server-names-hash-bucket-size} (default: @code{#f})
19879 Bucket size for the server names hash tables, defaults to @code{#f} to
19880 use the size of the processors cache line.
19882 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
19883 Maximum bucket size for the server names hash tables.
19885 @item @code{modules} (default: @code{'()})
19886 List of nginx dynamic modules to load. This should be a list of file
19887 names of loadable modules, as in this example:
19892 (file-append nginx-accept-language-module "\
19893 /etc/nginx/modules/ngx_http_accept_language_module.so")))
19896 @item @code{extra-content} (default: @code{""})
19897 Extra content for the @code{http} block. Should be string or a string
19898 valued G-expression.
19903 @deftp {Data Type} nginx-server-configuration
19904 Data type representing the configuration of an nginx server block.
19905 This type has the following parameters:
19908 @item @code{listen} (default: @code{'("80" "443 ssl")})
19909 Each @code{listen} directive sets the address and port for IP, or the
19910 path for a UNIX-domain socket on which the server will accept requests.
19911 Both address and port, or only address or only port can be specified.
19912 An address may also be a hostname, for example:
19915 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
19918 @item @code{server-name} (default: @code{(list 'default)})
19919 A list of server names this server represents. @code{'default} represents the
19920 default server for connections matching no other server.
19922 @item @code{root} (default: @code{"/srv/http"})
19923 Root of the website nginx will serve.
19925 @item @code{locations} (default: @code{'()})
19926 A list of @dfn{nginx-location-configuration} or
19927 @dfn{nginx-named-location-configuration} records to use within this
19930 @item @code{index} (default: @code{(list "index.html")})
19931 Index files to look for when clients ask for a directory. If it cannot be found,
19932 Nginx will send the list of files in the directory.
19934 @item @code{try-files} (default: @code{'()})
19935 A list of files whose existence is checked in the specified order.
19936 @code{nginx} will use the first file it finds to process the request.
19938 @item @code{ssl-certificate} (default: @code{#f})
19939 Where to find the certificate for secure connections. Set it to @code{#f} if
19940 you don't have a certificate or you don't want to use HTTPS.
19942 @item @code{ssl-certificate-key} (default: @code{#f})
19943 Where to find the private key for secure connections. Set it to @code{#f} if
19944 you don't have a key or you don't want to use HTTPS.
19946 @item @code{server-tokens?} (default: @code{#f})
19947 Whether the server should add its configuration to response.
19949 @item @code{raw-content} (default: @code{'()})
19950 A list of raw lines added to the server block.
19955 @deftp {Data Type} nginx-upstream-configuration
19956 Data type representing the configuration of an nginx @code{upstream}
19957 block. This type has the following parameters:
19961 Name for this group of servers.
19963 @item @code{servers}
19964 Specify the addresses of the servers in the group. The address can be
19965 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
19966 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
19967 prefix @samp{unix:}. For addresses using an IP address or domain name,
19968 the default port is 80, and a different port can be specified
19974 @deftp {Data Type} nginx-location-configuration
19975 Data type representing the configuration of an nginx @code{location}
19976 block. This type has the following parameters:
19980 URI which this location block matches.
19982 @anchor{nginx-location-configuration body}
19984 Body of the location block, specified as a list of strings. This can contain
19986 configuration directives. For example, to pass requests to a upstream
19987 server group defined using an @code{nginx-upstream-configuration} block,
19988 the following directive would be specified in the body @samp{(list "proxy_pass
19989 http://upstream-name;")}.
19994 @deftp {Data Type} nginx-named-location-configuration
19995 Data type representing the configuration of an nginx named location
19996 block. Named location blocks are used for request redirection, and not
19997 used for regular request processing. This type has the following
20002 Name to identify this location block.
20005 @xref{nginx-location-configuration body}, as the body for named location
20006 blocks can be used in a similar way to the
20007 @code{nginx-location-configuration body}. One restriction is that the
20008 body of a named location block cannot contain location blocks.
20013 @subsubheading Varnish Cache
20015 Varnish is a fast cache server that sits in between web applications
20016 and end users. It proxies requests from clients and caches the
20017 accessed URLs such that multiple requests for the same resource only
20018 creates one request to the back-end.
20020 @defvr {Scheme Variable} varnish-service-type
20021 Service type for the Varnish daemon.
20024 @deftp {Data Type} varnish-configuration
20025 Data type representing the @code{varnish} service configuration.
20026 This type has the following parameters:
20029 @item @code{package} (default: @code{varnish})
20030 The Varnish package to use.
20032 @item @code{name} (default: @code{"default"})
20033 A name for this Varnish instance. Varnish will create a directory in
20034 @file{/var/varnish/} with this name and keep temporary files there. If
20035 the name starts with a forward slash, it is interpreted as an absolute
20038 Pass the @code{-n} argument to other Varnish programs to connect to the
20039 named instance, e.g.@: @command{varnishncsa -n default}.
20041 @item @code{backend} (default: @code{"localhost:8080"})
20042 The backend to use. This option has no effect if @code{vcl} is set.
20044 @item @code{vcl} (default: #f)
20045 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
20046 is @code{#f}, Varnish will proxy @code{backend} using the default
20047 configuration. Otherwise this must be a file-like object with valid
20050 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
20051 For example, to mirror @url{http://www.gnu.org,www.gnu.org} with VCL you
20052 can do something along these lines:
20055 (define %gnu-mirror
20056 (plain-file "gnu.vcl"
20058 backend gnu @{ .host = \"www.gnu.org\"; @}"))
20062 (services (cons (service varnish-service-type
20063 (varnish-configuration
20065 (vcl %gnu-mirror)))
20069 The configuration of an already running Varnish instance can be inspected
20070 and changed using the @command{varnishadm} program.
20072 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
20073 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
20074 comprehensive documentation on Varnish and its configuration language.
20076 @item @code{listen} (default: @code{'("localhost:80")})
20077 List of addresses Varnish will listen on.
20079 @item @code{storage} (default: @code{'("malloc,128m")})
20080 List of storage backends that will be available in VCL.
20082 @item @code{parameters} (default: @code{'()})
20083 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
20085 @item @code{extra-options} (default: @code{'()})
20086 Additional arguments to pass to the @command{varnishd} process.
20091 @subsubheading Patchwork
20093 Patchwork is a patch tracking system. It can collect patches sent to a
20094 mailing list, and display them in a web interface.
20096 @defvr {Scheme Variable} patchwork-service-type
20097 Service type for Patchwork.
20100 The following example is an example of a minimal service for Patchwork, for
20101 the @code{patchwork.example.com} domain.
20104 (service patchwork-service-type
20105 (patchwork-configuration
20106 (domain "patchwork.example.com")
20108 (patchwork-settings-module
20109 (allowed-hosts (list domain))
20110 (default-from-email "patchwork@@patchwork.example.com")))
20111 (getmail-retriever-config
20112 (getmail-retriever-configuration
20113 (type "SimpleIMAPSSLRetriever")
20114 (server "imap.example.com")
20116 (username "patchwork")
20118 (list (file-append coreutils "/bin/cat")
20119 "/etc/getmail-patchwork-imap-password"))
20121 '((mailboxes . ("Patches"))))))))
20125 There are three records for configuring the Patchwork service. The
20126 @code{<patchwork-configuration>} relates to the configuration for Patchwork
20127 within the HTTPD service.
20129 The @code{settings-module} field within the @code{<patchwork-configuration>}
20130 record can be populated with the @code{<patchwork-settings-module>} record,
20131 which describes a settings module that is generated within the Guix store.
20133 For the @code{database-configuration} field within the
20134 @code{<patchwork-settings-module>}, the
20135 @code{<patchwork-database-configuration>} must be used.
20137 @deftp {Data Type} patchwork-configuration
20138 Data type representing the Patchwork service configuration. This type has the
20139 following parameters:
20142 @item @code{patchwork} (default: @code{patchwork})
20143 The Patchwork package to use.
20145 @item @code{domain}
20146 The domain to use for Patchwork, this is used in the HTTPD service virtual
20149 @item @code{settings-module}
20150 The settings module to use for Patchwork. As a Django application, Patchwork
20151 is configured with a Python module containing the settings. This can either be
20152 an instance of the @code{<patchwork-settings-module>} record, any other record
20153 that represents the settings in the store, or a directory outside of the
20156 @item @code{static-path} (default: @code{"/static/"})
20157 The path under which the HTTPD service should serve the static files.
20159 @item @code{getmail-retriever-config}
20160 The getmail-retriever-configuration record value to use with
20161 Patchwork. Getmail will be configured with this value, the messages will be
20162 delivered to Patchwork.
20167 @deftp {Data Type} patchwork-settings-module
20168 Data type representing a settings module for Patchwork. Some of these
20169 settings relate directly to Patchwork, but others relate to Django, the web
20170 framework used by Patchwork, or the Django Rest Framework library. This type
20171 has the following parameters:
20174 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
20175 The database connection settings used for Patchwork. See the
20176 @code{<patchwork-database-configuration>} record type for more information.
20178 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
20179 Patchwork, as a Django web application uses a secret key for cryptographically
20180 signing values. This file should contain a unique unpredictable value.
20182 If this file does not exist, it will be created and populated with a random
20183 value by the patchwork-setup shepherd service.
20185 This setting relates to Django.
20187 @item @code{allowed-hosts}
20188 A list of valid hosts for this Patchwork service. This should at least include
20189 the domain specified in the @code{<patchwork-configuration>} record.
20191 This is a Django setting.
20193 @item @code{default-from-email}
20194 The email address from which Patchwork should send email by default.
20196 This is a Patchwork setting.
20198 @item @code{static-url} (default: @code{#f})
20199 The URL to use when serving static assets. It can be part of a URL, or a full
20200 URL, but must end in a @code{/}.
20202 If the default value is used, the @code{static-path} value from the
20203 @code{<patchwork-configuration>} record will be used.
20205 This is a Django setting.
20207 @item @code{admins} (default: @code{'()})
20208 Email addresses to send the details of errors that occur. Each value should
20209 be a list containing two elements, the name and then the email address.
20211 This is a Django setting.
20213 @item @code{debug?} (default: @code{#f})
20214 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
20215 messages will be shown.
20217 This is a Django setting.
20219 @item @code{enable-rest-api?} (default: @code{#t})
20220 Whether to enable the Patchwork REST API.
20222 This is a Patchwork setting.
20224 @item @code{enable-xmlrpc?} (default: @code{#t})
20225 Whether to enable the XML RPC API.
20227 This is a Patchwork setting.
20229 @item @code{force-https-links?} (default: @code{#t})
20230 Whether to use HTTPS links on Patchwork pages.
20232 This is a Patchwork setting.
20234 @item @code{extra-settings} (default: @code{""})
20235 Extra code to place at the end of the Patchwork settings module.
20240 @deftp {Data Type} patchwork-database-configuration
20241 Data type representing the database configuration for Patchwork.
20244 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
20245 The database engine to use.
20247 @item @code{name} (default: @code{"patchwork"})
20248 The name of the database to use.
20250 @item @code{user} (default: @code{"httpd"})
20251 The user to connect to the database as.
20253 @item @code{password} (default: @code{""})
20254 The password to use when connecting to the database.
20256 @item @code{host} (default: @code{""})
20257 The host to make the database connection to.
20259 @item @code{port} (default: @code{""})
20260 The port on which to connect to the database.
20265 @subsubheading FastCGI
20268 FastCGI is an interface between the front-end and the back-end of a web
20269 service. It is a somewhat legacy facility; new web services should
20270 generally just talk HTTP between the front-end and the back-end.
20271 However there are a number of back-end services such as PHP or the
20272 optimized HTTP Git repository access that use FastCGI, so we have
20273 support for it in Guix.
20275 To use FastCGI, you configure the front-end web server (e.g., nginx) to
20276 dispatch some subset of its requests to the fastcgi backend, which
20277 listens on a local TCP or UNIX socket. There is an intermediary
20278 @code{fcgiwrap} program that sits between the actual backend process and
20279 the web server. The front-end indicates which backend program to run,
20280 passing that information to the @code{fcgiwrap} process.
20282 @defvr {Scheme Variable} fcgiwrap-service-type
20283 A service type for the @code{fcgiwrap} FastCGI proxy.
20286 @deftp {Data Type} fcgiwrap-configuration
20287 Data type representing the configuration of the @code{fcgiwrap} service.
20288 This type has the following parameters:
20290 @item @code{package} (default: @code{fcgiwrap})
20291 The fcgiwrap package to use.
20293 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
20294 The socket on which the @code{fcgiwrap} process should listen, as a
20295 string. Valid @var{socket} values include
20296 @code{unix:@var{/path/to/unix/socket}},
20297 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
20298 @code{tcp6:[@var{ipv6_addr}]:port}.
20300 @item @code{user} (default: @code{fcgiwrap})
20301 @itemx @code{group} (default: @code{fcgiwrap})
20302 The user and group names, as strings, under which to run the
20303 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
20304 the user asks for the specific user or group names @code{fcgiwrap} that
20305 the corresponding user and/or group is present on the system.
20307 It is possible to configure a FastCGI-backed web service to pass HTTP
20308 authentication information from the front-end to the back-end, and to
20309 allow @code{fcgiwrap} to run the back-end process as a corresponding
20310 local user. To enable this capability on the back-end, run
20311 @code{fcgiwrap} as the @code{root} user and group. Note that this
20312 capability also has to be configured on the front-end as well.
20317 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
20318 with some additional features useful for sites of any size.
20320 These features include:
20322 @item Adaptive process spawning
20323 @item Basic statistics (similar to Apache's mod_status)
20324 @item Advanced process management with graceful stop/start
20325 @item Ability to start workers with different uid/gid/chroot/environment
20326 and different php.ini (replaces safe_mode)
20327 @item Stdout & stderr logging
20328 @item Emergency restart in case of accidental opcode cache destruction
20329 @item Accelerated upload support
20330 @item Support for a "slowlog"
20331 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
20332 a special function to finish request & flush all data while continuing to do
20333 something time-consuming (video converting, stats processing, etc.)
20335 ...@: and much more.
20337 @defvr {Scheme Variable} php-fpm-service-type
20338 A Service type for @code{php-fpm}.
20341 @deftp {Data Type} php-fpm-configuration
20342 Data Type for php-fpm service configuration.
20344 @item @code{php} (default: @code{php})
20345 The php package to use.
20346 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
20347 The address on which to accept FastCGI requests. Valid syntaxes are:
20349 @item @code{"ip.add.re.ss:port"}
20350 Listen on a TCP socket to a specific address on a specific port.
20351 @item @code{"port"}
20352 Listen on a TCP socket to all addresses on a specific port.
20353 @item @code{"/path/to/unix/socket"}
20354 Listen on a unix socket.
20357 @item @code{user} (default: @code{php-fpm})
20358 User who will own the php worker processes.
20359 @item @code{group} (default: @code{php-fpm})
20360 Group of the worker processes.
20361 @item @code{socket-user} (default: @code{php-fpm})
20362 User who can speak to the php-fpm socket.
20363 @item @code{socket-group} (default: @code{nginx})
20364 Group that can speak to the php-fpm socket.
20365 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
20366 The process id of the php-fpm process is written to this file
20367 once the service has started.
20368 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
20369 Log for the php-fpm master process.
20370 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
20371 Detailed settings for the php-fpm process manager.
20374 @item @code{<php-fpm-dynamic-process-manager-configuration>}
20375 @item @code{<php-fpm-static-process-manager-configuration>}
20376 @item @code{<php-fpm-on-demand-process-manager-configuration>}
20378 @item @code{display-errors} (default @code{#f})
20379 Determines whether php errors and warning should be sent to clients
20380 and displayed in their browsers.
20381 This is useful for local php development, but a security risk for public sites,
20382 as error messages can reveal passwords and personal data.
20383 @item @code{timezone} (default @code{#f})
20384 Specifies @code{php_admin_value[date.timezone]} parameter.
20385 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
20386 This file will log the @code{stderr} outputs of php worker processes.
20387 Can be set to @code{#f} to disable logging.
20388 @item @code{file} (default @code{#f})
20389 An optional override of the whole configuration.
20390 You can use the @code{mixed-text-file} function or an absolute filepath for it.
20394 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
20395 Data Type for the @code{dynamic} php-fpm process manager. With the
20396 @code{dynamic} process manager, spare worker processes are kept around
20397 based on it's configured limits.
20399 @item @code{max-children} (default: @code{5})
20400 Maximum of worker processes.
20401 @item @code{start-servers} (default: @code{2})
20402 How many worker processes should be started on start-up.
20403 @item @code{min-spare-servers} (default: @code{1})
20404 How many spare worker processes should be kept around at minimum.
20405 @item @code{max-spare-servers} (default: @code{3})
20406 How many spare worker processes should be kept around at maximum.
20410 @deftp {Data type} php-fpm-static-process-manager-configuration
20411 Data Type for the @code{static} php-fpm process manager. With the
20412 @code{static} process manager, an unchanging number of worker processes
20415 @item @code{max-children} (default: @code{5})
20416 Maximum of worker processes.
20420 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
20421 Data Type for the @code{on-demand} php-fpm process manager. With the
20422 @code{on-demand} process manager, worker processes are only created as
20425 @item @code{max-children} (default: @code{5})
20426 Maximum of worker processes.
20427 @item @code{process-idle-timeout} (default: @code{10})
20428 The time in seconds after which a process with no requests is killed.
20433 @deffn {Scheme Procedure} nginx-php-fpm-location @
20434 [#:nginx-package nginx] @
20435 [socket (string-append "/var/run/php" @
20436 (version-major (package-version php)) @
20438 A helper function to quickly add php to an @code{nginx-server-configuration}.
20441 A simple services setup for nginx with php can look like this:
20443 (services (cons* (service dhcp-client-service-type)
20444 (service php-fpm-service-type)
20445 (service nginx-service-type
20446 (nginx-server-configuration
20447 (server-name '("example.com"))
20448 (root "/srv/http/")
20450 (list (nginx-php-fpm-location)))
20452 (ssl-certificate #f)
20453 (ssl-certificate-key #f)))
20457 @cindex cat-avatar-generator
20458 The cat avatar generator is a simple service to demonstrate the use of php-fpm
20459 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
20460 the hash of a user's email address.
20462 @deffn {Scheme Procedure} cat-avatar-generator-service @
20463 [#:cache-dir "/var/cache/cat-avatar-generator"] @
20464 [#:package cat-avatar-generator] @
20465 [#:configuration (nginx-server-configuration)]
20466 Returns an nginx-server-configuration that inherits @code{configuration}. It
20467 extends the nginx configuration to add a server block that serves @code{package},
20468 a version of cat-avatar-generator. During execution, cat-avatar-generator will
20469 be able to use @code{cache-dir} as its cache directory.
20472 A simple setup for cat-avatar-generator can look like this:
20474 (services (cons* (cat-avatar-generator-service
20476 (nginx-server-configuration
20477 (server-name '("example.com"))))
20482 @subsubheading Hpcguix-web
20484 @cindex hpcguix-web
20485 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
20486 program is a customizable web interface to browse Guix packages,
20487 initially designed for users of high-performance computing (HPC)
20490 @defvr {Scheme Variable} hpcguix-web-service-type
20491 The service type for @code{hpcguix-web}.
20494 @deftp {Data Type} hpcguix-web-configuration
20495 Data type for the hpcguix-web service configuration.
20499 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
20500 configuration. The main items available in this spec are:
20503 @item @code{title-prefix} (default: @code{"hpcguix | "})
20504 The page title prefix.
20506 @item @code{guix-command} (default: @code{"guix"})
20507 The @command{guix} command.
20509 @item @code{package-filter-proc} (default: @code{(const #t)})
20510 A procedure specifying how to filter packages that are displayed.
20512 @item @code{package-page-extension-proc} (default: @code{(const '())})
20513 Extension package for @code{hpcguix-web}.
20515 @item @code{menu} (default: @code{'()})
20516 Additional entry in page @code{menu}.
20518 @item @code{channels} (default: @code{%default-channels})
20519 List of channels from which the package list is built (@pxref{Channels}).
20521 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
20522 The expiration time, in seconds, after which the package list is rebuilt from
20523 the latest instances of the given channels.
20526 See the hpcguix-web repository for a
20527 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
20530 @item @code{package} (default: @code{hpcguix-web})
20531 The hpcguix-web package to use.
20535 A typical hpcguix-web service declaration looks like this:
20538 (service hpcguix-web-service-type
20539 (hpcguix-web-configuration
20541 #~(define site-config
20542 (hpcweb-configuration
20543 (title-prefix "Guix-HPC - ")
20544 (menu '(("/about" "ABOUT"))))))))
20548 The hpcguix-web service periodically updates the package list it publishes by
20549 pulling channels from Git. To that end, it needs to access X.509 certificates
20550 so that it can authenticate Git servers when communicating over HTTPS, and it
20551 assumes that @file{/etc/ssl/certs} contains those certificates.
20553 Thus, make sure to add @code{nss-certs} or another certificate package to the
20554 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
20555 more information on X.509 certificates.
20558 @node Certificate Services
20559 @subsection Certificate Services
20562 @cindex HTTP, HTTPS
20563 @cindex Let's Encrypt
20564 @cindex TLS certificates
20565 The @code{(gnu services certbot)} module provides a service to
20566 automatically obtain a valid TLS certificate from the Let's Encrypt
20567 certificate authority. These certificates can then be used to serve
20568 content securely over HTTPS or other TLS-based protocols, with the
20569 knowledge that the client will be able to verify the server's
20572 @url{https://letsencrypt.org/, Let's Encrypt} provides the
20573 @code{certbot} tool to automate the certification process. This tool
20574 first securely generates a key on the server. It then makes a request
20575 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
20576 checks that the request originates from the host in question by using a
20577 challenge-response protocol, requiring the server to provide its
20578 response over HTTP. If that protocol completes successfully, the CA
20579 signs the key, resulting in a certificate. That certificate is valid
20580 for a limited period of time, and therefore to continue to provide TLS
20581 services, the server needs to periodically ask the CA to renew its
20584 The certbot service automates this process: the initial key
20585 generation, the initial certification request to the Let's Encrypt
20586 service, the web server challenge/response integration, writing the
20587 certificate to disk, the automated periodic renewals, and the deployment
20588 tasks associated with the renewal (e.g.@: reloading services, copying keys
20589 with different permissions).
20591 Certbot is run twice a day, at a random minute within the hour. It
20592 won't do anything until your certificates are due for renewal or
20593 revoked, but running it regularly would give your service a chance of
20594 staying online in case a Let's Encrypt-initiated revocation happened for
20597 By using this service, you agree to the ACME Subscriber Agreement, which
20598 can be found there:
20599 @url{https://acme-v01.api.letsencrypt.org/directory}.
20601 @defvr {Scheme Variable} certbot-service-type
20602 A service type for the @code{certbot} Let's Encrypt client. Its value
20603 must be a @code{certbot-configuration} record as in this example:
20606 (define %nginx-deploy-hook
20608 "nginx-deploy-hook"
20609 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
20610 (kill pid SIGHUP))))
20612 (service certbot-service-type
20613 (certbot-configuration
20614 (email "foo@@example.net")
20617 (certificate-configuration
20618 (domains '("example.net" "www.example.net"))
20619 (deploy-hook %nginx-deploy-hook))
20620 (certificate-configuration
20621 (domains '("bar.example.net")))))))
20624 See below for details about @code{certbot-configuration}.
20627 @deftp {Data Type} certbot-configuration
20628 Data type representing the configuration of the @code{certbot} service.
20629 This type has the following parameters:
20632 @item @code{package} (default: @code{certbot})
20633 The certbot package to use.
20635 @item @code{webroot} (default: @code{/var/www})
20636 The directory from which to serve the Let's Encrypt challenge/response
20639 @item @code{certificates} (default: @code{()})
20640 A list of @code{certificates-configuration}s for which to generate
20641 certificates and request signatures. Each certificate has a @code{name}
20642 and several @code{domains}.
20645 Mandatory email used for registration, recovery contact, and important
20646 account notifications.
20648 @item @code{rsa-key-size} (default: @code{2048})
20649 Size of the RSA key.
20651 @item @code{default-location} (default: @i{see below})
20652 The default @code{nginx-location-configuration}. Because @code{certbot}
20653 needs to be able to serve challenges and responses, it needs to be able
20654 to run a web server. It does so by extending the @code{nginx} web
20655 service with an @code{nginx-server-configuration} listening on the
20656 @var{domains} on port 80, and which has a
20657 @code{nginx-location-configuration} for the @code{/.well-known/} URI
20658 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
20659 these nginx configuration data types.
20661 Requests to other URL paths will be matched by the
20662 @code{default-location}, which if present is added to all
20663 @code{nginx-server-configuration}s.
20665 By default, the @code{default-location} will issue a redirect from
20666 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
20667 you to define what to serve on your site via @code{https}.
20669 Pass @code{#f} to not issue a default location.
20673 @deftp {Data Type} certificate-configuration
20674 Data type representing the configuration of a certificate.
20675 This type has the following parameters:
20678 @item @code{name} (default: @i{see below})
20679 This name is used by Certbot for housekeeping and in file paths; it
20680 doesn't affect the content of the certificate itself. To see
20681 certificate names, run @code{certbot certificates}.
20683 Its default is the first provided domain.
20685 @item @code{domains} (default: @code{()})
20686 The first domain provided will be the subject CN of the certificate, and
20687 all domains will be Subject Alternative Names on the certificate.
20689 @item @code{challenge} (default: @code{#f})
20690 The challenge type that has to be run by certbot. If @code{#f} is specified,
20691 default to the HTTP challenge. If a value is specified, defaults to the
20692 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
20693 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
20694 and gives Let's Encrypt permission to log the public IP address of the
20695 requesting machine.
20697 @item @code{authentication-hook} (default: @code{#f})
20698 Command to be run in a shell once for each certificate challenge to be
20699 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
20700 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
20701 contains the validation string and @code{$CERTBOT_TOKEN} contains the
20702 file name of the resource requested when performing an HTTP-01 challenge.
20704 @item @code{cleanup-hook} (default: @code{#f})
20705 Command to be run in a shell once for each certificate challenge that
20706 have been answered by the @code{auth-hook}. For this command, the shell
20707 variables available in the @code{auth-hook} script are still available, and
20708 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
20709 of the @code{auth-hook} script.
20711 @item @code{deploy-hook} (default: @code{#f})
20712 Command to be run in a shell once for each successfully issued
20713 certificate. For this command, the shell variable
20714 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
20715 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
20716 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
20717 contain a space-delimited list of renewed certificate domains (for
20718 example, @samp{"example.com www.example.com"}.
20723 For each @code{certificate-configuration}, the certificate is saved to
20724 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
20725 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
20727 @subsection DNS Services
20728 @cindex DNS (domain name system)
20729 @cindex domain name system (DNS)
20731 The @code{(gnu services dns)} module provides services related to the
20732 @dfn{domain name system} (DNS). It provides a server service for hosting
20733 an @emph{authoritative} DNS server for multiple zones, slave or master.
20734 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
20735 caching and forwarding DNS server for the LAN, which uses
20736 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
20738 @subsubheading Knot Service
20740 An example configuration of an authoritative server for two zones, one master
20744 (define-zone-entries example.org.zone
20745 ;; Name TTL Class Type Data
20746 ("@@" "" "IN" "A" "127.0.0.1")
20747 ("@@" "" "IN" "NS" "ns")
20748 ("ns" "" "IN" "A" "127.0.0.1"))
20750 (define master-zone
20751 (knot-zone-configuration
20752 (domain "example.org")
20754 (origin "example.org")
20755 (entries example.org.zone)))))
20758 (knot-zone-configuration
20759 (domain "plop.org")
20760 (dnssec-policy "default")
20761 (master (list "plop-master"))))
20763 (define plop-master
20764 (knot-remote-configuration
20766 (address (list "208.76.58.171"))))
20770 (services (cons* (service knot-service-type
20771 (knot-configuration
20772 (remotes (list plop-master))
20773 (zones (list master-zone slave-zone))))
20778 @deffn {Scheme Variable} knot-service-type
20779 This is the type for the Knot DNS server.
20781 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
20782 zones, that is to say domain names you would buy from a registrar. This server
20783 is not a resolver, meaning that it can only resolve names for which it is
20784 authoritative. This server can be configured to serve zones as a master server
20785 or a slave server as a per-zone basis. Slave zones will get their data from
20786 masters, and will serve it as an authoritative server. From the point of view
20787 of a resolver, there is no difference between master and slave.
20789 The following data types are used to configure the Knot DNS server:
20792 @deftp {Data Type} knot-key-configuration
20793 Data type representing a key.
20794 This type has the following parameters:
20797 @item @code{id} (default: @code{""})
20798 An identifier for other configuration fields to refer to this key. IDs must
20799 be unique and must not be empty.
20801 @item @code{algorithm} (default: @code{#f})
20802 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
20803 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
20804 and @code{'hmac-sha512}.
20806 @item @code{secret} (default: @code{""})
20807 The secret key itself.
20812 @deftp {Data Type} knot-acl-configuration
20813 Data type representing an Access Control List (ACL) configuration.
20814 This type has the following parameters:
20817 @item @code{id} (default: @code{""})
20818 An identifier for ether configuration fields to refer to this key. IDs must be
20819 unique and must not be empty.
20821 @item @code{address} (default: @code{'()})
20822 An ordered list of IP addresses, network subnets, or network ranges represented
20823 with strings. The query must match one of them. Empty value means that
20824 address match is not required.
20826 @item @code{key} (default: @code{'()})
20827 An ordered list of references to keys represented with strings. The string
20828 must match a key ID defined in a @code{knot-key-configuration}. No key means
20829 that a key is not require to match that ACL.
20831 @item @code{action} (default: @code{'()})
20832 An ordered list of actions that are permitted or forbidden by this ACL. Possible
20833 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
20834 and @code{'update}.
20836 @item @code{deny?} (default: @code{#f})
20837 When true, the ACL defines restrictions. Listed actions are forbidden. When
20838 false, listed actions are allowed.
20843 @deftp {Data Type} zone-entry
20844 Data type represnting a record entry in a zone file.
20845 This type has the following parameters:
20848 @item @code{name} (default: @code{"@@"})
20849 The name of the record. @code{"@@"} refers to the origin of the zone. Names
20850 are relative to the origin of the zone. For example, in the @code{example.org}
20851 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
20852 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
20853 refers to @code{ns.example.org}.
20855 @item @code{ttl} (default: @code{""})
20856 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
20858 @item @code{class} (default: @code{"IN"})
20859 The class of the record. Knot currently supports only @code{"IN"} and
20860 partially @code{"CH"}.
20862 @item @code{type} (default: @code{"A"})
20863 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
20864 address), NS (Name Server) and MX (Mail eXchange). Many other types are
20867 @item @code{data} (default: @code{""})
20868 The data contained in the record. For instance an IP address associated with
20869 an A record, or a domain name associated with an NS record. Remember that
20870 domain names are relative to the origin unless they end with a dot.
20875 @deftp {Data Type} zone-file
20876 Data type representing the content of a zone file.
20877 This type has the following parameters:
20880 @item @code{entries} (default: @code{'()})
20881 The list of entries. The SOA record is taken care of, so you don't need to
20882 put it in the list of entries. This list should probably contain an entry
20883 for your primary authoritative DNS server. Other than using a list of entries
20884 directly, you can use @code{define-zone-entries} to define a object containing
20885 the list of entries more easily, that you can later pass to the @code{entries}
20886 field of the @code{zone-file}.
20888 @item @code{origin} (default: @code{""})
20889 The name of your zone. This parameter cannot be empty.
20891 @item @code{ns} (default: @code{"ns"})
20892 The domain of your primary authoritative DNS server. The name is relative to
20893 the origin, unless it ends with a dot. It is mandatory that this primary
20894 DNS server corresponds to an NS record in the zone and that it is associated
20895 to an IP address in the list of entries.
20897 @item @code{mail} (default: @code{"hostmaster"})
20898 An email address people can contact you at, as the owner of the zone. This
20899 is translated as @code{<mail>@@<origin>}.
20901 @item @code{serial} (default: @code{1})
20902 The serial number of the zone. As this is used to keep track of changes by
20903 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
20904 Always increment it when you make a change in your zone.
20906 @item @code{refresh} (default: @code{(* 2 24 3600)})
20907 The frequency at which slaves will do a zone transfer. This value is a number
20908 of seconds. It can be computed by multiplications or with
20909 @code{(string->duration)}.
20911 @item @code{retry} (default: @code{(* 15 60)})
20912 The period after which a slave will retry to contact its master when it fails
20913 to do so a first time.
20915 @item @code{expiry} (default: @code{(* 14 24 3600)})
20916 Default TTL of records. Existing records are considered correct for at most
20917 this amount of time. After this period, resolvers will invalidate their cache
20918 and check again that it still exists.
20920 @item @code{nx} (default: @code{3600})
20921 Default TTL of inexistant records. This delay is usually short because you want
20922 your new domains to reach everyone quickly.
20927 @deftp {Data Type} knot-remote-configuration
20928 Data type representing a remote configuration.
20929 This type has the following parameters:
20932 @item @code{id} (default: @code{""})
20933 An identifier for other configuration fields to refer to this remote. IDs must
20934 be unique and must not be empty.
20936 @item @code{address} (default: @code{'()})
20937 An ordered list of destination IP addresses. Addresses are tried in sequence.
20938 An optional port can be given with the @@ separator. For instance:
20939 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
20941 @item @code{via} (default: @code{'()})
20942 An ordered list of source IP addresses. An empty list will have Knot choose
20943 an appropriate source IP. An optional port can be given with the @@ separator.
20944 The default is to choose at random.
20946 @item @code{key} (default: @code{#f})
20947 A reference to a key, that is a string containing the identifier of a key
20948 defined in a @code{knot-key-configuration} field.
20953 @deftp {Data Type} knot-keystore-configuration
20954 Data type representing a keystore to hold dnssec keys.
20955 This type has the following parameters:
20958 @item @code{id} (default: @code{""})
20959 The id of the keystore. It must not be empty.
20961 @item @code{backend} (default: @code{'pem})
20962 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
20964 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
20965 The configuration string of the backend. An example for the PKCS#11 is:
20966 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
20967 For the pem backend, the string reprensents a path in the file system.
20972 @deftp {Data Type} knot-policy-configuration
20973 Data type representing a dnssec policy. Knot DNS is able to automatically
20974 sign your zones. It can either generate and manage your keys automatically or
20975 use keys that you generate.
20977 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
20978 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
20979 zone. In order to be trusted, the KSK needs to be present in the parent zone
20980 (usually a top-level domain). If your registrar supports dnssec, you will
20981 have to send them your KSK's hash so they can add a DS record in their zone.
20982 This is not automated and need to be done each time you change your KSK.
20984 The policy also defines the lifetime of keys. Usually, ZSK can be changed
20985 easily and use weaker cryptographic functions (they use lower parameters) in
20986 order to sign records quickly, so they are changed often. The KSK however
20987 requires manual interaction with the registrar, so they are changed less often
20988 and use stronger parameters because they sign only one record.
20990 This type has the following parameters:
20993 @item @code{id} (default: @code{""})
20994 The id of the policy. It must not be empty.
20996 @item @code{keystore} (default: @code{"default"})
20997 A reference to a keystore, that is a string containing the identifier of a
20998 keystore defined in a @code{knot-keystore-configuration} field. The
20999 @code{"default"} identifier means the default keystore (a kasp database that
21000 was setup by this service).
21002 @item @code{manual?} (default: @code{#f})
21003 Whether the key management is manual or automatic.
21005 @item @code{single-type-signing?} (default: @code{#f})
21006 When @code{#t}, use the Single-Type Signing Scheme.
21008 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
21009 An algorithm of signing keys and issued signatures.
21011 @item @code{ksk-size} (default: @code{256})
21012 The length of the KSK. Note that this value is correct for the default
21013 algorithm, but would be unsecure for other algorithms.
21015 @item @code{zsk-size} (default: @code{256})
21016 The length of the ZSK. Note that this value is correct for the default
21017 algorithm, but would be unsecure for other algorithms.
21019 @item @code{dnskey-ttl} (default: @code{'default})
21020 The TTL value for DNSKEY records added into zone apex. The special
21021 @code{'default} value means same as the zone SOA TTL.
21023 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
21024 The period between ZSK publication and the next rollover initiation.
21026 @item @code{propagation-delay} (default: @code{(* 24 3600)})
21027 An extra delay added for each key rollover step. This value should be high
21028 enough to cover propagation of data from the master server to all slaves.
21030 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
21031 A validity period of newly issued signatures.
21033 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
21034 A period how long before a signature expiration the signature will be refreshed.
21036 @item @code{nsec3?} (default: @code{#f})
21037 When @code{#t}, NSEC3 will be used instead of NSEC.
21039 @item @code{nsec3-iterations} (default: @code{5})
21040 The number of additional times the hashing is performed.
21042 @item @code{nsec3-salt-length} (default: @code{8})
21043 The length of a salt field in octets, which is appended to the original owner
21044 name before hashing.
21046 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
21047 The validity period of newly issued salt field.
21052 @deftp {Data Type} knot-zone-configuration
21053 Data type representing a zone served by Knot.
21054 This type has the following parameters:
21057 @item @code{domain} (default: @code{""})
21058 The domain served by this configuration. It must not be empty.
21060 @item @code{file} (default: @code{""})
21061 The file where this zone is saved. This parameter is ignored by master zones.
21062 Empty means default location that depends on the domain name.
21064 @item @code{zone} (default: @code{(zone-file)})
21065 The content of the zone file. This parameter is ignored by slave zones. It
21066 must contain a zone-file record.
21068 @item @code{master} (default: @code{'()})
21069 A list of master remotes. When empty, this zone is a master. When set, this
21070 zone is a slave. This is a list of remotes identifiers.
21072 @item @code{ddns-master} (default: @code{#f})
21073 The main master. When empty, it defaults to the first master in the list of
21076 @item @code{notify} (default: @code{'()})
21077 A list of slave remote identifiers.
21079 @item @code{acl} (default: @code{'()})
21080 A list of acl identifiers.
21082 @item @code{semantic-checks?} (default: @code{#f})
21083 When set, this adds more semantic checks to the zone.
21085 @item @code{disable-any?} (default: @code{#f})
21086 When set, this forbids queries of the ANY type.
21088 @item @code{zonefile-sync} (default: @code{0})
21089 The delay between a modification in memory and on disk. 0 means immediate
21092 @item @code{zonefile-load} (default: @code{#f})
21093 The way the zone file contents are applied during zone load. Possible values
21097 @item @code{#f} for using the default value from Knot,
21098 @item @code{'none} for not using the zone file at all,
21099 @item @code{'difference} for computing the difference between already available
21100 contents and zone contents and applying it to the current zone contents,
21101 @item @code{'difference-no-serial} for the same as @code{'difference}, but
21102 ignoring the SOA serial in the zone file, while the server takes care of it
21104 @item @code{'whole} for loading zone contents from the zone file.
21107 @item @code{journal-content} (default: @code{#f})
21108 The way the journal is used to store zone and its changes. Possible values
21109 are @code{'none} to not use it at all, @code{'changes} to store changes and
21110 @code{'all} to store contents. @code{#f} does not set this option, so the
21111 default value from Knot is used.
21113 @item @code{max-journal-usage} (default: @code{#f})
21114 The maximum size for the journal on disk. @code{#f} does not set this option,
21115 so the default value from Knot is used.
21117 @item @code{max-journal-depth} (default: @code{#f})
21118 The maximum size of the history. @code{#f} does not set this option, so the
21119 default value from Knot is used.
21121 @item @code{max-zone-size} (default: @code{#f})
21122 The maximum size of the zone file. This limit is enforced for incoming
21123 transfer and updates. @code{#f} does not set this option, so the default
21124 value from Knot is used.
21126 @item @code{dnssec-policy} (default: @code{#f})
21127 A reference to a @code{knot-policy-configuration} record, or the special
21128 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
21131 @item @code{serial-policy} (default: @code{'increment})
21132 A policy between @code{'increment} and @code{'unixtime}.
21137 @deftp {Data Type} knot-configuration
21138 Data type representing the Knot configuration.
21139 This type has the following parameters:
21142 @item @code{knot} (default: @code{knot})
21145 @item @code{run-directory} (default: @code{"/var/run/knot"})
21146 The run directory. This directory will be used for pid file and sockets.
21148 @item @code{includes} (default: @code{'()})
21149 A list of strings or file-like objects denoting other files that must be
21150 included at the top of the configuration file.
21152 @cindex secrets, Knot service
21153 This can be used to manage secrets out-of-band. For example, secret
21154 keys may be stored in an out-of-band file not managed by Guix, and
21155 thus not visible in @file{/gnu/store}---e.g., you could store secret
21156 key configuration in @file{/etc/knot/secrets.conf} and add this file
21157 to the @code{includes} list.
21159 One can generate a secret tsig key (for nsupdate and zone transfers with the
21160 keymgr command from the knot package. Note that the package is not automatically
21161 installed by the service. The following example shows how to generate a new
21165 keymgr -t mysecret > /etc/knot/secrets.conf
21166 chmod 600 /etc/knot/secrets.conf
21169 Also note that the generated key will be named @var{mysecret}, so it is the
21170 name that needs to be used in the @var{key} field of the
21171 @code{knot-acl-configuration} record and in other places that need to refer
21174 It can also be used to add configuration not supported by this interface.
21176 @item @code{listen-v4} (default: @code{"0.0.0.0"})
21177 An ip address on which to listen.
21179 @item @code{listen-v6} (default: @code{"::"})
21180 An ip address on which to listen.
21182 @item @code{listen-port} (default: @code{53})
21183 A port on which to listen.
21185 @item @code{keys} (default: @code{'()})
21186 The list of knot-key-configuration used by this configuration.
21188 @item @code{acls} (default: @code{'()})
21189 The list of knot-acl-configuration used by this configuration.
21191 @item @code{remotes} (default: @code{'()})
21192 The list of knot-remote-configuration used by this configuration.
21194 @item @code{zones} (default: @code{'()})
21195 The list of knot-zone-configuration used by this configuration.
21200 @subsubheading Knot Resolver Service
21202 @deffn {Scheme Variable} knot-resolver-service-type
21203 This this the type of the knot resolver service, whose value should be
21204 an @code{knot-resolver-configuration} object as in this example:
21207 (service knot-resolver-service-type
21208 (knot-resolver-configuration
21209 (kresd-config-file (plain-file "kresd.conf" "
21210 net.listen('192.168.0.1', 5353)
21211 user('knot-resolver', 'knot-resolver')
21212 modules = @{ 'hints > iterate', 'stats', 'predict' @}
21213 cache.size = 100 * MB
21217 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
21220 @deftp {Data Type} knot-resolver-configuration
21221 Data type representing the configuration of knot-resolver.
21224 @item @code{package} (default: @var{knot-resolver})
21225 Package object of the knot DNS resolver.
21227 @item @code{kresd-config-file} (default: %kresd.conf)
21228 File-like object of the kresd configuration file to use, by default it
21229 will listen on @code{127.0.0.1} and @code{::1}.
21231 @item @code{garbage-collection-interval} (default: 1000)
21232 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
21238 @subsubheading Dnsmasq Service
21240 @deffn {Scheme Variable} dnsmasq-service-type
21241 This is the type of the dnsmasq service, whose value should be an
21242 @code{dnsmasq-configuration} object as in this example:
21245 (service dnsmasq-service-type
21246 (dnsmasq-configuration
21248 (servers '("192.168.1.1"))))
21252 @deftp {Data Type} dnsmasq-configuration
21253 Data type representing the configuration of dnsmasq.
21256 @item @code{package} (default: @var{dnsmasq})
21257 Package object of the dnsmasq server.
21259 @item @code{no-hosts?} (default: @code{#f})
21260 When true, don't read the hostnames in /etc/hosts.
21262 @item @code{port} (default: @code{53})
21263 The port to listen on. Setting this to zero completely disables DNS
21264 responses, leaving only DHCP and/or TFTP functions.
21266 @item @code{local-service?} (default: @code{#t})
21267 Accept DNS queries only from hosts whose address is on a local subnet,
21268 ie a subnet for which an interface exists on the server.
21270 @item @code{listen-addresses} (default: @code{'()})
21271 Listen on the given IP addresses.
21273 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
21274 The file to read the IP address of the upstream nameservers from.
21276 @item @code{no-resolv?} (default: @code{#f})
21277 When true, don't read @var{resolv-file}.
21279 @item @code{servers} (default: @code{'()})
21280 Specify IP address of upstream servers directly.
21282 @item @code{cache-size} (default: @code{150})
21283 Set the size of dnsmasq's cache. Setting the cache size to zero
21286 @item @code{negative-cache?} (default: @code{#t})
21287 When false, disable negative caching.
21292 @subsubheading ddclient Service
21295 The ddclient service described below runs the ddclient daemon, which takes
21296 care of automatically updating DNS entries for service providers such as
21297 @uref{https://dyn.com/dns/, Dyn}.
21299 The following example show instantiates the service with its default
21303 (service ddclient-service-type)
21306 Note that ddclient needs to access credentials that are stored in a
21307 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
21308 @code{secret-file} below.) You are expected to create this file manually, in
21309 an ``out-of-band'' fashion (you @emph{could} make this file part of the
21310 service configuration, for instance by using @code{plain-file}, but it will be
21311 world-readable @i{via} @file{/gnu/store}.) See the examples in the
21312 @file{share/ddclient} directory of the @code{ddclient} package.
21314 @c %start of fragment
21316 Available @code{ddclient-configuration} fields are:
21318 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
21319 The ddclient package.
21323 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
21324 The period after which ddclient will retry to check IP and domain name.
21326 Defaults to @samp{300}.
21330 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
21331 Use syslog for the output.
21333 Defaults to @samp{#t}.
21337 @deftypevr {@code{ddclient-configuration} parameter} string mail
21340 Defaults to @samp{"root"}.
21344 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
21345 Mail failed update to user.
21347 Defaults to @samp{"root"}.
21351 @deftypevr {@code{ddclient-configuration} parameter} string pid
21352 The ddclient PID file.
21354 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
21358 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
21359 Enable SSL support.
21361 Defaults to @samp{#t}.
21365 @deftypevr {@code{ddclient-configuration} parameter} string user
21366 Specifies the user name or ID that is used when running ddclient
21369 Defaults to @samp{"ddclient"}.
21373 @deftypevr {@code{ddclient-configuration} parameter} string group
21374 Group of the user who will run the ddclient program.
21376 Defaults to @samp{"ddclient"}.
21380 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
21381 Secret file which will be appended to @file{ddclient.conf} file. This
21382 file contains credentials for use by ddclient. You are expected to
21383 create it manually.
21385 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
21389 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
21390 Extra options will be appended to @file{ddclient.conf} file.
21392 Defaults to @samp{()}.
21397 @c %end of fragment
21401 @subsection VPN Services
21402 @cindex VPN (virtual private network)
21403 @cindex virtual private network (VPN)
21405 The @code{(gnu services vpn)} module provides services related to
21406 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
21407 your machine to connect to a VPN, and a @emph{server} service for your machine
21408 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
21410 @deffn {Scheme Procedure} openvpn-client-service @
21411 [#:config (openvpn-client-configuration)]
21413 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
21416 @deffn {Scheme Procedure} openvpn-server-service @
21417 [#:config (openvpn-server-configuration)]
21419 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
21421 Both can be run simultaneously.
21424 @c %automatically generated documentation
21426 Available @code{openvpn-client-configuration} fields are:
21428 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
21429 The OpenVPN package.
21433 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
21434 The OpenVPN pid file.
21436 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21440 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
21441 The protocol (UDP or TCP) used to open a channel between clients and
21444 Defaults to @samp{udp}.
21448 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
21449 The device type used to represent the VPN connection.
21451 Defaults to @samp{tun}.
21455 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
21456 The certificate authority to check connections against.
21458 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21462 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
21463 The certificate of the machine the daemon is running on. It should be
21464 signed by the authority given in @code{ca}.
21466 Defaults to @samp{"/etc/openvpn/client.crt"}.
21470 @deftypevr {@code{openvpn-client-configuration} parameter} string key
21471 The key of the machine the daemon is running on. It must be the key whose
21472 certificate is @code{cert}.
21474 Defaults to @samp{"/etc/openvpn/client.key"}.
21478 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
21479 Whether to use the lzo compression algorithm.
21481 Defaults to @samp{#t}.
21485 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
21486 Don't re-read key files across SIGUSR1 or --ping-restart.
21488 Defaults to @samp{#t}.
21492 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
21493 Don't close and reopen TUN/TAP device or run up/down scripts across
21494 SIGUSR1 or --ping-restart restarts.
21496 Defaults to @samp{#t}.
21500 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
21503 Defaults to @samp{3}.
21507 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
21508 Add an additional layer of HMAC authentication on top of the TLS control
21509 channel to protect against DoS attacks.
21511 Defaults to @samp{#f}.
21515 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
21516 Whether to check the server certificate has server usage extension.
21518 Defaults to @samp{#t}.
21522 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
21523 Bind to a specific local port number.
21525 Defaults to @samp{#f}.
21529 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
21530 Retry resolving server address.
21532 Defaults to @samp{#t}.
21536 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
21537 A list of remote servers to connect to.
21539 Defaults to @samp{()}.
21541 Available @code{openvpn-remote-configuration} fields are:
21543 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
21546 Defaults to @samp{"my-server"}.
21550 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
21551 Port number the server listens to.
21553 Defaults to @samp{1194}.
21558 @c %end of automatic openvpn-client documentation
21560 @c %automatically generated documentation
21562 Available @code{openvpn-server-configuration} fields are:
21564 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
21565 The OpenVPN package.
21569 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
21570 The OpenVPN pid file.
21572 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
21576 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
21577 The protocol (UDP or TCP) used to open a channel between clients and
21580 Defaults to @samp{udp}.
21584 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
21585 The device type used to represent the VPN connection.
21587 Defaults to @samp{tun}.
21591 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
21592 The certificate authority to check connections against.
21594 Defaults to @samp{"/etc/openvpn/ca.crt"}.
21598 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
21599 The certificate of the machine the daemon is running on. It should be
21600 signed by the authority given in @code{ca}.
21602 Defaults to @samp{"/etc/openvpn/client.crt"}.
21606 @deftypevr {@code{openvpn-server-configuration} parameter} string key
21607 The key of the machine the daemon is running on. It must be the key whose
21608 certificate is @code{cert}.
21610 Defaults to @samp{"/etc/openvpn/client.key"}.
21614 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
21615 Whether to use the lzo compression algorithm.
21617 Defaults to @samp{#t}.
21621 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
21622 Don't re-read key files across SIGUSR1 or --ping-restart.
21624 Defaults to @samp{#t}.
21628 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
21629 Don't close and reopen TUN/TAP device or run up/down scripts across
21630 SIGUSR1 or --ping-restart restarts.
21632 Defaults to @samp{#t}.
21636 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
21639 Defaults to @samp{3}.
21643 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
21644 Add an additional layer of HMAC authentication on top of the TLS control
21645 channel to protect against DoS attacks.
21647 Defaults to @samp{#f}.
21651 @deftypevr {@code{openvpn-server-configuration} parameter} number port
21652 Specifies the port number on which the server listens.
21654 Defaults to @samp{1194}.
21658 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
21659 An ip and mask specifying the subnet inside the virtual network.
21661 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
21665 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
21666 A CIDR notation specifying the IPv6 subnet inside the virtual network.
21668 Defaults to @samp{#f}.
21672 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
21673 The Diffie-Hellman parameters file.
21675 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
21679 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
21680 The file that records client IPs.
21682 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
21686 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
21687 When true, the server will act as a gateway for its clients.
21689 Defaults to @samp{#f}.
21693 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
21694 When true, clients are allowed to talk to each other inside the VPN.
21696 Defaults to @samp{#f}.
21700 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
21701 Causes ping-like messages to be sent back and forth over the link so
21702 that each side knows when the other side has gone down. @code{keepalive}
21703 requires a pair. The first element is the period of the ping sending,
21704 and the second element is the timeout before considering the other side
21709 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
21710 The maximum number of clients.
21712 Defaults to @samp{100}.
21716 @deftypevr {@code{openvpn-server-configuration} parameter} string status
21717 The status file. This file shows a small report on current connection.
21718 It is truncated and rewritten every minute.
21720 Defaults to @samp{"/var/run/openvpn/status"}.
21724 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
21725 The list of configuration for some clients.
21727 Defaults to @samp{()}.
21729 Available @code{openvpn-ccd-configuration} fields are:
21731 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
21734 Defaults to @samp{"client"}.
21738 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
21741 Defaults to @samp{#f}.
21745 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
21748 Defaults to @samp{#f}.
21755 @c %end of automatic openvpn-server documentation
21758 @node Network File System
21759 @subsection Network File System
21762 The @code{(gnu services nfs)} module provides the following services,
21763 which are most commonly used in relation to mounting or exporting
21764 directory trees as @dfn{network file systems} (NFS).
21766 @subsubheading RPC Bind Service
21769 The RPC Bind service provides a facility to map program numbers into
21770 universal addresses.
21771 Many NFS related services use this facility. Hence it is automatically
21772 started when a dependent service starts.
21774 @defvr {Scheme Variable} rpcbind-service-type
21775 A service type for the RPC portmapper daemon.
21779 @deftp {Data Type} rpcbind-configuration
21780 Data type representing the configuration of the RPC Bind Service.
21781 This type has the following parameters:
21783 @item @code{rpcbind} (default: @code{rpcbind})
21784 The rpcbind package to use.
21786 @item @code{warm-start?} (default: @code{#t})
21787 If this parameter is @code{#t}, then the daemon will read a
21788 state file on startup thus reloading state information saved by a previous
21794 @subsubheading Pipefs Pseudo File System
21798 The pipefs file system is used to transfer NFS related data
21799 between the kernel and user space programs.
21801 @defvr {Scheme Variable} pipefs-service-type
21802 A service type for the pipefs pseudo file system.
21805 @deftp {Data Type} pipefs-configuration
21806 Data type representing the configuration of the pipefs pseudo file system service.
21807 This type has the following parameters:
21809 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21810 The directory to which the file system is to be attached.
21815 @subsubheading GSS Daemon Service
21818 @cindex global security system
21820 The @dfn{global security system} (GSS) daemon provides strong security for RPC
21822 Before exchanging RPC requests an RPC client must establish a security
21823 context. Typically this is done using the Kerberos command @command{kinit}
21824 or automatically at login time using PAM services (@pxref{Kerberos Services}).
21826 @defvr {Scheme Variable} gss-service-type
21827 A service type for the Global Security System (GSS) daemon.
21830 @deftp {Data Type} gss-configuration
21831 Data type representing the configuration of the GSS daemon service.
21832 This type has the following parameters:
21834 @item @code{nfs-utils} (default: @code{nfs-utils})
21835 The package in which the @command{rpc.gssd} command is to be found.
21837 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21838 The directory where the pipefs file system is mounted.
21844 @subsubheading IDMAP Daemon Service
21846 @cindex name mapper
21848 The idmap daemon service provides mapping between user IDs and user names.
21849 Typically it is required in order to access file systems mounted via NFSv4.
21851 @defvr {Scheme Variable} idmap-service-type
21852 A service type for the Identity Mapper (IDMAP) daemon.
21855 @deftp {Data Type} idmap-configuration
21856 Data type representing the configuration of the IDMAP daemon service.
21857 This type has the following parameters:
21859 @item @code{nfs-utils} (default: @code{nfs-utils})
21860 The package in which the @command{rpc.idmapd} command is to be found.
21862 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
21863 The directory where the pipefs file system is mounted.
21865 @item @code{domain} (default: @code{#f})
21866 The local NFSv4 domain name.
21867 This must be a string or @code{#f}.
21868 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
21873 @node Continuous Integration
21874 @subsection Continuous Integration
21876 @cindex continuous integration
21877 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
21878 continuous integration tool for Guix. It can be used both for development and
21879 for providing substitutes to others (@pxref{Substitutes}).
21881 The @code{(gnu services cuirass)} module provides the following service.
21883 @defvr {Scheme Procedure} cuirass-service-type
21884 The type of the Cuirass service. Its value must be a
21885 @code{cuirass-configuration} object, as described below.
21888 To add build jobs, you have to set the @code{specifications} field of the
21889 configuration. Here is an example of a service that polls the Guix repository
21890 and builds the packages from a manifest. Some of the packages are defined in
21891 the @code{"custom-packages"} input, which is the equivalent of
21892 @code{GUIX_PACKAGE_PATH}.
21895 (define %cuirass-specs
21897 '((#:name . "my-manifest")
21898 (#:load-path-inputs . ("guix"))
21899 (#:package-path-inputs . ("custom-packages"))
21900 (#:proc-input . "guix")
21901 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
21902 (#:proc . cuirass-jobs)
21903 (#:proc-args . ((subset . "manifests")
21904 (systems . ("x86_64-linux"))
21905 (manifests . (("config" . "guix/manifest.scm")))))
21906 (#:inputs . (((#:name . "guix")
21907 (#:url . "git://git.savannah.gnu.org/guix.git")
21908 (#:load-path . ".")
21909 (#:branch . "master")
21910 (#:no-compile? . #t))
21911 ((#:name . "config")
21912 (#:url . "https://git.example.org/config.git")
21913 (#:load-path . ".")
21914 (#:branch . "master")
21915 (#:no-compile? . #t))
21916 ((#:name . "custom-packages")
21917 (#:url . "https://git.example.org/custom-packages.git")
21918 (#:load-path . ".")
21919 (#:branch . "master")
21920 (#:no-compile? . #t)))))))
21922 (service cuirass-service-type
21923 (cuirass-configuration
21924 (specifications %cuirass-specs)))
21927 While information related to build jobs is located directly in the
21928 specifications, global settings for the @command{cuirass} process are
21929 accessible in other @code{cuirass-configuration} fields.
21931 @deftp {Data Type} cuirass-configuration
21932 Data type representing the configuration of Cuirass.
21935 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
21936 Location of the log file.
21938 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
21939 Location of the log file used by the web interface.
21941 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
21942 Location of the repository cache.
21944 @item @code{user} (default: @code{"cuirass"})
21945 Owner of the @code{cuirass} process.
21947 @item @code{group} (default: @code{"cuirass"})
21948 Owner's group of the @code{cuirass} process.
21950 @item @code{interval} (default: @code{60})
21951 Number of seconds between the poll of the repositories followed by the
21954 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
21955 Location of sqlite database which contains the build results and previously
21956 added specifications.
21958 @item @code{ttl} (default: @code{(* 30 24 3600)})
21959 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
21960 are registered for build results. This means that build results are protected
21961 from garbage collection for at least @var{ttl} seconds.
21963 @item @code{port} (default: @code{8081})
21964 Port number used by the HTTP server.
21966 @item @code{host} (default: @code{"localhost"})
21967 Listen on the network interface for @var{host}. The default is to
21968 accept connections from localhost.
21970 @item @code{specifications} (default: @code{#~'()})
21971 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
21972 where a specification is an association list
21973 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
21974 keys are keywords (@code{#:keyword-example}) as shown in the example
21977 @item @code{use-substitutes?} (default: @code{#f})
21978 This allows using substitutes to avoid building every dependencies of a job
21981 @item @code{one-shot?} (default: @code{#f})
21982 Only evaluate specifications and build derivations once.
21984 @item @code{fallback?} (default: @code{#f})
21985 When substituting a pre-built binary fails, fall back to building
21988 @item @code{cuirass} (default: @code{cuirass})
21989 The Cuirass package to use.
21993 @node Power Management Services
21994 @subsection Power Management Services
21997 @cindex power management with TLP
21998 @subsubheading TLP daemon
22000 The @code{(gnu services pm)} module provides a Guix service definition
22001 for the Linux power management tool TLP.
22003 TLP enables various powersaving modes in userspace and kernel.
22004 Contrary to @code{upower-service}, it is not a passive,
22005 monitoring tool, as it will apply custom settings each time a new power
22006 source is detected. More information can be found at
22007 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
22009 @deffn {Scheme Variable} tlp-service-type
22010 The service type for the TLP tool. Its value should be a valid
22011 TLP configuration (see below). To use the default settings, simply
22014 (service tlp-service-type)
22018 By default TLP does not need much configuration but most TLP parameters
22019 can be tweaked using @code{tlp-configuration}.
22021 Each parameter definition is preceded by its type; for example,
22022 @samp{boolean foo} indicates that the @code{foo} parameter
22023 should be specified as a boolean. Types starting with
22024 @code{maybe-} denote parameters that won't show up in TLP config file
22025 when their value is @code{'disabled}.
22027 @c The following documentation was initially generated by
22028 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
22029 @c documentation is better, so we shouldn't hesitate to edit below as
22030 @c needed. However if the change you want to make to this documentation
22031 @c can be done in an automated way, it's probably easier to change
22032 @c (generate-documentation) than to make it below and have to deal with
22033 @c the churn as TLP updates.
22035 Available @code{tlp-configuration} fields are:
22037 @deftypevr {@code{tlp-configuration} parameter} package tlp
22042 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
22043 Set to true if you wish to enable TLP.
22045 Defaults to @samp{#t}.
22049 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
22050 Default mode when no power supply can be detected. Alternatives are AC
22053 Defaults to @samp{"AC"}.
22057 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
22058 Number of seconds Linux kernel has to wait after the disk goes idle,
22059 before syncing on AC.
22061 Defaults to @samp{0}.
22065 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
22066 Same as @code{disk-idle-ac} but on BAT mode.
22068 Defaults to @samp{2}.
22072 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
22073 Dirty pages flushing periodicity, expressed in seconds.
22075 Defaults to @samp{15}.
22079 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
22080 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
22082 Defaults to @samp{60}.
22086 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
22087 CPU frequency scaling governor on AC mode. With intel_pstate driver,
22088 alternatives are powersave and performance. With acpi-cpufreq driver,
22089 alternatives are ondemand, powersave, performance and conservative.
22091 Defaults to @samp{disabled}.
22095 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
22096 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
22098 Defaults to @samp{disabled}.
22102 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
22103 Set the min available frequency for the scaling governor on AC.
22105 Defaults to @samp{disabled}.
22109 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
22110 Set the max available frequency for the scaling governor on AC.
22112 Defaults to @samp{disabled}.
22116 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
22117 Set the min available frequency for the scaling governor on BAT.
22119 Defaults to @samp{disabled}.
22123 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
22124 Set the max available frequency for the scaling governor on BAT.
22126 Defaults to @samp{disabled}.
22130 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
22131 Limit the min P-state to control the power dissipation of the CPU, in AC
22132 mode. Values are stated as a percentage of the available performance.
22134 Defaults to @samp{disabled}.
22138 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
22139 Limit the max P-state to control the power dissipation of the CPU, in AC
22140 mode. Values are stated as a percentage of the available performance.
22142 Defaults to @samp{disabled}.
22146 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
22147 Same as @code{cpu-min-perf-on-ac} on BAT mode.
22149 Defaults to @samp{disabled}.
22153 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
22154 Same as @code{cpu-max-perf-on-ac} on BAT mode.
22156 Defaults to @samp{disabled}.
22160 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
22161 Enable CPU turbo boost feature on AC mode.
22163 Defaults to @samp{disabled}.
22167 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
22168 Same as @code{cpu-boost-on-ac?} on BAT mode.
22170 Defaults to @samp{disabled}.
22174 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
22175 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
22176 used under light load conditions.
22178 Defaults to @samp{#f}.
22182 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
22183 Same as @code{sched-powersave-on-ac?} but on BAT mode.
22185 Defaults to @samp{#t}.
22189 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
22190 Enable Linux kernel NMI watchdog.
22192 Defaults to @samp{#f}.
22196 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
22197 For Linux kernels with PHC patch applied, change CPU voltages. An
22198 example value would be @samp{"F:V F:V F:V F:V"}.
22200 Defaults to @samp{disabled}.
22204 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
22205 Set CPU performance versus energy saving policy on AC. Alternatives are
22206 performance, normal, powersave.
22208 Defaults to @samp{"performance"}.
22212 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
22213 Same as @code{energy-perf-policy-ac} but on BAT mode.
22215 Defaults to @samp{"powersave"}.
22219 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
22224 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
22225 Hard disk advanced power management level.
22229 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
22230 Same as @code{disk-apm-bat} but on BAT mode.
22234 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
22235 Hard disk spin down timeout. One value has to be specified for each
22236 declared hard disk.
22238 Defaults to @samp{disabled}.
22242 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
22243 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
22245 Defaults to @samp{disabled}.
22249 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
22250 Select IO scheduler for disk devices. One value has to be specified for
22251 each declared hard disk. Example alternatives are cfq, deadline and
22254 Defaults to @samp{disabled}.
22258 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
22259 SATA aggressive link power management (ALPM) level. Alternatives are
22260 min_power, medium_power, max_performance.
22262 Defaults to @samp{"max_performance"}.
22266 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
22267 Same as @code{sata-linkpwr-ac} but on BAT mode.
22269 Defaults to @samp{"min_power"}.
22273 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
22274 Exclude specified SATA host devices for link power management.
22276 Defaults to @samp{disabled}.
22280 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
22281 Enable Runtime Power Management for AHCI controller and disks on AC
22284 Defaults to @samp{disabled}.
22288 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
22289 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
22291 Defaults to @samp{disabled}.
22295 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
22296 Seconds of inactivity before disk is suspended.
22298 Defaults to @samp{15}.
22302 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
22303 PCI Express Active State Power Management level. Alternatives are
22304 default, performance, powersave.
22306 Defaults to @samp{"performance"}.
22310 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
22311 Same as @code{pcie-aspm-ac} but on BAT mode.
22313 Defaults to @samp{"powersave"}.
22317 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
22318 Radeon graphics clock speed level. Alternatives are low, mid, high,
22321 Defaults to @samp{"high"}.
22325 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
22326 Same as @code{radeon-power-ac} but on BAT mode.
22328 Defaults to @samp{"low"}.
22332 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
22333 Radeon dynamic power management method (DPM). Alternatives are battery,
22336 Defaults to @samp{"performance"}.
22340 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
22341 Same as @code{radeon-dpm-state-ac} but on BAT mode.
22343 Defaults to @samp{"battery"}.
22347 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
22348 Radeon DPM performance level. Alternatives are auto, low, high.
22350 Defaults to @samp{"auto"}.
22354 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
22355 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
22357 Defaults to @samp{"auto"}.
22361 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
22362 Wifi power saving mode.
22364 Defaults to @samp{#f}.
22368 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
22369 Same as @code{wifi-power-ac?} but on BAT mode.
22371 Defaults to @samp{#t}.
22375 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
22376 Disable wake on LAN.
22378 Defaults to @samp{#t}.
22382 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
22383 Timeout duration in seconds before activating audio power saving on
22384 Intel HDA and AC97 devices. A value of 0 disables power saving.
22386 Defaults to @samp{0}.
22390 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
22391 Same as @code{sound-powersave-ac} but on BAT mode.
22393 Defaults to @samp{1}.
22397 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
22398 Disable controller in powersaving mode on Intel HDA devices.
22400 Defaults to @samp{#t}.
22404 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
22405 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
22406 powered on again by releasing (and reinserting) the eject lever or by
22407 pressing the disc eject button on newer models.
22409 Defaults to @samp{#f}.
22413 @deftypevr {@code{tlp-configuration} parameter} string bay-device
22414 Name of the optical drive device to power off.
22416 Defaults to @samp{"sr0"}.
22420 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
22421 Runtime Power Management for PCI(e) bus devices. Alternatives are on
22424 Defaults to @samp{"on"}.
22428 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
22429 Same as @code{runtime-pm-ac} but on BAT mode.
22431 Defaults to @samp{"auto"}.
22435 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
22436 Runtime Power Management for all PCI(e) bus devices, except blacklisted
22439 Defaults to @samp{#t}.
22443 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
22444 Exclude specified PCI(e) device addresses from Runtime Power Management.
22446 Defaults to @samp{disabled}.
22450 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
22451 Exclude PCI(e) devices assigned to the specified drivers from Runtime
22456 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
22457 Enable USB autosuspend feature.
22459 Defaults to @samp{#t}.
22463 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
22464 Exclude specified devices from USB autosuspend.
22466 Defaults to @samp{disabled}.
22470 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
22471 Exclude WWAN devices from USB autosuspend.
22473 Defaults to @samp{#t}.
22477 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
22478 Include specified devices into USB autosuspend, even if they are already
22479 excluded by the driver or via @code{usb-blacklist-wwan?}.
22481 Defaults to @samp{disabled}.
22485 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
22486 Enable USB autosuspend before shutdown.
22488 Defaults to @samp{disabled}.
22492 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
22493 Restore radio device state (bluetooth, wifi, wwan) from previous
22494 shutdown on system startup.
22496 Defaults to @samp{#f}.
22501 @cindex CPU frequency scaling with thermald
22502 @subsubheading Thermald daemon
22504 The @code{(gnu services pm)} module provides an interface to
22505 thermald, a CPU frequency scaling service which helps prevent overheating.
22507 @defvr {Scheme Variable} thermald-service-type
22508 This is the service type for
22509 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
22510 Thermal Daemon, which is responsible for controlling the thermal state
22511 of processors and preventing overheating.
22514 @deftp {Data Type} thermald-configuration
22515 Data type representing the configuration of @code{thermald-service-type}.
22518 @item @code{ignore-cpuid-check?} (default: @code{#f})
22519 Ignore cpuid check for supported CPU models.
22521 @item @code{thermald} (default: @var{thermald})
22522 Package object of thermald.
22527 @node Audio Services
22528 @subsection Audio Services
22530 The @code{(gnu services audio)} module provides a service to start MPD
22531 (the Music Player Daemon).
22534 @subsubheading Music Player Daemon
22536 The Music Player Daemon (MPD) is a service that can play music while
22537 being controlled from the local machine or over the network by a variety
22540 The following example shows how one might run @code{mpd} as user
22541 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
22544 (service mpd-service-type
22550 @defvr {Scheme Variable} mpd-service-type
22551 The service type for @command{mpd}
22554 @deftp {Data Type} mpd-configuration
22555 Data type representing the configuration of @command{mpd}.
22558 @item @code{user} (default: @code{"mpd"})
22559 The user to run mpd as.
22561 @item @code{music-dir} (default: @code{"~/Music"})
22562 The directory to scan for music files.
22564 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
22565 The directory to store playlists.
22567 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
22568 The location of the music database.
22570 @item @code{state-file} (default: @code{"~/.mpd/state"})
22571 The location of the file that stores current MPD's state.
22573 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
22574 The location of the sticker database.
22576 @item @code{port} (default: @code{"6600"})
22577 The port to run mpd on.
22579 @item @code{address} (default: @code{"any"})
22580 The address that mpd will bind to. To use a Unix domain socket,
22581 an absolute path can be specified here.
22583 @item @code{outputs} (default: @code{"(list (mpd-output))"})
22584 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
22589 @deftp {Data Type} mpd-output
22590 Data type representing an @command{mpd} audio output.
22593 @item @code{name} (default: @code{"MPD"})
22594 The name of the audio output.
22596 @item @code{type} (default: @code{"pulse"})
22597 The type of audio output.
22599 @item @code{enabled?} (default: @code{#t})
22600 Specifies whether this audio output is enabled when MPD is started. By
22601 default, all audio outputs are enabled. This is just the default
22602 setting when there is no state file; with a state file, the previous
22605 @item @code{tags?} (default: @code{#t})
22606 If set to @code{#f}, then MPD will not send tags to this output. This
22607 is only useful for output plugins that can receive tags, for example the
22608 @code{httpd} output plugin.
22610 @item @code{always-on?} (default: @code{#f})
22611 If set to @code{#t}, then MPD attempts to keep this audio output always
22612 open. This may be useful for streaming servers, when you don’t want to
22613 disconnect all listeners even when playback is accidentally stopped.
22615 @item @code{mixer-type}
22616 This field accepts a symbol that specifies which mixer should be used
22617 for this audio output: the @code{hardware} mixer, the @code{software}
22618 mixer, the @code{null} mixer (allows setting the volume, but with no
22619 effect; this can be used as a trick to implement an external mixer
22620 External Mixer) or no mixer (@code{none}).
22622 @item @code{extra-options} (default: @code{'()"})
22623 An association list of option symbols to string values to be appended to
22624 the audio output configuration.
22629 The following example shows a configuration of @code{mpd} that provides
22630 an HTTP audio streaming output.
22633 (service mpd-service-type
22641 `((encoder . "vorbis")
22642 (port . "8080"))))))))
22646 @node Virtualization Services
22647 @subsection Virtualization services
22649 The @code{(gnu services virtualization)} module provides services for
22650 the libvirt and virtlog daemons, as well as other virtualization-related
22653 @subsubheading Libvirt daemon
22654 @code{libvirtd} is the server side daemon component of the libvirt
22655 virtualization management system. This daemon runs on host servers
22656 and performs required management tasks for virtualized guests.
22658 @deffn {Scheme Variable} libvirt-service-type
22659 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
22660 Its value must be a @code{libvirt-configuration}.
22663 (service libvirt-service-type
22664 (libvirt-configuration
22665 (unix-sock-group "libvirt")
22666 (tls-port "16555")))
22670 @c Auto-generated with (generate-libvirt-documentation)
22671 Available @code{libvirt-configuration} fields are:
22673 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
22678 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
22679 Flag listening for secure TLS connections on the public TCP/IP port.
22680 must set @code{listen} for this to have any effect.
22682 It is necessary to setup a CA and issue server certificates before using
22685 Defaults to @samp{#t}.
22689 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
22690 Listen for unencrypted TCP connections on the public TCP/IP port. must
22691 set @code{listen} for this to have any effect.
22693 Using the TCP socket requires SASL authentication by default. Only SASL
22694 mechanisms which support data encryption are allowed. This is
22695 DIGEST_MD5 and GSSAPI (Kerberos5)
22697 Defaults to @samp{#f}.
22701 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
22702 Port for accepting secure TLS connections This can be a port number, or
22705 Defaults to @samp{"16514"}.
22709 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
22710 Port for accepting insecure TCP connections This can be a port number,
22713 Defaults to @samp{"16509"}.
22717 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
22718 IP address or hostname used for client connections.
22720 Defaults to @samp{"0.0.0.0"}.
22724 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
22725 Flag toggling mDNS advertisement of the libvirt service.
22727 Alternatively can disable for all services on a host by stopping the
22730 Defaults to @samp{#f}.
22734 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
22735 Default mDNS advertisement name. This must be unique on the immediate
22738 Defaults to @samp{"Virtualization Host <hostname>"}.
22742 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
22743 UNIX domain socket group ownership. This can be used to allow a
22744 'trusted' set of users access to management capabilities without
22747 Defaults to @samp{"root"}.
22751 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
22752 UNIX socket permissions for the R/O socket. This is used for monitoring
22755 Defaults to @samp{"0777"}.
22759 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
22760 UNIX socket permissions for the R/W socket. Default allows only root.
22761 If PolicyKit is enabled on the socket, the default will change to allow
22762 everyone (eg, 0777)
22764 Defaults to @samp{"0770"}.
22768 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
22769 UNIX socket permissions for the admin socket. Default allows only owner
22770 (root), do not change it unless you are sure to whom you are exposing
22773 Defaults to @samp{"0777"}.
22777 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
22778 The directory in which sockets will be found/created.
22780 Defaults to @samp{"/var/run/libvirt"}.
22784 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
22785 Authentication scheme for UNIX read-only sockets. By default socket
22786 permissions allow anyone to connect
22788 Defaults to @samp{"polkit"}.
22792 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
22793 Authentication scheme for UNIX read-write sockets. By default socket
22794 permissions only allow root. If PolicyKit support was compiled into
22795 libvirt, the default will be to use 'polkit' auth.
22797 Defaults to @samp{"polkit"}.
22801 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
22802 Authentication scheme for TCP sockets. If you don't enable SASL, then
22803 all TCP traffic is cleartext. Don't do this outside of a dev/test
22806 Defaults to @samp{"sasl"}.
22810 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
22811 Authentication scheme for TLS sockets. TLS sockets already have
22812 encryption provided by the TLS layer, and limited authentication is done
22815 It is possible to make use of any SASL authentication mechanism as well,
22816 by using 'sasl' for this option
22818 Defaults to @samp{"none"}.
22822 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
22823 API access control scheme.
22825 By default an authenticated user is allowed access to all APIs. Access
22826 drivers can place restrictions on this.
22828 Defaults to @samp{()}.
22832 @deftypevr {@code{libvirt-configuration} parameter} string key-file
22833 Server key file path. If set to an empty string, then no private key is
22836 Defaults to @samp{""}.
22840 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
22841 Server key file path. If set to an empty string, then no certificate is
22844 Defaults to @samp{""}.
22848 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
22849 Server key file path. If set to an empty string, then no CA certificate
22852 Defaults to @samp{""}.
22856 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
22857 Certificate revocation list path. If set to an empty string, then no
22860 Defaults to @samp{""}.
22864 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
22865 Disable verification of our own server certificates.
22867 When libvirtd starts it performs some sanity checks against its own
22870 Defaults to @samp{#f}.
22874 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
22875 Disable verification of client certificates.
22877 Client certificate verification is the primary authentication mechanism.
22878 Any client which does not present a certificate signed by the CA will be
22881 Defaults to @samp{#f}.
22885 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
22886 Whitelist of allowed x509 Distinguished Name.
22888 Defaults to @samp{()}.
22892 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
22893 Whitelist of allowed SASL usernames. The format for username depends on
22894 the SASL authentication mechanism.
22896 Defaults to @samp{()}.
22900 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
22901 Override the compile time default TLS priority string. The default is
22902 usually "NORMAL" unless overridden at build time. Only set this is it
22903 is desired for libvirt to deviate from the global default settings.
22905 Defaults to @samp{"NORMAL"}.
22909 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
22910 Maximum number of concurrent client connections to allow over all
22913 Defaults to @samp{5000}.
22917 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
22918 Maximum length of queue of connections waiting to be accepted by the
22919 daemon. Note, that some protocols supporting retransmission may obey
22920 this so that a later reattempt at connection succeeds.
22922 Defaults to @samp{1000}.
22926 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
22927 Maximum length of queue of accepted but not yet authenticated clients.
22928 Set this to zero to turn this feature off
22930 Defaults to @samp{20}.
22934 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
22935 Number of workers to start up initially.
22937 Defaults to @samp{5}.
22941 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
22942 Maximum number of worker threads.
22944 If the number of active clients exceeds @code{min-workers}, then more
22945 threads are spawned, up to max_workers limit. Typically you'd want
22946 max_workers to equal maximum number of clients allowed.
22948 Defaults to @samp{20}.
22952 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
22953 Number of priority workers. If all workers from above pool are stuck,
22954 some calls marked as high priority (notably domainDestroy) can be
22955 executed in this pool.
22957 Defaults to @samp{5}.
22961 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
22962 Total global limit on concurrent RPC calls.
22964 Defaults to @samp{20}.
22968 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
22969 Limit on concurrent requests from a single client connection. To avoid
22970 one client monopolizing the server this should be a small fraction of
22971 the global max_requests and max_workers parameter.
22973 Defaults to @samp{5}.
22977 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
22978 Same as @code{min-workers} but for the admin interface.
22980 Defaults to @samp{1}.
22984 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
22985 Same as @code{max-workers} but for the admin interface.
22987 Defaults to @samp{5}.
22991 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
22992 Same as @code{max-clients} but for the admin interface.
22994 Defaults to @samp{5}.
22998 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
22999 Same as @code{max-queued-clients} but for the admin interface.
23001 Defaults to @samp{5}.
23005 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
23006 Same as @code{max-client-requests} but for the admin interface.
23008 Defaults to @samp{5}.
23012 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
23013 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23015 Defaults to @samp{3}.
23019 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
23022 A filter allows to select a different logging level for a given category
23023 of logs The format for a filter is one of:
23034 where @code{name} is a string which is matched against the category
23035 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23036 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23037 be a substring of the full category name, in order to match multiple
23038 similar categories), the optional "+" prefix tells libvirt to log stack
23039 trace for each message matching name, and @code{x} is the minimal level
23040 where matching messages should be logged:
23057 Multiple filters can be defined in a single filters statement, they just
23058 need to be separated by spaces.
23060 Defaults to @samp{"3:remote 4:event"}.
23064 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
23067 An output is one of the places to save logging information. The format
23068 for an output can be:
23072 output goes to stderr
23074 @item x:syslog:name
23075 use syslog for the output and use the given name as the ident
23077 @item x:file:file_path
23078 output to a file, with the given filepath
23081 output to journald logging system
23085 In all case the x prefix is the minimal level, acting as a filter
23102 Multiple outputs can be defined, they just need to be separated by
23105 Defaults to @samp{"3:stderr"}.
23109 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
23110 Allows usage of the auditing subsystem to be altered
23114 0: disable all auditing
23117 1: enable auditing, only if enabled on host
23120 2: enable auditing, and exit if disabled on host.
23124 Defaults to @samp{1}.
23128 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
23129 Send audit messages via libvirt logging infrastructure.
23131 Defaults to @samp{#f}.
23135 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
23136 Host UUID. UUID must not have all digits be the same.
23138 Defaults to @samp{""}.
23142 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
23143 Source to read host UUID.
23147 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
23150 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
23154 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
23157 Defaults to @samp{"smbios"}.
23161 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
23162 A keepalive message is sent to a client after @code{keepalive_interval}
23163 seconds of inactivity to check if the client is still responding. If
23164 set to -1, libvirtd will never send keepalive requests; however clients
23165 can still send them and the daemon will send responses.
23167 Defaults to @samp{5}.
23171 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
23172 Maximum number of keepalive messages that are allowed to be sent to the
23173 client without getting any response before the connection is considered
23176 In other words, the connection is automatically closed approximately
23177 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
23178 the last message received from the client. When @code{keepalive-count}
23179 is set to 0, connections will be automatically closed after
23180 @code{keepalive-interval} seconds of inactivity without sending any
23181 keepalive messages.
23183 Defaults to @samp{5}.
23187 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
23188 Same as above but for admin interface.
23190 Defaults to @samp{5}.
23194 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
23195 Same as above but for admin interface.
23197 Defaults to @samp{5}.
23201 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
23202 Timeout for Open vSwitch calls.
23204 The @code{ovs-vsctl} utility is used for the configuration and its
23205 timeout option is set by default to 5 seconds to avoid potential
23206 infinite waits blocking libvirt.
23208 Defaults to @samp{5}.
23212 @c %end of autogenerated docs
23214 @subsubheading Virtlog daemon
23215 The virtlogd service is a server side daemon component of libvirt that is
23216 used to manage logs from virtual machine consoles.
23218 This daemon is not used directly by libvirt client applications, rather it
23219 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
23220 standalone daemon, the main @code{libvirtd} daemon can be restarted without
23221 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
23222 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
23224 @deffn {Scheme Variable} virtlog-service-type
23225 This is the type of the virtlog daemon.
23226 Its value must be a @code{virtlog-configuration}.
23229 (service virtlog-service-type
23230 (virtlog-configuration
23231 (max-clients 1000)))
23235 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
23236 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
23238 Defaults to @samp{3}.
23242 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
23245 A filter allows to select a different logging level for a given category
23246 of logs The format for a filter is one of:
23257 where @code{name} is a string which is matched against the category
23258 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
23259 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
23260 be a substring of the full category name, in order to match multiple
23261 similar categories), the optional "+" prefix tells libvirt to log stack
23262 trace for each message matching name, and @code{x} is the minimal level
23263 where matching messages should be logged:
23280 Multiple filters can be defined in a single filters statement, they just
23281 need to be separated by spaces.
23283 Defaults to @samp{"3:remote 4:event"}.
23287 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
23290 An output is one of the places to save logging information The format
23291 for an output can be:
23295 output goes to stderr
23297 @item x:syslog:name
23298 use syslog for the output and use the given name as the ident
23300 @item x:file:file_path
23301 output to a file, with the given filepath
23304 output to journald logging system
23308 In all case the x prefix is the minimal level, acting as a filter
23325 Multiple outputs can be defined, they just need to be separated by
23328 Defaults to @samp{"3:stderr"}.
23332 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
23333 Maximum number of concurrent client connections to allow over all
23336 Defaults to @samp{1024}.
23340 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
23341 Maximum file size before rolling over.
23343 Defaults to @samp{2MB}
23347 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
23348 Maximum number of backup files to keep.
23350 Defaults to @samp{3}
23354 @subsubheading Transparent Emulation with QEMU
23357 @cindex @code{binfmt_misc}
23358 @code{qemu-binfmt-service-type} provides support for transparent
23359 emulation of program binaries built for different architectures---e.g.,
23360 it allows you to transparently execute an ARMv7 program on an x86_64
23361 machine. It achieves this by combining the @uref{https://www.qemu.org,
23362 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
23364 @defvr {Scheme Variable} qemu-binfmt-service-type
23365 This is the type of the QEMU/binfmt service for transparent emulation.
23366 Its value must be a @code{qemu-binfmt-configuration} object, which
23367 specifies the QEMU package to use as well as the architecture we want to
23371 (service qemu-binfmt-service-type
23372 (qemu-binfmt-configuration
23373 (platforms (lookup-qemu-platforms "arm" "aarch64" "mips64el"))))
23376 In this example, we enable transparent emulation for the ARM and aarch64
23377 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
23378 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
23379 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
23382 @deftp {Data Type} qemu-binfmt-configuration
23383 This is the configuration for the @code{qemu-binfmt} service.
23386 @item @code{platforms} (default: @code{'()})
23387 The list of emulated QEMU platforms. Each item must be a @dfn{platform
23388 object} as returned by @code{lookup-qemu-platforms} (see below).
23390 @item @code{guix-support?} (default: @code{#f})
23391 When it is true, QEMU and all its dependencies are added to the build
23392 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
23393 @code{--chroot-directory} option}). This allows the @code{binfmt_misc}
23394 handlers to be used within the build environment, which in turn means
23395 that you can transparently build programs for another architecture.
23397 For example, let's suppose you're on an x86_64 machine and you have this
23401 (service qemu-binfmt-service-type
23402 (qemu-binfmt-configuration
23403 (platforms (lookup-qemu-platforms "arm"))
23404 (guix-support? #t)))
23410 guix build -s armhf-linux inkscape
23414 and it will build Inkscape for ARMv7 @emph{as if it were a native
23415 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
23416 if you'd like to test a package build for an architecture you don't have
23419 @item @code{qemu} (default: @code{qemu})
23420 The QEMU package to use.
23424 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
23425 Return the list of QEMU platform objects corresponding to
23426 @var{platforms}@dots{}. @var{platforms} must be a list of strings
23427 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
23428 @code{"mips64el"}, and so on.
23431 @deffn {Scheme Procedure} qemu-platform? @var{obj}
23432 Return true if @var{obj} is a platform object.
23435 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
23436 Return the name of @var{platform}---a string such as @code{"arm"}.
23439 @node Version Control Services
23440 @subsection Version Control Services
23442 The @code{(gnu services version-control)} module provides a service to
23443 allow remote access to local Git repositories. There are three options:
23444 the @code{git-daemon-service}, which provides access to repositories via
23445 the @code{git://} unsecured TCP-based protocol, extending the
23446 @code{nginx} web server to proxy some requests to
23447 @code{git-http-backend}, or providing a web interface with
23448 @code{cgit-service-type}.
23450 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
23452 Return a service that runs @command{git daemon}, a simple TCP server to
23453 expose repositories over the Git protocol for anonymous access.
23455 The optional @var{config} argument should be a
23456 @code{<git-daemon-configuration>} object, by default it allows read-only
23457 access to exported@footnote{By creating the magic file
23458 "git-daemon-export-ok" in the repository directory.} repositories under
23463 @deftp {Data Type} git-daemon-configuration
23464 Data type representing the configuration for @code{git-daemon-service}.
23467 @item @code{package} (default: @var{git})
23468 Package object of the Git distributed version control system.
23470 @item @code{export-all?} (default: @var{#f})
23471 Whether to allow access for all Git repositories, even if they do not
23472 have the @file{git-daemon-export-ok} file.
23474 @item @code{base-path} (default: @file{/srv/git})
23475 Whether to remap all the path requests as relative to the given path.
23476 If you run git daemon with @var{(base-path "/srv/git")} on example.com,
23477 then if you later try to pull @code{git://example.com/hello.git}, git
23478 daemon will interpret the path as @code{/srv/git/hello.git}.
23480 @item @code{user-path} (default: @var{#f})
23481 Whether to allow @code{~user} notation to be used in requests. When
23482 specified with empty string, requests to @code{git://host/~alice/foo} is
23483 taken as a request to access @code{foo} repository in the home directory
23484 of user @code{alice}. If @var{(user-path "path")} is specified, the
23485 same request is taken as a request to access @code{path/foo} repository
23486 in the home directory of user @code{alice}.
23488 @item @code{listen} (default: @var{'()})
23489 Whether to listen on specific IP addresses or hostnames, defaults to
23492 @item @code{port} (default: @var{#f})
23493 Whether to listen on an alternative port, which defaults to 9418.
23495 @item @code{whitelist} (default: @var{'()})
23496 If not empty, only allow access to this list of directories.
23498 @item @code{extra-options} (default: @var{'()})
23499 Extra options will be passed to @code{git daemon}, please run
23500 @command{man git-daemon} for more information.
23505 The @code{git://} protocol lacks authentication. When you pull from a
23506 repository fetched via @code{git://}, you don't know whether the data you
23507 receive was modified or is even coming from the specified host, and your
23508 connection is subject to eavesdropping. It's better to use an authenticated
23509 and encrypted transport, such as @code{https}. Although Git allows you
23510 to serve repositories using unsophisticated file-based web servers,
23511 there is a faster protocol implemented by the @code{git-http-backend}
23512 program. This program is the back-end of a proper Git web service. It
23513 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
23514 on running the necessary @code{fcgiwrap} daemon.
23516 Guix has a separate configuration data type for serving Git repositories
23519 @deftp {Data Type} git-http-configuration
23520 Data type representing the configuration for @code{git-http-service}.
23523 @item @code{package} (default: @var{git})
23524 Package object of the Git distributed version control system.
23526 @item @code{git-root} (default: @file{/srv/git})
23527 Directory containing the Git repositories to expose to the world.
23529 @item @code{export-all?} (default: @var{#f})
23530 Whether to expose access for all Git repositories in @var{git-root},
23531 even if they do not have the @file{git-daemon-export-ok} file.
23533 @item @code{uri-path} (default: @file{/git/})
23534 Path prefix for Git access. With the default @code{/git/} prefix, this
23535 will map @code{http://@var{server}/git/@var{repo}.git} to
23536 @code{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
23537 with this prefix are not passed on to this Git instance.
23539 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
23540 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
23545 There is no @code{git-http-service-type}, currently; instead you can
23546 create an @code{nginx-location-configuration} from a
23547 @code{git-http-configuration} and then add that location to a web
23550 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
23551 [config=(git-http-configuration)]
23552 Compute an @code{nginx-location-configuration} that corresponds to the
23553 given Git http configuration. An example nginx service definition to
23554 serve the default @file{/srv/git} over HTTPS might be:
23557 (service nginx-service-type
23558 (nginx-configuration
23561 (nginx-server-configuration
23562 (listen '("443 ssl"))
23563 (server-name "git.my-host.org")
23565 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
23566 (ssl-certificate-key
23567 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
23570 (git-http-nginx-location-configuration
23571 (git-http-configuration (uri-path "/"))))))))))
23574 This example assumes that you are using Let's Encrypt to get your TLS
23575 certificate. @xref{Certificate Services}. The default @code{certbot}
23576 service will redirect all HTTP traffic on @code{git.my-host.org} to
23577 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
23578 system services. @xref{Web Services}.
23581 @subsubheading Cgit Service
23583 @cindex Cgit service
23584 @cindex Git, web interface
23585 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
23586 repositories written in C.
23588 The following example will configure the service with default values.
23589 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
23592 (service cgit-service-type)
23595 The @code{file-object} type designates either a file-like object
23596 (@pxref{G-Expressions, file-like objects}) or a string.
23598 @c %start of fragment
23600 Available @code{cgit-configuration} fields are:
23602 @deftypevr {@code{cgit-configuration} parameter} package package
23607 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
23608 NGINX configuration.
23612 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
23613 Specifies a command which will be invoked to format the content of about
23614 pages (both top-level and for each repository).
23616 Defaults to @samp{""}.
23620 @deftypevr {@code{cgit-configuration} parameter} string agefile
23621 Specifies a path, relative to each repository path, which can be used to
23622 specify the date and time of the youngest commit in the repository.
23624 Defaults to @samp{""}.
23628 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
23629 Specifies a command that will be invoked for authenticating repository
23632 Defaults to @samp{""}.
23636 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
23637 Flag which, when set to @samp{age}, enables date ordering in the branch
23638 ref list, and when set @samp{name} enables ordering by branch name.
23640 Defaults to @samp{"name"}.
23644 @deftypevr {@code{cgit-configuration} parameter} string cache-root
23645 Path used to store the cgit cache entries.
23647 Defaults to @samp{"/var/cache/cgit"}.
23651 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
23652 Number which specifies the time-to-live, in minutes, for the cached
23653 version of repository pages accessed with a fixed SHA1.
23655 Defaults to @samp{-1}.
23659 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
23660 Number which specifies the time-to-live, in minutes, for the cached
23661 version of repository pages accessed without a fixed SHA1.
23663 Defaults to @samp{5}.
23667 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
23668 Number which specifies the time-to-live, in minutes, for the cached
23669 version of the repository summary page.
23671 Defaults to @samp{5}.
23675 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
23676 Number which specifies the time-to-live, in minutes, for the cached
23677 version of the repository index page.
23679 Defaults to @samp{5}.
23683 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
23684 Number which specifies the time-to-live, in minutes, for the result of
23685 scanning a path for Git repositories.
23687 Defaults to @samp{15}.
23691 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
23692 Number which specifies the time-to-live, in minutes, for the cached
23693 version of the repository about page.
23695 Defaults to @samp{15}.
23699 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
23700 Number which specifies the time-to-live, in minutes, for the cached
23701 version of snapshots.
23703 Defaults to @samp{5}.
23707 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
23708 The maximum number of entries in the cgit cache. When set to @samp{0},
23709 caching is disabled.
23711 Defaults to @samp{0}.
23715 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
23716 Sort items in the repo list case sensitively.
23718 Defaults to @samp{#t}.
23722 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
23723 List of common prefixes which, when combined with a repository URL,
23724 generates valid clone URLs for the repository.
23726 Defaults to @samp{()}.
23730 @deftypevr {@code{cgit-configuration} parameter} list clone-url
23731 List of @code{clone-url} templates.
23733 Defaults to @samp{()}.
23737 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
23738 Command which will be invoked to format commit messages.
23740 Defaults to @samp{""}.
23744 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
23745 Flag which, when set to @samp{date}, enables strict date ordering in the
23746 commit log, and when set to @samp{topo} enables strict topological
23749 Defaults to @samp{"git log"}.
23753 @deftypevr {@code{cgit-configuration} parameter} file-object css
23754 URL which specifies the css document to include in all cgit pages.
23756 Defaults to @samp{"/share/cgit/cgit.css"}.
23760 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
23761 Specifies a command which will be invoked to format names and email
23762 address of committers, authors, and taggers, as represented in various
23763 places throughout the cgit interface.
23765 Defaults to @samp{""}.
23769 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
23770 Flag which, when set to @samp{#t}, will make cgit generate a HTML
23771 fragment suitable for embedding in other HTML pages.
23773 Defaults to @samp{#f}.
23777 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
23778 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
23779 commit history graph to the left of the commit messages in the
23780 repository log page.
23782 Defaults to @samp{#f}.
23786 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
23787 Flag which, when set to @samp{#t}, allows all filter settings to be
23788 overridden in repository-specific cgitrc files.
23790 Defaults to @samp{#f}.
23794 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
23795 Flag which, when set to @samp{#t}, allows users to follow a file in the
23798 Defaults to @samp{#f}.
23802 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
23803 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
23806 Defaults to @samp{#t}.
23810 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
23811 Flag which, when set to @samp{#t}, will make cgit generate extra links
23812 "summary", "commit", "tree" for each repo in the repository index.
23814 Defaults to @samp{#f}.
23818 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
23819 Flag which, when set to @samp{#t}, will make cgit display the owner of
23820 each repo in the repository index.
23822 Defaults to @samp{#t}.
23826 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
23827 Flag which, when set to @samp{#t}, will make cgit print the number of
23828 modified files for each commit on the repository log page.
23830 Defaults to @samp{#f}.
23834 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
23835 Flag which, when set to @samp{#t}, will make cgit print the number of
23836 added and removed lines for each commit on the repository log page.
23838 Defaults to @samp{#f}.
23842 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
23843 Flag which, when set to @code{#t}, will make cgit display remote
23844 branches in the summary and refs views.
23846 Defaults to @samp{#f}.
23850 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
23851 Flag which, when set to @code{1}, will make cgit use the subject of the
23852 parent commit as link text when generating links to parent commits in
23855 Defaults to @samp{#f}.
23859 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
23860 Flag which, when set to @samp{#t}, will make cgit use the subject of the
23861 parent commit as link text when generating links to parent commits in
23864 Defaults to @samp{#f}.
23868 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
23869 Flag which, when set to @samp{#t}, will make cgit generate linenumber
23870 links for plaintext blobs printed in the tree view.
23872 Defaults to @samp{#t}.
23876 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
23877 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
23878 set any repo specific settings.
23880 Defaults to @samp{#f}.
23884 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
23885 URL used as link to a shortcut icon for cgit.
23887 Defaults to @samp{"/favicon.ico"}.
23891 @deftypevr {@code{cgit-configuration} parameter} string footer
23892 The content of the file specified with this option will be included
23893 verbatim at the bottom of all pages (i.e.@: it replaces the standard
23894 "generated by..."@: message).
23896 Defaults to @samp{""}.
23900 @deftypevr {@code{cgit-configuration} parameter} string head-include
23901 The content of the file specified with this option will be included
23902 verbatim in the HTML HEAD section on all pages.
23904 Defaults to @samp{""}.
23908 @deftypevr {@code{cgit-configuration} parameter} string header
23909 The content of the file specified with this option will be included
23910 verbatim at the top of all pages.
23912 Defaults to @samp{""}.
23916 @deftypevr {@code{cgit-configuration} parameter} file-object include
23917 Name of a configfile to include before the rest of the current config-
23920 Defaults to @samp{""}.
23924 @deftypevr {@code{cgit-configuration} parameter} string index-header
23925 The content of the file specified with this option will be included
23926 verbatim above the repository index.
23928 Defaults to @samp{""}.
23932 @deftypevr {@code{cgit-configuration} parameter} string index-info
23933 The content of the file specified with this option will be included
23934 verbatim below the heading on the repository index page.
23936 Defaults to @samp{""}.
23940 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
23941 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
23942 in the servers timezone.
23944 Defaults to @samp{#f}.
23948 @deftypevr {@code{cgit-configuration} parameter} file-object logo
23949 URL which specifies the source of an image which will be used as a logo
23952 Defaults to @samp{"/share/cgit/cgit.png"}.
23956 @deftypevr {@code{cgit-configuration} parameter} string logo-link
23957 URL loaded when clicking on the cgit logo image.
23959 Defaults to @samp{""}.
23963 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
23964 Command which will be invoked to format the Owner column of the main
23967 Defaults to @samp{""}.
23971 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
23972 Number of items to display in atom feeds view.
23974 Defaults to @samp{10}.
23978 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
23979 Number of entries to list per page in "log" view.
23981 Defaults to @samp{50}.
23985 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
23986 Number of commit message characters to display in "log" view.
23988 Defaults to @samp{80}.
23992 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
23993 Specifies the number of entries to list per page on the repository index
23996 Defaults to @samp{50}.
24000 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
24001 Specifies the maximum number of repo description characters to display
24002 on the repository index page.
24004 Defaults to @samp{80}.
24008 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
24009 Specifies the maximum size of a blob to display HTML for in KBytes.
24011 Defaults to @samp{0}.
24015 @deftypevr {@code{cgit-configuration} parameter} string max-stats
24016 Maximum statistics period. Valid values are @samp{week},@samp{month},
24017 @samp{quarter} and @samp{year}.
24019 Defaults to @samp{""}.
24023 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
24024 Mimetype for the specified filename extension.
24026 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
24027 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
24028 "image/png") (svg "image/svg+xml"))}.
24032 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
24033 Specifies the file to use for automatic mimetype lookup.
24035 Defaults to @samp{""}.
24039 @deftypevr {@code{cgit-configuration} parameter} string module-link
24040 Text which will be used as the formatstring for a hyperlink when a
24041 submodule is printed in a directory listing.
24043 Defaults to @samp{""}.
24047 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
24048 If set to the value @samp{#t} caching will be disabled.
24050 Defaults to @samp{#f}.
24054 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
24055 If set to @samp{#t} showing full author email addresses will be
24058 Defaults to @samp{#f}.
24062 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
24063 Flag which, when set to @samp{#t}, will make cgit omit the standard
24064 header on all pages.
24066 Defaults to @samp{#f}.
24070 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
24071 A list of subdirectories inside of @code{repository-directory}, relative
24072 to it, that should loaded as Git repositories. An empty list means that
24073 all subdirectories will be loaded.
24075 Defaults to @samp{()}.
24079 @deftypevr {@code{cgit-configuration} parameter} file-object readme
24080 Text which will be used as default value for @code{cgit-repo-readme}.
24082 Defaults to @samp{""}.
24086 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
24087 If set to @code{#t} and @code{repository-directory} is enabled, if any
24088 repositories are found with a suffix of @code{.git}, this suffix will be
24089 removed for the URL and name.
24091 Defaults to @samp{#f}.
24095 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
24096 Maximum number of files to consider when detecting renames.
24098 Defaults to @samp{-1}.
24102 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
24103 The way in which repositories in each section are sorted.
24105 Defaults to @samp{""}.
24109 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
24110 Text used as content for the @code{robots} meta-tag.
24112 Defaults to @samp{("noindex" "nofollow")}.
24116 @deftypevr {@code{cgit-configuration} parameter} string root-desc
24117 Text printed below the heading on the repository index page.
24119 Defaults to @samp{"a fast webinterface for the git dscm"}.
24123 @deftypevr {@code{cgit-configuration} parameter} string root-readme
24124 The content of the file specified with this option will be included
24125 verbatim below thef "about" link on the repository index page.
24127 Defaults to @samp{""}.
24131 @deftypevr {@code{cgit-configuration} parameter} string root-title
24132 Text printed as heading on the repository index page.
24134 Defaults to @samp{""}.
24138 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
24139 If set to @samp{#t} and repository-directory is enabled,
24140 repository-directory will recurse into directories whose name starts
24141 with a period. Otherwise, repository-directory will stay away from such
24142 directories, considered as "hidden". Note that this does not apply to
24143 the ".git" directory in non-bare repos.
24145 Defaults to @samp{#f}.
24149 @deftypevr {@code{cgit-configuration} parameter} list snapshots
24150 Text which specifies the default set of snapshot formats that cgit
24151 generates links for.
24153 Defaults to @samp{()}.
24157 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
24158 Name of the directory to scan for repositories (represents
24161 Defaults to @samp{"/srv/git"}.
24165 @deftypevr {@code{cgit-configuration} parameter} string section
24166 The name of the current repository section - all repositories defined
24167 after this option will inherit the current section name.
24169 Defaults to @samp{""}.
24173 @deftypevr {@code{cgit-configuration} parameter} string section-sort
24174 Flag which, when set to @samp{1}, will sort the sections on the
24175 repository listing by name.
24177 Defaults to @samp{""}.
24181 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
24182 A number which, if defined prior to repository-directory, specifies how
24183 many path elements from each repo path to use as a default section name.
24185 Defaults to @samp{0}.
24189 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
24190 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
24193 Defaults to @samp{#f}.
24197 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
24198 Specifies a command which will be invoked to format plaintext blobs in
24201 Defaults to @samp{""}.
24205 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
24206 Specifies the number of branches to display in the repository "summary"
24209 Defaults to @samp{10}.
24213 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
24214 Specifies the number of log entries to display in the repository
24217 Defaults to @samp{10}.
24221 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
24222 Specifies the number of tags to display in the repository "summary"
24225 Defaults to @samp{10}.
24229 @deftypevr {@code{cgit-configuration} parameter} string strict-export
24230 Filename which, if specified, needs to be present within the repository
24231 for cgit to allow access to that repository.
24233 Defaults to @samp{""}.
24237 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
24238 URL which, if specified, will be used as root for all cgit links.
24240 Defaults to @samp{"/"}.
24244 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
24245 A list of @dfn{cgit-repo} records to use with config.
24247 Defaults to @samp{()}.
24249 Available @code{repository-cgit-configuration} fields are:
24251 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
24252 A mask of snapshot formats for this repo that cgit generates links for,
24253 restricted by the global @code{snapshots} setting.
24255 Defaults to @samp{()}.
24259 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
24260 Override the default @code{source-filter}.
24262 Defaults to @samp{""}.
24266 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
24267 The relative URL used to access the repository.
24269 Defaults to @samp{""}.
24273 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
24274 Override the default @code{about-filter}.
24276 Defaults to @samp{""}.
24280 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
24281 Flag which, when set to @samp{age}, enables date ordering in the branch
24282 ref list, and when set to @samp{name} enables ordering by branch name.
24284 Defaults to @samp{""}.
24288 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
24289 A list of URLs which can be used to clone repo.
24291 Defaults to @samp{()}.
24295 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
24296 Override the default @code{commit-filter}.
24298 Defaults to @samp{""}.
24302 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
24303 Flag which, when set to @samp{date}, enables strict date ordering in the
24304 commit log, and when set to @samp{topo} enables strict topological
24307 Defaults to @samp{""}.
24311 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
24312 The name of the default branch for this repository. If no such branch
24313 exists in the repository, the first branch name (when sorted) is used as
24314 default instead. By default branch pointed to by HEAD, or "master" if
24315 there is no suitable HEAD.
24317 Defaults to @samp{""}.
24321 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
24322 The value to show as repository description.
24324 Defaults to @samp{""}.
24328 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
24329 The value to show as repository homepage.
24331 Defaults to @samp{""}.
24335 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
24336 Override the default @code{email-filter}.
24338 Defaults to @samp{""}.
24342 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
24343 A flag which can be used to disable the global setting
24344 @code{enable-commit-graph?}.
24346 Defaults to @samp{disabled}.
24350 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
24351 A flag which can be used to disable the global setting
24352 @code{enable-log-filecount?}.
24354 Defaults to @samp{disabled}.
24358 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
24359 A flag which can be used to disable the global setting
24360 @code{enable-log-linecount?}.
24362 Defaults to @samp{disabled}.
24366 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
24367 Flag which, when set to @code{#t}, will make cgit display remote
24368 branches in the summary and refs views.
24370 Defaults to @samp{disabled}.
24374 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
24375 A flag which can be used to override the global setting
24376 @code{enable-subject-links?}.
24378 Defaults to @samp{disabled}.
24382 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
24383 A flag which can be used to override the global setting
24384 @code{enable-html-serving?}.
24386 Defaults to @samp{disabled}.
24390 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
24391 Flag which, when set to @code{#t}, hides the repository from the
24394 Defaults to @samp{#f}.
24398 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
24399 Flag which, when set to @samp{#t}, ignores the repository.
24401 Defaults to @samp{#f}.
24405 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
24406 URL which specifies the source of an image which will be used as a logo
24407 on this repo’s pages.
24409 Defaults to @samp{""}.
24413 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
24414 URL loaded when clicking on the cgit logo image.
24416 Defaults to @samp{""}.
24420 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
24421 Override the default @code{owner-filter}.
24423 Defaults to @samp{""}.
24427 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
24428 Text which will be used as the formatstring for a hyperlink when a
24429 submodule is printed in a directory listing. The arguments for the
24430 formatstring are the path and SHA1 of the submodule commit.
24432 Defaults to @samp{""}.
24436 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
24437 Text which will be used as the formatstring for a hyperlink when a
24438 submodule with the specified subdirectory path is printed in a directory
24441 Defaults to @samp{()}.
24445 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
24446 Override the default maximum statistics period.
24448 Defaults to @samp{""}.
24452 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
24453 The value to show as repository name.
24455 Defaults to @samp{""}.
24459 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
24460 A value used to identify the owner of the repository.
24462 Defaults to @samp{""}.
24466 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
24467 An absolute path to the repository directory.
24469 Defaults to @samp{""}.
24473 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
24474 A path (relative to repo) which specifies a file to include verbatim as
24475 the "About" page for this repo.
24477 Defaults to @samp{""}.
24481 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
24482 The name of the current repository section - all repositories defined
24483 after this option will inherit the current section name.
24485 Defaults to @samp{""}.
24489 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
24490 Extra options will be appended to cgitrc file.
24492 Defaults to @samp{()}.
24498 @deftypevr {@code{cgit-configuration} parameter} list extra-options
24499 Extra options will be appended to cgitrc file.
24501 Defaults to @samp{()}.
24506 @c %end of fragment
24508 However, it could be that you just want to get a @code{cgitrc} up and
24509 running. In that case, you can pass an @code{opaque-cgit-configuration}
24510 as a record to @code{cgit-service-type}. As its name indicates, an
24511 opaque configuration does not have easy reflective capabilities.
24513 Available @code{opaque-cgit-configuration} fields are:
24515 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
24519 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
24520 The contents of the @code{cgitrc}, as a string.
24523 For example, if your @code{cgitrc} is just the empty string, you
24524 could instantiate a cgit service like this:
24527 (service cgit-service-type
24528 (opaque-cgit-configuration
24532 @subsubheading Gitolite Service
24534 @cindex Gitolite service
24535 @cindex Git, hosting
24536 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
24537 repositories on a central server.
24539 Gitolite can handle multiple repositories and users, and supports flexible
24540 configuration of the permissions for the users on the repositories.
24542 The following example will configure Gitolite using the default @code{git}
24543 user, and the provided SSH public key.
24546 (service gitolite-service-type
24547 (gitolite-configuration
24548 (admin-pubkey (plain-file
24550 "ssh-rsa AAAA... guix@@example.com"))))
24553 Gitolite is configured through a special admin repository which you can clone,
24554 for example, if you setup Gitolite on @code{example.com}, you would run the
24555 following command to clone the admin repository.
24558 git clone git@@example.com:gitolite-admin
24561 When the Gitolite service is activated, the provided @code{admin-pubkey} will
24562 be inserted in to the @file{keydir} directory in the gitolite-admin
24563 repository. If this results in a change in the repository, it will be
24564 committed using the message ``gitolite setup by GNU Guix''.
24566 @deftp {Data Type} gitolite-configuration
24567 Data type representing the configuration for @code{gitolite-service-type}.
24570 @item @code{package} (default: @var{gitolite})
24571 Gitolite package to use.
24573 @item @code{user} (default: @var{git})
24574 User to use for Gitolite. This will be user that you use when accessing
24577 @item @code{group} (default: @var{git})
24578 Group to use for Gitolite.
24580 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
24581 Directory in which to store the Gitolite configuration and repositories.
24583 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
24584 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
24585 representing the configuration for Gitolite.
24587 @item @code{admin-pubkey} (default: @var{#f})
24588 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
24589 setup Gitolite. This will be inserted in to the @file{keydir} directory
24590 within the gitolite-admin repository.
24592 To specify the SSH key as a string, use the @code{plain-file} function.
24595 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
24601 @deftp {Data Type} gitolite-rc-file
24602 Data type representing the Gitolite RC file.
24605 @item @code{umask} (default: @code{#o0077})
24606 This controls the permissions Gitolite sets on the repositories and their
24609 A value like @code{#o0027} will give read access to the group used by Gitolite
24610 (by default: @code{git}). This is necessary when using Gitolite with software
24611 like cgit or gitweb.
24613 @item @code{git-config-keys} (default: @code{""})
24614 Gitolite allows you to set git config values using the "config" keyword. This
24615 setting allows control over the config keys to accept.
24617 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
24618 Set the role names allowed to be used by users running the perms command.
24620 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
24621 This setting controls the commands and features to enable within Gitolite.
24627 @node Game Services
24628 @subsection Game Services
24630 @subsubheading The Battle for Wesnoth Service
24632 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
24633 based tactical strategy game, with several single player campaigns, and
24634 multiplayer games (both networked and local).
24636 @defvar {Scheme Variable} wesnothd-service-type
24637 Service type for the wesnothd service. Its value must be a
24638 @code{wesnothd-configuration} object. To run wesnothd in the default
24639 configuration, instantiate it as:
24642 (service wesnothd-service-type)
24646 @deftp {Data Type} wesnothd-configuration
24647 Data type representing the configuration of @command{wesnothd}.
24650 @item @code{package} (default: @code{wesnoth-server})
24651 The wesnoth server package to use.
24653 @item @code{port} (default: @code{15000})
24654 The port to bind the server to.
24659 @node Guix Services
24660 @subsection Guix Services
24662 @subsubheading Guix Data Service
24663 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
24664 and provides data about GNU Guix. This includes information about
24665 packages, derivations and lint warnings.
24667 The data is stored in a PostgreSQL database, and available through a web
24670 @defvar {Scheme Variable} guix-data-service-type
24671 Service type for the Guix Data Service. Its value must be a
24672 @code{guix-data-service-configuration} object. The service optionally
24673 extends the getmail service, as the guix-commits mailing list is used to
24674 find out about changes in the Guix git repository.
24677 @deftp {Data Type} guix-data-service-configuration
24678 Data type representing the configuration of the Guix Data Service.
24681 @item @code{package} (default: @code{guix-data-service})
24682 The Guix Data Service package to use.
24684 @item @code{user} (default: @code{"guix-data-service"})
24685 The system user to run the service as.
24687 @item @code{group} (default: @code{"guix-data-service"})
24688 The system group to run the service as.
24690 @item @code{port} (default: @code{8765})
24691 The port to bind the web service to.
24693 @item @code{host} (default: @code{"127.0.0.1"})
24694 The host to bind the web service to.
24696 @item @code{getmail-idle-mailboxes} (default: @code{#f})
24697 If set, this is the list of mailboxes that the getmail service will be
24698 configured to listen to.
24700 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
24701 If set, this is the @code{getmail-retriever-configuration} object with
24702 which to configure getmail to fetch mail from the guix-commits mailing
24709 @node Miscellaneous Services
24710 @subsection Miscellaneous Services
24712 @cindex fingerprint
24713 @subsubheading Fingerprint Service
24715 The @code{(gnu services authentication)} module provides a DBus service to
24716 read and identify fingerprints via a fingerprint sensor.
24718 @defvr {Scheme Variable} fprintd-service-type
24719 The service type for @command{fprintd}, which provides the fingerprint
24720 reading capability.
24723 (service fprintd-service-type)
24728 @subsubheading System Control Service
24730 The @code{(gnu services sysctl)} provides a service to configure kernel
24731 parameters at boot.
24733 @defvr {Scheme Variable} sysctl-service-type
24734 The service type for @command{sysctl}, which modifies kernel parameters
24735 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
24739 (service sysctl-service-type
24740 (sysctl-configuration
24741 (settings '(("net.ipv4.ip_forward" . "1")))))
24745 @deftp {Data Type} sysctl-configuration
24746 The data type representing the configuration of @command{sysctl}.
24749 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
24750 The @command{sysctl} executable to use.
24752 @item @code{settings} (default: @code{'()})
24753 An association list specifies kernel parameters and their values.
24758 @subsubheading PC/SC Smart Card Daemon Service
24760 The @code{(gnu services security-token)} module provides the following service
24761 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
24762 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
24763 manager that coordinates communications with smart card readers, smart cards
24764 and cryptographic tokens that are connected to the system.
24766 @defvr {Scheme Variable} pcscd-service-type
24767 Service type for the @command{pcscd} service. Its value must be a
24768 @code{pcscd-configuration} object. To run pcscd in the default
24769 configuration, instantiate it as:
24772 (service pcscd-service-type)
24776 @deftp {Data Type} pcscd-configuration
24777 The data type representing the configuration of @command{pcscd}.
24780 @item @code{pcsc-lite} (default: @code{pcsc-lite})
24781 The pcsc-lite package that provides pcscd.
24782 @item @code{usb-drivers} (default: @code{(list ccid)})
24783 List of packages that provide USB drivers to pcscd. Drivers are expected to be
24784 under @file{pcsc/drivers} in the store directory of the package.
24789 @subsubheading Lirc Service
24791 The @code{(gnu services lirc)} module provides the following service.
24793 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
24794 [#:device #f] [#:driver #f] [#:config-file #f] @
24795 [#:extra-options '()]
24796 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
24797 decodes infrared signals from remote controls.
24799 Optionally, @var{device}, @var{driver} and @var{config-file}
24800 (configuration file name) may be specified. See @command{lircd} manual
24803 Finally, @var{extra-options} is a list of additional command-line options
24804 passed to @command{lircd}.
24808 @subsubheading Spice Service
24810 The @code{(gnu services spice)} module provides the following service.
24812 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
24813 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
24814 that enables sharing the clipboard with a vm and setting the guest display
24815 resolution when the graphical console window resizes.
24818 @cindex inputattach
24819 @subsubheading inputattach Service
24821 @cindex tablet input, for Xorg
24822 @cindex touchscreen input, for Xorg
24823 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
24824 use input devices such as Wacom tablets, touchscreens, or joysticks with the
24825 Xorg display server.
24827 @deffn {Scheme Variable} inputattach-service-type
24828 Type of a service that runs @command{inputattach} on a device and
24829 dispatches events from it.
24832 @deftp {Data Type} inputattach-configuration
24834 @item @code{device-type} (default: @code{"wacom"})
24835 The type of device to connect to. Run @command{inputattach --help}, from the
24836 @code{inputattach} package, to see the list of supported device types.
24838 @item @code{device} (default: @code{"/dev/ttyS0"})
24839 The device file to connect to the device.
24841 @item @code{baud-rate} (default: @code{#f})
24842 Baud rate to use for the serial connection.
24843 Should be a number or @code{#f}.
24845 @item @code{log-file} (default: @code{#f})
24846 If true, this must be the name of a file to log messages to.
24850 @subsection Dictionary Services
24852 The @code{(gnu services dict)} module provides the following service:
24854 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
24855 Return a service that runs the @command{dicod} daemon, an implementation
24856 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
24858 The optional @var{config} argument specifies the configuration for
24859 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
24860 default it serves the GNU Collaborative International Dictonary of English.
24862 You can add @command{open localhost} to your @file{~/.dico} file to make
24863 @code{localhost} the default server for @command{dico} client
24864 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
24867 @deftp {Data Type} dicod-configuration
24868 Data type representing the configuration of dicod.
24871 @item @code{dico} (default: @var{dico})
24872 Package object of the GNU Dico dictionary server.
24874 @item @code{interfaces} (default: @var{'("localhost")})
24875 This is the list of IP addresses and ports and possibly socket file
24876 names to listen to (@pxref{Server Settings, @code{listen} directive,,
24877 dico, GNU Dico Manual}).
24879 @item @code{handlers} (default: @var{'()})
24880 List of @code{<dicod-handler>} objects denoting handlers (module instances).
24882 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
24883 List of @code{<dicod-database>} objects denoting dictionaries to be served.
24887 @deftp {Data Type} dicod-handler
24888 Data type representing a dictionary handler (module instance).
24892 Name of the handler (module instance).
24894 @item @code{module} (default: @var{#f})
24895 Name of the dicod module of the handler (instance). If it is @code{#f},
24896 the module has the same name as the handler.
24897 (@pxref{Modules,,, dico, GNU Dico Manual}).
24899 @item @code{options}
24900 List of strings or gexps representing the arguments for the module handler
24904 @deftp {Data Type} dicod-database
24905 Data type representing a dictionary database.
24909 Name of the database, will be used in DICT commands.
24911 @item @code{handler}
24912 Name of the dicod handler (module instance) used by this database
24913 (@pxref{Handlers,,, dico, GNU Dico Manual}).
24915 @item @code{complex?} (default: @var{#f})
24916 Whether the database configuration complex. The complex configuration
24917 will need a corresponding @code{<dicod-handler>} object, otherwise not.
24919 @item @code{options}
24920 List of strings or gexps representing the arguments for the database
24921 (@pxref{Databases,,, dico, GNU Dico Manual}).
24925 @defvr {Scheme Variable} %dicod-database:gcide
24926 A @code{<dicod-database>} object serving the GNU Collaborative International
24927 Dictionary of English using the @code{gcide} package.
24930 The following is an example @code{dicod-service} configuration.
24933 (dicod-service #:config
24934 (dicod-configuration
24935 (handlers (list (dicod-handler
24939 (list #~(string-append "dbdir=" #$wordnet))))))
24940 (databases (list (dicod-database
24943 (handler "wordnet")
24944 (options '("database=wn")))
24945 %dicod-database:gcide))))
24949 @subsubheading Docker Service
24951 The @code{(gnu services docker)} module provides the following services.
24953 @defvr {Scheme Variable} docker-service-type
24955 This is the type of the service that runs @url{https://www.docker.com,Docker},
24956 a daemon that can execute application bundles (sometimes referred to as
24957 ``containers'') in isolated environments.
24961 @deftp {Data Type} docker-configuration
24962 This is the data type representing the configuration of Docker and Containerd.
24966 @item @code{package} (default: @code{docker})
24967 The Docker package to use.
24969 @item @code{containerd} (default: @var{containerd})
24970 The Containerd package to use.
24976 @subsubheading Auditd Service
24978 The @code{(gnu services auditd)} module provides the following service.
24980 @defvr {Scheme Variable} auditd-service-type
24982 This is the type of the service that runs
24983 @url{https://people.redhat.com/sgrubb/audit/,auditd},
24984 a daemon that tracks security-relevant information on your system.
24986 Examples of things that can be tracked:
24996 Failed login attempts
25003 @command{auditctl} from the @code{audit} package can be used in order
25004 to add or remove events to be tracked (until the next reboot).
25005 In order to permanently track events, put the command line arguments
25006 of auditctl into @file{/etc/audit/audit.rules}.
25007 @command{aureport} from the @code{audit} package can be used in order
25008 to view a report of all recorded events.
25009 The audit daemon usually logs into the directory @file{/var/log/audit}.
25013 @deftp {Data Type} auditd-configuration
25014 This is the data type representing the configuration of auditd.
25018 @item @code{audit} (default: @code{audit})
25019 The audit package to use.
25024 @defvr {Scheme Variable} singularity-service-type
25025 This is the type of the service that allows you to run
25026 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
25027 create and run application bundles (aka. ``containers''). The value for this
25028 service is the Singularity package to use.
25030 The service does not install a daemon; instead, it installs helper programs as
25031 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
25032 @command{singularity run} and similar commands.
25036 @subsubheading Nix service
25038 The @code{(gnu services nix)} module provides the following service.
25040 @defvr {Scheme Variable} nix-service-type
25042 This is the type of the service that runs build daemon of the
25043 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
25047 (use-modules (gnu))
25048 (use-service-modules nix)
25049 (use-package-modules package-management)
25053 (packages (append (list nix)
25056 (services (append (list (service nix-service-type))
25060 After @command{guix system reconfigure} configure Nix for your user:
25063 @item Add a Nix channel and update it. See
25064 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
25066 @item Create a symlink to your profile and activate Nix profile:
25070 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
25071 $ source /run/current-system/profile/etc/profile.d/nix.sh
25076 @node Setuid Programs
25077 @section Setuid Programs
25079 @cindex setuid programs
25080 Some programs need to run with ``root'' privileges, even when they are
25081 launched by unprivileged users. A notorious example is the
25082 @command{passwd} program, which users can run to change their
25083 password, and which needs to access the @file{/etc/passwd} and
25084 @file{/etc/shadow} files---something normally restricted to root, for
25085 obvious security reasons. To address that, these executables are
25086 @dfn{setuid-root}, meaning that they always run with root privileges
25087 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
25088 for more info about the setuid mechanism.)
25090 The store itself @emph{cannot} contain setuid programs: that would be a
25091 security issue since any user on the system can write derivations that
25092 populate the store (@pxref{The Store}). Thus, a different mechanism is
25093 used: instead of changing the setuid bit directly on files that are in
25094 the store, we let the system administrator @emph{declare} which programs
25095 should be setuid root.
25097 The @code{setuid-programs} field of an @code{operating-system}
25098 declaration contains a list of G-expressions denoting the names of
25099 programs to be setuid-root (@pxref{Using the Configuration System}).
25100 For instance, the @command{passwd} program, which is part of the Shadow
25101 package, can be designated by this G-expression (@pxref{G-Expressions}):
25104 #~(string-append #$shadow "/bin/passwd")
25107 A default set of setuid programs is defined by the
25108 @code{%setuid-programs} variable of the @code{(gnu system)} module.
25110 @defvr {Scheme Variable} %setuid-programs
25111 A list of G-expressions denoting common programs that are setuid-root.
25113 The list includes commands such as @command{passwd}, @command{ping},
25114 @command{su}, and @command{sudo}.
25117 Under the hood, the actual setuid programs are created in the
25118 @file{/run/setuid-programs} directory at system activation time. The
25119 files in this directory refer to the ``real'' binaries, which are in the
25122 @node X.509 Certificates
25123 @section X.509 Certificates
25125 @cindex HTTPS, certificates
25126 @cindex X.509 certificates
25128 Web servers available over HTTPS (that is, HTTP over the transport-layer
25129 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
25130 that the client can then use to @emph{authenticate} the server. To do
25131 that, clients verify that the server's certificate is signed by a
25132 so-called @dfn{certificate authority} (CA). But to verify the CA's
25133 signature, clients must have first acquired the CA's certificate.
25135 Web browsers such as GNU@tie{}IceCat include their own set of CA
25136 certificates, such that they are able to verify CA signatures
25139 However, most other programs that can talk HTTPS---@command{wget},
25140 @command{git}, @command{w3m}, etc.---need to be told where CA
25141 certificates can be found.
25143 @cindex @code{nss-certs}
25144 In Guix, this is done by adding a package that provides certificates
25145 to the @code{packages} field of the @code{operating-system} declaration
25146 (@pxref{operating-system Reference}). Guix includes one such package,
25147 @code{nss-certs}, which is a set of CA certificates provided as part of
25148 Mozilla's Network Security Services.
25150 Note that it is @emph{not} part of @code{%base-packages}, so you need to
25151 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
25152 most applications and libraries look for certificates by default, points
25153 to the certificates installed globally.
25155 Unprivileged users, including users of Guix on a foreign distro,
25156 can also install their own certificate package in
25157 their profile. A number of environment variables need to be defined so
25158 that applications and libraries know where to find them. Namely, the
25159 OpenSSL library honors the @code{SSL_CERT_DIR} and @code{SSL_CERT_FILE}
25160 variables. Some applications add their own environment variables; for
25161 instance, the Git version control system honors the certificate bundle
25162 pointed to by the @code{GIT_SSL_CAINFO} environment variable. Thus, you
25163 would typically run something like:
25166 $ guix install nss-certs
25167 $ export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
25168 $ export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25169 $ export GIT_SSL_CAINFO="$SSL_CERT_FILE"
25172 As another example, R requires the @code{CURL_CA_BUNDLE} environment
25173 variable to point to a certificate bundle, so you would have to run
25174 something like this:
25177 $ guix install nss-certs
25178 $ export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
25181 For other applications you may want to look up the required environment
25182 variable in the relevant documentation.
25185 @node Name Service Switch
25186 @section Name Service Switch
25188 @cindex name service switch
25190 The @code{(gnu system nss)} module provides bindings to the
25191 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
25192 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
25193 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
25194 extended with new ``name'' lookup methods for system databases, which
25195 includes host names, service names, user accounts, and more (@pxref{Name
25196 Service Switch, System Databases and Name Service Switch,, libc, The GNU
25197 C Library Reference Manual}).
25199 The NSS configuration specifies, for each system database, which lookup
25200 method is to be used, and how the various methods are chained
25201 together---for instance, under which circumstances NSS should try the
25202 next method in the list. The NSS configuration is given in the
25203 @code{name-service-switch} field of @code{operating-system} declarations
25204 (@pxref{operating-system Reference, @code{name-service-switch}}).
25207 @cindex .local, host name lookup
25208 As an example, the declaration below configures the NSS to use the
25209 @uref{http://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
25210 back-end}, which supports host name lookups over multicast DNS (mDNS)
25211 for host names ending in @code{.local}:
25214 (name-service-switch
25215 (hosts (list %files ;first, check /etc/hosts
25217 ;; If the above did not succeed, try
25218 ;; with 'mdns_minimal'.
25220 (name "mdns_minimal")
25222 ;; 'mdns_minimal' is authoritative for
25223 ;; '.local'. When it returns "not found",
25224 ;; no need to try the next methods.
25225 (reaction (lookup-specification
25226 (not-found => return))))
25228 ;; Then fall back to DNS.
25232 ;; Finally, try with the "full" 'mdns'.
25237 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
25238 contains this configuration, so you will not have to type it if all you
25239 want is to have @code{.local} host lookup working.
25241 Note that, in this case, in addition to setting the
25242 @code{name-service-switch} of the @code{operating-system} declaration,
25243 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
25244 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
25245 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
25246 to the name service cache daemon (@pxref{Base Services,
25247 @code{nscd-service}}).
25249 For convenience, the following variables provide typical NSS
25252 @defvr {Scheme Variable} %default-nss
25253 This is the default name service switch configuration, a
25254 @code{name-service-switch} object.
25257 @defvr {Scheme Variable} %mdns-host-lookup-nss
25258 This is the name service switch configuration with support for host name
25259 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
25262 The reference for name service switch configuration is given below. It
25263 is a direct mapping of the configuration file format of the C library , so
25264 please refer to the C library manual for more information (@pxref{NSS
25265 Configuration File,,, libc, The GNU C Library Reference Manual}).
25266 Compared to the configuration file format of libc NSS, it has the advantage
25267 not only of adding this warm parenthetic feel that we like, but also
25268 static checks: you will know about syntax errors and typos as soon as you
25269 run @command{guix system}.
25271 @deftp {Data Type} name-service-switch
25273 This is the data type representation the configuration of libc's name
25274 service switch (NSS). Each field below represents one of the supported
25291 The system databases handled by the NSS. Each of these fields must be a
25292 list of @code{<name-service>} objects (see below).
25296 @deftp {Data Type} name-service
25298 This is the data type representing an actual name service and the
25299 associated lookup action.
25303 A string denoting the name service (@pxref{Services in the NSS
25304 configuration,,, libc, The GNU C Library Reference Manual}).
25306 Note that name services listed here must be visible to nscd. This is
25307 achieved by passing the @code{#:name-services} argument to
25308 @code{nscd-service} the list of packages providing the needed name
25309 services (@pxref{Base Services, @code{nscd-service}}).
25312 An action specified using the @code{lookup-specification} macro
25313 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
25314 Reference Manual}). For example:
25317 (lookup-specification (unavailable => continue)
25318 (success => return))
25323 @node Initial RAM Disk
25324 @section Initial RAM Disk
25327 @cindex initial RAM disk
25328 For bootstrapping purposes, the Linux-Libre kernel is passed an
25329 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
25330 root file system as well as an initialization script. The latter is
25331 responsible for mounting the real root file system, and for loading any
25332 kernel modules that may be needed to achieve that.
25334 The @code{initrd-modules} field of an @code{operating-system}
25335 declaration allows you to specify Linux-libre kernel modules that must
25336 be available in the initrd. In particular, this is where you would list
25337 modules needed to actually drive the hard disk where your root partition
25338 is---although the default value of @code{initrd-modules} should cover
25339 most use cases. For example, assuming you need the @code{megaraid_sas}
25340 module in addition to the default modules to be able to access your root
25341 file system, you would write:
25346 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
25349 @defvr {Scheme Variable} %base-initrd-modules
25350 This is the list of kernel modules included in the initrd by default.
25353 Furthermore, if you need lower-level customization, the @code{initrd}
25354 field of an @code{operating-system} declaration allows
25355 you to specify which initrd you would like to use. The @code{(gnu
25356 system linux-initrd)} module provides three ways to build an initrd: the
25357 high-level @code{base-initrd} procedure and the low-level
25358 @code{raw-initrd} and @code{expression->initrd} procedures.
25360 The @code{base-initrd} procedure is intended to cover most common uses.
25361 For example, if you want to add a bunch of kernel modules to be loaded
25362 at boot time, you can define the @code{initrd} field of the operating
25363 system declaration like this:
25366 (initrd (lambda (file-systems . rest)
25367 ;; Create a standard initrd but set up networking
25368 ;; with the parameters QEMU expects by default.
25369 (apply base-initrd file-systems
25370 #:qemu-networking? #t
25374 The @code{base-initrd} procedure also handles common use cases that
25375 involves using the system as a QEMU guest, or as a ``live'' system with
25376 volatile root file system.
25378 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
25379 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
25380 such as trying to guess which kernel modules and packages should be included
25381 to the initrd. An example use of @code{raw-initrd} is when a user has
25382 a custom Linux kernel configuration and default kernel modules included by
25383 @code{base-initrd} are not available.
25385 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
25386 honors several options passed on the Linux kernel command line
25387 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
25388 @code{-append} option of QEMU), notably:
25391 @item --load=@var{boot}
25392 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
25393 program, once it has mounted the root file system.
25395 Guix uses this option to yield control to a boot program that runs the
25396 service activation programs and then spawns the GNU@tie{}Shepherd, the
25397 initialization system.
25399 @item --root=@var{root}
25400 Mount @var{root} as the root file system. @var{root} can be a
25401 device name like @code{/dev/sda1}, a file system label, or a file system
25404 @item --system=@var{system}
25405 Have @file{/run/booted-system} and @file{/run/current-system} point to
25408 @item modprobe.blacklist=@var{modules}@dots{}
25409 @cindex module, black-listing
25410 @cindex black list, of kernel modules
25411 Instruct the initial RAM disk as well as the @command{modprobe} command
25412 (from the kmod package) to refuse to load @var{modules}. @var{modules}
25413 must be a comma-separated list of module names---e.g.,
25414 @code{usbkbd,9pnet}.
25417 Start a read-eval-print loop (REPL) from the initial RAM disk before it
25418 tries to load kernel modules and to mount the root file system. Our
25419 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
25420 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
25421 Manual}, for more information on Guile's REPL.
25425 Now that you know all the features that initial RAM disks produced by
25426 @code{base-initrd} and @code{raw-initrd} provide,
25427 here is how to use it and customize it further.
25430 @cindex initial RAM disk
25431 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
25432 [#:linux-modules '()] [#:mapped-devices '()] @
25433 [#:keyboard-layout #f] @
25434 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
25435 Return a derivation that builds a raw initrd. @var{file-systems} is
25436 a list of file systems to be mounted by the initrd, possibly in addition to
25437 the root file system specified on the kernel command line via @code{--root}.
25438 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
25439 @var{mapped-devices} is a list of device mappings to realize before
25440 @var{file-systems} are mounted (@pxref{Mapped Devices}).
25441 @var{helper-packages} is a list of packages to be copied in the initrd. It may
25442 include @code{e2fsck/static} or other packages needed by the initrd to check
25443 the root file system.
25445 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25446 the desired console keyboard layout. This is done before @var{mapped-devices}
25447 are set up and before @var{file-systems} are mounted such that, should the
25448 user need to enter a passphrase or use the REPL, this happens using the
25449 intended keyboard layout.
25451 When @var{qemu-networking?} is true, set up networking with the standard QEMU
25452 parameters. When @var{virtio?} is true, load additional modules so that the
25453 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
25455 When @var{volatile-root?} is true, the root file system is writable but any changes
25459 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
25460 [#:mapped-devices '()] [#:keyboard-layout #f] @
25461 [#:qemu-networking? #f] [#:volatile-root? #f] @
25462 [#:linux-modules '()]
25463 Return as a file-like object a generic initrd, with kernel
25464 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
25465 mounted by the initrd, possibly in addition to the root file system specified
25466 on the kernel command line via @code{--root}. @var{mapped-devices} is a list of device
25467 mappings to realize before @var{file-systems} are mounted.
25469 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
25470 the desired console keyboard layout. This is done before @var{mapped-devices}
25471 are set up and before @var{file-systems} are mounted such that, should the
25472 user need to enter a passphrase or use the REPL, this happens using the
25473 intended keyboard layout.
25475 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
25477 The initrd is automatically populated with all the kernel modules necessary
25478 for @var{file-systems} and for the given options. Additional kernel
25479 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
25480 loaded at boot time in the order in which they appear.
25483 Needless to say, the initrds we produce and use embed a
25484 statically-linked Guile, and the initialization program is a Guile
25485 program. That gives a lot of flexibility. The
25486 @code{expression->initrd} procedure builds such an initrd, given the
25487 program to run in that initrd.
25489 @deffn {Scheme Procedure} expression->initrd @var{exp} @
25490 [#:guile %guile-static-stripped] [#:name "guile-initrd"]
25491 Return as a file-like object a Linux initrd (a gzipped cpio archive)
25492 containing @var{guile} and that evaluates @var{exp}, a G-expression,
25493 upon booting. All the derivations referenced by @var{exp} are
25494 automatically copied to the initrd.
25497 @node Bootloader Configuration
25498 @section Bootloader Configuration
25501 @cindex boot loader
25503 The operating system supports multiple bootloaders. The bootloader is
25504 configured using @code{bootloader-configuration} declaration. All the
25505 fields of this structure are bootloader agnostic except for one field,
25506 @code{bootloader} that indicates the bootloader to be configured and
25509 Some of the bootloaders do not honor every field of
25510 @code{bootloader-configuration}. For instance, the extlinux
25511 bootloader does not support themes and thus ignores the @code{theme}
25514 @deftp {Data Type} bootloader-configuration
25515 The type of a bootloader configuration declaration.
25519 @item @code{bootloader}
25520 @cindex EFI, bootloader
25521 @cindex UEFI, bootloader
25522 @cindex BIOS, bootloader
25523 The bootloader to use, as a @code{bootloader} object. For now
25524 @code{grub-bootloader}, @code{grub-efi-bootloader},
25525 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
25527 @vindex grub-efi-bootloader
25528 @code{grub-efi-bootloader} allows to boot on modern systems using the
25529 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
25530 use if the installation image contains a @file{/sys/firmware/efi} directory
25531 when you boot it on your system.
25533 @vindex grub-bootloader
25534 @code{grub-bootloader} allows you to boot in particular Intel-based machines
25535 in ``legacy'' BIOS mode.
25537 @cindex ARM, bootloaders
25538 @cindex AArch64, bootloaders
25539 Available bootloaders are described in @code{(gnu bootloader @dots{})}
25540 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
25541 of bootloaders for a wide range of ARM and AArch64 systems, using the
25542 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
25544 @item @code{target}
25545 This is a string denoting the target onto which to install the
25548 The interpretation depends on the bootloader in question. For
25549 @code{grub-bootloader}, for example, it should be a device name understood by
25550 the bootloader @command{installer} command, such as @code{/dev/sda} or
25551 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
25552 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
25553 system, usually @file{/boot/efi}.
25555 @item @code{menu-entries} (default: @code{()})
25556 A possibly empty list of @code{menu-entry} objects (see below), denoting
25557 entries to appear in the bootloader menu, in addition to the current
25558 system entry and the entry pointing to previous system generations.
25560 @item @code{default-entry} (default: @code{0})
25561 The index of the default boot menu entry. Index 0 is for the entry of the
25564 @item @code{timeout} (default: @code{5})
25565 The number of seconds to wait for keyboard input before booting. Set to
25566 0 to boot immediately, and to -1 to wait indefinitely.
25568 @cindex keyboard layout, for the bootloader
25569 @item @code{keyboard-layout} (default: @code{#f})
25570 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
25571 layout, usually US@tie{}English (``qwerty'').
25573 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
25577 This option is currently ignored by bootloaders other than @code{grub} and
25581 @item @code{theme} (default: @var{#f})
25582 The bootloader theme object describing the theme to use. If no theme
25583 is provided, some bootloaders might use a default theme, that's true
25586 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
25587 The output terminals used for the bootloader boot menu, as a list of
25588 symbols. GRUB accepts the values: @code{console}, @code{serial},
25589 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
25590 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
25591 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
25592 configuration,,, grub,GNU GRUB manual}).
25594 @item @code{terminal-inputs} (default: @code{'()})
25595 The input terminals used for the bootloader boot menu, as a list of
25596 symbols. For GRUB, the default is the native platform terminal as
25597 determined at run-time. GRUB accepts the values: @code{console},
25598 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
25599 @code{usb_keyboard}. This field corresponds to the GRUB variable
25600 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
25603 @item @code{serial-unit} (default: @code{#f})
25604 The serial unit used by the bootloader, as an integer from 0 to 3.
25605 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
25606 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25608 @item @code{serial-speed} (default: @code{#f})
25609 The speed of the serial interface, as an integer. For GRUB, the
25610 default value is chosen at run-time; currently GRUB chooses
25611 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
25618 Should you want to list additional boot menu entries @i{via} the
25619 @code{menu-entries} field above, you will need to create them with the
25620 @code{menu-entry} form. For example, imagine you want to be able to
25621 boot another distro (hard to imagine!), you can define a menu entry
25626 (label "The Other Distro")
25627 (linux "/boot/old/vmlinux-2.6.32")
25628 (linux-arguments '("root=/dev/sda2"))
25629 (initrd "/boot/old/initrd"))
25634 @deftp {Data Type} menu-entry
25635 The type of an entry in the bootloader menu.
25640 The label to show in the menu---e.g., @code{"GNU"}.
25643 The Linux kernel image to boot, for example:
25646 (file-append linux-libre "/bzImage")
25649 For GRUB, it is also possible to specify a device explicitly in the
25650 file path using GRUB's device naming convention (@pxref{Naming
25651 convention,,, grub, GNU GRUB manual}), for example:
25654 "(hd0,msdos1)/boot/vmlinuz"
25657 If the device is specified explicitly as above, then the @code{device}
25658 field is ignored entirely.
25660 @item @code{linux-arguments} (default: @code{()})
25661 The list of extra Linux kernel command-line arguments---e.g.,
25662 @code{("console=ttyS0")}.
25664 @item @code{initrd}
25665 A G-Expression or string denoting the file name of the initial RAM disk
25666 to use (@pxref{G-Expressions}).
25667 @item @code{device} (default: @code{#f})
25668 The device where the kernel and initrd are to be found---i.e., for GRUB,
25669 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
25671 This may be a file system label (a string), a file system UUID (a
25672 bytevector, @pxref{File Systems}), or @code{#f}, in which case
25673 the bootloader will search the device containing the file specified by
25674 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
25675 must @emph{not} be an OS device name such as @file{/dev/sda1}.
25680 @c FIXME: Write documentation once it's stable.
25681 For now only GRUB has theme support. GRUB themes are created using
25682 the @code{grub-theme} form, which is not documented yet.
25684 @defvr {Scheme Variable} %default-theme
25685 This is the default GRUB theme used by the operating system if no
25686 @code{theme} field is specified in @code{bootloader-configuration}
25689 It comes with a fancy background image displaying the GNU and Guix
25694 @node Invoking guix system
25695 @section Invoking @code{guix system}
25697 Once you have written an operating system declaration as seen in the
25698 previous section, it can be @dfn{instantiated} using the @command{guix
25699 system} command. The synopsis is:
25702 guix system @var{options}@dots{} @var{action} @var{file}
25705 @var{file} must be the name of a file containing an
25706 @code{operating-system} declaration. @var{action} specifies how the
25707 operating system is instantiated. Currently the following values are
25712 Display available service type definitions that match the given regular
25713 expressions, sorted by relevance:
25716 $ guix system search console font
25717 name: console-fonts
25718 location: gnu/services/base.scm:729:2
25719 extends: shepherd-root
25720 description: Install the given fonts on the specified ttys (fonts are
25721 + per virtual console on GNU/Linux). The value of this service is a list
25722 + of tty/font pairs like:
25724 + '(("tty1" . "LatGrkCyr-8x16"))
25728 location: gnu/services/base.scm:1048:2
25729 extends: shepherd-root
25730 description: Provide console login using the `mingetty' program.
25734 location: gnu/services/base.scm:775:2
25736 description: Provide a console log-in service as specified by its
25737 + configuration value, a `login-configuration' object.
25743 As for @command{guix package --search}, the result is written in
25744 @code{recutils} format, which makes it easy to filter the output
25745 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
25748 Build the operating system described in @var{file}, activate it, and
25749 switch to it@footnote{This action (and the related actions
25750 @code{switch-generation} and @code{roll-back}) are usable only on
25751 systems already running Guix System.}.
25753 This effects all the configuration specified in @var{file}: user
25754 accounts, system services, global package list, setuid programs, etc.
25755 The command starts system services specified in @var{file} that are not
25756 currently running; if a service is currently running this command will
25757 arrange for it to be upgraded the next time it is stopped (e.g.@: by
25758 @code{herd stop X} or @code{herd restart X}).
25760 This command creates a new generation whose number is one greater than
25761 the current generation (as reported by @command{guix system
25762 list-generations}). If that generation already exists, it will be
25763 overwritten. This behavior mirrors that of @command{guix package}
25764 (@pxref{Invoking guix package}).
25766 It also adds a bootloader menu entry for the new OS configuration,
25767 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
25768 entries for older configurations to a submenu, allowing you to choose
25769 an older system generation at boot time should you need it.
25772 @c The paragraph below refers to the problem discussed at
25773 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
25774 It is highly recommended to run @command{guix pull} once before you run
25775 @command{guix system reconfigure} for the first time (@pxref{Invoking
25776 guix pull}). Failing to do that you would see an older version of Guix
25777 once @command{reconfigure} has completed.
25780 @item switch-generation
25781 @cindex generations
25782 Switch to an existing system generation. This action atomically
25783 switches the system profile to the specified system generation. It
25784 also rearranges the system's existing bootloader menu entries. It
25785 makes the menu entry for the specified system generation the default,
25786 and it moves the entries for the other generatiors to a submenu, if
25787 supported by the bootloader being used. The next time the system
25788 boots, it will use the specified system generation.
25790 The bootloader itself is not being reinstalled when using this
25791 command. Thus, the installed bootloader is used with an updated
25792 configuration file.
25794 The target generation can be specified explicitly by its generation
25795 number. For example, the following invocation would switch to system
25799 guix system switch-generation 7
25802 The target generation can also be specified relative to the current
25803 generation with the form @code{+N} or @code{-N}, where @code{+3} means
25804 ``3 generations ahead of the current generation,'' and @code{-1} means
25805 ``1 generation prior to the current generation.'' When specifying a
25806 negative value such as @code{-1}, you must precede it with @code{--} to
25807 prevent it from being parsed as an option. For example:
25810 guix system switch-generation -- -1
25813 Currently, the effect of invoking this action is @emph{only} to switch
25814 the system profile to an existing generation and rearrange the
25815 bootloader menu entries. To actually start using the target system
25816 generation, you must reboot after running this action. In the future,
25817 it will be updated to do the same things as @command{reconfigure},
25818 like activating and deactivating services.
25820 This action will fail if the specified generation does not exist.
25823 @cindex rolling back
25824 Switch to the preceding system generation. The next time the system
25825 boots, it will use the preceding system generation. This is the inverse
25826 of @command{reconfigure}, and it is exactly the same as invoking
25827 @command{switch-generation} with an argument of @code{-1}.
25829 Currently, as with @command{switch-generation}, you must reboot after
25830 running this action to actually start using the preceding system
25833 @item delete-generations
25834 @cindex deleting system generations
25835 @cindex saving space
25836 Delete system generations, making them candidates for garbage collection
25837 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
25840 This works in the same way as @command{guix package --delete-generations}
25841 (@pxref{Invoking guix package, @code{--delete-generations}}). With no
25842 arguments, all system generations but the current one are deleted:
25845 guix system delete-generations
25848 You can also select the generations you want to delete. The example below
25849 deletes all the system generations that are more than two month old:
25852 guix system delete-generations 2m
25855 Running this command automatically reinstalls the bootloader with an updated
25856 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
25857 longer lists the generations that have been deleted.
25860 Build the derivation of the operating system, which includes all the
25861 configuration files and programs needed to boot and run the system.
25862 This action does not actually install anything.
25865 Populate the given directory with all the files necessary to run the
25866 operating system specified in @var{file}. This is useful for first-time
25867 installations of Guix System. For instance:
25870 guix system init my-os-config.scm /mnt
25873 copies to @file{/mnt} all the store items required by the configuration
25874 specified in @file{my-os-config.scm}. This includes configuration
25875 files, packages, and so on. It also creates other essential files
25876 needed for the system to operate correctly---e.g., the @file{/etc},
25877 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
25879 This command also installs bootloader on the target specified in
25880 @file{my-os-config}, unless the @option{--no-bootloader} option was
25884 @cindex virtual machine
25886 @anchor{guix system vm}
25887 Build a virtual machine that contains the operating system declared in
25888 @var{file}, and return a script to run that virtual machine (VM).
25891 The @code{vm} action and others below
25892 can use KVM support in the Linux-libre kernel. Specifically, if the
25893 machine has hardware virtualization support, the corresponding
25894 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
25895 must exist and be readable and writable by the user and by the
25896 build users of the daemon (@pxref{Build Environment Setup}).
25899 Arguments given to the script are passed to QEMU as in the example
25900 below, which enables networking and requests 1@tie{}GiB of RAM for the
25904 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -net user
25907 The VM shares its store with the host system.
25909 Additional file systems can be shared between the host and the VM using
25910 the @code{--share} and @code{--expose} command-line options: the former
25911 specifies a directory to be shared with write access, while the latter
25912 provides read-only access to the shared directory.
25914 The example below creates a VM in which the user's home directory is
25915 accessible read-only, and where the @file{/exchange} directory is a
25916 read-write mapping of @file{$HOME/tmp} on the host:
25919 guix system vm my-config.scm \
25920 --expose=$HOME --share=$HOME/tmp=/exchange
25923 On GNU/Linux, the default is to boot directly to the kernel; this has
25924 the advantage of requiring only a very tiny root disk image since the
25925 store of the host can then be mounted.
25927 The @code{--full-boot} option forces a complete boot sequence, starting
25928 with the bootloader. This requires more disk space since a root image
25929 containing at least the kernel, initrd, and bootloader data files must
25930 be created. The @code{--image-size} option can be used to specify the
25933 @cindex System images, creation in various formats
25934 @cindex Creating system images in various formats
25937 @itemx docker-image
25938 Return a virtual machine, disk image, or Docker image of the operating
25939 system declared in @var{file} that stands alone. By default,
25940 @command{guix system} estimates the size of the image needed to store
25941 the system, but you can use the @option{--image-size} option to specify
25942 a value. Docker images are built to contain exactly what they need, so
25943 the @option{--image-size} option is ignored in the case of
25944 @code{docker-image}.
25946 You can specify the root file system type by using the
25947 @option{--file-system-type} option. It defaults to @code{ext4}.
25949 When using @code{vm-image}, the returned image is in qcow2 format, which
25950 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
25951 for more information on how to run the image in a virtual machine.
25953 When using @code{disk-image}, a raw disk image is produced; it can be
25954 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
25955 the device corresponding to a USB stick, one can copy the image to it
25956 using the following command:
25959 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc
25962 When using @code{docker-image}, a Docker image is produced. Guix builds
25963 the image from scratch, not from a pre-existing Docker base image. As a
25964 result, it contains @emph{exactly} what you define in the operating
25965 system configuration file. You can then load the image and launch a
25966 Docker container using commands like the following:
25969 image_id="`docker load < guix-system-docker-image.tar.gz`"
25970 container_id="`docker create $image_id`"
25971 docker start $container_id
25974 This command starts a new Docker container from the specified image. It
25975 will boot the Guix system in the usual manner, which means it will
25976 start any services you have defined in the operating system
25977 configuration. You can get an interactive shell running in the container
25978 using @command{docker exec}:
25981 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
25984 Depending on what you run in the Docker container, it
25985 may be necessary to give the container additional permissions. For
25986 example, if you intend to build software using Guix inside of the Docker
25987 container, you may need to pass the @option{--privileged} option to
25988 @code{docker create}.
25991 Return a script to run the operating system declared in @var{file}
25992 within a container. Containers are a set of lightweight isolation
25993 mechanisms provided by the kernel Linux-libre. Containers are
25994 substantially less resource-demanding than full virtual machines since
25995 the kernel, shared objects, and other resources can be shared with the
25996 host system; this also means they provide thinner isolation.
25998 Currently, the script must be run as root in order to support more than
25999 a single user and group. The container shares its store with the host
26002 As with the @code{vm} action (@pxref{guix system vm}), additional file
26003 systems to be shared between the host and container can be specified
26004 using the @option{--share} and @option{--expose} options:
26007 guix system container my-config.scm \
26008 --expose=$HOME --share=$HOME/tmp=/exchange
26012 This option requires Linux-libre 3.19 or newer.
26017 @var{options} can contain any of the common build options (@pxref{Common
26018 Build Options}). In addition, @var{options} can contain one of the
26022 @item --expression=@var{expr}
26023 @itemx -e @var{expr}
26024 Consider the operating-system @var{expr} evaluates to.
26025 This is an alternative to specifying a file which evaluates to an
26027 This is used to generate the Guix system installer @pxref{Building the
26028 Installation Image}).
26030 @item --system=@var{system}
26031 @itemx -s @var{system}
26032 Attempt to build for @var{system} instead of the host system type.
26033 This works as per @command{guix build} (@pxref{Invoking guix build}).
26037 Return the derivation file name of the given operating system without
26040 @item --file-system-type=@var{type}
26041 @itemx -t @var{type}
26042 For the @code{disk-image} action, create a file system of the given
26043 @var{type} on the image.
26045 When this option is omitted, @command{guix system} uses @code{ext4}.
26047 @cindex ISO-9660 format
26048 @cindex CD image format
26049 @cindex DVD image format
26050 @code{--file-system-type=iso9660} produces an ISO-9660 image, suitable
26051 for burning on CDs and DVDs.
26053 @item --image-size=@var{size}
26054 For the @code{vm-image} and @code{disk-image} actions, create an image
26055 of the given @var{size}. @var{size} may be a number of bytes, or it may
26056 include a unit as a suffix (@pxref{Block size, size specifications,,
26057 coreutils, GNU Coreutils}).
26059 When this option is omitted, @command{guix system} computes an estimate
26060 of the image size as a function of the size of the system declared in
26065 For the @code{container} action, allow containers to access the host network,
26066 that is, do not create a network namespace.
26068 @item --root=@var{file}
26069 @itemx -r @var{file}
26070 Make @var{file} a symlink to the result, and register it as a garbage
26073 @item --skip-checks
26074 Skip pre-installation safety checks.
26076 By default, @command{guix system init} and @command{guix system
26077 reconfigure} perform safety checks: they make sure the file systems that
26078 appear in the @code{operating-system} declaration actually exist
26079 (@pxref{File Systems}), and that any Linux kernel modules that may be
26080 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
26081 RAM Disk}). Passing this option skips these tests altogether.
26084 @cindex on-error strategy
26085 @cindex error strategy
26086 @item --on-error=@var{strategy}
26087 Apply @var{strategy} when an error occurs when reading @var{file}.
26088 @var{strategy} may be one of the following:
26091 @item nothing-special
26092 Report the error concisely and exit. This is the default strategy.
26095 Likewise, but also display a backtrace.
26098 Report the error and enter Guile's debugger. From there, you can run
26099 commands such as @code{,bt} to get a backtrace, @code{,locals} to
26100 display local variable values, and more generally inspect the state of the
26101 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
26102 a list of available debugging commands.
26106 Once you have built, configured, re-configured, and re-re-configured
26107 your Guix installation, you may find it useful to list the operating
26108 system generations available on disk---and that you can choose from the
26109 bootloader boot menu:
26113 @item list-generations
26114 List a summary of each generation of the operating system available on
26115 disk, in a human-readable way. This is similar to the
26116 @option{--list-generations} option of @command{guix package}
26117 (@pxref{Invoking guix package}).
26119 Optionally, one can specify a pattern, with the same syntax that is used
26120 in @command{guix package --list-generations}, to restrict the list of
26121 generations displayed. For instance, the following command displays
26122 generations that are up to 10 days old:
26125 $ guix system list-generations 10d
26130 The @command{guix system} command has even more to offer! The following
26131 sub-commands allow you to visualize how your system services relate to
26134 @anchor{system-extension-graph}
26137 @item extension-graph
26138 Emit in Dot/Graphviz format to standard output the @dfn{service
26139 extension graph} of the operating system defined in @var{file}
26140 (@pxref{Service Composition}, for more information on service
26146 $ guix system extension-graph @var{file} | dot -Tpdf > services.pdf
26149 produces a PDF file showing the extension relations among services.
26151 @anchor{system-shepherd-graph}
26152 @item shepherd-graph
26153 Emit in Dot/Graphviz format to standard output the @dfn{dependency
26154 graph} of shepherd services of the operating system defined in
26155 @var{file}. @xref{Shepherd Services}, for more information and for an
26160 @node Invoking guix deploy
26161 @section Invoking @code{guix deploy}
26163 We've already seen @code{operating-system} declarations used to manage a
26164 machine's configuration locally. Suppose you need to configure multiple
26165 machines, though---perhaps you're managing a service on the web that's
26166 comprised of several servers. @command{guix deploy} enables you to use those
26167 same @code{operating-system} declarations to manage multiple remote hosts at
26168 once as a logical ``deployment''.
26171 The functionality described in this section is still under development
26172 and is subject to change. Get in touch with us on
26173 @email{guix-devel@@gnu.org}!
26177 guix deploy @var{file}
26180 Such an invocation will deploy the machines that the code within @var{file}
26181 evaluates to. As an example, @var{file} might contain a definition like this:
26184 ;; This is a Guix deployment of a "bare bones" setup, with
26185 ;; no X11 display server, to a machine with an SSH daemon
26186 ;; listening on localhost:2222. A configuration such as this
26187 ;; may be appropriate for virtual machine with ports
26188 ;; forwarded to the host's loopback interface.
26190 (use-service-modules networking ssh)
26191 (use-package-modules bootloaders)
26195 (host-name "gnu-deployed")
26196 (timezone "Etc/UTC")
26197 (bootloader (bootloader-configuration
26198 (bootloader grub-bootloader)
26199 (target "/dev/vda")
26200 (terminal-outputs '(console))))
26201 (file-systems (cons (file-system
26203 (device "/dev/vda1")
26205 %base-file-systems))
26207 (append (list (service dhcp-client-service-type)
26208 (service openssh-service-type
26209 (openssh-configuration
26210 (permit-root-login #t)
26211 (allow-empty-passwords? #t))))
26215 (operating-system %system)
26216 (environment managed-host-environment-type)
26217 (configuration (machine-ssh-configuration
26218 (host-name "localhost")
26219 (system "x86_64-linux")
26221 (identity "./id_rsa")
26225 The file should evaluate to a list of @var{machine} objects. This example,
26226 upon being deployed, will create a new generation on the remote system
26227 realizing the @code{operating-system} declaration @var{%system}.
26228 @var{environment} and @var{configuration} specify how the machine should be
26229 provisioned---that is, how the computing resources should be created and
26230 managed. The above example does not create any resources, as a
26231 @code{'managed-host} is a machine that is already running the Guix system and
26232 available over the network. This is a particularly simple case; a more
26233 complex deployment may involve, for example, starting virtual machines through
26234 a Virtual Private Server (VPS) provider. In such a case, a different
26235 @var{environment} type would be used.
26237 Do note that you first need to generate a key pair on the coordinator machine
26238 to allow the daemon to export signed archives of files from the store
26239 (@pxref{Invoking guix archive}).
26242 # guix archive --generate-key
26246 Each target machine must authorize the key of the master machine so that it
26247 accepts store items it receives from the coordinator:
26250 # guix archive --authorize < coordinator-public-key.txt
26253 @code{user}, in this example, specifies the name of the user account to log in
26254 as to perform the deployment. Its default value is @code{root}, but root
26255 login over SSH may be forbidden in some cases. To work around this,
26256 @command{guix deploy} can log in as an unprivileged user and employ
26257 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
26258 currently installed on the remote and can be invoked non-interactively as
26259 @code{user}. That is: the line in @code{sudoers} granting @code{user} the
26260 ability to use @code{sudo} must contain the @code{NOPASSWD} tag.
26262 @deftp {Data Type} machine
26263 This is the data type representing a single machine in a heterogeneous Guix
26267 @item @code{operating-system}
26268 The object of the operating system configuration to deploy.
26270 @item @code{environment}
26271 An @code{environment-type} describing how the machine should be provisioned.
26273 @item @code{configuration} (default: @code{#f})
26274 An object describing the configuration for the machine's @code{environment}.
26275 If the @code{environment} has a default configuration, @code{#f} may be used.
26276 If @code{#f} is used for an environment with no default configuration,
26277 however, an error will be thrown.
26281 @deftp {Data Type} machine-ssh-configuration
26282 This is the data type representing the SSH client parameters for a machine
26283 with an @code{environment} of @code{managed-host-environment-type}.
26286 @item @code{host-name}
26287 @item @code{build-locally?} (default: @code{#t})
26288 If false, system derivations will be built on the machine being deployed to.
26289 @item @code{system}
26290 The system type describing the architecture of the machine being deployed
26291 to---e.g., @code{"x86_64-linux"}.
26292 @item @code{authorize?} (default: @code{#t})
26293 If true, the coordinator's signing key will be added to the remote's ACL
26295 @item @code{port} (default: @code{22})
26296 @item @code{user} (default: @code{"root"})
26297 @item @code{identity} (default: @code{#f})
26298 If specified, the path to the SSH private key to use to authenticate with the
26303 @deftp {Data Type} digital-ocean-configuration
26304 This is the data type describing the Droplet that should be created for a
26305 machine with an @code{environment} of @code{digital-ocean-environment-type}.
26308 @item @code{ssh-key}
26309 The path to the SSH private key to use to authenticate with the remote
26310 host. In the future, this field may not exist.
26312 A list of string ``tags'' that uniquely identify the machine. Must be given
26313 such that no two machines in the deployment have the same set of tags.
26314 @item @code{region}
26315 A Digital Ocean region slug, such as @code{"nyc3"}.
26317 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
26318 @item @code{enable-ipv6?}
26319 Whether or not the droplet should be created with IPv6 networking.
26323 @node Running Guix in a VM
26324 @section Running Guix in a Virtual Machine
26326 @cindex virtual machine
26327 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
26329 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
26330 This image is a compressed image in QCOW format. You will first need to
26331 decompress with @command{xz -d}, and then you can pass it to an emulator such
26332 as QEMU (see below for details).
26334 This image boots the Xfce graphical environment and it contains some
26335 commonly-used tools. You can install more software in the image by running
26336 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
26337 also reconfigure the system based on its initial configuration file available
26338 as @file{/etc/config.scm} (@pxref{Using the Configuration System}).
26340 Instead of using this pre-built image, one can also build their own virtual
26341 machine image using @command{guix system vm-image} (@pxref{Invoking guix
26342 system}). The returned image is in qcow2 format, which the
26343 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
26346 If you built your own image, you must copy it out of the store
26347 (@pxref{The Store}) and give yourself permission to write to the copy
26348 before you can use it. When invoking QEMU, you must choose a system
26349 emulator that is suitable for your hardware platform. Here is a minimal
26350 QEMU invocation that will boot the result of @command{guix system
26351 vm-image} on x86_64 hardware:
26354 $ qemu-system-x86_64 \
26355 -net user -net nic,model=virtio \
26356 -enable-kvm -m 1024 \
26357 -device virtio-blk,drive=myhd \
26358 -drive if=none,file=/tmp/qemu-image,id=myhd
26361 Here is what each of these options means:
26364 @item qemu-system-x86_64
26365 This specifies the hardware platform to emulate. This should match the
26369 Enable the unprivileged user-mode network stack. The guest OS can
26370 access the host but not vice versa. This is the simplest way to get the
26373 @item -net nic,model=virtio
26374 You must create a network interface of a given model. If you do not
26375 create a NIC, the boot will fail. Assuming your hardware platform is
26376 x86_64, you can get a list of available NIC models by running
26377 @command{qemu-system-x86_64 -net nic,model=help}.
26380 If your system has hardware virtualization extensions, enabling the
26381 virtual machine support (KVM) of the Linux kernel will make things run
26384 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
26386 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
26387 which may be insufficient for some operations.
26389 @item -device virtio-blk,drive=myhd
26390 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
26391 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
26392 better performance than if it were emulating a complete disk drive. See the
26393 QEMU and KVM documentation for more info.
26395 @item -drive if=none,file=/tmp/qemu-image,id=myhd
26396 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
26397 the ``myhd'' drive.
26400 The default @command{run-vm.sh} script that is returned by an invocation of
26401 @command{guix system vm} does not add a @command{-net user} flag by default.
26402 To get network access from within the vm add the @code{(dhcp-client-service)}
26403 to your system definition and start the VM using
26404 @command{`guix system vm config.scm` -net user}. An important caveat of using
26405 @command{-net user} for networking is that @command{ping} will not work, because
26406 it uses the ICMP protocol. You'll have to use a different command to check for
26407 network connectivity, for example @command{guix download}.
26409 @subsection Connecting Through SSH
26413 To enable SSH inside a VM you need to add an SSH server like
26414 @code{openssh-service-type} to your VM (@pxref{Networking Services,
26415 @code{openssh-service-type}}). In addition you need to forward the SSH port,
26416 22 by default, to the host. You can do this with
26419 `guix system vm config.scm` -net user,hostfwd=tcp::10022-:22
26422 To connect to the VM you can run
26425 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
26428 The @command{-p} tells @command{ssh} the port you want to connect to.
26429 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
26430 every time you modify your @command{config.scm} file and the
26431 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
26432 connection to an unknown host every time you connect.
26434 @subsection Using @command{virt-viewer} with Spice
26436 As an alternative to the default @command{qemu} graphical client you can
26437 use the @command{remote-viewer} from the @command{virt-viewer} package. To
26438 connect pass the @command{-spice port=5930,disable-ticketing} flag to
26439 @command{qemu}. See previous section for further information on how to do this.
26441 Spice also allows you to do some nice stuff like share your clipboard with your
26442 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
26445 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
26446 -chardev spicevmc,name=vdagent,id=vdagent
26447 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
26448 name=com.redhat.spice.0
26451 You'll also need to add the @pxref{Miscellaneous Services, Spice service}.
26453 @node Defining Services
26454 @section Defining Services
26456 The previous sections show the available services and how one can combine
26457 them in an @code{operating-system} declaration. But how do we define
26458 them in the first place? And what is a service anyway?
26461 * Service Composition:: The model for composing services.
26462 * Service Types and Services:: Types and services.
26463 * Service Reference:: API reference.
26464 * Shepherd Services:: A particular type of service.
26467 @node Service Composition
26468 @subsection Service Composition
26472 Here we define a @dfn{service} as, broadly, something that extends the
26473 functionality of the operating system. Often a service is a process---a
26474 @dfn{daemon}---started when the system boots: a secure shell server, a
26475 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
26476 whose execution can be triggered by another daemon---e.g., an FTP server
26477 started by @command{inetd} or a D-Bus service activated by
26478 @command{dbus-daemon}. Occasionally, a service does not map to a
26479 daemon. For instance, the ``account'' service collects user accounts
26480 and makes sure they exist when the system runs; the ``udev'' service
26481 collects device management rules and makes them available to the eudev
26482 daemon; the @file{/etc} service populates the @file{/etc} directory
26485 @cindex service extensions
26486 Guix system services are connected by @dfn{extensions}. For instance, the
26487 secure shell service @emph{extends} the Shepherd---the
26488 initialization system, running as PID@tie{}1---by giving it the command
26489 lines to start and stop the secure shell daemon (@pxref{Networking
26490 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
26491 service by passing it its @file{.service} specification, and extends the
26492 udev service by passing it device management rules (@pxref{Desktop
26493 Services, @code{upower-service}}); the Guix daemon service extends the
26494 Shepherd by passing it the command lines to start and stop the daemon,
26495 and extends the account service by passing it a list of required build
26496 user accounts (@pxref{Base Services}).
26498 All in all, services and their ``extends'' relations form a directed
26499 acyclic graph (DAG). If we represent services as boxes and extensions
26500 as arrows, a typical system might provide something like this:
26502 @image{images/service-graph,,5in,Typical service extension graph.}
26504 @cindex system service
26505 At the bottom, we see the @dfn{system service}, which produces the
26506 directory containing everything to run and boot the system, as returned
26507 by the @command{guix system build} command. @xref{Service Reference},
26508 to learn about the other service types shown here.
26509 @xref{system-extension-graph, the @command{guix system extension-graph}
26510 command}, for information on how to generate this representation for a
26511 particular operating system definition.
26513 @cindex service types
26514 Technically, developers can define @dfn{service types} to express these
26515 relations. There can be any number of services of a given type on the
26516 system---for instance, a system running two instances of the GNU secure
26517 shell server (lsh) has two instances of @code{lsh-service-type}, with
26518 different parameters.
26520 The following section describes the programming interface for service
26521 types and services.
26523 @node Service Types and Services
26524 @subsection Service Types and Services
26526 A @dfn{service type} is a node in the DAG described above. Let us start
26527 with a simple example, the service type for the Guix build daemon
26528 (@pxref{Invoking guix-daemon}):
26531 (define guix-service-type
26535 (list (service-extension shepherd-root-service-type guix-shepherd-service)
26536 (service-extension account-service-type guix-accounts)
26537 (service-extension activation-service-type guix-activation)))
26538 (default-value (guix-configuration))))
26542 It defines three things:
26546 A name, whose sole purpose is to make inspection and debugging easier.
26549 A list of @dfn{service extensions}, where each extension designates the
26550 target service type and a procedure that, given the parameters of the
26551 service, returns a list of objects to extend the service of that type.
26553 Every service type has at least one service extension. The only
26554 exception is the @dfn{boot service type}, which is the ultimate service.
26557 Optionally, a default value for instances of this type.
26560 In this example, @code{guix-service-type} extends three services:
26563 @item shepherd-root-service-type
26564 The @code{guix-shepherd-service} procedure defines how the Shepherd
26565 service is extended. Namely, it returns a @code{<shepherd-service>}
26566 object that defines how @command{guix-daemon} is started and stopped
26567 (@pxref{Shepherd Services}).
26569 @item account-service-type
26570 This extension for this service is computed by @code{guix-accounts},
26571 which returns a list of @code{user-group} and @code{user-account}
26572 objects representing the build user accounts (@pxref{Invoking
26575 @item activation-service-type
26576 Here @code{guix-activation} is a procedure that returns a gexp, which is
26577 a code snippet to run at ``activation time''---e.g., when the service is
26581 A service of this type is instantiated like this:
26584 (service guix-service-type
26585 (guix-configuration
26587 (use-substitutes? #f)))
26590 The second argument to the @code{service} form is a value representing
26591 the parameters of this specific service instance.
26592 @xref{guix-configuration-type, @code{guix-configuration}}, for
26593 information about the @code{guix-configuration} data type. When the
26594 value is omitted, the default value specified by
26595 @code{guix-service-type} is used:
26598 (service guix-service-type)
26601 @code{guix-service-type} is quite simple because it extends other
26602 services but is not extensible itself.
26604 @c @subsubsubsection Extensible Service Types
26606 The service type for an @emph{extensible} service looks like this:
26609 (define udev-service-type
26610 (service-type (name 'udev)
26612 (list (service-extension shepherd-root-service-type
26613 udev-shepherd-service)))
26615 (compose concatenate) ;concatenate the list of rules
26616 (extend (lambda (config rules)
26618 (($ <udev-configuration> udev initial-rules)
26619 (udev-configuration
26620 (udev udev) ;the udev package to use
26621 (rules (append initial-rules rules)))))))))
26624 This is the service type for the
26625 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
26626 management daemon}. Compared to the previous example, in addition to an
26627 extension of @code{shepherd-root-service-type}, we see two new fields:
26631 This is the procedure to @dfn{compose} the list of extensions to
26632 services of this type.
26634 Services can extend the udev service by passing it lists of rules; we
26635 compose those extensions simply by concatenating them.
26638 This procedure defines how the value of the service is @dfn{extended} with
26639 the composition of the extensions.
26641 Udev extensions are composed into a list of rules, but the udev service
26642 value is itself a @code{<udev-configuration>} record. So here, we
26643 extend that record by appending the list of rules it contains to the
26644 list of contributed rules.
26647 This is a string giving an overview of the service type. The string can
26648 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
26649 @command{guix system search} command searches these strings and displays
26650 them (@pxref{Invoking guix system}).
26653 There can be only one instance of an extensible service type such as
26654 @code{udev-service-type}. If there were more, the
26655 @code{service-extension} specifications would be ambiguous.
26657 Still here? The next section provides a reference of the programming
26658 interface for services.
26660 @node Service Reference
26661 @subsection Service Reference
26663 We have seen an overview of service types (@pxref{Service Types and
26664 Services}). This section provides a reference on how to manipulate
26665 services and service types. This interface is provided by the
26666 @code{(gnu services)} module.
26668 @deffn {Scheme Procedure} service @var{type} [@var{value}]
26669 Return a new service of @var{type}, a @code{<service-type>} object (see
26670 below.) @var{value} can be any object; it represents the parameters of
26671 this particular service instance.
26673 When @var{value} is omitted, the default value specified by @var{type}
26674 is used; if @var{type} does not specify a default value, an error is
26677 For instance, this:
26680 (service openssh-service-type)
26684 is equivalent to this:
26687 (service openssh-service-type
26688 (openssh-configuration))
26691 In both cases the result is an instance of @code{openssh-service-type}
26692 with the default configuration.
26695 @deffn {Scheme Procedure} service? @var{obj}
26696 Return true if @var{obj} is a service.
26699 @deffn {Scheme Procedure} service-kind @var{service}
26700 Return the type of @var{service}---i.e., a @code{<service-type>} object.
26703 @deffn {Scheme Procedure} service-value @var{service}
26704 Return the value associated with @var{service}. It represents its
26708 Here is an example of how a service is created and manipulated:
26712 (service nginx-service-type
26713 (nginx-configuration
26715 (log-directory log-directory)
26716 (run-directory run-directory)
26717 (file config-file))))
26722 (eq? (service-kind s) nginx-service-type)
26726 The @code{modify-services} form provides a handy way to change the
26727 parameters of some of the services of a list such as
26728 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
26729 evaluates to a list of services. Of course, you could always use
26730 standard list combinators such as @code{map} and @code{fold} to do that
26731 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
26732 @code{modify-services} simply provides a more concise form for this
26735 @deffn {Scheme Syntax} modify-services @var{services} @
26736 (@var{type} @var{variable} => @var{body}) @dots{}
26738 Modify the services listed in @var{services} according to the given
26739 clauses. Each clause has the form:
26742 (@var{type} @var{variable} => @var{body})
26745 where @var{type} is a service type---e.g.,
26746 @code{guix-service-type}---and @var{variable} is an identifier that is
26747 bound within the @var{body} to the service parameters---e.g., a
26748 @code{guix-configuration} instance---of the original service of that
26751 The @var{body} should evaluate to the new service parameters, which will
26752 be used to configure the new service. This new service will replace the
26753 original in the resulting list. Because a service's service parameters
26754 are created using @code{define-record-type*}, you can write a succinct
26755 @var{body} that evaluates to the new service parameters by using the
26756 @code{inherit} feature that @code{define-record-type*} provides.
26758 @xref{Using the Configuration System}, for example usage.
26762 Next comes the programming interface for service types. This is
26763 something you want to know when writing new service definitions, but not
26764 necessarily when simply looking for ways to customize your
26765 @code{operating-system} declaration.
26767 @deftp {Data Type} service-type
26768 @cindex service type
26769 This is the representation of a @dfn{service type} (@pxref{Service Types
26774 This is a symbol, used only to simplify inspection and debugging.
26776 @item @code{extensions}
26777 A non-empty list of @code{<service-extension>} objects (see below).
26779 @item @code{compose} (default: @code{#f})
26780 If this is @code{#f}, then the service type denotes services that cannot
26781 be extended---i.e., services that do not receive ``values'' from other
26784 Otherwise, it must be a one-argument procedure. The procedure is called
26785 by @code{fold-services} and is passed a list of values collected from
26786 extensions. It may return any single value.
26788 @item @code{extend} (default: @code{#f})
26789 If this is @code{#f}, services of this type cannot be extended.
26791 Otherwise, it must be a two-argument procedure: @code{fold-services}
26792 calls it, passing it the initial value of the service as the first
26793 argument and the result of applying @code{compose} to the extension
26794 values as the second argument. It must return a value that is a valid
26795 parameter value for the service instance.
26798 @xref{Service Types and Services}, for examples.
26801 @deffn {Scheme Procedure} service-extension @var{target-type} @
26803 Return a new extension for services of type @var{target-type}.
26804 @var{compute} must be a one-argument procedure: @code{fold-services}
26805 calls it, passing it the value associated with the service that provides
26806 the extension; it must return a valid value for the target service.
26809 @deffn {Scheme Procedure} service-extension? @var{obj}
26810 Return true if @var{obj} is a service extension.
26813 Occasionally, you might want to simply extend an existing service. This
26814 involves creating a new service type and specifying the extension of
26815 interest, which can be verbose; the @code{simple-service} procedure
26816 provides a shorthand for this.
26818 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
26819 Return a service that extends @var{target} with @var{value}. This works
26820 by creating a singleton service type @var{name}, of which the returned
26821 service is an instance.
26823 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
26827 (simple-service 'my-mcron-job mcron-service-type
26828 #~(job '(next-hour (3)) "guix gc -F 2G"))
26832 At the core of the service abstraction lies the @code{fold-services}
26833 procedure, which is responsible for ``compiling'' a list of services
26834 down to a single directory that contains everything needed to boot and
26835 run the system---the directory shown by the @command{guix system build}
26836 command (@pxref{Invoking guix system}). In essence, it propagates
26837 service extensions down the service graph, updating each node parameters
26838 on the way, until it reaches the root node.
26840 @deffn {Scheme Procedure} fold-services @var{services} @
26841 [#:target-type @var{system-service-type}]
26842 Fold @var{services} by propagating their extensions down to the root of
26843 type @var{target-type}; return the root service adjusted accordingly.
26846 Lastly, the @code{(gnu services)} module also defines several essential
26847 service types, some of which are listed below.
26849 @defvr {Scheme Variable} system-service-type
26850 This is the root of the service graph. It produces the system directory
26851 as returned by the @command{guix system build} command.
26854 @defvr {Scheme Variable} boot-service-type
26855 The type of the ``boot service'', which produces the @dfn{boot script}.
26856 The boot script is what the initial RAM disk runs when booting.
26859 @defvr {Scheme Variable} etc-service-type
26860 The type of the @file{/etc} service. This service is used to create
26861 files under @file{/etc} and can be extended by
26862 passing it name/file tuples such as:
26865 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
26868 In this example, the effect would be to add an @file{/etc/issue} file
26869 pointing to the given file.
26872 @defvr {Scheme Variable} setuid-program-service-type
26873 Type for the ``setuid-program service''. This service collects lists of
26874 executable file names, passed as gexps, and adds them to the set of
26875 setuid-root programs on the system (@pxref{Setuid Programs}).
26878 @defvr {Scheme Variable} profile-service-type
26879 Type of the service that populates the @dfn{system profile}---i.e., the
26880 programs under @file{/run/current-system/profile}. Other services can
26881 extend it by passing it lists of packages to add to the system profile.
26885 @node Shepherd Services
26886 @subsection Shepherd Services
26888 @cindex shepherd services
26890 @cindex init system
26891 The @code{(gnu services shepherd)} module provides a way to define
26892 services managed by the GNU@tie{}Shepherd, which is the
26893 initialization system---the first process that is started when the
26894 system boots, also known as PID@tie{}1
26895 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
26897 Services in the Shepherd can depend on each other. For instance, the
26898 SSH daemon may need to be started after the syslog daemon has been
26899 started, which in turn can only happen once all the file systems have
26900 been mounted. The simple operating system defined earlier (@pxref{Using
26901 the Configuration System}) results in a service graph like this:
26903 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
26905 You can actually generate such a graph for any operating system
26906 definition using the @command{guix system shepherd-graph} command
26907 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
26909 The @code{%shepherd-root-service} is a service object representing
26910 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
26911 by passing it lists of @code{<shepherd-service>} objects.
26913 @deftp {Data Type} shepherd-service
26914 The data type representing a service managed by the Shepherd.
26917 @item @code{provision}
26918 This is a list of symbols denoting what the service provides.
26920 These are the names that may be passed to @command{herd start},
26921 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
26922 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
26923 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
26925 @item @code{requirement} (default: @code{'()})
26926 List of symbols denoting the Shepherd services this one depends on.
26928 @cindex one-shot services, for the Shepherd
26929 @item @code{one-shot?} (default: @code{#f})
26930 Whether this service is @dfn{one-shot}. One-shot services stop immediately
26931 after their @code{start} action has completed. @xref{Slots of services,,,
26932 shepherd, The GNU Shepherd Manual}, for more info.
26934 @item @code{respawn?} (default: @code{#t})
26935 Whether to restart the service when it stops, for instance when the
26936 underlying process dies.
26939 @itemx @code{stop} (default: @code{#~(const #f)})
26940 The @code{start} and @code{stop} fields refer to the Shepherd's
26941 facilities to start and stop processes (@pxref{Service De- and
26942 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
26943 G-expressions that get expanded in the Shepherd configuration file
26944 (@pxref{G-Expressions}).
26946 @item @code{actions} (default: @code{'()})
26947 @cindex actions, of Shepherd services
26948 This is a list of @code{shepherd-action} objects (see below) defining
26949 @dfn{actions} supported by the service, in addition to the standard
26950 @code{start} and @code{stop} actions. Actions listed here become available as
26951 @command{herd} sub-commands:
26954 herd @var{action} @var{service} [@var{arguments}@dots{}]
26957 @item @code{auto-start?} (default: @code{#t})
26958 Whether this service should be started automatically by the Shepherd. If it
26959 is @code{#f} the service has to be started manually with @code{herd start}.
26961 @item @code{documentation}
26962 A documentation string, as shown when running:
26965 herd doc @var{service-name}
26968 where @var{service-name} is one of the symbols in @code{provision}
26969 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
26971 @item @code{modules} (default: @code{%default-modules})
26972 This is the list of modules that must be in scope when @code{start} and
26973 @code{stop} are evaluated.
26978 @deftp {Data Type} shepherd-action
26979 This is the data type that defines additional actions implemented by a
26980 Shepherd service (see above).
26984 Symbol naming the action.
26986 @item documentation
26987 This is a documentation string for the action. It can be viewed by running:
26990 herd doc @var{service} action @var{action}
26994 This should be a gexp that evaluates to a procedure of at least one argument,
26995 which is the ``running value'' of the service (@pxref{Slots of services,,,
26996 shepherd, The GNU Shepherd Manual}).
26999 The following example defines an action called @code{say-hello} that kindly
27005 (documentation "Say hi!")
27006 (procedure #~(lambda (running . args)
27007 (format #t "Hello, friend! arguments: ~s\n"
27012 Assuming this action is added to the @code{example} service, then you can do:
27015 # herd say-hello example
27016 Hello, friend! arguments: ()
27017 # herd say-hello example a b c
27018 Hello, friend! arguments: ("a" "b" "c")
27021 This, as you can see, is a fairly sophisticated way to say hello.
27022 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
27026 @defvr {Scheme Variable} shepherd-root-service-type
27027 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
27029 This is the service type that extensions target when they want to create
27030 shepherd services (@pxref{Service Types and Services}, for an example).
27031 Each extension must pass a list of @code{<shepherd-service>}.
27034 @defvr {Scheme Variable} %shepherd-root-service
27035 This service represents PID@tie{}1.
27039 @node Documentation
27040 @chapter Documentation
27042 @cindex documentation, searching for
27043 @cindex searching for documentation
27044 @cindex Info, documentation format
27046 @cindex manual pages
27047 In most cases packages installed with Guix come with documentation.
27048 There are two main documentation formats: ``Info'', a browseable
27049 hypertext format used for GNU software, and ``manual pages'' (or ``man
27050 pages''), the linear documentation format traditionally found on Unix.
27051 Info manuals are accessed with the @command{info} command or with Emacs,
27052 and man pages are accessed using @command{man}.
27054 You can look for documentation of software installed on your system by
27055 keyword. For example, the following command searches for information
27056 about ``TLS'' in Info manuals:
27060 "(emacs)Network Security" -- STARTTLS
27061 "(emacs)Network Security" -- TLS
27062 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
27063 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
27068 The command below searches for the same keyword in man pages:
27072 SSL (7) - OpenSSL SSL/TLS library
27073 certtool (1) - GnuTLS certificate tool
27077 These searches are purely local to your computer so you have the
27078 guarantee that documentation you find corresponds to what you have
27079 actually installed, you can access it off-line, and your privacy is
27082 Once you have these results, you can view the relevant documentation by
27086 $ info "(gnutls)Core TLS API"
27096 Info manuals contain sections and indices as well as hyperlinks like
27097 those found in Web pages. The @command{info} reader (@pxref{Top, Info
27098 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
27099 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
27100 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
27101 Introduction}, for an introduction to Info navigation.
27103 @node Installing Debugging Files
27104 @chapter Installing Debugging Files
27106 @cindex debugging files
27107 Program binaries, as produced by the GCC compilers for instance, are
27108 typically written in the ELF format, with a section containing
27109 @dfn{debugging information}. Debugging information is what allows the
27110 debugger, GDB, to map binary code to source code; it is required to
27111 debug a compiled program in good conditions.
27113 The problem with debugging information is that is takes up a fair amount
27114 of disk space. For example, debugging information for the GNU C Library
27115 weighs in at more than 60 MiB. Thus, as a user, keeping all the
27116 debugging info of all the installed programs is usually not an option.
27117 Yet, space savings should not come at the cost of an impediment to
27118 debugging---especially in the GNU system, which should make it easier
27119 for users to exert their computing freedom (@pxref{GNU Distribution}).
27121 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
27122 mechanism that allows users to get the best of both worlds: debugging
27123 information can be stripped from the binaries and stored in separate
27124 files. GDB is then able to load debugging information from those files,
27125 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
27128 The GNU distribution takes advantage of this by storing debugging
27129 information in the @code{lib/debug} sub-directory of a separate package
27130 output unimaginatively called @code{debug} (@pxref{Packages with
27131 Multiple Outputs}). Users can choose to install the @code{debug} output
27132 of a package when they need it. For instance, the following command
27133 installs the debugging information for the GNU C Library and for GNU
27137 guix install glibc:debug guile:debug
27140 GDB must then be told to look for debug files in the user's profile, by
27141 setting the @code{debug-file-directory} variable (consider setting it
27142 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
27146 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
27149 From there on, GDB will pick up debugging information from the
27150 @code{.debug} files under @file{~/.guix-profile/lib/debug}.
27152 In addition, you will most likely want GDB to be able to show the source
27153 code being debugged. To do that, you will have to unpack the source
27154 code of the package of interest (obtained with @code{guix build
27155 --source}, @pxref{Invoking guix build}), and to point GDB to that source
27156 directory using the @code{directory} command (@pxref{Source Path,
27157 @code{directory},, gdb, Debugging with GDB}).
27159 @c XXX: keep me up-to-date
27160 The @code{debug} output mechanism in Guix is implemented by the
27161 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
27162 opt-in---debugging information is available only for the packages
27163 with definitions explicitly declaring a @code{debug} output. This may be
27164 changed to opt-out in the future if our build farm servers can handle
27165 the load. To check whether a package has a @code{debug} output, use
27166 @command{guix package --list-available} (@pxref{Invoking guix package}).
27169 @node Security Updates
27170 @chapter Security Updates
27172 @cindex security updates
27173 @cindex security vulnerabilities
27174 Occasionally, important security vulnerabilities are discovered in software
27175 packages and must be patched. Guix developers try hard to keep track of
27176 known vulnerabilities and to apply fixes as soon as possible in the
27177 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
27178 containing only security updates.) The @command{guix lint} tool helps
27179 developers find out about vulnerable versions of software packages in the
27184 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
27185 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
27186 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
27190 @xref{Invoking guix lint}, for more information.
27192 Guix follows a functional
27193 package management discipline (@pxref{Introduction}), which implies
27194 that, when a package is changed, @emph{every package that depends on it}
27195 must be rebuilt. This can significantly slow down the deployment of
27196 fixes in core packages such as libc or Bash, since basically the whole
27197 distribution would need to be rebuilt. Using pre-built binaries helps
27198 (@pxref{Substitutes}), but deployment may still take more time than
27202 To address this, Guix implements @dfn{grafts}, a mechanism that allows
27203 for fast deployment of critical updates without the costs associated
27204 with a whole-distribution rebuild. The idea is to rebuild only the
27205 package that needs to be patched, and then to ``graft'' it onto packages
27206 explicitly installed by the user and that were previously referring to
27207 the original package. The cost of grafting is typically very low, and
27208 order of magnitudes lower than a full rebuild of the dependency chain.
27210 @cindex replacements of packages, for grafts
27211 For instance, suppose a security update needs to be applied to Bash.
27212 Guix developers will provide a package definition for the ``fixed''
27213 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
27214 Packages}). Then, the original package definition is augmented with a
27215 @code{replacement} field pointing to the package containing the bug fix:
27222 (replacement bash-fixed)))
27225 From there on, any package depending directly or indirectly on Bash---as
27226 reported by @command{guix gc --requisites} (@pxref{Invoking guix
27227 gc})---that is installed is automatically ``rewritten'' to refer to
27228 @code{bash-fixed} instead of @code{bash}. This grafting process takes
27229 time proportional to the size of the package, usually less than a
27230 minute for an ``average'' package on a recent machine. Grafting is
27231 recursive: when an indirect dependency requires grafting, then grafting
27232 ``propagates'' up to the package that the user is installing.
27234 Currently, the length of the name and version of the graft and that of
27235 the package it replaces (@code{bash-fixed} and @code{bash} in the example
27236 above) must be equal. This restriction mostly comes from the fact that
27237 grafting works by patching files, including binary files, directly.
27238 Other restrictions may apply: for instance, when adding a graft to a
27239 package providing a shared library, the original shared library and its
27240 replacement must have the same @code{SONAME} and be binary-compatible.
27242 The @option{--no-grafts} command-line option allows you to forcefully
27243 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
27247 guix build bash --no-grafts
27251 returns the store file name of the original Bash, whereas:
27258 returns the store file name of the ``fixed'', replacement Bash. This
27259 allows you to distinguish between the two variants of Bash.
27261 To verify which Bash your whole profile refers to, you can run
27262 (@pxref{Invoking guix gc}):
27265 guix gc -R `readlink -f ~/.guix-profile` | grep bash
27269 @dots{} and compare the store file names that you get with those above.
27270 Likewise for a complete Guix system generation:
27273 guix gc -R `guix system build my-config.scm` | grep bash
27276 Lastly, to check which Bash running processes are using, you can use the
27277 @command{lsof} command:
27280 lsof | grep /gnu/store/.*bash
27284 @node Bootstrapping
27285 @chapter Bootstrapping
27287 @c Adapted from the ELS 2013 paper.
27289 @cindex bootstrapping
27291 Bootstrapping in our context refers to how the distribution gets built
27292 ``from nothing''. Remember that the build environment of a derivation
27293 contains nothing but its declared inputs (@pxref{Introduction}). So
27294 there's an obvious chicken-and-egg problem: how does the first package
27295 get built? How does the first compiler get compiled? Note that this is
27296 a question of interest only to the curious hacker, not to the regular
27297 user, so you can shamelessly skip this section if you consider yourself
27298 a ``regular user''.
27300 @cindex bootstrap binaries
27301 The GNU system is primarily made of C code, with libc at its core. The
27302 GNU build system itself assumes the availability of a Bourne shell and
27303 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
27304 `grep'. Furthermore, build programs---programs that run
27305 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
27306 (@pxref{Derivations}). Consequently, to be able to build anything at
27307 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
27308 Binutils, libc, and the other packages mentioned above---the
27309 @dfn{bootstrap binaries}.
27311 These bootstrap binaries are ``taken for granted'', though we can also
27312 re-create them if needed (more on that later).
27314 For @code{i686-linux} and @code{x86_64-linux} the Guix bootstrap process is
27315 more elaborate, @pxref{Reduced Binary Seed Bootstrap}.
27318 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
27319 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
27322 @node Reduced Binary Seed Bootstrap
27323 @section The Reduced Binary Seed Bootstrap
27325 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
27326 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
27327 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
27328 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
27329 ``taken for granted.''
27331 Taking these binaries for granted means that we consider them to be a correct
27332 and trustworthy `seed' for building the complete system. Therein lies a
27333 problem: the current combined size of these bootstrap binaries is about 250MB
27334 (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing or even inspecting
27335 these is next to impossible.
27337 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a ``Reduced
27338 Binary Seed'' bootstrap @footnote{We would like to say: ``Full Source
27339 Bootstrap'' and while we are working towards that goal it would be hyperbole
27340 to use that term for what we do now.}.
27342 The Reduced Binary Seed bootstrap removes the most critical tools---from a
27343 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
27344 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
27345 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
27346 written in Scheme and the Mes C Library, built for TinyCC and for GCC). Using
27347 these new binary seeds and a new set of
27349 packages@footnote{@c
27364 gcc-mesboot1-wrapper,
27365 glibc-headers-mesboot,
27369 gcc-mesboot-wrapper.
27372 the ``missing'' Binutils, GCC, and the GNU C Library are built from source.
27373 From here on the more traditional bootstrap process resumes. This approach
27374 has reduced the bootstrap binaries in size to about 130MB. Work is ongoing to
27375 reduce this further. If you are interested, join us on @code{#bootstrappable}
27376 on the Freenode IRC network.
27378 @c ./pre-inst-env guix graph --type=bag -e '(begin (use-modules (guix packages)) (%current-system "i686-linux") (@@ (gnu packages commencement) gcc-mesboot))' > doc/images/gcc-mesboot-bag-graph.dot
27379 @c dot -T png doc/images/gcc-mesboot-bag-graph.dot > doc/images/gcc-mesboot-bag-graph.png
27381 Below is the generated dependency graph for @code{gcc-mesboot}, the bootstrap
27382 compiler used to build the rest of GuixSD.
27384 @image{images/gcc-mesboot-bag-graph,6in,,Dependency graph of the gcc-mesboot}
27386 @node Preparing to Use the Bootstrap Binaries
27387 @section Preparing to Use the Bootstrap Binaries
27389 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
27390 @c large image, it's hard to scroll. Oh well.
27391 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
27393 The figure above shows the very beginning of the dependency graph of the
27394 distribution, corresponding to the package definitions of the @code{(gnu
27395 packages bootstrap)} module. A similar figure can be generated with
27396 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
27399 guix graph -t derivation \
27400 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
27401 | dot -Tps > gcc.ps
27404 or, for the Reduced Binary Seed bootstrap
27407 guix graph -t derivation \
27408 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
27409 | dot -Tps > mes.ps
27412 At this level of detail, things are
27413 slightly complex. First, Guile itself consists of an ELF executable,
27414 along with many source and compiled Scheme files that are dynamically
27415 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
27416 tarball shown in this graph. This tarball is part of Guix's ``source''
27417 distribution, and gets inserted into the store with @code{add-to-store}
27418 (@pxref{The Store}).
27420 But how do we write a derivation that unpacks this tarball and adds it
27421 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
27422 derivation---the first one that gets built---uses @code{bash} as its
27423 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
27424 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
27425 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
27426 the Guix source distribution, whose sole purpose is to allow the Guile
27427 tarball to be unpacked.
27429 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
27430 Guile that can be used to run subsequent build programs. Its first task
27431 is to download tarballs containing the other pre-built binaries---this
27432 is what the @code{.tar.xz.drv} derivations do. Guix modules such as
27433 @code{ftp-client.scm} are used for this purpose. The
27434 @code{module-import.drv} derivations import those modules in a directory
27435 in the store, using the original layout. The
27436 @code{module-import-compiled.drv} derivations compile those modules, and
27437 write them in an output directory with the right layout. This
27438 corresponds to the @code{#:modules} argument of
27439 @code{build-expression->derivation} (@pxref{Derivations}).
27441 Finally, the various tarballs are unpacked by the derivations
27442 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
27443 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
27444 point we have a working C tool chain.
27446 @unnumberedsec Building the Build Tools
27448 Bootstrapping is complete when we have a full tool chain that does not
27449 depend on the pre-built bootstrap tools discussed above. This
27450 no-dependency requirement is verified by checking whether the files of
27451 the final tool chain contain references to the @file{/gnu/store}
27452 directories of the bootstrap inputs. The process that leads to this
27453 ``final'' tool chain is described by the package definitions found in
27454 the @code{(gnu packages commencement)} module.
27456 The @command{guix graph} command allows us to ``zoom out'' compared to
27457 the graph above, by looking at the level of package objects instead of
27458 individual derivations---remember that a package may translate to
27459 several derivations, typically one derivation to download its source,
27460 one to build the Guile modules it needs, and one to actually build the
27461 package from source. The command:
27464 guix graph -t bag \
27465 -e '(@@@@ (gnu packages commencement)
27466 glibc-final-with-bootstrap-bash)' | dot -Tps > t.ps
27470 produces the dependency graph leading to the ``final'' C
27471 library@footnote{You may notice the @code{glibc-intermediate} label,
27472 suggesting that it is not @emph{quite} final, but as a good
27473 approximation, we will consider it final.}, depicted below.
27475 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
27477 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
27478 The first tool that gets built with the bootstrap binaries is
27479 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
27480 for all the following packages. From there Findutils and Diffutils get
27483 Then come the first-stage Binutils and GCC, built as pseudo cross
27484 tools---i.e., with @code{--target} equal to @code{--host}. They are
27485 used to build libc. Thanks to this cross-build trick, this libc is
27486 guaranteed not to hold any reference to the initial tool chain.
27488 From there the final Binutils and GCC (not shown above) are built.
27490 from the final Binutils, and links programs against the just-built libc.
27491 This tool chain is used to build the other packages used by Guix and by
27492 the GNU Build System: Guile, Bash, Coreutils, etc.
27494 And voilà! At this point we have the complete set of build tools that
27495 the GNU Build System expects. These are in the @code{%final-inputs}
27496 variable of the @code{(gnu packages commencement)} module, and are
27497 implicitly used by any package that uses @code{gnu-build-system}
27498 (@pxref{Build Systems, @code{gnu-build-system}}).
27501 @unnumberedsec Building the Bootstrap Binaries
27503 @cindex bootstrap binaries
27504 Because the final tool chain does not depend on the bootstrap binaries,
27505 those rarely need to be updated. Nevertheless, it is useful to have an
27506 automated way to produce them, should an update occur, and this is what
27507 the @code{(gnu packages make-bootstrap)} module provides.
27509 The following command builds the tarballs containing the bootstrap binaries
27510 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
27511 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
27512 and Guile, and a tarball containing a mixture of Coreutils and other basic
27513 command-line tools):
27516 guix build bootstrap-tarballs
27519 The generated tarballs are those that should be referred to in the
27520 @code{(gnu packages bootstrap)} module mentioned at the beginning of
27523 Still here? Then perhaps by now you've started to wonder: when do we
27524 reach a fixed point? That is an interesting question! The answer is
27525 unknown, but if you would like to investigate further (and have
27526 significant computational and storage resources to do so), then let us
27529 @unnumberedsec Reducing the Set of Bootstrap Binaries
27531 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
27532 binary code! Why is that a problem? It's a problem because these big chunks
27533 of binary code are practically non-auditable, which makes it hard to establish
27534 what source code produced them. Every unauditable binary also leaves us
27535 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
27536 paper @emph{Reflections on Trusting Trust}.
27538 This is mitigated by the fact that our bootstrap binaries were generated
27539 from an earlier Guix revision. Nevertheless it lacks the level of
27540 transparency that we get in the rest of the package dependency graph,
27541 where Guix always gives us a source-to-binary mapping. Thus, our goal
27542 is to reduce the set of bootstrap binaries to the bare minimum.
27544 The @uref{http://bootstrappable.org, Bootstrappable.org web site} lists
27545 on-going projects to do that. One of these is about replacing the
27546 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
27547 of increasing complexity, which could be built from source starting from
27548 a simple and auditable assembler.
27550 Our first major achievement is the replacement of of GCC, the GNU C Library
27551 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
27552 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
27553 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
27554 bootstrapped yet and thus we inject them as binary seeds. We call this the
27555 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
27556 binaries! Also, it has eliminated the C compiler binary; i686-linux and
27557 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
27559 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
27560 also looking at any other bootstrap binaries. Your help is welcome!
27563 @chapter Porting to a New Platform
27565 As discussed above, the GNU distribution is self-contained, and
27566 self-containment is achieved by relying on pre-built ``bootstrap
27567 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
27568 operating system kernel, CPU architecture, and application binary
27569 interface (ABI). Thus, to port the distribution to a platform that is
27570 not yet supported, one must build those bootstrap binaries, and update
27571 the @code{(gnu packages bootstrap)} module to use them on that platform.
27573 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
27574 When everything goes well, and assuming the GNU tool chain supports the
27575 target platform, this can be as simple as running a command like this
27579 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
27582 For this to work, the @code{glibc-dynamic-linker} procedure in
27583 @code{(gnu packages bootstrap)} must be augmented to return the right
27584 file name for libc's dynamic linker on that platform; likewise,
27585 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
27586 taught about the new platform.
27588 Once these are built, the @code{(gnu packages bootstrap)} module needs
27589 to be updated to refer to these binaries on the target platform. That
27590 is, the hashes and URLs of the bootstrap tarballs for the new platform
27591 must be added alongside those of the currently supported platforms. The
27592 bootstrap Guile tarball is treated specially: it is expected to be
27593 available locally, and @file{gnu/local.mk} has rules to download it for
27594 the supported architectures; a rule for the new platform must be added
27597 In practice, there may be some complications. First, it may be that the
27598 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
27599 above) is not recognized by all the GNU tools. Typically, glibc
27600 recognizes some of these, whereas GCC uses an extra @code{--with-abi}
27601 configure flag (see @code{gcc.scm} for examples of how to handle this).
27602 Second, some of the required packages could fail to build for that
27603 platform. Lastly, the generated binaries could be broken for some
27606 @c *********************************************************************
27607 @include contributing.texi
27609 @c *********************************************************************
27610 @node Acknowledgments
27611 @chapter Acknowledgments
27613 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
27614 which was designed and
27615 implemented by Eelco Dolstra, with contributions from other people (see
27616 the @file{nix/AUTHORS} file in Guix.) Nix pioneered functional package
27617 management, and promoted unprecedented features, such as transactional
27618 package upgrades and rollbacks, per-user profiles, and referentially
27619 transparent build processes. Without this work, Guix would not exist.
27621 The Nix-based software distributions, Nixpkgs and NixOS, have also been
27622 an inspiration for Guix.
27624 GNU@tie{}Guix itself is a collective work with contributions from a
27625 number of people. See the @file{AUTHORS} file in Guix for more
27626 information on these fine people. The @file{THANKS} file lists people
27627 who have helped by reporting bugs, taking care of the infrastructure,
27628 providing artwork and themes, making suggestions, and more---thank you!
27631 @c *********************************************************************
27632 @node GNU Free Documentation License
27633 @appendix GNU Free Documentation License
27634 @cindex license, GNU Free Documentation License
27635 @include fdl-1.3.texi
27637 @c *********************************************************************
27638 @node Concept Index
27639 @unnumbered Concept Index
27642 @node Programming Index
27643 @unnumbered Programming Index
27644 @syncodeindex tp fn
27645 @syncodeindex vr fn
27650 @c Local Variables:
27651 @c ispell-local-dictionary: "american";