6 @documentencoding UTF-8
7 @settitle GNU Guix Reference Manual
12 @c Identifier of the OpenPGP key used to sign tarballs and such.
13 @set OPENPGP-SIGNING-KEY-ID 3CE464558A84FDC69DB40CFB090B11993D9AEBB5
14 @set OPENPGP-SIGNING-KEY-URL https://sv.gnu.org/people/viewgpg.php?user_id=15145
16 @c Base URL for downloads.
17 @set BASE-URL https://ftp.gnu.org/gnu/guix
19 @c The official substitute server used by default.
20 @set SUBSTITUTE-SERVER ci.guix.gnu.org
21 @set SUBSTITUTE-URL https://@value{SUBSTITUTE-SERVER}
24 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès@*
25 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
26 Copyright @copyright{} 2013 Nikita Karetnikov@*
27 Copyright @copyright{} 2014, 2015, 2016 Alex Kost@*
28 Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
29 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
30 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
31 Copyright @copyright{} 2015, 2016, 2017, 2019, 2020 Leo Famulari@*
32 Copyright @copyright{} 2015, 2016, 2017, 2018, 2019, 2020 Ricardo Wurmus@*
33 Copyright @copyright{} 2016 Ben Woodcroft@*
34 Copyright @copyright{} 2016, 2017, 2018 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 Nikita Gillmann@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019, 2020 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, 2020 Florian Pelz@*
63 Copyright @copyright{} 2018 Laura Lazzati@*
64 Copyright @copyright{} 2018 Alex Vong@*
65 Copyright @copyright{} 2019 Josh Holland@*
66 Copyright @copyright{} 2019, 2020 Diego Nicola Barbato@*
67 Copyright @copyright{} 2019 Ivan Petkov@*
68 Copyright @copyright{} 2019 Jakob L. Kreuze@*
69 Copyright @copyright{} 2019 Kyle Andrews@*
70 Copyright @copyright{} 2019 Alex Griffin@*
71 Copyright @copyright{} 2019 Guillaume Le Vaillant@*
72 Copyright @copyright{} 2020 Leo Prikler@*
73 Copyright @copyright{} 2019, 2020 Simon Tournier@*
74 Copyright @copyright{} 2020 Wiktor Żelazny@*
75 Copyright @copyright{} 2020 Damien Cassou@*
76 Copyright @copyright{} 2020 Jakub Kądziołka@*
77 Copyright @copyright{} 2020 Jack Hill@*
78 Copyright @copyright{} 2020 Naga Malleswari@*
79 Copyright @copyright{} 2020 Brice Waegeneire@*
80 Copyright @copyright{} 2020 R Veera Kumar@*
81 Copyright @copyright{} 2020 Pierre Langlois@*
82 Copyright @copyright{} 2020 pinoaffe@*
84 Permission is granted to copy, distribute and/or modify this document
85 under the terms of the GNU Free Documentation License, Version 1.3 or
86 any later version published by the Free Software Foundation; with no
87 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
88 copy of the license is included in the section entitled ``GNU Free
89 Documentation License''.
92 @dircategory System administration
94 * Guix: (guix). Manage installed software and system configuration.
95 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
96 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
97 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
98 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
99 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
102 @dircategory Software development
104 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
105 * guix build: (guix)Invoking guix build. Building packages.
106 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
110 @title GNU Guix Reference Manual
111 @subtitle Using the GNU Guix Functional Package Manager
112 @author The GNU Guix Developers
115 @vskip 0pt plus 1filll
116 Edition @value{EDITION} @*
124 @c *********************************************************************
128 This document describes GNU Guix version @value{VERSION}, a functional
129 package management tool written for the GNU system.
131 @c TRANSLATORS: You can replace the following paragraph with information on
132 @c how to join your own translation team and how to report issues with the
134 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
135 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
136 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
137 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
138 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
139 would like to translate it in your native language, consider joining the
140 @uref{https://translationproject.org/domain/guix-manual.html, Translation
144 * Introduction:: What is Guix about?
145 * Installation:: Installing Guix.
146 * System Installation:: Installing the whole operating system.
147 * Getting Started:: Your first steps.
148 * Package Management:: Package installation, upgrade, etc.
149 * Development:: Guix-aided software development.
150 * Programming Interface:: Using Guix in Scheme.
151 * Utilities:: Package management commands.
152 * System Configuration:: Configuring the operating system.
153 * Documentation:: Browsing software user manuals.
154 * Installing Debugging Files:: Feeding the debugger.
155 * Security Updates:: Deploying security fixes quickly.
156 * Bootstrapping:: GNU/Linux built from scratch.
157 * Porting:: Targeting another platform or kernel.
158 * Contributing:: Your help needed!
160 * Acknowledgments:: Thanks!
161 * GNU Free Documentation License:: The license of this manual.
162 * Concept Index:: Concepts.
163 * Programming Index:: Data types, functions, and variables.
166 --- The Detailed Node Listing ---
170 * Managing Software the Guix Way:: What's special.
171 * GNU Distribution:: The packages and tools.
175 * Binary Installation:: Getting Guix running in no time!
176 * Requirements:: Software needed to build and run Guix.
177 * Running the Test Suite:: Testing Guix.
178 * Setting Up the Daemon:: Preparing the build daemon's environment.
179 * Invoking guix-daemon:: Running the build daemon.
180 * Application Setup:: Application-specific setup.
182 Setting Up the Daemon
184 * Build Environment Setup:: Preparing the isolated build environment.
185 * Daemon Offload Setup:: Offloading builds to remote machines.
186 * SELinux Support:: Using an SELinux policy for the daemon.
190 * Limitations:: What you can expect.
191 * Hardware Considerations:: Supported hardware.
192 * USB Stick and DVD Installation:: Preparing the installation medium.
193 * Preparing for Installation:: Networking, partitioning, etc.
194 * Guided Graphical Installation:: Easy graphical installation.
195 * Manual Installation:: Manual installation for wizards.
196 * After System Installation:: When installation succeeded.
197 * Installing Guix in a VM:: Guix System playground.
198 * Building the Installation Image:: How this comes to be.
204 * Keyboard Layout and Networking and Partitioning:: Initial setup.
205 * Proceeding with the Installation:: Installing.
209 * Features:: How Guix will make your life brighter.
210 * Invoking guix package:: Package installation, removal, etc.
211 * Substitutes:: Downloading pre-built binaries.
212 * Packages with Multiple Outputs:: Single source package, multiple outputs.
213 * Invoking guix gc:: Running the garbage collector.
214 * Invoking guix pull:: Fetching the latest Guix and distribution.
215 * Channels:: Customizing the package collection.
216 * Invoking guix time-machine:: Running an older revision of Guix.
217 * Inferiors:: Interacting with another revision of Guix.
218 * Invoking guix describe:: Display information about your Guix revision.
219 * Invoking guix archive:: Exporting and importing store files.
223 * Official Substitute Server:: One particular source of substitutes.
224 * Substitute Server Authorization:: How to enable or disable substitutes.
225 * Substitute Authentication:: How Guix verifies substitutes.
226 * Proxy Settings:: How to get substitutes via proxy.
227 * Substitution Failure:: What happens when substitution fails.
228 * On Trusting Binaries:: How can you trust that binary blob?
232 * Invoking guix environment:: Setting up development environments.
233 * Invoking guix pack:: Creating software bundles.
234 * The GCC toolchain:: Working with languages supported by GCC.
236 Programming Interface
238 * Package Modules:: Packages from the programmer's viewpoint.
239 * Defining Packages:: Defining new packages.
240 * Build Systems:: Specifying how packages are built.
241 * The Store:: Manipulating the package store.
242 * Derivations:: Low-level interface to package derivations.
243 * The Store Monad:: Purely functional interface to the store.
244 * G-Expressions:: Manipulating build expressions.
245 * Invoking guix repl:: Programming Guix in Guile
249 * package Reference:: The package data type.
250 * origin Reference:: The origin data type.
254 * Invoking guix build:: Building packages from the command line.
255 * Invoking guix edit:: Editing package definitions.
256 * Invoking guix download:: Downloading a file and printing its hash.
257 * Invoking guix hash:: Computing the cryptographic hash of a file.
258 * Invoking guix import:: Importing package definitions.
259 * Invoking guix refresh:: Updating package definitions.
260 * Invoking guix lint:: Finding errors in package definitions.
261 * Invoking guix size:: Profiling disk usage.
262 * Invoking guix graph:: Visualizing the graph of packages.
263 * Invoking guix publish:: Sharing substitutes.
264 * Invoking guix challenge:: Challenging substitute servers.
265 * Invoking guix copy:: Copying to and from a remote store.
266 * Invoking guix container:: Process isolation.
267 * Invoking guix weather:: Assessing substitute availability.
268 * Invoking guix processes:: Listing client processes.
270 Invoking @command{guix build}
272 * Common Build Options:: Build options for most commands.
273 * Package Transformation Options:: Creating variants of packages.
274 * Additional Build Options:: Options specific to 'guix build'.
275 * Debugging Build Failures:: Real life packaging experience.
279 * Using the Configuration System:: Customizing your GNU system.
280 * operating-system Reference:: Detail of operating-system declarations.
281 * File Systems:: Configuring file system mounts.
282 * Mapped Devices:: Block device extra processing.
283 * User Accounts:: Specifying user accounts.
284 * Keyboard Layout:: How the system interprets key strokes.
285 * Locales:: Language and cultural convention settings.
286 * Services:: Specifying system services.
287 * Setuid Programs:: Programs running with root privileges.
288 * X.509 Certificates:: Authenticating HTTPS servers.
289 * Name Service Switch:: Configuring libc's name service switch.
290 * Initial RAM Disk:: Linux-Libre bootstrapping.
291 * Bootloader Configuration:: Configuring the boot loader.
292 * Invoking guix system:: Instantiating a system configuration.
293 * Invoking guix deploy:: Deploying a system configuration to a remote host.
294 * Running Guix in a VM:: How to run Guix System in a virtual machine.
295 * Defining Services:: Adding new service definitions.
299 * Base Services:: Essential system services.
300 * Scheduled Job Execution:: The mcron service.
301 * Log Rotation:: The rottlog service.
302 * Networking Services:: Network setup, SSH daemon, etc.
303 * X Window:: Graphical display.
304 * Printing Services:: Local and remote printer support.
305 * Desktop Services:: D-Bus and desktop services.
306 * Sound Services:: ALSA and Pulseaudio services.
307 * Database Services:: SQL databases, key-value stores, etc.
308 * Mail Services:: IMAP, POP3, SMTP, and all that.
309 * Messaging Services:: Messaging services.
310 * Telephony Services:: Telephony services.
311 * Monitoring Services:: Monitoring services.
312 * Kerberos Services:: Kerberos services.
313 * Web Services:: Web servers.
314 * Certificate Services:: TLS certificates via Let's Encrypt.
315 * DNS Services:: DNS daemons.
316 * VPN Services:: VPN daemons.
317 * Network File System:: NFS related services.
318 * Continuous Integration:: The Cuirass service.
319 * Power Management Services:: Extending battery life.
320 * Audio Services:: The MPD.
321 * Virtualization Services:: Virtualization services.
322 * Version Control Services:: Providing remote access to Git repositories.
323 * Game Services:: Game servers.
324 * PAM Mount Service:: Service to mount volumes when logging in.
325 * Guix Services:: Services relating specifically to Guix.
326 * Linux Services:: Services tied to the Linux kernel.
327 * Hurd Services:: Services specific to a Hurd System.
328 * Miscellaneous Services:: Other services.
332 * Service Composition:: The model for composing services.
333 * Service Types and Services:: Types and services.
334 * Service Reference:: API reference.
335 * Shepherd Services:: A particular type of service.
340 @c *********************************************************************
342 @chapter Introduction
345 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
346 using the international phonetic alphabet (IPA).} is a package
347 management tool for and distribution of the GNU system.
348 Guix makes it easy for unprivileged
349 users to install, upgrade, or remove software packages, to roll back to a
350 previous package set, to build packages from source, and generally
351 assists with the creation and maintenance of software environments.
354 @cindex GuixSD, now Guix System
355 @cindex Guix System Distribution, now Guix System
356 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
357 complements the available tools without interference (@pxref{Installation}),
358 or you can use it as a standalone operating system distribution,
359 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
360 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
361 group everything under the ``Guix'' banner since, after all, Guix System is
362 readily available through the @command{guix system} command, even if you're
363 using a different distro underneath!}. @xref{GNU Distribution}.
366 * Managing Software the Guix Way:: What's special.
367 * GNU Distribution:: The packages and tools.
370 @node Managing Software the Guix Way
371 @section Managing Software the Guix Way
373 @cindex user interfaces
374 Guix provides a command-line package management interface
375 (@pxref{Package Management}), tools to help with software development
376 (@pxref{Development}), command-line utilities for more advanced usage,
377 (@pxref{Utilities}), as well as Scheme programming interfaces
378 (@pxref{Programming Interface}).
380 Its @dfn{build daemon} is responsible for building packages on behalf of
381 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
382 binaries from authorized sources (@pxref{Substitutes}).
384 @cindex extensibility of the distribution
385 @cindex customization, of packages
386 Guix includes package definitions for many GNU and non-GNU packages, all
387 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
388 user's computing freedom}. It is @emph{extensible}: users can write
389 their own package definitions (@pxref{Defining Packages}) and make them
390 available as independent package modules (@pxref{Package Modules}). It
391 is also @emph{customizable}: users can @emph{derive} specialized package
392 definitions from existing ones, including from the command line
393 (@pxref{Package Transformation Options}).
395 @cindex functional package management
397 Under the hood, Guix implements the @dfn{functional package management}
398 discipline pioneered by Nix (@pxref{Acknowledgments}).
399 In Guix, the package build and installation process is seen
400 as a @emph{function}, in the mathematical sense. That function takes inputs,
401 such as build scripts, a compiler, and libraries, and
402 returns an installed package. As a pure function, its result depends
403 solely on its inputs---for instance, it cannot refer to software or
404 scripts that were not explicitly passed as inputs. A build function
405 always produces the same result when passed a given set of inputs. It
406 cannot alter the environment of the running system in
407 any way; for instance, it cannot create, modify, or delete files outside
408 of its build and installation directories. This is achieved by running
409 build processes in isolated environments (or @dfn{containers}), where only their
410 explicit inputs are visible.
413 The result of package build functions is @dfn{cached} in the file
414 system, in a special directory called @dfn{the store} (@pxref{The
415 Store}). Each package is installed in a directory of its own in the
416 store---by default under @file{/gnu/store}. The directory name contains
417 a hash of all the inputs used to build that package; thus, changing an
418 input yields a different directory name.
420 This approach is the foundation for the salient features of Guix: support
421 for transactional package upgrade and rollback, per-user installation, and
422 garbage collection of packages (@pxref{Features}).
425 @node GNU Distribution
426 @section GNU Distribution
429 Guix comes with a distribution of the GNU system consisting entirely of
430 free software@footnote{The term ``free'' here refers to the
431 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
432 users of that software}.}. The
433 distribution can be installed on its own (@pxref{System Installation}),
434 but it is also possible to install Guix as a package manager on top of
435 an installed GNU/Linux system (@pxref{Installation}). When we need to
436 distinguish between the two, we refer to the standalone distribution as
439 The distribution provides core GNU packages such as GNU libc, GCC, and
440 Binutils, as well as many GNU and non-GNU applications. The complete
441 list of available packages can be browsed
442 @url{https://www.gnu.org/software/guix/packages,on-line} or by
443 running @command{guix package} (@pxref{Invoking guix package}):
446 guix package --list-available
449 Our goal is to provide a practical 100% free software distribution of
450 Linux-based and other variants of GNU, with a focus on the promotion and
451 tight integration of GNU components, and an emphasis on programs and
452 tools that help users exert that freedom.
454 Packages are currently available on the following platforms:
459 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel;
462 Intel 32-bit architecture (IA32), Linux-Libre kernel;
465 ARMv7-A architecture with hard float, Thumb-2 and NEON,
466 using the EABI hard-float application binary interface (ABI),
467 and Linux-Libre kernel.
470 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
472 @item mips64el-linux (deprecated)
473 little-endian 64-bit MIPS processors, specifically the Loongson series,
474 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
475 supported; in particular, there is no ongoing work to ensure that this
476 architecture still works. Should someone decide they wish to revive this
477 architecture then the code is still available.
481 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
482 configuration and Guix takes care of instantiating the configuration in a
483 transactional, reproducible, and stateless fashion (@pxref{System
484 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
485 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
486 Manual}), the well-known GNU utilities and tool chain, as well as the
487 graphical environment or system services of your choice.
489 Guix System is available on all the above platforms except
490 @code{mips64el-linux}.
493 For information on porting to other architectures or kernels,
496 Building this distribution is a cooperative effort, and you are invited
497 to join! @xref{Contributing}, for information about how you can help.
500 @c *********************************************************************
502 @chapter Installation
504 @cindex installing Guix
507 We recommend the use of this
508 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
509 shell installer script} to install Guix on top of a running GNU/Linux system,
510 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
511 with the installation of the package manager, which can be done on top of a
512 running GNU/Linux system. If, instead, you want to install the complete GNU
513 operating system, @pxref{System Installation}.} The script automates the
514 download, installation, and initial configuration of Guix. It should be run
518 @cindex foreign distro
519 @cindex directories related to foreign distro
520 When installed on a foreign distro, GNU@tie{}Guix complements the available
521 tools without interference. Its data lives exclusively in two directories,
522 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
523 such as @file{/etc}, are left untouched.
525 Once installed, Guix can be updated by running @command{guix pull}
526 (@pxref{Invoking guix pull}).
528 If you prefer to perform the installation steps manually or want to tweak
529 them, you may find the following subsections useful. They describe the
530 software requirements of Guix, as well as how to install it manually and get
534 * Binary Installation:: Getting Guix running in no time!
535 * Requirements:: Software needed to build and run Guix.
536 * Running the Test Suite:: Testing Guix.
537 * Setting Up the Daemon:: Preparing the build daemon's environment.
538 * Invoking guix-daemon:: Running the build daemon.
539 * Application Setup:: Application-specific setup.
540 * Upgrading Guix:: Upgrading Guix and its build daemon.
543 @node Binary Installation
544 @section Binary Installation
546 @cindex installing Guix from binaries
547 @cindex installer script
548 This section describes how to install Guix on an arbitrary system from a
549 self-contained tarball providing binaries for Guix and for all its
550 dependencies. This is often quicker than installing from source, which
551 is described in the next sections. The only requirement is to have
554 @c Note duplicated from the ``Installation'' node.
556 We recommend the use of this
557 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
558 shell installer script}. The script automates the download, installation, and
559 initial configuration steps described below. It should be run as the root
560 user. As root, you can thus run this:
564 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
565 chmod +x guix-install.sh
569 When you're done, @pxref{Application Setup} for extra configuration you
570 might need, and @ref{Getting Started} for your first steps!
573 Installing goes along these lines:
577 @cindex downloading Guix binary
578 Download the binary tarball from
579 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
580 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
581 @code{i686} (32-bits) machine already running the kernel Linux, and so on
582 (@pxref{GNU Distribution}).
584 @c The following is somewhat duplicated in ``System Installation''.
585 Make sure to download the associated @file{.sig} file and to verify the
586 authenticity of the tarball against it, along these lines:
589 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
590 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
593 If that command fails because you do not have the required public key,
594 then run this command to import it:
597 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
598 -qO - | gpg --import -
602 and rerun the @code{gpg --verify} command.
604 Take note that a warning like ``This key is not certified with a trusted
605 signature!'' is normal.
607 @c end authentication part
610 Now, you need to become the @code{root} user. Depending on your distribution,
611 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
615 # tar --warning=no-timestamp -xf \
616 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
617 # mv var/guix /var/ && mv gnu /
620 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
621 The latter contains a ready-to-use profile for @code{root} (see next
624 Do @emph{not} unpack the tarball on a working Guix system since that
625 would overwrite its own essential files.
627 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
628 not emit warnings about ``implausibly old time stamps'' (such
629 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
631 They stem from the fact that all the
632 files in the archive have their modification time set to zero (which
633 means January 1st, 1970). This is done on purpose to make sure the
634 archive content is independent of its creation time, thus making it
638 Make the profile available under @file{~root/.config/guix/current}, which is
639 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
642 # mkdir -p ~root/.config/guix
643 # ln -sf /var/guix/profiles/per-user/root/current-guix \
644 ~root/.config/guix/current
647 Source @file{etc/profile} to augment @env{PATH} and other relevant
648 environment variables:
651 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
652 source $GUIX_PROFILE/etc/profile
656 Create the group and user accounts for build users as explained below
657 (@pxref{Build Environment Setup}).
660 Run the daemon, and set it to automatically start on boot.
662 If your host distro uses the systemd init system, this can be achieved
665 @c Versions of systemd that supported symlinked service files are not
666 @c yet widely deployed, so we should suggest that users copy the service
669 @c See this thread for more information:
670 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
673 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
674 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
676 # systemctl enable --now gnu-store.mount guix-daemon
679 If your host distro uses the Upstart init system:
682 # initctl reload-configuration
683 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
688 Otherwise, you can still start the daemon manually with:
691 # ~root/.config/guix/current/bin/guix-daemon \
692 --build-users-group=guixbuild
696 Make the @command{guix} command available to other users on the machine,
700 # mkdir -p /usr/local/bin
702 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
705 It is also a good idea to make the Info version of this manual available
709 # mkdir -p /usr/local/share/info
710 # cd /usr/local/share/info
711 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
715 That way, assuming @file{/usr/local/share/info} is in the search path,
716 running @command{info guix} will open this manual (@pxref{Other Info
717 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
721 @cindex substitutes, authorization thereof
722 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
723 (@pxref{Substitutes}), authorize them:
726 # guix archive --authorize < \
727 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
731 Each user may need to perform a few additional steps to make their Guix
732 environment ready for use, @pxref{Application Setup}.
735 Voilà, the installation is complete!
737 You can confirm that Guix is working by installing a sample package into
744 The binary installation tarball can be (re)produced and verified simply
745 by running the following command in the Guix source tree:
748 make guix-binary.@var{system}.tar.xz
752 ...@: which, in turn, runs:
755 guix pack -s @var{system} --localstatedir \
756 --profile-name=current-guix guix
759 @xref{Invoking guix pack}, for more info on this handy tool.
762 @section Requirements
764 This section lists requirements when building Guix from source. The
765 build procedure for Guix is the same as for other GNU software, and is
766 not covered here. Please see the files @file{README} and @file{INSTALL}
767 in the Guix source tree for additional details.
769 @cindex official website
770 GNU Guix is available for download from its website at
771 @url{https://www.gnu.org/software/guix/}.
773 GNU Guix depends on the following packages:
776 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
778 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
781 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
782 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
783 Guile,, gnutls-guile, GnuTLS-Guile});
785 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
787 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
788 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
790 @c FIXME: Specify a version number once a release has been made.
791 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, from August
793 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
795 @item @url{https://www.gnu.org/software/make/, GNU Make}.
798 The following dependencies are optional:
802 @c Note: We need at least 0.13.0 for #:nodelay.
803 Support for build offloading (@pxref{Daemon Offload Setup}) and
804 @command{guix copy} (@pxref{Invoking guix copy}) depends on
805 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
806 version 0.13.0 or later.
809 When @url{https://www.nongnu.org/lzip/lzlib.html, lzlib} is available, lzlib
810 substitutes can be used and @command{guix publish} can compress substitutes
814 When @url{http://www.bzip.org, libbz2} is available,
815 @command{guix-daemon} can use it to compress build logs.
818 Unless @option{--disable-daemon} was passed to @command{configure}, the
819 following packages are also needed:
822 @item @url{https://gnupg.org/, GNU libgcrypt};
823 @item @url{https://sqlite.org, SQLite 3};
824 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
828 @cindex state directory
829 When configuring Guix on a system that already has a Guix installation,
830 be sure to specify the same state directory as the existing installation
831 using the @option{--localstatedir} option of the @command{configure}
832 script (@pxref{Directory Variables, @code{localstatedir},, standards,
833 GNU Coding Standards}). Usually, this @var{localstatedir} option is
834 set to the value @file{/var}. The @command{configure} script protects
835 against unintended misconfiguration of @var{localstatedir} so you do not
836 inadvertently corrupt your store (@pxref{The Store}).
838 @node Running the Test Suite
839 @section Running the Test Suite
842 After a successful @command{configure} and @code{make} run, it is a good
843 idea to run the test suite. It can help catch issues with the setup or
844 environment, or bugs in Guix itself---and really, reporting test
845 failures is a good way to help improve the software. To run the test
852 Test cases can run in parallel: you can use the @code{-j} option of
853 GNU@tie{}make to speed things up. The first run may take a few minutes
854 on a recent machine; subsequent runs will be faster because the store
855 that is created for test purposes will already have various things in
858 It is also possible to run a subset of the tests by defining the
859 @code{TESTS} makefile variable as in this example:
862 make check TESTS="tests/store.scm tests/cpio.scm"
865 By default, tests results are displayed at a file level. In order to
866 see the details of every individual test cases, it is possible to define
867 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
870 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
873 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
874 @file{test-suite.log} file. Please specify the Guix version being used
875 as well as version numbers of the dependencies (@pxref{Requirements}) in
878 Guix also comes with a whole-system test suite that tests complete
879 Guix System instances. It can only run on systems where
880 Guix is already installed, using:
887 or, again, by defining @code{TESTS} to select a subset of tests to run:
890 make check-system TESTS="basic mcron"
893 These system tests are defined in the @code{(gnu tests @dots{})}
894 modules. They work by running the operating systems under test with
895 lightweight instrumentation in a virtual machine (VM). They can be
896 computationally intensive or rather cheap, depending on whether
897 substitutes are available for their dependencies (@pxref{Substitutes}).
898 Some of them require a lot of storage space to hold VM images.
900 Again in case of test failures, please send @email{bug-guix@@gnu.org}
903 @node Setting Up the Daemon
904 @section Setting Up the Daemon
907 Operations such as building a package or running the garbage collector
908 are all performed by a specialized process, the @dfn{build daemon}, on
909 behalf of clients. Only the daemon may access the store and its
910 associated database. Thus, any operation that manipulates the store
911 goes through the daemon. For instance, command-line tools such as
912 @command{guix package} and @command{guix build} communicate with the
913 daemon (@i{via} remote procedure calls) to instruct it what to do.
915 The following sections explain how to prepare the build daemon's
916 environment. See also @ref{Substitutes}, for information on how to allow
917 the daemon to download pre-built binaries.
920 * Build Environment Setup:: Preparing the isolated build environment.
921 * Daemon Offload Setup:: Offloading builds to remote machines.
922 * SELinux Support:: Using an SELinux policy for the daemon.
925 @node Build Environment Setup
926 @subsection Build Environment Setup
928 @cindex build environment
929 In a standard multi-user setup, Guix and its daemon---the
930 @command{guix-daemon} program---are installed by the system
931 administrator; @file{/gnu/store} is owned by @code{root} and
932 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
933 Guix tools to build packages or otherwise access the store, and the
934 daemon will do it on their behalf, ensuring that the store is kept in a
935 consistent state, and allowing built packages to be shared among users.
938 When @command{guix-daemon} runs as @code{root}, you may not want package
939 build processes themselves to run as @code{root} too, for obvious
940 security reasons. To avoid that, a special pool of @dfn{build users}
941 should be created for use by build processes started by the daemon.
942 These build users need not have a shell and a home directory: they will
943 just be used when the daemon drops @code{root} privileges in build
944 processes. Having several such users allows the daemon to launch
945 distinct build processes under separate UIDs, which guarantees that they
946 do not interfere with each other---an essential feature since builds are
947 regarded as pure functions (@pxref{Introduction}).
949 On a GNU/Linux system, a build user pool may be created like this (using
950 Bash syntax and the @code{shadow} commands):
952 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
953 @c for why `-G' is needed.
955 # groupadd --system guixbuild
956 # for i in `seq -w 1 10`;
958 useradd -g guixbuild -G guixbuild \
959 -d /var/empty -s `which nologin` \
960 -c "Guix build user $i" --system \
966 The number of build users determines how many build jobs may run in
967 parallel, as specified by the @option{--max-jobs} option
968 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
969 @command{guix system vm} and related commands, you may need to add the
970 build users to the @code{kvm} group so they can access @file{/dev/kvm},
971 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
972 (@pxref{Invoking guix system}).
974 The @code{guix-daemon} program may then be run as @code{root} with the
975 following command@footnote{If your machine uses the systemd init system,
976 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
977 file in @file{/etc/systemd/system} will ensure that
978 @command{guix-daemon} is automatically started. Similarly, if your
979 machine uses the Upstart init system, drop the
980 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
981 file in @file{/etc/init}.}:
984 # guix-daemon --build-users-group=guixbuild
989 This way, the daemon starts build processes in a chroot, under one of
990 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
991 environment contains nothing but:
993 @c Keep this list in sync with libstore/build.cc! -----------------------
996 a minimal @code{/dev} directory, created mostly independently from the
997 host @code{/dev}@footnote{``Mostly'', because while the set of files
998 that appear in the chroot's @code{/dev} is fixed, most of these files
999 can only be created if the host has them.};
1002 the @code{/proc} directory; it only shows the processes of the container
1003 since a separate PID name space is used;
1006 @file{/etc/passwd} with an entry for the current user and an entry for
1010 @file{/etc/group} with an entry for the user's group;
1013 @file{/etc/hosts} with an entry that maps @code{localhost} to
1017 a writable @file{/tmp} directory.
1020 You can influence the directory where the daemon stores build trees
1021 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1022 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1023 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1024 This way, the value of @env{TMPDIR} does not leak inside build
1025 environments, which avoids discrepancies in cases where build processes
1026 capture the name of their build tree.
1030 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1031 environment variables for HTTP and HTTPS downloads it performs, be it
1032 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1033 (@pxref{Substitutes}).
1035 If you are installing Guix as an unprivileged user, it is still possible
1036 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1037 However, build processes will not be isolated from one another, and not
1038 from the rest of the system. Thus, build processes may interfere with
1039 each other, and may access programs, libraries, and other files
1040 available on the system---making it much harder to view them as
1041 @emph{pure} functions.
1044 @node Daemon Offload Setup
1045 @subsection Using the Offload Facility
1049 When desired, the build daemon can @dfn{offload} derivation builds to
1050 other machines running Guix, using the @code{offload} @dfn{build
1051 hook}@footnote{This feature is available only when
1052 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1053 present.}. When that feature is enabled, a list of user-specified build
1054 machines is read from @file{/etc/guix/machines.scm}; every time a build
1055 is requested, for instance via @code{guix build}, the daemon attempts to
1056 offload it to one of the machines that satisfy the constraints of the
1057 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1058 A single machine can have multiple system types, either because its
1059 architecture natively supports it, via emulation (@pxref{Transparent
1060 Emulation with QEMU}), or both. Missing prerequisites for the build are
1061 copied over SSH to the target machine, which then proceeds with the
1062 build; upon success the output(s) of the build are copied back to the
1065 The @file{/etc/guix/machines.scm} file typically looks like this:
1068 (list (build-machine
1069 (name "eightysix.example.org")
1070 (systems (list "x86_64-linux" "i686-linux"))
1071 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1073 (speed 2.)) ;incredibly fast!
1076 (name "armeight.example.org")
1077 (systems (list "aarch64-linux"))
1078 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1081 (string-append (getenv "HOME")
1082 "/.ssh/identity-for-guix"))))
1086 In the example above we specify a list of two build machines, one for
1087 the @code{x86_64} and @code{i686} architectures and one for the
1088 @code{aarch64} architecture.
1090 In fact, this file is---not surprisingly!---a Scheme file that is
1091 evaluated when the @code{offload} hook is started. Its return value
1092 must be a list of @code{build-machine} objects. While this example
1093 shows a fixed list of build machines, one could imagine, say, using
1094 DNS-SD to return a list of potential build machines discovered in the
1095 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1096 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1099 @deftp {Data Type} build-machine
1100 This data type represents build machines to which the daemon may offload
1101 builds. The important fields are:
1106 The host name of the remote machine.
1109 The system types the remote machine supports---e.g., @code{(list
1110 "x86_64-linux" "i686-linux")}.
1113 The user account to use when connecting to the remote machine over SSH.
1114 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1115 allow non-interactive logins.
1118 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1119 This is used to authenticate the machine when we connect to it. It is a
1120 long string that looks like this:
1123 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1126 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1127 key can be found in a file such as
1128 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1130 If the machine is running the SSH daemon of GNU@tie{}lsh,
1131 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1132 similar file. It can be converted to the OpenSSH format using
1133 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1136 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1137 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1142 A number of optional fields may be specified:
1146 @item @code{port} (default: @code{22})
1147 Port number of SSH server on the machine.
1149 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1150 The SSH private key file to use when connecting to the machine, in
1151 OpenSSH format. This key must not be protected with a passphrase.
1153 Note that the default value is the private key @emph{of the root
1154 account}. Make sure it exists if you use the default.
1156 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1157 @itemx @code{compression-level} (default: @code{3})
1158 The SSH-level compression methods and compression level requested.
1160 Note that offloading relies on SSH compression to reduce bandwidth usage
1161 when transferring files to and from build machines.
1163 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1164 File name of the Unix-domain socket @command{guix-daemon} is listening
1167 @item @code{parallel-builds} (default: @code{1})
1168 The number of builds that may run in parallel on the machine.
1170 @item @code{speed} (default: @code{1.0})
1171 A ``relative speed factor''. The offload scheduler will tend to prefer
1172 machines with a higher speed factor.
1174 @item @code{features} (default: @code{'()})
1175 A list of strings denoting specific features supported by the machine.
1176 An example is @code{"kvm"} for machines that have the KVM Linux modules
1177 and corresponding hardware support. Derivations can request features by
1178 name, and they will be scheduled on matching build machines.
1183 The @command{guix} command must be in the search path on the build
1184 machines. You can check whether this is the case by running:
1187 ssh build-machine guix repl --version
1190 There is one last thing to do once @file{machines.scm} is in place. As
1191 explained above, when offloading, files are transferred back and forth
1192 between the machine stores. For this to work, you first need to
1193 generate a key pair on each machine to allow the daemon to export signed
1194 archives of files from the store (@pxref{Invoking guix archive}):
1197 # guix archive --generate-key
1201 Each build machine must authorize the key of the master machine so that
1202 it accepts store items it receives from the master:
1205 # guix archive --authorize < master-public-key.txt
1209 Likewise, the master machine must authorize the key of each build machine.
1211 All the fuss with keys is here to express pairwise mutual trust
1212 relations between the master and the build machines. Concretely, when
1213 the master receives files from a build machine (and @i{vice versa}), its
1214 build daemon can make sure they are genuine, have not been tampered
1215 with, and that they are signed by an authorized key.
1217 @cindex offload test
1218 To test whether your setup is operational, run this command on the
1225 This will attempt to connect to each of the build machines specified in
1226 @file{/etc/guix/machines.scm}, make sure Guile and the Guix modules are
1227 available on each machine, attempt to export to the machine and import
1228 from it, and report any error in the process.
1230 If you want to test a different machine file, just specify it on the
1234 # guix offload test machines-qualif.scm
1237 Last, you can test the subset of the machines whose name matches a
1238 regular expression like this:
1241 # guix offload test machines.scm '\.gnu\.org$'
1244 @cindex offload status
1245 To display the current load of all build hosts, run this command on the
1249 # guix offload status
1253 @node SELinux Support
1254 @subsection SELinux Support
1256 @cindex SELinux, daemon policy
1257 @cindex mandatory access control, SELinux
1258 @cindex security, guix-daemon
1259 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1260 can be installed on a system where SELinux is enabled, in order to label
1261 Guix files and to specify the expected behavior of the daemon. Since
1262 Guix System does not provide an SELinux base policy, the daemon policy cannot
1263 be used on Guix System.
1265 @subsubsection Installing the SELinux policy
1266 @cindex SELinux, policy installation
1267 To install the policy run this command as root:
1270 semodule -i etc/guix-daemon.cil
1273 Then relabel the file system with @code{restorecon} or by a different
1274 mechanism provided by your system.
1276 Once the policy is installed, the file system has been relabeled, and
1277 the daemon has been restarted, it should be running in the
1278 @code{guix_daemon_t} context. You can confirm this with the following
1282 ps -Zax | grep guix-daemon
1285 Monitor the SELinux log files as you run a command like @code{guix build
1286 hello} to convince yourself that SELinux permits all necessary
1289 @subsubsection Limitations
1290 @cindex SELinux, limitations
1292 This policy is not perfect. Here is a list of limitations or quirks
1293 that should be considered when deploying the provided SELinux policy for
1298 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1299 operations involve contexts that have anything to do with
1300 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1301 but it would be preferrable to define socket rules for only this label.
1304 @code{guix gc} cannot access arbitrary links to profiles. By design,
1305 the file label of the destination of a symlink is independent of the
1306 file label of the link itself. Although all profiles under
1307 $localstatedir are labelled, the links to these profiles inherit the
1308 label of the directory they are in. For links in the user’s home
1309 directory this will be @code{user_home_t}. But for links from the root
1310 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1311 directory, etc, this won’t work. @code{guix gc} would be prevented from
1312 reading and following these links.
1315 The daemon’s feature to listen for TCP connections might no longer work.
1316 This might require extra rules, because SELinux treats network sockets
1317 differently from files.
1320 Currently all files with a name matching the regular expression
1321 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1322 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1323 that name in any profile would be permitted to run in the
1324 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1325 build a package that provides this executable and convince a user to
1326 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1327 At that point SELinux could not prevent it from accessing files that are
1328 allowed for processes in that domain.
1330 We could generate a much more restrictive policy at installation time,
1331 so that only the @emph{exact} file name of the currently installed
1332 @code{guix-daemon} executable would be labelled with
1333 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1334 The downside is that root would have to install or upgrade the policy at
1335 installation time whenever the Guix package that provides the
1336 effectively running @code{guix-daemon} executable is upgraded.
1339 @node Invoking guix-daemon
1340 @section Invoking @command{guix-daemon}
1342 The @command{guix-daemon} program implements all the functionality to
1343 access the store. This includes launching build processes, running the
1344 garbage collector, querying the availability of a build result, etc. It
1345 is normally run as @code{root} like this:
1348 # guix-daemon --build-users-group=guixbuild
1352 For details on how to set it up, @pxref{Setting Up the Daemon}.
1355 @cindex container, build environment
1356 @cindex build environment
1357 @cindex reproducible builds
1358 By default, @command{guix-daemon} launches build processes under
1359 different UIDs, taken from the build group specified with
1360 @option{--build-users-group}. In addition, each build process is run in a
1361 chroot environment that only contains the subset of the store that the
1362 build process depends on, as specified by its derivation
1363 (@pxref{Programming Interface, derivation}), plus a set of specific
1364 system directories. By default, the latter contains @file{/dev} and
1365 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1366 @dfn{container}: in addition to having its own file system tree, it has
1367 a separate mount name space, its own PID name space, network name space,
1368 etc. This helps achieve reproducible builds (@pxref{Features}).
1370 When the daemon performs a build on behalf of the user, it creates a
1371 build directory under @file{/tmp} or under the directory specified by
1372 its @env{TMPDIR} environment variable. This directory is shared with
1373 the container for the duration of the build, though within the container,
1374 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1376 The build directory is automatically deleted upon completion, unless the
1377 build failed and the client specified @option{--keep-failed}
1378 (@pxref{Invoking guix build, @option{--keep-failed}}).
1380 The daemon listens for connections and spawns one sub-process for each session
1381 started by a client (one of the @command{guix} sub-commands). The
1382 @command{guix processes} command allows you to get an overview of the activity
1383 on your system by viewing each of the active sessions and clients.
1384 @xref{Invoking guix processes}, for more information.
1386 The following command-line options are supported:
1389 @item --build-users-group=@var{group}
1390 Take users from @var{group} to run build processes (@pxref{Setting Up
1391 the Daemon, build users}).
1393 @item --no-substitutes
1395 Do not use substitutes for build products. That is, always build things
1396 locally instead of allowing downloads of pre-built binaries
1397 (@pxref{Substitutes}).
1399 When the daemon runs with @option{--no-substitutes}, clients can still
1400 explicitly enable substitution @i{via} the @code{set-build-options}
1401 remote procedure call (@pxref{The Store}).
1403 @item --substitute-urls=@var{urls}
1404 @anchor{daemon-substitute-urls}
1405 Consider @var{urls} the default whitespace-separated list of substitute
1406 source URLs. When this option is omitted,
1407 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1409 This means that substitutes may be downloaded from @var{urls}, as long
1410 as they are signed by a trusted signature (@pxref{Substitutes}).
1414 Do not use offload builds to other machines (@pxref{Daemon Offload
1415 Setup}). That is, always build things locally instead of offloading
1416 builds to remote machines.
1418 @item --cache-failures
1419 Cache build failures. By default, only successful builds are cached.
1421 When this option is used, @command{guix gc --list-failures} can be used
1422 to query the set of store items marked as failed; @command{guix gc
1423 --clear-failures} removes store items from the set of cached failures.
1424 @xref{Invoking guix gc}.
1426 @item --cores=@var{n}
1428 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1431 The default value is @code{0}, but it may be overridden by clients, such
1432 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1435 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1436 in the build process, which can then use it to exploit internal
1437 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1439 @item --max-jobs=@var{n}
1441 Allow at most @var{n} build jobs in parallel. The default value is
1442 @code{1}. Setting it to @code{0} means that no builds will be performed
1443 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1444 Setup}), or simply fail.
1446 @item --max-silent-time=@var{seconds}
1447 When the build or substitution process remains silent for more than
1448 @var{seconds}, terminate it and report a build failure.
1450 The default value is @code{0}, which disables the timeout.
1452 The value specified here can be overridden by clients (@pxref{Common
1453 Build Options, @option{--max-silent-time}}).
1455 @item --timeout=@var{seconds}
1456 Likewise, when the build or substitution process lasts for more than
1457 @var{seconds}, terminate it and report a build failure.
1459 The default value is @code{0}, which disables the timeout.
1461 The value specified here can be overridden by clients (@pxref{Common
1462 Build Options, @option{--timeout}}).
1464 @item --rounds=@var{N}
1465 Build each derivation @var{n} times in a row, and raise an error if
1466 consecutive build results are not bit-for-bit identical. Note that this
1467 setting can be overridden by clients such as @command{guix build}
1468 (@pxref{Invoking guix build}).
1470 When used in conjunction with @option{--keep-failed}, the differing
1471 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1472 This makes it easy to look for differences between the two results.
1475 Produce debugging output.
1477 This is useful to debug daemon start-up issues, but then it may be
1478 overridden by clients, for example the @option{--verbosity} option of
1479 @command{guix build} (@pxref{Invoking guix build}).
1481 @item --chroot-directory=@var{dir}
1482 Add @var{dir} to the build chroot.
1484 Doing this may change the result of build processes---for instance if
1485 they use optional dependencies found in @var{dir} when it is available,
1486 and not otherwise. For that reason, it is not recommended to do so.
1487 Instead, make sure that each derivation declares all the inputs that it
1490 @item --disable-chroot
1491 Disable chroot builds.
1493 Using this option is not recommended since, again, it would allow build
1494 processes to gain access to undeclared dependencies. It is necessary,
1495 though, when @command{guix-daemon} is running under an unprivileged user
1498 @item --log-compression=@var{type}
1499 Compress build logs according to @var{type}, one of @code{gzip},
1500 @code{bzip2}, or @code{none}.
1502 Unless @option{--lose-logs} is used, all the build logs are kept in the
1503 @var{localstatedir}. To save space, the daemon automatically compresses
1504 them with Bzip2 by default.
1506 @item --disable-deduplication
1507 @cindex deduplication
1508 Disable automatic file ``deduplication'' in the store.
1510 By default, files added to the store are automatically ``deduplicated'':
1511 if a newly added file is identical to another one found in the store,
1512 the daemon makes the new file a hard link to the other file. This can
1513 noticeably reduce disk usage, at the expense of slightly increased
1514 input/output load at the end of a build process. This option disables
1517 @item --gc-keep-outputs[=yes|no]
1518 Tell whether the garbage collector (GC) must keep outputs of live
1522 @cindex garbage collector roots
1523 When set to @code{yes}, the GC will keep the outputs of any live
1524 derivation available in the store---the @file{.drv} files. The default
1525 is @code{no}, meaning that derivation outputs are kept only if they are
1526 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1529 @item --gc-keep-derivations[=yes|no]
1530 Tell whether the garbage collector (GC) must keep derivations
1531 corresponding to live outputs.
1533 When set to @code{yes}, as is the case by default, the GC keeps
1534 derivations---i.e., @file{.drv} files---as long as at least one of their
1535 outputs is live. This allows users to keep track of the origins of
1536 items in their store. Setting it to @code{no} saves a bit of disk
1539 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1540 liveness to flow from outputs to derivations, and setting
1541 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1542 derivations to outputs. When both are set to @code{yes}, the effect is
1543 to keep all the build prerequisites (the sources, compiler, libraries,
1544 and other build-time tools) of live objects in the store, regardless of
1545 whether these prerequisites are reachable from a GC root. This is
1546 convenient for developers since it saves rebuilds or downloads.
1548 @item --impersonate-linux-2.6
1549 On Linux-based systems, impersonate Linux 2.6. This means that the
1550 kernel's @command{uname} system call will report 2.6 as the release number.
1552 This might be helpful to build programs that (usually wrongfully) depend
1553 on the kernel version number.
1556 Do not keep build logs. By default they are kept under
1557 @file{@var{localstatedir}/guix/log}.
1559 @item --system=@var{system}
1560 Assume @var{system} as the current system type. By default it is the
1561 architecture/kernel pair found at configure time, such as
1562 @code{x86_64-linux}.
1564 @item --listen=@var{endpoint}
1565 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1566 as the file name of a Unix-domain socket if it starts with
1567 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1568 host name or host name and port to listen to. Here are a few examples:
1571 @item --listen=/gnu/var/daemon
1572 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1573 creating it if needed.
1575 @item --listen=localhost
1576 @cindex daemon, remote access
1577 @cindex remote access to the daemon
1578 @cindex daemon, cluster setup
1579 @cindex clusters, daemon setup
1580 Listen for TCP connections on the network interface corresponding to
1581 @code{localhost}, on port 44146.
1583 @item --listen=128.0.0.42:1234
1584 Listen for TCP connections on the network interface corresponding to
1585 @code{128.0.0.42}, on port 1234.
1588 This option can be repeated multiple times, in which case
1589 @command{guix-daemon} accepts connections on all the specified
1590 endpoints. Users can tell client commands what endpoint to connect to
1591 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1592 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1595 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1596 @option{--listen=@var{host}} is suitable on local networks, such as
1597 clusters, where only trusted nodes may connect to the build daemon. In
1598 other cases where remote access to the daemon is needed, we recommend
1599 using Unix-domain sockets along with SSH.
1602 When @option{--listen} is omitted, @command{guix-daemon} listens for
1603 connections on the Unix-domain socket located at
1604 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1608 @node Application Setup
1609 @section Application Setup
1611 @cindex foreign distro
1612 When using Guix on top of GNU/Linux distribution other than Guix System---a
1613 so-called @dfn{foreign distro}---a few additional steps are needed to
1614 get everything in place. Here are some of them.
1618 @anchor{locales-and-locpath}
1619 @cindex locales, when not on Guix System
1621 @vindex GUIX_LOCPATH
1622 Packages installed @i{via} Guix will not use the locale data of the
1623 host system. Instead, you must first install one of the locale packages
1624 available with Guix and then define the @env{GUIX_LOCPATH} environment
1628 $ guix install glibc-locales
1629 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1632 Note that the @code{glibc-locales} package contains data for all the
1633 locales supported by the GNU@tie{}libc and weighs in at around
1634 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1635 limited to a few UTF-8 locales.
1637 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1638 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1639 Manual}). There are two important differences though:
1643 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1644 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1645 to make sure the programs of the foreign distro will not end up loading
1646 incompatible locale data.
1649 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1650 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1651 should your Guix profile contain a mixture of programs linked against
1652 different libc version, each libc version will only try to load locale
1653 data in the right format.
1656 This is important because the locale data format used by different libc
1657 versions may be incompatible.
1659 @subsection Name Service Switch
1661 @cindex name service switch, glibc
1662 @cindex NSS (name service switch), glibc
1663 @cindex nscd (name service caching daemon)
1664 @cindex name service caching daemon (nscd)
1665 When using Guix on a foreign distro, we @emph{strongly recommend} that
1666 the system run the GNU C library's @dfn{name service cache daemon},
1667 @command{nscd}, which should be listening on the
1668 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1669 installed with Guix may fail to look up host names or user accounts, or
1670 may even crash. The next paragraphs explain why.
1672 @cindex @file{nsswitch.conf}
1673 The GNU C library implements a @dfn{name service switch} (NSS), which is
1674 an extensible mechanism for ``name lookups'' in general: host name
1675 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1676 The GNU C Library Reference Manual}).
1678 @cindex Network information service (NIS)
1679 @cindex NIS (Network information service)
1680 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1681 lookup implementations: for example, the @code{nss-mdns} plugin allow
1682 resolution of @code{.local} host names, the @code{nis} plugin allows
1683 user account lookup using the Network information service (NIS), and so
1684 on. These extra ``lookup services'' are configured system-wide in
1685 @file{/etc/nsswitch.conf}, and all the programs running on the system
1686 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1689 When they perform a name lookup---for instance by calling the
1690 @code{getaddrinfo} function in C---applications first try to connect to
1691 the nscd; on success, nscd performs name lookups on their behalf. If
1692 the nscd is not running, then they perform the name lookup by
1693 themselves, by loading the name lookup services into their own address
1694 space and running it. These name lookup services---the
1695 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1696 the host system's C library, rather than from the C library the
1697 application is linked against (the C library coming from Guix).
1699 And this is where the problem is: if your application is linked against
1700 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1701 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1702 likely crash or have its name lookups fail unexpectedly.
1704 Running @command{nscd} on the system, among other advantages, eliminates
1705 this binary incompatibility problem because those @code{libnss_*.so}
1706 files are loaded in the @command{nscd} process, not in applications
1709 @subsection X11 Fonts
1712 The majority of graphical applications use Fontconfig to locate and
1713 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1714 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1715 by default. Thus, to allow graphical applications installed with Guix
1716 to display fonts, you have to install fonts with Guix as well.
1717 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1718 @code{font-gnu-freefont}.
1720 @cindex @code{fc-cache}
1722 Once you have installed or removed fonts, or when you notice an
1723 application that does not find fonts, you may need to install Fontconfig
1724 and to force an update of its font cache by running:
1727 guix install fontconfig
1731 To display text written in Chinese languages, Japanese, or Korean in
1732 graphical applications, consider installing
1733 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1734 has multiple outputs, one per language family (@pxref{Packages with
1735 Multiple Outputs}). For instance, the following command installs fonts
1736 for Chinese languages:
1739 guix install font-adobe-source-han-sans:cn
1742 @cindex @code{xterm}
1743 Older programs such as @command{xterm} do not use Fontconfig and instead
1744 rely on server-side font rendering. Such programs require to specify a
1745 full name of a font using XLFD (X Logical Font Description), like this:
1748 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1751 To be able to use such full names for the TrueType fonts installed in
1752 your Guix profile, you need to extend the font path of the X server:
1754 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1755 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1757 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1760 @cindex @code{xlsfonts}
1761 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1762 to make sure your TrueType fonts are listed there.
1765 @subsection X.509 Certificates
1767 @cindex @code{nss-certs}
1768 The @code{nss-certs} package provides X.509 certificates, which allow
1769 programs to authenticate Web servers accessed over HTTPS.
1771 When using Guix on a foreign distro, you can install this package and
1772 define the relevant environment variables so that packages know where to
1773 look for certificates. @xref{X.509 Certificates}, for detailed
1776 @subsection Emacs Packages
1778 @cindex @code{emacs}
1779 When you install Emacs packages with Guix, the Elisp files are placed
1780 under the @file{share/emacs/site-lisp/} directory of the profile in
1781 which they are installed. The Elisp libraries are made available to
1782 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1783 set when installing Emacs itself.
1785 Additionally, autoload definitions are automatically evaluated at the
1786 initialization of Emacs, by the Guix-specific
1787 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1788 want to avoid auto-loading the Emacs packages installed with Guix, you
1789 can do so by running Emacs with the @option{--no-site-file} option
1790 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1793 @node Upgrading Guix
1794 @section Upgrading Guix
1796 @cindex Upgrading Guix, on a foreign distro
1798 To upgrade Guix, run:
1804 @xref{Invoking guix pull}, for more information.
1806 @cindex upgrading Guix for the root user, on a foreign distro
1807 @cindex upgrading the Guix daemon, on a foreign distro
1808 @cindex @command{guix pull} for the root user, on a foreign distro
1810 On a foreign distro, you can upgrade the build daemon by running:
1817 followed by (assuming your distro uses the systemd service management
1821 systemctl restart guix-daemon.service
1824 On Guix System, upgrading the daemon is achieved by reconfiguring the
1825 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1829 @c *********************************************************************
1830 @node System Installation
1831 @chapter System Installation
1833 @cindex installing Guix System
1834 @cindex Guix System, installation
1835 This section explains how to install Guix System
1836 on a machine. Guix, as a package manager, can
1837 also be installed on top of a running GNU/Linux system,
1838 @pxref{Installation}.
1842 @c This paragraph is for people reading this from tty2 of the
1843 @c installation image.
1844 You are reading this documentation with an Info reader. For details on
1845 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1846 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1847 Info}. Hit @kbd{l} afterwards to come back here.
1849 Alternatively, run @command{info info} in another tty to keep the manual
1855 * Limitations:: What you can expect.
1856 * Hardware Considerations:: Supported hardware.
1857 * USB Stick and DVD Installation:: Preparing the installation medium.
1858 * Preparing for Installation:: Networking, partitioning, etc.
1859 * Guided Graphical Installation:: Easy graphical installation.
1860 * Manual Installation:: Manual installation for wizards.
1861 * After System Installation:: When installation succeeded.
1862 * Installing Guix in a VM:: Guix System playground.
1863 * Building the Installation Image:: How this comes to be.
1867 @section Limitations
1869 We consider Guix System to be ready for a wide range of ``desktop'' and server
1870 use cases. The reliability guarantees it provides---transactional upgrades
1871 and rollbacks, reproducibility---make it a solid foundation.
1873 Nevertheless, before you proceed with the installation, be aware of the
1874 following noteworthy limitations applicable to version @value{VERSION}:
1878 Support for the Logical Volume Manager (LVM) is missing.
1881 More and more system services are provided (@pxref{Services}), but some
1885 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
1886 as well as a number of X11 window managers. However, KDE is currently
1890 More than a disclaimer, this is an invitation to report issues (and success
1891 stories!), and to join us in improving it. @xref{Contributing}, for more
1895 @node Hardware Considerations
1896 @section Hardware Considerations
1898 @cindex hardware support on Guix System
1899 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
1900 builds around the kernel Linux-libre, which means that only hardware for
1901 which free software drivers and firmware exist is supported. Nowadays,
1902 a wide range of off-the-shelf hardware is supported on
1903 GNU/Linux-libre---from keyboards to graphics cards to scanners and
1904 Ethernet controllers. Unfortunately, there are still areas where
1905 hardware vendors deny users control over their own computing, and such
1906 hardware is not supported on Guix System.
1908 @cindex WiFi, hardware support
1909 One of the main areas where free drivers or firmware are lacking is WiFi
1910 devices. WiFi devices known to work include those using Atheros chips
1911 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
1912 driver, and those using Broadcom/AirForce chips (BCM43xx with
1913 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
1914 Linux-libre driver. Free firmware exists for both and is available
1915 out-of-the-box on Guix System, as part of @code{%base-firmware}
1916 (@pxref{operating-system Reference, @code{firmware}}).
1918 @cindex RYF, Respects Your Freedom
1919 The @uref{https://www.fsf.org/, Free Software Foundation} runs
1920 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
1921 certification program for hardware products that respect your freedom
1922 and your privacy and ensure that you have control over your device. We
1923 encourage you to check the list of RYF-certified devices.
1925 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
1926 web site. It contains a catalog of hardware devices with information
1927 about their support in GNU/Linux.
1930 @node USB Stick and DVD Installation
1931 @section USB Stick and DVD Installation
1933 An ISO-9660 installation image that can be written to a USB stick or
1934 burnt to a DVD can be downloaded from
1935 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
1936 where you can replace @code{x86_64-linux} with one of:
1940 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
1943 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
1946 @c start duplication of authentication part from ``Binary Installation''
1947 Make sure to download the associated @file{.sig} file and to verify the
1948 authenticity of the image against it, along these lines:
1951 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1952 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
1955 If that command fails because you do not have the required public key,
1956 then run this command to import it:
1959 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
1960 -qO - | gpg --import -
1964 and rerun the @code{gpg --verify} command.
1966 Take note that a warning like ``This key is not certified with a trusted
1967 signature!'' is normal.
1971 This image contains the tools necessary for an installation.
1972 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
1974 @unnumberedsubsec Copying to a USB Stick
1976 To copy the image to a USB stick, follow these steps:
1980 Decompress the image using the @command{xz} command:
1983 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
1987 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
1988 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
1989 copy the image with:
1992 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
1996 Access to @file{/dev/sdX} usually requires root privileges.
1999 @unnumberedsubsec Burning on a DVD
2001 To copy the image to a DVD, follow these steps:
2005 Decompress the image using the @command{xz} command:
2008 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2012 Insert a blank DVD into your machine, and determine
2013 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2014 copy the image with:
2017 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2020 Access to @file{/dev/srX} usually requires root privileges.
2023 @unnumberedsubsec Booting
2025 Once this is done, you should be able to reboot the system and boot from
2026 the USB stick or DVD. The latter usually requires you to get in the
2027 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2028 In order to boot from Libreboot, switch to the command mode by pressing
2029 the @kbd{c} key and type @command{search_grub usb}.
2031 @xref{Installing Guix in a VM}, if, instead, you would like to install
2032 Guix System in a virtual machine (VM).
2035 @node Preparing for Installation
2036 @section Preparing for Installation
2038 Once you have booted, you can use the guided graphical installer, which makes
2039 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2040 if you are already familiar with GNU/Linux and if you want more control than
2041 what the graphical installer provides, you can choose the ``manual''
2042 installation process (@pxref{Manual Installation}).
2044 The graphical installer is available on TTY1. You can obtain root shells on
2045 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2046 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2047 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2048 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2049 which allows you to select text with the left mouse button and to paste it
2050 with the middle button.
2053 Installation requires access to the Internet so that any missing
2054 dependencies of your system configuration can be downloaded. See the
2055 ``Networking'' section below.
2058 @node Guided Graphical Installation
2059 @section Guided Graphical Installation
2061 The graphical installer is a text-based user interface. It will guide you,
2062 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2064 The first dialog boxes allow you to set up the system as you use it during the
2065 installation: you can choose the language, keyboard layout, and set up
2066 networking, which will be used during the installation. The image below shows
2067 the networking dialog.
2069 @image{images/installer-network,5in,, networking setup with the graphical installer}
2071 Later steps allow you to partition your hard disk, as shown in the image
2072 below, to choose whether or not to use encrypted file systems, to enter the
2073 host name and root password, and to create an additional account, among other
2076 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2078 Note that, at any time, the installer allows you to exit the current
2079 installation step and resume at a previous step, as show in the image below.
2081 @image{images/installer-resume,5in,, resuming the installation process}
2083 Once you're done, the installer produces an operating system configuration and
2084 displays it (@pxref{Using the Configuration System}). At that point you can
2085 hit ``OK'' and installation will proceed. On success, you can reboot into the
2086 new system and enjoy. @xref{After System Installation}, for what's next!
2089 @node Manual Installation
2090 @section Manual Installation
2092 This section describes how you would ``manually'' install GNU@tie{}Guix System
2093 on your machine. This option requires familiarity with GNU/Linux, with the
2094 shell, and with common administration tools. If you think this is not for
2095 you, consider using the guided graphical installer (@pxref{Guided Graphical
2098 The installation system provides root shells on TTYs 3 to 6; press
2099 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2100 many common tools needed to install the system. But it is also a full-blown
2101 Guix System, which means that you can install additional packages, should you
2102 need it, using @command{guix package} (@pxref{Invoking guix package}).
2105 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2106 * Proceeding with the Installation:: Installing.
2109 @node Keyboard Layout and Networking and Partitioning
2110 @subsection Keyboard Layout, Networking, and Partitioning
2112 Before you can install the system, you may want to adjust the keyboard layout,
2113 set up networking, and partition your target hard disk. This section will
2114 guide you through this.
2116 @subsubsection Keyboard Layout
2118 @cindex keyboard layout
2119 The installation image uses the US qwerty keyboard layout. If you want
2120 to change it, you can use the @command{loadkeys} command. For example,
2121 the following command selects the Dvorak keyboard layout:
2127 See the files under @file{/run/current-system/profile/share/keymaps} for
2128 a list of available keyboard layouts. Run @command{man loadkeys} for
2131 @subsubsection Networking
2133 Run the following command to see what your network interfaces are called:
2140 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2146 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2147 Wired interfaces have a name starting with @samp{e}; for example, the
2148 interface corresponding to the first on-board Ethernet controller is
2149 called @samp{eno1}. Wireless interfaces have a name starting with
2150 @samp{w}, like @samp{w1p2s0}.
2153 @item Wired connection
2154 To configure a wired network run the following command, substituting
2155 @var{interface} with the name of the wired interface you want to use.
2158 ifconfig @var{interface} up
2162 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2165 ip link set @var{interface} up
2168 @item Wireless connection
2171 To configure wireless networking, you can create a configuration file
2172 for the @command{wpa_supplicant} configuration tool (its location is not
2173 important) using one of the available text editors such as
2177 nano wpa_supplicant.conf
2180 As an example, the following stanza can go to this file and will work
2181 for many wireless networks, provided you give the actual SSID and
2182 passphrase for the network you are connecting to:
2186 ssid="@var{my-ssid}"
2188 psk="the network's secret passphrase"
2192 Start the wireless service and run it in the background with the
2193 following command (substitute @var{interface} with the name of the
2194 network interface you want to use):
2197 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2200 Run @command{man wpa_supplicant} for more information.
2204 At this point, you need to acquire an IP address. On a network where IP
2205 addresses are automatically assigned @i{via} DHCP, you can run:
2208 dhclient -v @var{interface}
2211 Try to ping a server to see if networking is up and running:
2217 Setting up network access is almost always a requirement because the
2218 image does not contain all the software and tools that may be needed.
2220 @cindex proxy, during system installation
2221 If you need HTTP and HTTPS access to go through a proxy, run the
2225 herd set-http-proxy guix-daemon @var{URL}
2229 where @var{URL} is the proxy URL, for example
2230 @code{http://example.org:8118}.
2232 @cindex installing over SSH
2233 If you want to, you can continue the installation remotely by starting
2237 herd start ssh-daemon
2240 Make sure to either set a password with @command{passwd}, or configure
2241 OpenSSH public key authentication before logging in.
2243 @subsubsection Disk Partitioning
2245 Unless this has already been done, the next step is to partition, and
2246 then format the target partition(s).
2248 The installation image includes several partitioning tools, including
2249 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2250 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2251 the partition layout you want:
2257 If your disk uses the GUID Partition Table (GPT) format and you plan to
2258 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2259 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2262 @cindex EFI, installation
2263 @cindex UEFI, installation
2264 @cindex ESP, EFI system partition
2265 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2266 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2267 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2270 parted /dev/sda set 1 esp on
2274 @vindex grub-bootloader
2275 @vindex grub-efi-bootloader
2276 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2277 @file{/sys/firmware/efi} exists in the installation image, then you should
2278 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2279 Otherwise you should use the BIOS-based GRUB, known as
2280 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2284 Once you are done partitioning the target hard disk drive, you have to
2285 create a file system on the relevant partition(s)@footnote{Currently
2286 Guix System only supports ext4, btrfs, and JFS file systems. In particular,
2287 code that reads file system UUIDs and labels only works for these file system
2288 types.}. For the ESP, if you have one and assuming it is
2289 @file{/dev/sda1}, run:
2292 mkfs.fat -F32 /dev/sda1
2295 For the root file system, ext4 is the most widely used format. Other
2296 file systems, such as Btrfs, support compression, which is reported to
2297 nicely complement file deduplication that the daemon performs
2298 independently of the file system (@pxref{Invoking guix-daemon,
2301 Preferably, assign file systems a label so that you can easily and
2302 reliably refer to them in @code{file-system} declarations (@pxref{File
2303 Systems}). This is typically done using the @code{-L} option of
2304 @command{mkfs.ext4} and related commands. So, assuming the target root
2305 partition lives at @file{/dev/sda2}, a file system with the label
2306 @code{my-root} can be created with:
2309 mkfs.ext4 -L my-root /dev/sda2
2312 @cindex encrypted disk
2313 If you are instead planning to encrypt the root partition, you can use
2314 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2315 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2316 @code{man cryptsetup}} for more information). Assuming you want to
2317 store the root partition on @file{/dev/sda2}, the command sequence would
2318 be along these lines:
2321 cryptsetup luksFormat /dev/sda2
2322 cryptsetup open --type luks /dev/sda2 my-partition
2323 mkfs.ext4 -L my-root /dev/mapper/my-partition
2326 Once that is done, mount the target file system under @file{/mnt}
2327 with a command like (again, assuming @code{my-root} is the label of the
2331 mount LABEL=my-root /mnt
2334 Also mount any other file systems you would like to use on the target
2335 system relative to this path. If you have opted for @file{/boot/efi} as an
2336 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2337 found by @code{guix system init} afterwards.
2339 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2340 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2341 sure to initialize them with @command{mkswap}. Assuming you have one
2342 swap partition on @file{/dev/sda3}, you would run:
2349 Alternatively, you may use a swap file. For example, assuming that in
2350 the new system you want to use the file @file{/swapfile} as a swap file,
2351 you would run@footnote{This example will work for many types of file
2352 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2353 btrfs), the required steps may be different. For details, see the
2354 manual pages for @command{mkswap} and @command{swapon}.}:
2357 # This is 10 GiB of swap space. Adjust "count" to change the size.
2358 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2359 # For security, make the file readable and writable only by root.
2360 chmod 600 /mnt/swapfile
2361 mkswap /mnt/swapfile
2362 swapon /mnt/swapfile
2365 Note that if you have encrypted the root partition and created a swap
2366 file in its file system as described above, then the encryption also
2367 protects the swap file, just like any other file in that file system.
2369 @node Proceeding with the Installation
2370 @subsection Proceeding with the Installation
2372 With the target partitions ready and the target root mounted on
2373 @file{/mnt}, we're ready to go. First, run:
2376 herd start cow-store /mnt
2379 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2380 during the installation phase are written to the target disk on @file{/mnt}
2381 rather than kept in memory. This is necessary because the first phase of
2382 the @command{guix system init} command (see below) entails downloads or
2383 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2385 Next, you have to edit a file and
2386 provide the declaration of the operating system to be installed. To
2387 that end, the installation system comes with three text editors. We
2388 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2389 supports syntax highlighting and parentheses matching; other editors
2390 include GNU Zile (an Emacs clone), and
2391 nvi (a clone of the original BSD @command{vi} editor).
2392 We strongly recommend storing that file on the target root file system, say,
2393 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2394 configuration file once you have rebooted into the newly-installed system.
2396 @xref{Using the Configuration System}, for an overview of the
2397 configuration file. The example configurations discussed in that
2398 section are available under @file{/etc/configuration} in the
2399 installation image. Thus, to get started with a system configuration
2400 providing a graphical display server (a ``desktop'' system), you can run
2401 something along these lines:
2405 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2406 # nano /mnt/etc/config.scm
2409 You should pay attention to what your configuration file contains, and
2414 Make sure the @code{bootloader-configuration} form refers to the target
2415 you want to install GRUB on. It should mention @code{grub-bootloader} if
2416 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2417 for newer UEFI systems. For legacy systems, the @code{target} field
2418 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2419 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2420 currently mounted and a @code{file-system} entry is specified in your
2424 Be sure that your file system labels match the value of their respective
2425 @code{device} fields in your @code{file-system} configuration, assuming
2426 your @code{file-system} configuration uses the @code{file-system-label}
2427 procedure in its @code{device} field.
2430 If there are encrypted or RAID partitions, make sure to add a
2431 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2434 Once you are done preparing the configuration file, the new system must
2435 be initialized (remember that the target root file system is mounted
2439 guix system init /mnt/etc/config.scm /mnt
2443 This copies all the necessary files and installs GRUB on
2444 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2445 more information, @pxref{Invoking guix system}. This command may trigger
2446 downloads or builds of missing packages, which can take some time.
2448 Once that command has completed---and hopefully succeeded!---you can run
2449 @command{reboot} and boot into the new system. The @code{root} password
2450 in the new system is initially empty; other users' passwords need to be
2451 initialized by running the @command{passwd} command as @code{root},
2452 unless your configuration specifies otherwise
2453 (@pxref{user-account-password, user account passwords}).
2454 @xref{After System Installation}, for what's next!
2457 @node After System Installation
2458 @section After System Installation
2460 Success, you've now booted into Guix System! From then on, you can update the
2461 system whenever you want by running, say:
2465 sudo guix system reconfigure /etc/config.scm
2469 This builds a new system generation with the latest packages and services
2470 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2471 your system includes the latest security updates (@pxref{Security Updates}).
2473 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2475 @cindex sudo vs. @command{guix pull}
2476 Note that @command{sudo guix} runs your user's @command{guix} command and
2477 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2478 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2480 The difference matters here, because @command{guix pull} updates
2481 the @command{guix} command and package definitions only for the user it is ran
2482 as. This means that if you choose to use @command{guix system reconfigure} in
2483 root's login shell, you'll need to @command{guix pull} separately.
2486 Now, @pxref{Getting Started}, and
2487 join us on @code{#guix} on the Freenode IRC network or on
2488 @email{guix-devel@@gnu.org} to share your experience!
2491 @node Installing Guix in a VM
2492 @section Installing Guix in a Virtual Machine
2494 @cindex virtual machine, Guix System installation
2495 @cindex virtual private server (VPS)
2496 @cindex VPS (virtual private server)
2497 If you'd like to install Guix System in a virtual machine (VM) or on a
2498 virtual private server (VPS) rather than on your beloved machine, this
2501 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2502 disk image, follow these steps:
2506 First, retrieve and decompress the Guix system installation image as
2507 described previously (@pxref{USB Stick and DVD Installation}).
2510 Create a disk image that will hold the installed system. To make a
2511 qcow2-formatted disk image, use the @command{qemu-img} command:
2514 qemu-img create -f qcow2 guix-system.img 50G
2517 The resulting file will be much smaller than 50 GB (typically less than
2518 1 MB), but it will grow as the virtualized storage device is filled up.
2521 Boot the USB installation image in an VM:
2524 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2525 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2526 -drive file=guix-system.img \
2527 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2530 @code{-enable-kvm} is optional, but significantly improves performance,
2531 @pxref{Running Guix in a VM}.
2534 You're now root in the VM, proceed with the installation process.
2535 @xref{Preparing for Installation}, and follow the instructions.
2538 Once installation is complete, you can boot the system that's on your
2539 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2542 @node Building the Installation Image
2543 @section Building the Installation Image
2545 @cindex installation image
2546 The installation image described above was built using the @command{guix
2547 system} command, specifically:
2550 guix system disk-image --file-system-type=iso9660 \
2551 gnu/system/install.scm
2554 Have a look at @file{gnu/system/install.scm} in the source tree,
2555 and see also @ref{Invoking guix system} for more information
2556 about the installation image.
2558 @section Building the Installation Image for ARM Boards
2560 Many ARM boards require a specific variant of the
2561 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2563 If you build a disk image and the bootloader is not available otherwise
2564 (on another boot drive etc), it's advisable to build an image that
2565 includes the bootloader, specifically:
2568 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2571 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2572 board, a list of possible boards will be printed.
2574 @c *********************************************************************
2575 @node Getting Started
2576 @chapter Getting Started
2578 Presumably, you've reached this section because either you have
2579 installed Guix on top of another distribution (@pxref{Installation}), or
2580 you've installed the standalone Guix System (@pxref{System
2581 Installation}). It's time for you to get started using Guix and this
2582 section aims to help you do that and give you a feel of what it's like.
2584 Guix is about installing software, so probably the first thing you'll
2585 want to do is to actually look for software. Let's say you're looking
2586 for a text editor, you can run:
2589 guix search text editor
2592 This command shows you a number of matching @dfn{packages}, each time
2593 showing the package's name, version, a description, and additional info.
2594 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2595 you can go ahead and install it (run this command as a regular user,
2596 @emph{no need for root privileges}!):
2602 You've installed your first package, congrats! In the process, you've
2603 probably noticed that Guix downloaded pre-built binaries; or, if you
2604 explicitly chose to @emph{not} use pre-built binaries, then probably
2605 Guix is still building software (@pxref{Substitutes}, for more info).
2607 Unless you're using Guix System, the @command{guix install} command must
2608 have printed this hint:
2611 hint: Consider setting the necessary environment variables by running:
2613 GUIX_PROFILE="$HOME/.guix-profile"
2614 . "$GUIX_PROFILE/etc/profile"
2616 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2619 Indeed, you must now tell your shell where @command{emacs} and other
2620 programs installed with Guix are to be found. Pasting the two lines
2621 above will do just that: it will add
2622 @code{$HOME/.guix-profile/bin}---which is where the installed package
2623 is---to the @code{PATH} environment variable. You can paste these two
2624 lines in your shell so they take effect right away, but more importantly
2625 you should add them to @file{~/.bash_profile} (or equivalent file if you
2626 do not use Bash) so that environment variables are set next time you
2627 spawn a shell. You only need to do this once and other search paths
2628 environment variables will be taken care of similarly---e.g., if you
2629 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2632 You can go on installing packages at your will. To list installed
2636 guix package --list-installed
2639 To remove a package, you would unsurprisingly run @command{guix remove}.
2640 A distinguishing feature is the ability to @dfn{roll back} any operation
2641 you made---installation, removal, upgrade---by simply typing:
2644 guix package --roll-back
2647 This is because each operation is in fact a @dfn{transaction} that
2648 creates a new @dfn{generation}. These generations and the difference
2649 between them can be displayed by running:
2652 guix package --list-generations
2655 Now you know the basics of package management!
2657 @quotation Going further
2658 @xref{Package Management}, for more about package management. You may
2659 like @dfn{declarative} package management with @command{guix package
2660 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2661 deleting old generations, collecting garbage, and other nifty features
2662 that will come in handy as you become more familiar with Guix. If you
2663 are a developer, @pxref{Development} for additional tools. And if
2664 you're curious, @pxref{Features}, to peek under the hood.
2667 Once you've installed a set of packages, you will want to periodically
2668 @emph{upgrade} them to the latest and greatest version. To do that, you
2669 will first pull the latest revision of Guix and its package collection:
2675 The end result is a new @command{guix} command, under
2676 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2677 first time you run @command{guix pull}, be sure to follow the hint that
2678 the command prints and, similar to what we saw above, paste these two
2679 lines in your terminal and @file{.bash_profile}:
2682 GUIX_PROFILE="$HOME/.config/guix/current/etc/profile"
2683 . "$GUIX_PROFILE/etc/profile"
2687 You must also instruct your shell to point to this new @command{guix}:
2693 At this point, you're running a brand new Guix. You can thus go ahead
2694 and actually upgrade all the packages you previously installed:
2700 As you run this command, you will see that binaries are downloaded (or
2701 perhaps some packages are built), and eventually you end up with the
2702 upgraded packages. Should one of these upgraded packages not be to your
2703 liking, remember you can always roll back!
2705 You can display the exact revision of Guix you're currently using by
2712 The information it displays is @emph{all it takes to reproduce the exact
2713 same Guix}, be it at a different point in time or on a different
2716 @quotation Going further
2717 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2718 how to specify additional @dfn{channels} to pull packages from, how to
2719 replicate Guix, and more. You may also find @command{time-machine}
2720 handy (@pxref{Invoking guix time-machine}).
2723 If you installed Guix System, one of the first things you'll want to do
2724 is to upgrade your system. Once you've run @command{guix pull} to get
2725 the latest Guix, you can upgrade the system like this:
2728 sudo guix system reconfigure /etc/config.scm
2731 Upon completion, the system runs the latest versions of its software
2732 packages. When you eventually reboot, you'll notice a sub-menu in the
2733 bootloader that reads ``Old system generations'': it's what allows you
2734 to boot @emph{an older generation of your system}, should the latest
2735 generation be ``broken'' or otherwise unsatisfying. Just like for
2736 packages, you can always @emph{roll back} to a previous generation
2737 @emph{of the whole system}:
2740 sudo guix system roll-back
2743 There are many things you'll probably want to tweak on your system:
2744 adding new user accounts, adding new system services, fiddling with the
2745 configuration of those services, etc. The system configuration is
2746 @emph{entirely} described in the @file{/etc/config.scm} file.
2747 @xref{Using the Configuration System}, to learn how to change it.
2749 Now you know enough to get started!
2751 @quotation Resources
2752 The rest of this manual provides a reference for all things Guix. Here
2753 are some additional resources you may find useful:
2757 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2758 ``how-to'' style of recipes for a variety of applications.
2761 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2762 Card} lists in two pages most of the commands and options you'll ever
2766 The web site contains @uref{https://guix.gnu.org/en/videos/,
2767 instructional videos} covering topics such as everyday use of Guix, how
2768 to get help, and how to become a contributor.
2771 @xref{Documentation}, to learn how to access documentation on your
2775 We hope you will enjoy Guix as much as the community enjoys building it!
2778 @c *********************************************************************
2779 @node Package Management
2780 @chapter Package Management
2783 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2784 remove software packages, without having to know about their build
2785 procedures or dependencies. Guix also goes beyond this obvious set of
2788 This chapter describes the main features of Guix, as well as the
2789 package management tools it provides. Along with the command-line
2790 interface described below (@pxref{Invoking guix package, @code{guix
2791 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2792 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2793 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2797 guix install emacs-guix
2801 * Features:: How Guix will make your life brighter.
2802 * Invoking guix package:: Package installation, removal, etc.
2803 * Substitutes:: Downloading pre-built binaries.
2804 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2805 * Invoking guix gc:: Running the garbage collector.
2806 * Invoking guix pull:: Fetching the latest Guix and distribution.
2807 * Channels:: Customizing the package collection.
2808 * Invoking guix time-machine:: Running an older revision of Guix.
2809 * Inferiors:: Interacting with another revision of Guix.
2810 * Invoking guix describe:: Display information about your Guix revision.
2811 * Invoking guix archive:: Exporting and importing store files.
2817 Here we assume you've already made your first steps with Guix
2818 (@pxref{Getting Started}) and would like to get an overview about what's
2819 going on under the hood.
2821 When using Guix, each package ends up in the @dfn{package store}, in its
2822 own directory---something that resembles
2823 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2825 Instead of referring to these directories, users have their own
2826 @dfn{profile}, which points to the packages that they actually want to
2827 use. These profiles are stored within each user's home directory, at
2828 @code{$HOME/.guix-profile}.
2830 For example, @code{alice} installs GCC 4.7.2. As a result,
2831 @file{/home/alice/.guix-profile/bin/gcc} points to
2832 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2833 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2834 simply continues to point to
2835 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2836 coexist on the same system without any interference.
2838 The @command{guix package} command is the central tool to manage
2839 packages (@pxref{Invoking guix package}). It operates on the per-user
2840 profiles, and can be used @emph{with normal user privileges}.
2842 @cindex transactions
2843 The command provides the obvious install, remove, and upgrade
2844 operations. Each invocation is actually a @emph{transaction}: either
2845 the specified operation succeeds, or nothing happens. Thus, if the
2846 @command{guix package} process is terminated during the transaction,
2847 or if a power outage occurs during the transaction, then the user's
2848 profile remains in its previous state, and remains usable.
2850 In addition, any package transaction may be @emph{rolled back}. So, if,
2851 for example, an upgrade installs a new version of a package that turns
2852 out to have a serious bug, users may roll back to the previous instance
2853 of their profile, which was known to work well. Similarly, the global
2854 system configuration on Guix is subject to
2855 transactional upgrades and roll-back
2856 (@pxref{Using the Configuration System}).
2858 All packages in the package store may be @emph{garbage-collected}.
2859 Guix can determine which packages are still referenced by user
2860 profiles, and remove those that are provably no longer referenced
2861 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2862 generations of their profile so that the packages they refer to can be
2865 @cindex reproducibility
2866 @cindex reproducible builds
2867 Guix takes a @dfn{purely functional} approach to package
2868 management, as described in the introduction (@pxref{Introduction}).
2869 Each @file{/gnu/store} package directory name contains a hash of all the
2870 inputs that were used to build that package---compiler, libraries, build
2871 scripts, etc. This direct correspondence allows users to make sure a
2872 given package installation matches the current state of their
2873 distribution. It also helps maximize @dfn{build reproducibility}:
2874 thanks to the isolated build environments that are used, a given build
2875 is likely to yield bit-identical files when performed on different
2876 machines (@pxref{Invoking guix-daemon, container}).
2879 This foundation allows Guix to support @dfn{transparent binary/source
2880 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2881 available from an external source---a @dfn{substitute}, Guix just
2882 downloads it and unpacks it;
2883 otherwise, it builds the package from source, locally
2884 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2885 reproducible, users do not have to trust servers that provide
2886 substitutes: they can force a local build and @emph{challenge} providers
2887 (@pxref{Invoking guix challenge}).
2889 Control over the build environment is a feature that is also useful for
2890 developers. The @command{guix environment} command allows developers of
2891 a package to quickly set up the right development environment for their
2892 package, without having to manually install the dependencies of the
2893 package into their profile (@pxref{Invoking guix environment}).
2895 @cindex replication, of software environments
2896 @cindex provenance tracking, of software artifacts
2897 All of Guix and its package definitions is version-controlled, and
2898 @command{guix pull} allows you to ``travel in time'' on the history of Guix
2899 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
2900 Guix instance on a different machine or at a later point in time, which in
2901 turn allows you to @emph{replicate complete software environments}, while
2902 retaining precise @dfn{provenance tracking} of the software.
2904 @node Invoking guix package
2905 @section Invoking @command{guix package}
2907 @cindex installing packages
2908 @cindex removing packages
2909 @cindex package installation
2910 @cindex package removal
2911 The @command{guix package} command is the tool that allows users to
2912 install, upgrade, and remove packages, as well as rolling back to
2913 previous configurations. It operates only on the user's own profile,
2914 and works with normal user privileges (@pxref{Features}). Its syntax
2918 guix package @var{options}
2921 @cindex transactions
2922 Primarily, @var{options} specifies the operations to be performed during
2923 the transaction. Upon completion, a new profile is created, but
2924 previous @dfn{generations} of the profile remain available, should the user
2927 For example, to remove @code{lua} and install @code{guile} and
2928 @code{guile-cairo} in a single transaction:
2931 guix package -r lua -i guile guile-cairo
2934 @cindex aliases, for @command{guix package}
2935 For your convenience, we also provide the following aliases:
2939 @command{guix search} is an alias for @command{guix package -s},
2941 @command{guix install} is an alias for @command{guix package -i},
2943 @command{guix remove} is an alias for @command{guix package -r},
2945 @command{guix upgrade} is an alias for @command{guix package -u},
2947 and @command{guix show} is an alias for @command{guix package --show=}.
2950 These aliases are less expressive than @command{guix package} and provide
2951 fewer options, so in some cases you'll probably want to use @command{guix
2954 @command{guix package} also supports a @dfn{declarative approach}
2955 whereby the user specifies the exact set of packages to be available and
2956 passes it @i{via} the @option{--manifest} option
2957 (@pxref{profile-manifest, @option{--manifest}}).
2960 For each user, a symlink to the user's default profile is automatically
2961 created in @file{$HOME/.guix-profile}. This symlink always points to the
2962 current generation of the user's default profile. Thus, users can add
2963 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
2964 variable, and so on.
2965 @cindex search paths
2966 If you are not using Guix System, consider adding the
2967 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
2968 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
2969 shells get all the right environment variable definitions:
2972 GUIX_PROFILE="$HOME/.guix-profile" ; \
2973 source "$HOME/.guix-profile/etc/profile"
2976 In a multi-user setup, user profiles are stored in a place registered as
2977 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
2978 to (@pxref{Invoking guix gc}). That directory is normally
2979 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
2980 @var{localstatedir} is the value passed to @code{configure} as
2981 @option{--localstatedir}, and @var{user} is the user name. The
2982 @file{per-user} directory is created when @command{guix-daemon} is
2983 started, and the @var{user} sub-directory is created by @command{guix
2986 The @var{options} can be among the following:
2990 @item --install=@var{package} @dots{}
2991 @itemx -i @var{package} @dots{}
2992 Install the specified @var{package}s.
2994 Each @var{package} may specify either a simple package name, such as
2995 @code{guile}, or a package name followed by an at-sign and version number,
2996 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
2997 case, the newest version prefixed by @code{1.8} is selected).
2999 If no version number is specified, the
3000 newest available version will be selected. In addition, @var{package}
3001 may contain a colon, followed by the name of one of the outputs of the
3002 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3003 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3004 name (and optionally version) are searched for among the GNU
3005 distribution modules (@pxref{Package Modules}).
3007 @cindex propagated inputs
3008 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3009 that automatically get installed along with the required package
3010 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3011 @code{package} objects}, for information about propagated inputs in
3012 package definitions).
3014 @anchor{package-cmd-propagated-inputs}
3015 An example is the GNU MPC library: its C header files refer to those of
3016 the GNU MPFR library, which in turn refer to those of the GMP library.
3017 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3018 in the profile; removing MPC also removes MPFR and GMP---unless they had
3019 also been explicitly installed by the user.
3021 Besides, packages sometimes rely on the definition of environment
3022 variables for their search paths (see explanation of
3023 @option{--search-paths} below). Any missing or possibly incorrect
3024 environment variable definitions are reported here.
3026 @item --install-from-expression=@var{exp}
3028 Install the package @var{exp} evaluates to.
3030 @var{exp} must be a Scheme expression that evaluates to a
3031 @code{<package>} object. This option is notably useful to disambiguate
3032 between same-named variants of a package, with expressions such as
3033 @code{(@@ (gnu packages base) guile-final)}.
3035 Note that this option installs the first output of the specified
3036 package, which may be insufficient when needing a specific output of a
3037 multiple-output package.
3039 @item --install-from-file=@var{file}
3040 @itemx -f @var{file}
3041 Install the package that the code within @var{file} evaluates to.
3043 As an example, @var{file} might contain a definition like this
3044 (@pxref{Defining Packages}):
3047 @include package-hello.scm
3050 Developers may find it useful to include such a @file{guix.scm} file
3051 in the root of their project source tree that can be used to test
3052 development snapshots and create reproducible development environments
3053 (@pxref{Invoking guix environment}).
3055 The @var{file} may also contain a JSON representation of one or more
3056 package definitions. Running @code{guix package -f} on
3057 @file{hello.json} with the following contents would result in installing
3058 the package @code{greeter} after building @code{myhello}:
3061 @verbatiminclude package-hello.json
3064 @item --remove=@var{package} @dots{}
3065 @itemx -r @var{package} @dots{}
3066 Remove the specified @var{package}s.
3068 As for @option{--install}, each @var{package} may specify a version number
3069 and/or output name in addition to the package name. For instance,
3070 @samp{-r glibc:debug} would remove the @code{debug} output of
3073 @item --upgrade[=@var{regexp} @dots{}]
3074 @itemx -u [@var{regexp} @dots{}]
3075 @cindex upgrading packages
3076 Upgrade all the installed packages. If one or more @var{regexp}s are
3077 specified, upgrade only installed packages whose name matches a
3078 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3080 Note that this upgrades package to the latest version of packages found
3081 in the distribution currently installed. To update your distribution,
3082 you should regularly run @command{guix pull} (@pxref{Invoking guix
3085 @item --do-not-upgrade[=@var{regexp} @dots{}]
3086 When used together with the @option{--upgrade} option, do @emph{not}
3087 upgrade any packages whose name matches a @var{regexp}. For example, to
3088 upgrade all packages in the current profile except those containing the
3089 substring ``emacs'':
3092 $ guix package --upgrade . --do-not-upgrade emacs
3095 @item @anchor{profile-manifest}--manifest=@var{file}
3096 @itemx -m @var{file}
3097 @cindex profile declaration
3098 @cindex profile manifest
3099 Create a new generation of the profile from the manifest object
3100 returned by the Scheme code in @var{file}. This option can be repeated
3101 several times, in which case the manifests are concatenated.
3103 This allows you to @emph{declare} the profile's contents rather than
3104 constructing it through a sequence of @option{--install} and similar
3105 commands. The advantage is that @var{file} can be put under version
3106 control, copied to different machines to reproduce the same profile, and
3109 @c FIXME: Add reference to (guix profile) documentation when available.
3110 @var{file} must return a @dfn{manifest} object, which is roughly a list
3113 @findex packages->manifest
3115 (use-package-modules guile emacs)
3120 ;; Use a specific package output.
3121 (list guile-2.0 "debug")))
3124 @findex specifications->manifest
3125 In this example we have to know which modules define the @code{emacs}
3126 and @code{guile-2.0} variables to provide the right
3127 @code{use-package-modules} line, which can be cumbersome. We can
3128 instead provide regular package specifications and let
3129 @code{specifications->manifest} look up the corresponding package
3133 (specifications->manifest
3134 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3138 @cindex rolling back
3139 @cindex undoing transactions
3140 @cindex transactions, undoing
3141 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3142 the last transaction.
3144 When combined with options such as @option{--install}, roll back occurs
3145 before any other actions.
3147 When rolling back from the first generation that actually contains
3148 installed packages, the profile is made to point to the @dfn{zeroth
3149 generation}, which contains no files apart from its own metadata.
3151 After having rolled back, installing, removing, or upgrading packages
3152 overwrites previous future generations. Thus, the history of the
3153 generations in a profile is always linear.
3155 @item --switch-generation=@var{pattern}
3156 @itemx -S @var{pattern}
3158 Switch to a particular generation defined by @var{pattern}.
3160 @var{pattern} may be either a generation number or a number prefixed
3161 with ``+'' or ``-''. The latter means: move forward/backward by a
3162 specified number of generations. For example, if you want to return to
3163 the latest generation after @option{--roll-back}, use
3164 @option{--switch-generation=+1}.
3166 The difference between @option{--roll-back} and
3167 @option{--switch-generation=-1} is that @option{--switch-generation} will
3168 not make a zeroth generation, so if a specified generation does not
3169 exist, the current generation will not be changed.
3171 @item --search-paths[=@var{kind}]
3172 @cindex search paths
3173 Report environment variable definitions, in Bash syntax, that may be
3174 needed in order to use the set of installed packages. These environment
3175 variables are used to specify @dfn{search paths} for files used by some
3176 of the installed packages.
3178 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3179 environment variables to be defined so it can look for headers and
3180 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3181 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3182 library are installed in the profile, then @option{--search-paths} will
3183 suggest setting these variables to @file{@var{profile}/include} and
3184 @file{@var{profile}/lib}, respectively.
3186 The typical use case is to define these environment variables in the
3190 $ eval `guix package --search-paths`
3193 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3194 meaning that the returned environment variable definitions will either
3195 be exact settings, or prefixes or suffixes of the current value of these
3196 variables. When omitted, @var{kind} defaults to @code{exact}.
3198 This option can also be used to compute the @emph{combined} search paths
3199 of several profiles. Consider this example:
3202 $ guix package -p foo -i guile
3203 $ guix package -p bar -i guile-json
3204 $ guix package -p foo -p bar --search-paths
3207 The last command above reports about the @env{GUILE_LOAD_PATH}
3208 variable, even though, taken individually, neither @file{foo} nor
3209 @file{bar} would lead to that recommendation.
3212 @item --profile=@var{profile}
3213 @itemx -p @var{profile}
3214 Use @var{profile} instead of the user's default profile.
3216 @var{profile} must be the name of a file that will be created upon
3217 completion. Concretely, @var{profile} will be a mere symbolic link
3218 (``symlink'') pointing to the actual profile where packages are
3222 $ guix install hello -p ~/code/my-profile
3224 $ ~/code/my-profile/bin/hello
3228 All it takes to get rid of the profile is to remove this symlink and its
3229 siblings that point to specific generations:
3232 $ rm ~/code/my-profile ~/code/my-profile-*-link
3235 @item --list-profiles
3236 List all the user's profiles:
3239 $ guix package --list-profiles
3240 /home/charlie/.guix-profile
3241 /home/charlie/code/my-profile
3242 /home/charlie/code/devel-profile
3243 /home/charlie/tmp/test
3246 When running as root, list all the profiles of all the users.
3248 @cindex collisions, in a profile
3249 @cindex colliding packages in profiles
3250 @cindex profile collisions
3251 @item --allow-collisions
3252 Allow colliding packages in the new profile. Use at your own risk!
3254 By default, @command{guix package} reports as an error @dfn{collisions}
3255 in the profile. Collisions happen when two or more different versions
3256 or variants of a given package end up in the profile.
3259 Use the bootstrap Guile to build the profile. This option is only
3260 useful to distribution developers.
3264 In addition to these actions, @command{guix package} supports the
3265 following options to query the current state of a profile, or the
3266 availability of packages:
3270 @item --search=@var{regexp}
3271 @itemx -s @var{regexp}
3272 @anchor{guix-search}
3273 @cindex searching for packages
3274 List the available packages whose name, synopsis, or description matches
3275 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3276 Print all the metadata of matching packages in
3277 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3278 GNU recutils manual}).
3280 This allows specific fields to be extracted using the @command{recsel}
3281 command, for instance:
3284 $ guix package -s malloc | recsel -p name,version,relevance
3298 Similarly, to show the name of all the packages available under the
3299 terms of the GNU@tie{}LGPL version 3:
3302 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3309 It is also possible to refine search results using several @code{-s} flags to
3310 @command{guix package}, or several arguments to @command{guix search}. For
3311 example, the following command returns a list of board games (this time using
3312 the @command{guix search} alias):
3315 $ guix search '\<board\>' game | recsel -p name
3320 If we were to omit @code{-s game}, we would also get software packages
3321 that deal with printed circuit boards; removing the angle brackets
3322 around @code{board} would further add packages that have to do with
3325 And now for a more elaborate example. The following command searches
3326 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3327 libraries, and prints the name and synopsis of the matching packages:
3330 $ guix search crypto library | \
3331 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3335 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3336 information on @dfn{selection expressions} for @code{recsel -e}.
3338 @item --show=@var{package}
3339 Show details about @var{package}, taken from the list of available packages, in
3340 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3344 $ guix package --show=python | recsel -p name,version
3352 You may also specify the full name of a package to only get details about a
3353 specific version of it (this time using the @command{guix show} alias):
3355 $ guix show python@@3.4 | recsel -p name,version
3362 @item --list-installed[=@var{regexp}]
3363 @itemx -I [@var{regexp}]
3364 List the currently installed packages in the specified profile, with the
3365 most recently installed packages shown last. When @var{regexp} is
3366 specified, list only installed packages whose name matches @var{regexp}.
3368 For each installed package, print the following items, separated by
3369 tabs: the package name, its version string, the part of the package that
3370 is installed (for instance, @code{out} for the default output,
3371 @code{include} for its headers, etc.), and the path of this package in
3374 @item --list-available[=@var{regexp}]
3375 @itemx -A [@var{regexp}]
3376 List packages currently available in the distribution for this system
3377 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3378 available packages whose name matches @var{regexp}.
3380 For each package, print the following items separated by tabs: its name,
3381 its version string, the parts of the package (@pxref{Packages with
3382 Multiple Outputs}), and the source location of its definition.
3384 @item --list-generations[=@var{pattern}]
3385 @itemx -l [@var{pattern}]
3387 Return a list of generations along with their creation dates; for each
3388 generation, show the installed packages, with the most recently
3389 installed packages shown last. Note that the zeroth generation is never
3392 For each installed package, print the following items, separated by
3393 tabs: the name of a package, its version string, the part of the package
3394 that is installed (@pxref{Packages with Multiple Outputs}), and the
3395 location of this package in the store.
3397 When @var{pattern} is used, the command returns only matching
3398 generations. Valid patterns include:
3401 @item @emph{Integers and comma-separated integers}. Both patterns denote
3402 generation numbers. For instance, @option{--list-generations=1} returns
3405 And @option{--list-generations=1,8,2} outputs three generations in the
3406 specified order. Neither spaces nor trailing commas are allowed.
3408 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3409 specified generations and everything in between. Note that the start of
3410 a range must be smaller than its end.
3412 It is also possible to omit the endpoint. For example,
3413 @option{--list-generations=2..}, returns all generations starting from the
3416 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3417 or months by passing an integer along with the first letter of the
3418 duration. For example, @option{--list-generations=20d} lists generations
3419 that are up to 20 days old.
3422 @item --delete-generations[=@var{pattern}]
3423 @itemx -d [@var{pattern}]
3424 When @var{pattern} is omitted, delete all generations except the current
3427 This command accepts the same patterns as @option{--list-generations}.
3428 When @var{pattern} is specified, delete the matching generations. When
3429 @var{pattern} specifies a duration, generations @emph{older} than the
3430 specified duration match. For instance, @option{--delete-generations=1m}
3431 deletes generations that are more than one month old.
3433 If the current generation matches, it is @emph{not} deleted. Also, the
3434 zeroth generation is never deleted.
3436 Note that deleting generations prevents rolling back to them.
3437 Consequently, this command must be used with care.
3441 Finally, since @command{guix package} may actually start build
3442 processes, it supports all the common build options (@pxref{Common Build
3443 Options}). It also supports package transformation options, such as
3444 @option{--with-source} (@pxref{Package Transformation Options}).
3445 However, note that package transformations are lost when upgrading; to
3446 preserve transformations across upgrades, you should define your own
3447 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3448 (@pxref{Defining Packages}).
3451 @section Substitutes
3454 @cindex pre-built binaries
3455 Guix supports transparent source/binary deployment, which means that it
3456 can either build things locally, or download pre-built items from a
3457 server, or both. We call these pre-built items @dfn{substitutes}---they
3458 are substitutes for local build results. In many cases, downloading a
3459 substitute is much faster than building things locally.
3461 Substitutes can be anything resulting from a derivation build
3462 (@pxref{Derivations}). Of course, in the common case, they are
3463 pre-built package binaries, but source tarballs, for instance, which
3464 also result from derivation builds, can be available as substitutes.
3467 * Official Substitute Server:: One particular source of substitutes.
3468 * Substitute Server Authorization:: How to enable or disable substitutes.
3469 * Substitute Authentication:: How Guix verifies substitutes.
3470 * Proxy Settings:: How to get substitutes via proxy.
3471 * Substitution Failure:: What happens when substitution fails.
3472 * On Trusting Binaries:: How can you trust that binary blob?
3475 @node Official Substitute Server
3476 @subsection Official Substitute Server
3479 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3480 that builds packages from Guix continuously for some
3481 architectures, and makes them available as substitutes. This is the
3482 default source of substitutes; it can be overridden by passing the
3483 @option{--substitute-urls} option either to @command{guix-daemon}
3484 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3485 or to client tools such as @command{guix package}
3486 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3489 Substitute URLs can be either HTTP or HTTPS.
3490 HTTPS is recommended because communications are encrypted; conversely,
3491 using HTTP makes all communications visible to an eavesdropper, who
3492 could use the information gathered to determine, for instance, whether
3493 your system has unpatched security vulnerabilities.
3495 Substitutes from the official build farm are enabled by default when
3496 using Guix System (@pxref{GNU Distribution}). However,
3497 they are disabled by default when using Guix on a foreign distribution,
3498 unless you have explicitly enabled them via one of the recommended
3499 installation steps (@pxref{Installation}). The following paragraphs
3500 describe how to enable or disable substitutes for the official build
3501 farm; the same procedure can also be used to enable substitutes for any
3502 other substitute server.
3504 @node Substitute Server Authorization
3505 @subsection Substitute Server Authorization
3508 @cindex substitutes, authorization thereof
3509 @cindex access control list (ACL), for substitutes
3510 @cindex ACL (access control list), for substitutes
3511 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3513 must add its public key to the access control list (ACL) of archive
3514 imports, using the @command{guix archive} command (@pxref{Invoking guix
3515 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3516 be compromised and to serve genuine substitutes.
3518 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3519 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3520 the installation prefix of Guix. If you installed Guix from source,
3521 make sure you checked the GPG signature of
3522 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3523 Then, you can run something like this:
3526 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3529 Once this is in place, the output of a command like @code{guix build}
3530 should change from something like:
3533 $ guix build emacs --dry-run
3534 The following derivations would be built:
3535 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3536 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3537 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3538 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3546 $ guix build emacs --dry-run
3547 112.3 MB would be downloaded:
3548 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3549 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3550 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3551 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3556 The text changed from ``The following derivations would be built'' to
3557 ``112.3 MB would be downloaded''. This indicates that substitutes from
3558 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3559 possible, for future builds.
3561 @cindex substitutes, how to disable
3562 The substitute mechanism can be disabled globally by running
3563 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3564 guix-daemon}). It can also be disabled temporarily by passing the
3565 @option{--no-substitutes} option to @command{guix package},
3566 @command{guix build}, and other command-line tools.
3568 @node Substitute Authentication
3569 @subsection Substitute Authentication
3571 @cindex digital signatures
3572 Guix detects and raises an error when attempting to use a substitute
3573 that has been tampered with. Likewise, it ignores substitutes that are
3574 not signed, or that are not signed by one of the keys listed in the ACL.
3576 There is one exception though: if an unauthorized server provides
3577 substitutes that are @emph{bit-for-bit identical} to those provided by
3578 an authorized server, then the unauthorized server becomes eligible for
3579 downloads. For example, assume we have chosen two substitute servers
3583 --substitute-urls="https://a.example.org https://b.example.org"
3587 @cindex reproducible builds
3588 If the ACL contains only the key for @samp{b.example.org}, and if
3589 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3590 then Guix will download substitutes from @samp{a.example.org} because it
3591 comes first in the list and can be considered a mirror of
3592 @samp{b.example.org}. In practice, independent build machines usually
3593 produce the same binaries, thanks to bit-reproducible builds (see
3596 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3597 (in other words, the server is not authenticated), contrary to what
3598 HTTPS clients such as Web browsers usually do. This is because Guix
3599 authenticates substitute information itself, as explained above, which
3600 is what we care about (whereas X.509 certificates are about
3601 authenticating bindings between domain names and public keys).
3603 @node Proxy Settings
3604 @subsection Proxy Settings
3608 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3609 @env{https_proxy} environment variables can be set in the environment of
3610 @command{guix-daemon} and are honored for downloads of substitutes.
3611 Note that the value of those environment variables in the environment
3612 where @command{guix build}, @command{guix package}, and other client
3613 commands are run has @emph{absolutely no effect}.
3615 @node Substitution Failure
3616 @subsection Substitution Failure
3618 Even when a substitute for a derivation is available, sometimes the
3619 substitution attempt will fail. This can happen for a variety of
3620 reasons: the substitute server might be offline, the substitute may
3621 recently have been deleted, the connection might have been interrupted,
3624 When substitutes are enabled and a substitute for a derivation is
3625 available, but the substitution attempt fails, Guix will attempt to
3626 build the derivation locally depending on whether or not
3627 @option{--fallback} was given (@pxref{fallback-option,, common build
3628 option @option{--fallback}}). Specifically, if @option{--fallback} was
3629 omitted, then no local build will be performed, and the derivation is
3630 considered to have failed. However, if @option{--fallback} was given,
3631 then Guix will attempt to build the derivation locally, and the success
3632 or failure of the derivation depends on the success or failure of the
3633 local build. Note that when substitutes are disabled or no substitute
3634 is available for the derivation in question, a local build will
3635 @emph{always} be performed, regardless of whether or not
3636 @option{--fallback} was given.
3638 To get an idea of how many substitutes are available right now, you can
3639 try running the @command{guix weather} command (@pxref{Invoking guix
3640 weather}). This command provides statistics on the substitutes provided
3643 @node On Trusting Binaries
3644 @subsection On Trusting Binaries
3646 @cindex trust, of pre-built binaries
3647 Today, each individual's control over their own computing is at the
3648 mercy of institutions, corporations, and groups with enough power and
3649 determination to subvert the computing infrastructure and exploit its
3650 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3651 convenient, we encourage users to also build on their own, or even run
3652 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3653 interesting target. One way to help is by publishing the software you
3654 build using @command{guix publish} so that others have one more choice
3655 of server to download substitutes from (@pxref{Invoking guix publish}).
3657 Guix has the foundations to maximize build reproducibility
3658 (@pxref{Features}). In most cases, independent builds of a given
3659 package or derivation should yield bit-identical results. Thus, through
3660 a diverse set of independent package builds, we can strengthen the
3661 integrity of our systems. The @command{guix challenge} command aims to
3662 help users assess substitute servers, and to assist developers in
3663 finding out about non-deterministic package builds (@pxref{Invoking guix
3664 challenge}). Similarly, the @option{--check} option of @command{guix
3665 build} allows users to check whether previously-installed substitutes
3666 are genuine by rebuilding them locally (@pxref{build-check,
3667 @command{guix build --check}}).
3669 In the future, we want Guix to have support to publish and retrieve
3670 binaries to/from other users, in a peer-to-peer fashion. If you would
3671 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3673 @node Packages with Multiple Outputs
3674 @section Packages with Multiple Outputs
3676 @cindex multiple-output packages
3677 @cindex package outputs
3680 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3681 source package leads to exactly one directory in the store. When running
3682 @command{guix install glibc}, one installs the default output of the
3683 GNU libc package; the default output is called @code{out}, but its name
3684 can be omitted as shown in this command. In this particular case, the
3685 default output of @code{glibc} contains all the C header files, shared
3686 libraries, static libraries, Info documentation, and other supporting
3689 Sometimes it is more appropriate to separate the various types of files
3690 produced from a single source package into separate outputs. For
3691 instance, the GLib C library (used by GTK+ and related packages)
3692 installs more than 20 MiB of reference documentation as HTML pages.
3693 To save space for users who do not need it, the documentation goes to a
3694 separate output, called @code{doc}. To install the main GLib output,
3695 which contains everything but the documentation, one would run:
3701 @cindex documentation
3702 The command to install its documentation is:
3705 guix install glib:doc
3708 Some packages install programs with different ``dependency footprints''.
3709 For instance, the WordNet package installs both command-line tools and
3710 graphical user interfaces (GUIs). The former depend solely on the C
3711 library, whereas the latter depend on Tcl/Tk and the underlying X
3712 libraries. In this case, we leave the command-line tools in the default
3713 output, whereas the GUIs are in a separate output. This allows users
3714 who do not need the GUIs to save space. The @command{guix size} command
3715 can help find out about such situations (@pxref{Invoking guix size}).
3716 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3718 There are several such multiple-output packages in the GNU distribution.
3719 Other conventional output names include @code{lib} for libraries and
3720 possibly header files, @code{bin} for stand-alone programs, and
3721 @code{debug} for debugging information (@pxref{Installing Debugging
3722 Files}). The outputs of a packages are listed in the third column of
3723 the output of @command{guix package --list-available} (@pxref{Invoking
3727 @node Invoking guix gc
3728 @section Invoking @command{guix gc}
3730 @cindex garbage collector
3732 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3733 The @command{guix gc} command allows users to explicitly run the garbage
3734 collector to reclaim space from the @file{/gnu/store} directory. It is
3735 the @emph{only} way to remove files from @file{/gnu/store}---removing
3736 files or directories manually may break it beyond repair!
3739 @cindex garbage collector roots
3740 The garbage collector has a set of known @dfn{roots}: any file under
3741 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3742 cannot be deleted; any other file is considered @dfn{dead} and may be
3743 deleted. The set of garbage collector roots (``GC roots'' for short)
3744 includes default user profiles; by default, the symlinks under
3745 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3746 added with @command{guix build --root}, for example (@pxref{Invoking
3747 guix build}). The @command{guix gc --list-roots} command lists them.
3749 Prior to running @code{guix gc --collect-garbage} to make space, it is
3750 often useful to remove old generations from user profiles; that way, old
3751 package builds referenced by those generations can be reclaimed. This
3752 is achieved by running @code{guix package --delete-generations}
3753 (@pxref{Invoking guix package}).
3755 Our recommendation is to run a garbage collection periodically, or when
3756 you are short on disk space. For instance, to guarantee that at least
3757 5@tie{}GB are available on your disk, simply run:
3763 It is perfectly safe to run as a non-interactive periodic job
3764 (@pxref{Scheduled Job Execution}, for how to set up such a job).
3765 Running @command{guix gc} with no arguments will collect as
3766 much garbage as it can, but that is often inconvenient: you may find
3767 yourself having to rebuild or re-download software that is ``dead'' from
3768 the GC viewpoint but that is necessary to build other pieces of
3769 software---e.g., the compiler tool chain.
3771 The @command{guix gc} command has three modes of operation: it can be
3772 used to garbage-collect any dead files (the default), to delete specific
3773 files (the @option{--delete} option), to print garbage-collector
3774 information, or for more advanced queries. The garbage collection
3775 options are as follows:
3778 @item --collect-garbage[=@var{min}]
3779 @itemx -C [@var{min}]
3780 Collect garbage---i.e., unreachable @file{/gnu/store} files and
3781 sub-directories. This is the default operation when no option is
3784 When @var{min} is given, stop once @var{min} bytes have been collected.
3785 @var{min} may be a number of bytes, or it may include a unit as a
3786 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
3787 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
3789 When @var{min} is omitted, collect all the garbage.
3791 @item --free-space=@var{free}
3792 @itemx -F @var{free}
3793 Collect garbage until @var{free} space is available under
3794 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
3795 as @code{500MiB}, as described above.
3797 When @var{free} or more is already available in @file{/gnu/store}, do
3798 nothing and exit immediately.
3800 @item --delete-generations[=@var{duration}]
3801 @itemx -d [@var{duration}]
3802 Before starting the garbage collection process, delete all the generations
3803 older than @var{duration}, for all the user profiles; when run as root, this
3804 applies to all the profiles @emph{of all the users}.
3806 For example, this command deletes all the generations of all your profiles
3807 that are older than 2 months (except generations that are current), and then
3808 proceeds to free space until at least 10 GiB are available:
3811 guix gc -d 2m -F 10G
3816 Attempt to delete all the store files and directories specified as
3817 arguments. This fails if some of the files are not in the store, or if
3818 they are still live.
3820 @item --list-failures
3821 List store items corresponding to cached build failures.
3823 This prints nothing unless the daemon was started with
3824 @option{--cache-failures} (@pxref{Invoking guix-daemon,
3825 @option{--cache-failures}}).
3828 List the GC roots owned by the user; when run as root, list @emph{all} the GC
3832 List store items in use by currently running processes. These store
3833 items are effectively considered GC roots: they cannot be deleted.
3835 @item --clear-failures
3836 Remove the specified store items from the failed-build cache.
3838 Again, this option only makes sense when the daemon is started with
3839 @option{--cache-failures}. Otherwise, it does nothing.
3842 Show the list of dead files and directories still present in the
3843 store---i.e., files and directories no longer reachable from any root.
3846 Show the list of live store files and directories.
3850 In addition, the references among existing store files can be queried:
3856 @cindex package dependencies
3857 List the references (respectively, the referrers) of store files given
3863 List the requisites of the store files passed as arguments. Requisites
3864 include the store files themselves, their references, and the references
3865 of these, recursively. In other words, the returned list is the
3866 @dfn{transitive closure} of the store files.
3868 @xref{Invoking guix size}, for a tool to profile the size of the closure
3869 of an element. @xref{Invoking guix graph}, for a tool to visualize
3870 the graph of references.
3874 Return the derivation(s) leading to the given store items
3875 (@pxref{Derivations}).
3877 For example, this command:
3880 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
3884 returns the @file{.drv} file(s) leading to the @code{emacs} package
3885 installed in your profile.
3887 Note that there may be zero matching @file{.drv} files, for instance
3888 because these files have been garbage-collected. There can also be more
3889 than one matching @file{.drv} due to fixed-output derivations.
3892 Lastly, the following options allow you to check the integrity of the
3893 store and to control disk usage.
3897 @item --verify[=@var{options}]
3898 @cindex integrity, of the store
3899 @cindex integrity checking
3900 Verify the integrity of the store.
3902 By default, make sure that all the store items marked as valid in the
3903 database of the daemon actually exist in @file{/gnu/store}.
3905 When provided, @var{options} must be a comma-separated list containing one
3906 or more of @code{contents} and @code{repair}.
3908 When passing @option{--verify=contents}, the daemon computes the
3909 content hash of each store item and compares it against its hash in the
3910 database. Hash mismatches are reported as data corruptions. Because it
3911 traverses @emph{all the files in the store}, this command can take a
3912 long time, especially on systems with a slow disk drive.
3914 @cindex repairing the store
3915 @cindex corruption, recovering from
3916 Using @option{--verify=repair} or @option{--verify=contents,repair}
3917 causes the daemon to try to repair corrupt store items by fetching
3918 substitutes for them (@pxref{Substitutes}). Because repairing is not
3919 atomic, and thus potentially dangerous, it is available only to the
3920 system administrator. A lightweight alternative, when you know exactly
3921 which items in the store are corrupt, is @command{guix build --repair}
3922 (@pxref{Invoking guix build}).
3925 @cindex deduplication
3926 Optimize the store by hard-linking identical files---this is
3927 @dfn{deduplication}.
3929 The daemon performs deduplication after each successful build or archive
3930 import, unless it was started with @option{--disable-deduplication}
3931 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
3932 this option is primarily useful when the daemon was running with
3933 @option{--disable-deduplication}.
3937 @node Invoking guix pull
3938 @section Invoking @command{guix pull}
3940 @cindex upgrading Guix
3941 @cindex updating Guix
3942 @cindex @command{guix pull}
3944 @cindex security, @command{guix pull}
3945 @cindex authenticity, of code obtained with @command{guix pull}
3946 Packages are installed or upgraded to the latest version available in
3947 the distribution currently available on your local machine. To update
3948 that distribution, along with the Guix tools, you must run @command{guix
3949 pull}: the command downloads the latest Guix source code and package
3950 descriptions, and deploys it. Source code is downloaded from a
3951 @uref{https://git-scm.com, Git} repository, by default the official
3952 GNU@tie{}Guix repository, though this can be customized. @command{guix
3953 pull} ensures that the code it downloads is @emph{authentic} by
3954 verifying that commits are signed by Guix developers.
3956 Specifically, @command{guix pull} downloads code from the @dfn{channels}
3957 (@pxref{Channels}) specified by one of the followings, in this order:
3961 the @option{--channels} option;
3963 the user's @file{~/.config/guix/channels.scm} file;
3965 the system-wide @file{/etc/guix/channels.scm} file;
3967 the built-in default channels specified in the @code{%default-channels}
3971 On completion, @command{guix package} will use packages and package
3972 versions from this just-retrieved copy of Guix. Not only that, but all
3973 the Guix commands and Scheme modules will also be taken from that latest
3974 version. New @command{guix} sub-commands added by the update also
3977 Any user can update their Guix copy using @command{guix pull}, and the
3978 effect is limited to the user who ran @command{guix pull}. For
3979 instance, when user @code{root} runs @command{guix pull}, this has no
3980 effect on the version of Guix that user @code{alice} sees, and vice
3983 The result of running @command{guix pull} is a @dfn{profile} available
3984 under @file{~/.config/guix/current} containing the latest Guix. Thus,
3985 make sure to add it to the beginning of your search path so that you use
3986 the latest version, and similarly for the Info manual
3987 (@pxref{Documentation}):
3990 export PATH="$HOME/.config/guix/current/bin:$PATH"
3991 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
3994 The @option{--list-generations} or @option{-l} option lists past generations
3995 produced by @command{guix pull}, along with details about their provenance:
3999 Generation 1 Jun 10 2018 00:18:18
4001 repository URL: https://git.savannah.gnu.org/git/guix.git
4002 branch: origin/master
4003 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4005 Generation 2 Jun 11 2018 11:02:49
4007 repository URL: https://git.savannah.gnu.org/git/guix.git
4008 branch: origin/master
4009 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4010 2 new packages: keepalived, libnfnetlink
4011 6 packages upgraded: emacs-nix-mode@@2.0.4,
4012 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4013 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4015 Generation 3 Jun 13 2018 23:31:07 (current)
4017 repository URL: https://git.savannah.gnu.org/git/guix.git
4018 branch: origin/master
4019 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4020 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4021 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4024 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4025 describe the current status of Guix.
4027 This @code{~/.config/guix/current} profile works exactly like the profiles
4028 created by @command{guix package} (@pxref{Invoking guix package}). That
4029 is, you can list generations, roll back to the previous
4030 generation---i.e., the previous Guix---and so on:
4033 $ guix pull --roll-back
4034 switched from generation 3 to 2
4035 $ guix pull --delete-generations=1
4036 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4039 You can also use @command{guix package} (@pxref{Invoking guix package})
4040 to manage the profile by naming it explicitly:
4042 $ guix package -p ~/.config/guix/current --roll-back
4043 switched from generation 3 to 2
4044 $ guix package -p ~/.config/guix/current --delete-generations=1
4045 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4048 The @command{guix pull} command is usually invoked with no arguments,
4049 but it supports the following options:
4052 @item --url=@var{url}
4053 @itemx --commit=@var{commit}
4054 @itemx --branch=@var{branch}
4055 Download code for the @code{guix} channel from the specified @var{url}, at the
4056 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4057 string), or @var{branch}.
4059 @cindex @file{channels.scm}, configuration file
4060 @cindex configuration file for channels
4061 These options are provided for convenience, but you can also specify your
4062 configuration in the @file{~/.config/guix/channels.scm} file or using the
4063 @option{--channels} option (see below).
4065 @item --channels=@var{file}
4066 @itemx -C @var{file}
4067 Read the list of channels from @var{file} instead of
4068 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4069 @var{file} must contain Scheme code that
4070 evaluates to a list of channel objects. @xref{Channels}, for more
4073 @cindex channel news
4076 Display the list of packages added or upgraded since the previous
4077 generation, as well as, occasionally, news written by channel authors
4078 for their users (@pxref{Channels, Writing Channel News}).
4080 The package information is the same as displayed upon @command{guix
4081 pull} completion, but without ellipses; it is also similar to the output
4082 of @command{guix pull -l} for the last generation (see below).
4084 @item --list-generations[=@var{pattern}]
4085 @itemx -l [@var{pattern}]
4086 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4087 is provided, the subset of generations that match @var{pattern}.
4088 The syntax of @var{pattern} is the same as with @code{guix package
4089 --list-generations} (@pxref{Invoking guix package}).
4092 @cindex rolling back
4093 @cindex undoing transactions
4094 @cindex transactions, undoing
4095 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4096 undo the last transaction.
4098 @item --switch-generation=@var{pattern}
4099 @itemx -S @var{pattern}
4101 Switch to a particular generation defined by @var{pattern}.
4103 @var{pattern} may be either a generation number or a number prefixed
4104 with ``+'' or ``-''. The latter means: move forward/backward by a
4105 specified number of generations. For example, if you want to return to
4106 the latest generation after @option{--roll-back}, use
4107 @option{--switch-generation=+1}.
4109 @item --delete-generations[=@var{pattern}]
4110 @itemx -d [@var{pattern}]
4111 When @var{pattern} is omitted, delete all generations except the current
4114 This command accepts the same patterns as @option{--list-generations}.
4115 When @var{pattern} is specified, delete the matching generations. When
4116 @var{pattern} specifies a duration, generations @emph{older} than the
4117 specified duration match. For instance, @option{--delete-generations=1m}
4118 deletes generations that are more than one month old.
4120 If the current generation matches, it is @emph{not} deleted.
4122 Note that deleting generations prevents rolling back to them.
4123 Consequently, this command must be used with care.
4125 @xref{Invoking guix describe}, for a way to display information about the
4126 current generation only.
4128 @item --profile=@var{profile}
4129 @itemx -p @var{profile}
4130 Use @var{profile} instead of @file{~/.config/guix/current}.
4134 Show which channel commit(s) would be used and what would be built or
4135 substituted but do not actually do it.
4137 @item --allow-downgrades
4138 Allow pulling older or unrelated revisions of channels than those
4141 @cindex downgrade attacks, protection against
4142 By default, @command{guix pull} protects against so-called ``downgrade
4143 attacks'' whereby the Git repository of a channel would be reset to an
4144 earlier or unrelated revision of itself, potentially leading you to
4145 install older, known-vulnerable versions of software packages.
4148 Make sure you understand its security implications before using
4149 @option{--allow-downgrades}.
4152 @item --disable-authentication
4153 Allow pulling channel code without authenticating it.
4155 @cindex authentication, of channel code
4156 By default, @command{guix pull} authenticates code downloaded from
4157 channels by verifying that its commits are signed by authorized
4158 developers, and raises an error if this is not the case. This option
4159 instructs it to not perform any such verification.
4162 Make sure you understand its security implications before using
4163 @option{--disable-authentication}.
4166 @item --system=@var{system}
4167 @itemx -s @var{system}
4168 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4169 the system type of the build host.
4172 Use the bootstrap Guile to build the latest Guix. This option is only
4173 useful to Guix developers.
4176 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4177 repository and branch to pull from, as well as @emph{additional} repositories
4178 containing package modules that should be deployed. @xref{Channels}, for more
4181 In addition, @command{guix pull} supports all the common build options
4182 (@pxref{Common Build Options}).
4188 @cindex @file{channels.scm}, configuration file
4189 @cindex configuration file for channels
4190 @cindex @command{guix pull}, configuration file
4191 @cindex configuration of @command{guix pull}
4192 Guix and its package collection are updated by running @command{guix pull}
4193 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4194 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4195 customized by defining @dfn{channels} in the
4196 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4197 of a Git repository to be deployed, and @command{guix pull} can be instructed
4198 to pull from one or more channels. In other words, channels can be used
4199 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4200 Before that, some security considerations.
4202 @subsection Channel Authentication
4204 @anchor{channel-authentication}
4205 @cindex authentication, of channel code
4206 The @command{guix pull} and @command{guix time-machine} commands
4207 @dfn{authenticate} the code retrieved from channels: they make sure each
4208 commit that is fetched is signed by an authorized developer. The goal
4209 is to protect from unauthorized modifications to the channel that would
4210 lead users to run malicious code.
4212 As a user, you must provide a @dfn{channel introduction} in your
4213 channels file so that Guix knows how to authenticate its first commit.
4214 A channel specification, including its introduction, looks something
4220 (url "https://example.org/my-channel.git")
4222 (make-channel-introduction
4223 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
4224 (openpgp-fingerprint
4225 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4228 The specification above shows the name and URL of the channel. The call
4229 to @code{make-channel-introduction} above specifies that authentication
4230 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
4231 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
4233 For the main channel, called @code{guix}, you automatically get that
4234 information from your Guix installation. For other channels, include
4235 the channel introduction provided by the channel authors in your
4236 @file{channels.scm} file. Make sure you retrieve the channel
4237 introduction from a trusted source since that is the root of your trust.
4239 If you're curious about the authentication mechanics, read on!
4241 @subsection Using a Custom Guix Channel
4243 The channel called @code{guix} specifies where Guix itself---its command-line
4244 tools as well as its package collection---should be downloaded. For instance,
4245 suppose you want to update from your own copy of the Guix repository at
4246 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4247 write in @code{~/.config/guix/channels.scm} this specification:
4250 ;; Tell 'guix pull' to use my own repo.
4253 (url "https://example.org/my-guix.git")
4254 (branch "super-hacks")))
4258 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4259 branch of the repository at @code{example.org}.
4261 @subsection Specifying Additional Channels
4263 @cindex extending the package collection (channels)
4264 @cindex personal packages (channels)
4265 @cindex channels, for personal packages
4266 You can also specify @emph{additional channels} to pull from. Let's say you
4267 have a bunch of custom package variants or personal packages that you think
4268 would make little sense to contribute to the Guix project, but would like to
4269 have these packages transparently available to you at the command line. You
4270 would first write modules containing those package definitions (@pxref{Package
4271 Modules}), maintain them in a Git repository, and then you and anyone else can
4272 use it as an additional channel to get packages from. Neat, no?
4274 @c What follows stems from discussions at
4275 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
4276 @c earlier discussions on guix-devel@gnu.org.
4278 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
4279 publish your personal channel to the world, we would like to share a few words
4284 Before publishing a channel, please consider contributing your package
4285 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
4286 to free software of all sorts, and packages in Guix proper are readily
4287 available to all Guix users and benefit from the project's quality assurance
4291 When you maintain package definitions outside Guix, we, Guix developers,
4292 consider that @emph{the compatibility burden is on you}. Remember that
4293 package modules and package definitions are just Scheme code that uses various
4294 programming interfaces (APIs). We want to remain free to change these APIs to
4295 keep improving Guix, possibly in ways that break your channel. We never
4296 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
4300 Corollary: if you're using an external channel and that channel breaks, please
4301 @emph{report the issue to the channel authors}, not to the Guix project.
4304 You've been warned! Having said this, we believe external channels are a
4305 practical way to exert your freedom to augment Guix' package collection and to
4306 share your improvements, which are basic tenets of
4307 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
4308 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
4311 To use a channel, write @code{~/.config/guix/channels.scm} to instruct
4312 @command{guix pull} to pull from it @emph{in addition} to the default Guix
4315 @vindex %default-channels
4317 ;; Add my personal packages to those Guix provides.
4319 (name 'my-personal-packages)
4320 (url "https://example.org/personal-packages.git"))
4325 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4326 add a channel the list of channels that the variable @code{%default-channels}
4327 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4328 Manual}). With this file in place, @command{guix pull} builds not only Guix
4329 but also the package modules from your own repository. The result in
4330 @file{~/.config/guix/current} is the union of Guix with your own package
4334 $ guix pull --list-generations
4336 Generation 19 Aug 27 2018 16:20:48
4338 repository URL: https://git.savannah.gnu.org/git/guix.git
4340 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4341 my-personal-packages dd3df5e
4342 repository URL: https://example.org/personal-packages.git
4344 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4345 11 new packages: my-gimp, my-emacs-with-cool-features, @dots{}
4346 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4350 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4351 both Guix and packages from the @code{my-personal-packages} channel. Among
4352 the new and upgraded packages that are listed, some like @code{my-gimp} and
4353 @code{my-emacs-with-cool-features} might come from
4354 @code{my-personal-packages}, while others come from the Guix default channel.
4356 To create a channel, create a Git repository containing your own package
4357 modules and make it available. The repository can contain anything, but a
4358 useful channel will contain Guile modules that export packages. Once you
4359 start using a channel, Guix will behave as if the root directory of that
4360 channel's Git repository has been added to the Guile load path (@pxref{Load
4361 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
4362 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
4363 module, then the module will be available under the name @code{(my-packages
4364 my-tools)}, and you will be able to use it like any other module
4365 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
4367 @cindex dependencies, channels
4368 @cindex meta-data, channels
4369 @subsection Declaring Channel Dependencies
4371 Channel authors may decide to augment a package collection provided by other
4372 channels. They can declare their channel to be dependent on other channels in
4373 a meta-data file @file{.guix-channel}, which is to be placed in the root of
4374 the channel repository.
4376 The meta-data file should contain a simple S-expression like this:
4383 (name some-collection)
4384 (url "https://example.org/first-collection.git")
4386 ;; The 'introduction' bit below is optional: you would
4387 ;; provide it for dependencies that can be authenticated.
4389 (channel-introduction
4391 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
4392 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
4394 (name some-other-collection)
4395 (url "https://example.org/second-collection.git")
4396 (branch "testing"))))
4399 In the above example this channel is declared to depend on two other channels,
4400 which will both be fetched automatically. The modules provided by the channel
4401 will be compiled in an environment where the modules of all these declared
4402 channels are available.
4404 For the sake of reliability and maintainability, you should avoid dependencies
4405 on channels that you don't control, and you should aim to keep the number of
4406 dependencies to a minimum.
4408 @cindex subdirectory, channels
4409 @subsection Package Modules in a Sub-directory
4411 As a channel author, you may want to keep your channel modules in a
4412 sub-directory. If your modules are in the sub-directory @file{guix}, you must
4413 add a meta-data file @file{.guix-channel} that contains:
4421 @cindex channel authorizations
4422 @subsection Specifying Channel Authorizations
4424 @anchor{channel-authorizations}
4425 As we saw above, Guix ensures the source code it pulls from channels
4426 comes from authorized developers. As a channel author, you need to
4427 specify the list of authorized developers in the
4428 @file{.guix-authorizations} file in the channel's Git repository. The
4429 authentication rule is simple: each commit must be signed by a key
4430 listed in the @file{.guix-authorizations} file of its parent
4431 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
4432 (DAG). Each commit can have zero or more parents; ``regular'' commits
4433 have one parent and merge commits have two parent commits. Read
4434 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
4435 for Computer Scientists}} for a great overview.} The
4436 @file{.guix-authorizations} file looks like this:
4439 ;; Example '.guix-authorizations' file.
4442 (version 0) ;current file format version
4444 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
4446 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
4448 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
4452 Each fingerprint is followed by optional key/value pairs, as in the
4453 example above. Currently these key/value pairs are ignored.
4455 This authentication rule creates a chicken-and-egg issue: how do we
4456 authenticate the first commit? Related to that: how do we deal with
4457 channels whose repository history contains unsigned commits and lack
4458 @file{.guix-authorizations}? And how do we fork existing channels?
4460 @cindex channel introduction
4461 Channel introductions answer these questions by describing the first
4462 commit of a channel that should be authenticated. The first time a
4463 channel is fetched with @command{guix pull} or @command{guix
4464 time-machine}, the command looks up the introductory commit and verifies
4465 that it is signed by the specified OpenPGP key. From then on, it
4466 authenticates commits according to the rule above.
4468 Additionally, your channel must provide all the OpenPGP keys that were
4469 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
4470 files, which can be either binary or ``ASCII-armored''. By default,
4471 those @file{.key} files are searched for in the branch named
4472 @code{keyring} but you can specify a different branch name in
4473 @code{.guix-channel} like so:
4478 (keyring-reference "my-keyring-branch"))
4481 To summarize, as the author of a channel, there are three things you have
4482 to do to allow users to authenticate your code:
4486 Export the OpenPGP keys of past and present committers with @command{gpg
4487 --export} and store them in @file{.key} files, by default in a branch
4488 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
4491 Introduce an initial @file{.guix-authorizations} in the channel's
4492 repository. Do that in a signed commit (@pxref{Commit Access}, for
4493 information on how to sign Git commits.)
4496 Advertise the channel introduction, for instance on your channel's web
4497 page. The channel introduction, as we saw above, is the commit/key
4498 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
4499 the fingerprint of the OpenPGP used to sign it.
4502 Before pushing to your public Git repository, you can run @command{guix
4503 git-authenticate} to verify that you did sign all the commits you are
4504 about to push with an authorized key:
4507 guix git authenticate @var{commit} @var{signer}
4511 where @var{commit} and @var{signer} are your channel introduction.
4512 @xref{Invoking guix git authenticate}, for details.
4514 Publishing a signed channel requires discipline: any mistake, such as an
4515 unsigned commit or a commit signed by an unauthorized key, will prevent
4516 users from pulling from your channel---well, that's the whole point of
4517 authentication! Pay attention to merges in particular: merge commits
4518 are considered authentic if and only if they are signed by a key present
4519 in the @file{.guix-authorizations} file of @emph{both} branches.
4521 @cindex primary URL, channels
4522 @subsection Primary URL
4524 Channel authors can indicate the primary URL of their channel's Git
4525 repository in the @file{.guix-channel} file, like so:
4530 (url "https://example.org/guix.git"))
4533 This allows @command{guix pull} to determine whether it is pulling code
4534 from a mirror of the channel; when that is the case, it warns the user
4535 that the mirror might be stale and displays the primary URL. That way,
4536 users cannot be tricked into fetching code from a stale mirror that does
4537 not receive security updates.
4539 This feature only makes sense for authenticated repositories, such as
4540 the official @code{guix} channel, for which @command{guix pull} ensures
4541 the code it fetches is authentic.
4543 @cindex news, for channels
4544 @subsection Writing Channel News
4546 Channel authors may occasionally want to communicate to their users
4547 information about important changes in the channel. You'd send them all
4548 an email, but that's not convenient.
4550 Instead, channels can provide a @dfn{news file}; when the channel users
4551 run @command{guix pull}, that news file is automatically read and
4552 @command{guix pull --news} can display the announcements that correspond
4553 to the new commits that have been pulled, if any.
4555 To do that, channel authors must first declare the name of the news file
4556 in their @file{.guix-channel} file:
4561 (news-file "etc/news.txt"))
4564 The news file itself, @file{etc/news.txt} in this example, must look
4565 something like this:
4570 (entry (tag "the-bug-fix")
4571 (title (en "Fixed terrible bug")
4573 (body (en "@@emph@{Good news@}! It's fixed!")
4574 (eo "Certe ĝi pli bone funkcias nun!")))
4575 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
4576 (title (en "Added a great package")
4577 (ca "Què vol dir guix?"))
4578 (body (en "Don't miss the @@code@{hello@} package!"))))
4581 While the news file is using the Scheme syntax, avoid naming it with a
4582 @file{.scm} extension or else it will get picked up when building the
4583 channel and yield an error since it is not a valid module.
4584 Alternatively, you can move the channel module to a subdirectory and
4585 store the news file in another directory.
4587 The file consists of a list of @dfn{news entries}. Each entry is
4588 associated with a commit or tag: it describes changes made in this
4589 commit, possibly in preceding commits as well. Users see entries only
4590 the first time they obtain the commit the entry refers to.
4592 The @code{title} field should be a one-line summary while @code{body}
4593 can be arbitrarily long, and both can contain Texinfo markup
4594 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
4595 a list of language tag/message tuples, which allows @command{guix pull}
4596 to display news in the language that corresponds to the user's locale.
4598 If you want to translate news using a gettext-based workflow, you can
4599 extract translatable strings with @command{xgettext} (@pxref{xgettext
4600 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
4601 you write news entries in English first, the command below creates a PO
4602 file containing the strings to translate:
4605 xgettext -o news.po -l scheme -ken etc/news.txt
4608 To sum up, yes, you could use your channel as a blog. But beware, this
4609 is @emph{not quite} what your users might expect.
4611 @subsection Replicating Guix
4613 @cindex pinning, channels
4614 @cindex replicating Guix
4615 @cindex reproducibility, of Guix
4616 The @command{guix pull --list-generations} output above shows precisely which
4617 commits were used to build this instance of Guix. We can thus replicate it,
4618 say, on another machine, by providing a channel specification in
4619 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
4622 ;; Deploy specific commits of my channels of interest.
4625 (url "https://git.savannah.gnu.org/git/guix.git")
4626 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
4628 (name 'my-personal-packages)
4629 (url "https://example.org/personal-packages.git")
4630 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
4633 The @command{guix describe --format=channels} command can even generate this
4634 list of channels directly (@pxref{Invoking guix describe}). The resulting
4635 file can be used with the -C options of @command{guix pull}
4636 (@pxref{Invoking guix pull}) or @command{guix time-machine}
4637 (@pxref{Invoking guix time-machine}).
4639 At this point the two machines run the @emph{exact same Guix}, with access to
4640 the @emph{exact same packages}. The output of @command{guix build gimp} on
4641 one machine will be exactly the same, bit for bit, as the output of the same
4642 command on the other machine. It also means both machines have access to all
4643 the source code of Guix and, transitively, to all the source code of every
4646 This gives you super powers, allowing you to track the provenance of binary
4647 artifacts with very fine grain, and to reproduce software environments at
4648 will---some sort of ``meta reproducibility'' capabilities, if you will.
4649 @xref{Inferiors}, for another way to take advantage of these super powers.
4651 @node Invoking guix time-machine
4652 @section Invoking @command{guix time-machine}
4654 @cindex @command{guix time-machine}
4655 @cindex pinning, channels
4656 @cindex replicating Guix
4657 @cindex reproducibility, of Guix
4659 The @command{guix time-machine} command provides access to other
4660 revisions of Guix, for example to install older versions of packages,
4661 or to reproduce a computation in an identical environment. The revision
4662 of Guix to be used is defined by a commit or by a channel
4663 description file created by @command{guix describe}
4664 (@pxref{Invoking guix describe}).
4666 The general syntax is:
4669 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4672 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4673 @command{guix} command of the specified revision. The @var{options} that define
4674 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4677 @item --url=@var{url}
4678 @itemx --commit=@var{commit}
4679 @itemx --branch=@var{branch}
4680 Use the @code{guix} channel from the specified @var{url}, at the
4681 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4682 string), or @var{branch}.
4684 @item --channels=@var{file}
4685 @itemx -C @var{file}
4686 Read the list of channels from @var{file}. @var{file} must contain
4687 Scheme code that evaluates to a list of channel objects.
4688 @xref{Channels} for more information.
4691 As for @command{guix pull}, the absence of any options means that the
4692 the latest commit on the master branch will be used. The command
4695 guix time-machine -- build hello
4698 will thus build the package @code{hello} as defined in the master branch,
4699 which is in general a newer revision of Guix than you have installed.
4700 Time travel works in both directions!
4702 Note that @command{guix time-machine} can trigger builds of channels and
4703 their dependencies, and these are controlled by the standard build
4704 options (@pxref{Common Build Options}).
4709 @c TODO: Remove this once we're more confident about API stability.
4711 The functionality described here is a ``technology preview'' as of version
4712 @value{VERSION}. As such, the interface is subject to change.
4716 @cindex composition of Guix revisions
4717 Sometimes you might need to mix packages from the revision of Guix you're
4718 currently running with packages available in a different revision of Guix.
4719 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4720 revisions in arbitrary ways.
4722 @cindex inferior packages
4723 Technically, an ``inferior'' is essentially a separate Guix process connected
4724 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4725 @code{(guix inferior)} module allows you to create inferiors and to
4726 communicate with them. It also provides a high-level interface to browse and
4727 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4729 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4730 to interact with a separate revision of Guix. For example, let's assume you
4731 want to install in your profile the current @code{guile} package, along with
4732 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4733 because the newer @code{guile-json} has an incompatible API and you want to
4734 run your code against the old API@. To do that, you could write a manifest for
4735 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4736 manifest, you would create an inferior for that old Guix revision you care
4737 about, and you would look up the @code{guile-json} package in the inferior:
4740 (use-modules (guix inferior) (guix channels)
4741 (srfi srfi-1)) ;for 'first'
4744 ;; This is the old revision from which we want to
4745 ;; extract guile-json.
4748 (url "https://git.savannah.gnu.org/git/guix.git")
4750 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4753 ;; An inferior representing the above revision.
4754 (inferior-for-channels channels))
4756 ;; Now create a manifest with the current "guile" package
4757 ;; and the old "guile-json" package.
4759 (list (first (lookup-inferior-packages inferior "guile-json"))
4760 (specification->package "guile")))
4763 On its first run, @command{guix package --manifest} might have to build the
4764 channel you specified before it can create the inferior; subsequent runs will
4765 be much faster because the Guix revision will be cached.
4767 The @code{(guix inferior)} module provides the following procedures to open an
4770 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4771 [#:cache-directory] [#:ttl]
4772 Return an inferior for @var{channels}, a list of channels. Use the cache at
4773 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4774 This procedure opens a new connection to the build daemon.
4776 As a side effect, this procedure may build or substitute binaries for
4777 @var{channels}, which can take time.
4780 @deffn {Scheme Procedure} open-inferior @var{directory} @
4781 [#:command "bin/guix"]
4782 Open the inferior Guix in @var{directory}, running
4783 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4784 the inferior could not be launched.
4787 @cindex inferior packages
4788 The procedures listed below allow you to obtain and manipulate inferior
4791 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4792 Return the list of packages known to @var{inferior}.
4795 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4797 Return the sorted list of inferior packages matching @var{name} in
4798 @var{inferior}, with highest version numbers first. If @var{version} is true,
4799 return only packages with a version number prefixed by @var{version}.
4802 @deffn {Scheme Procedure} inferior-package? @var{obj}
4803 Return true if @var{obj} is an inferior package.
4806 @deffn {Scheme Procedure} inferior-package-name @var{package}
4807 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4808 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4809 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4810 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4811 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4812 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4813 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4814 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4815 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4816 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4817 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4818 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4819 These procedures are the counterpart of package record accessors
4820 (@pxref{package Reference}). Most of them work by querying the inferior
4821 @var{package} comes from, so the inferior must still be live when you call
4825 Inferior packages can be used transparently like any other package or
4826 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4827 transparently handled by the @code{packages->manifest} procedure, which is
4828 commonly use in manifests (@pxref{Invoking guix package, the
4829 @option{--manifest} option of @command{guix package}}). Thus you can insert
4830 an inferior package pretty much anywhere you would insert a regular package:
4831 in manifests, in the @code{packages} field of your @code{operating-system}
4832 declaration, and so on.
4834 @node Invoking guix describe
4835 @section Invoking @command{guix describe}
4837 @cindex reproducibility
4838 @cindex replicating Guix
4839 Often you may want to answer questions like: ``Which revision of Guix am I
4840 using?'' or ``Which channels am I using?'' This is useful information in many
4841 situations: if you want to @emph{replicate} an environment on a different
4842 machine or user account, if you want to report a bug or to determine what
4843 change in the channels you are using caused it, or if you want to record your
4844 system state for reproducibility purposes. The @command{guix describe}
4845 command answers these questions.
4847 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4848 displays the channel(s) that it was built from, including their repository URL
4849 and commit IDs (@pxref{Channels}):
4853 Generation 10 Sep 03 2018 17:32:44 (current)
4855 repository URL: https://git.savannah.gnu.org/git/guix.git
4857 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4860 If you're familiar with the Git version control system, this is similar in
4861 spirit to @command{git describe}; the output is also similar to that of
4862 @command{guix pull --list-generations}, but limited to the current generation
4863 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4864 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4865 information is all it takes to describe the revision of Guix you're using, and
4866 also to replicate it.
4868 To make it easier to replicate Guix, @command{guix describe} can also be asked
4869 to return a list of channels instead of the human-readable description above:
4872 $ guix describe -f channels
4875 (url "https://git.savannah.gnu.org/git/guix.git")
4877 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4879 (make-channel-introduction
4880 "9edb3f66fd807b096b48283debdcddccfea34bad"
4881 (openpgp-fingerprint
4882 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4886 You can save this to a file and feed it to @command{guix pull -C} on some
4887 other machine or at a later point in time, which will instantiate @emph{this
4888 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4889 From there on, since you're able to deploy the same revision of Guix, you can
4890 just as well @emph{replicate a complete software environment}. We humbly
4891 think that this is @emph{awesome}, and we hope you'll like it too!
4893 The details of the options supported by @command{guix describe} are as
4897 @item --format=@var{format}
4898 @itemx -f @var{format}
4899 Produce output in the specified @var{format}, one of:
4903 produce human-readable output;
4905 produce a list of channel specifications that can be passed to @command{guix
4906 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4908 @item channels-sans-intro
4909 like @code{channels}, but omit the @code{introduction} field; use it to
4910 produce a channel specification suitable for Guix version 1.1.0 or
4911 earlier---the @code{introduction} field has to do with channel
4912 authentication (@pxref{Channels, Channel Authentication}) and is not
4913 supported by these older versions;
4916 produce a list of channel specifications in JSON format;
4918 produce a list of channel specifications in Recutils format.
4921 @item --list-formats
4922 Display available formats for @option{--format} option.
4924 @item --profile=@var{profile}
4925 @itemx -p @var{profile}
4926 Display information about @var{profile}.
4929 @node Invoking guix archive
4930 @section Invoking @command{guix archive}
4932 @cindex @command{guix archive}
4934 The @command{guix archive} command allows users to @dfn{export} files
4935 from the store into a single archive, and to later @dfn{import} them on
4936 a machine that runs Guix.
4937 In particular, it allows store files to be transferred from one machine
4938 to the store on another machine.
4941 If you're looking for a way to produce archives in a format suitable for
4942 tools other than Guix, @pxref{Invoking guix pack}.
4945 @cindex exporting store items
4946 To export store files as an archive to standard output, run:
4949 guix archive --export @var{options} @var{specifications}...
4952 @var{specifications} may be either store file names or package
4953 specifications, as for @command{guix package} (@pxref{Invoking guix
4954 package}). For instance, the following command creates an archive
4955 containing the @code{gui} output of the @code{git} package and the main
4956 output of @code{emacs}:
4959 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4962 If the specified packages are not built yet, @command{guix archive}
4963 automatically builds them. The build process may be controlled with the
4964 common build options (@pxref{Common Build Options}).
4966 To transfer the @code{emacs} package to a machine connected over SSH,
4970 guix archive --export -r emacs | ssh the-machine guix archive --import
4974 Similarly, a complete user profile may be transferred from one machine
4975 to another like this:
4978 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4979 ssh the-machine guix archive --import
4983 However, note that, in both examples, all of @code{emacs} and the
4984 profile as well as all of their dependencies are transferred (due to
4985 @option{-r}), regardless of what is already available in the store on
4986 the target machine. The @option{--missing} option can help figure out
4987 which items are missing from the target store. The @command{guix copy}
4988 command simplifies and optimizes this whole process, so this is probably
4989 what you should use in this case (@pxref{Invoking guix copy}).
4991 @cindex nar, archive format
4992 @cindex normalized archive (nar)
4993 @cindex nar bundle, archive format
4994 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4995 format (described below), and the output of @command{guix archive
4996 --export} (and input of @command{guix archive --import}) is a @dfn{nar
5000 comparable in spirit to `tar', but with differences
5001 that make it more appropriate for our purposes. First, rather than
5002 recording all Unix metadata for each file, the nar format only mentions
5003 the file type (regular, directory, or symbolic link); Unix permissions
5004 and owner/group are dismissed. Second, the order in which directory
5005 entries are stored always follows the order of file names according to
5006 the C locale collation order. This makes archive production fully
5009 That nar bundle format is essentially the concatenation of zero or more
5010 nars along with metadata for each store item it contains: its file name,
5011 references, corresponding derivation, and a digital signature.
5013 When exporting, the daemon digitally signs the contents of the archive,
5014 and that digital signature is appended. When importing, the daemon
5015 verifies the signature and rejects the import in case of an invalid
5016 signature or if the signing key is not authorized.
5017 @c FIXME: Add xref to daemon doc about signatures.
5019 The main options are:
5023 Export the specified store files or packages (see below). Write the
5024 resulting archive to the standard output.
5026 Dependencies are @emph{not} included in the output, unless
5027 @option{--recursive} is passed.
5031 When combined with @option{--export}, this instructs @command{guix archive}
5032 to include dependencies of the given items in the archive. Thus, the
5033 resulting archive is self-contained: it contains the closure of the
5034 exported store items.
5037 Read an archive from the standard input, and import the files listed
5038 therein into the store. Abort if the archive has an invalid digital
5039 signature, or if it is signed by a public key not among the authorized
5040 keys (see @option{--authorize} below).
5043 Read a list of store file names from the standard input, one per line,
5044 and write on the standard output the subset of these files missing from
5047 @item --generate-key[=@var{parameters}]
5048 @cindex signing, archives
5049 Generate a new key pair for the daemon. This is a prerequisite before
5050 archives can be exported with @option{--export}. Note that this
5051 operation usually takes time, because it needs to gather enough entropy
5052 to generate the key pair.
5054 The generated key pair is typically stored under @file{/etc/guix}, in
5055 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
5056 key, which must be kept secret). When @var{parameters} is omitted,
5057 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
5058 versions before 1.6.0, it is a 4096-bit RSA key.
5059 Alternatively, @var{parameters} can specify
5060 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
5061 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
5062 Libgcrypt Reference Manual}).
5065 @cindex authorizing, archives
5066 Authorize imports signed by the public key passed on standard input.
5067 The public key must be in ``s-expression advanced format''---i.e., the
5068 same format as the @file{signing-key.pub} file.
5070 The list of authorized keys is kept in the human-editable file
5071 @file{/etc/guix/acl}. The file contains
5072 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
5073 s-expressions''} and is structured as an access-control list in the
5074 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
5077 @item --extract=@var{directory}
5078 @itemx -x @var{directory}
5079 Read a single-item archive as served by substitute servers
5080 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
5081 low-level operation needed in only very narrow use cases; see below.
5083 For example, the following command extracts the substitute for Emacs
5084 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
5088 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
5089 | gunzip | guix archive -x /tmp/emacs
5092 Single-item archives are different from multiple-item archives produced
5093 by @command{guix archive --export}; they contain a single store item,
5094 and they do @emph{not} embed a signature. Thus this operation does
5095 @emph{no} signature verification and its output should be considered
5098 The primary purpose of this operation is to facilitate inspection of
5099 archive contents coming from possibly untrusted substitute servers
5100 (@pxref{Invoking guix challenge}).
5104 Read a single-item archive as served by substitute servers
5105 (@pxref{Substitutes}) and print the list of files it contains, as in
5110 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
5111 | lzip -d | guix archive -t
5117 @c *********************************************************************
5119 @chapter Development
5121 @cindex software development
5122 If you are a software developer, Guix provides tools that you should find
5123 helpful---independently of the language you're developing in. This is what
5124 this chapter is about.
5126 The @command{guix environment} command provides a convenient way to set up
5127 @dfn{development environments} containing all the dependencies and tools
5128 necessary to work on the software package of your choice. The @command{guix
5129 pack} command allows you to create @dfn{application bundles} that can be
5130 easily distributed to users who do not run Guix.
5133 * Invoking guix environment:: Setting up development environments.
5134 * Invoking guix pack:: Creating software bundles.
5135 * The GCC toolchain:: Working with languages supported by GCC.
5136 * Invoking guix git authenticate:: Authenticating Git repositories.
5139 @node Invoking guix environment
5140 @section Invoking @command{guix environment}
5142 @cindex reproducible build environments
5143 @cindex development environments
5144 @cindex @command{guix environment}
5145 @cindex environment, package build environment
5146 The purpose of @command{guix environment} is to assist hackers in
5147 creating reproducible development environments without polluting their
5148 package profile. The @command{guix environment} tool takes one or more
5149 packages, builds all of their inputs, and creates a shell
5150 environment to use them.
5152 The general syntax is:
5155 guix environment @var{options} @var{package}@dots{}
5158 The following example spawns a new shell set up for the development of
5162 guix environment guile
5165 If the needed dependencies are not built yet, @command{guix environment}
5166 automatically builds them. The environment of the new shell is an
5167 augmented version of the environment that @command{guix environment} was
5168 run in. It contains the necessary search paths for building the given
5169 package added to the existing environment variables. To create
5170 a ``pure'' environment, in which the original environment variables have
5171 been unset, use the @option{--pure} option@footnote{Users sometimes
5172 wrongfully augment environment variables such as @env{PATH} in their
5173 @file{~/.bashrc} file. As a consequence, when @command{guix
5174 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5175 introducing ``impurities'' in these environment variables. It is an
5176 error to define such environment variables in @file{.bashrc}; instead,
5177 they should be defined in @file{.bash_profile}, which is sourced only by
5178 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5179 Manual}, for details on Bash start-up files.}.
5181 @vindex GUIX_ENVIRONMENT
5182 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5183 variable in the shell it spawns; its value is the file name of the
5184 profile of this environment. This allows users to, say, define a
5185 specific prompt for development environments in their @file{.bashrc}
5186 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5189 if [ -n "$GUIX_ENVIRONMENT" ]
5191 export PS1="\u@@\h \w [dev]\$ "
5196 ...@: or to browse the profile:
5199 $ ls "$GUIX_ENVIRONMENT/bin"
5202 Additionally, more than one package may be specified, in which case the
5203 union of the inputs for the given packages are used. For example, the
5204 command below spawns a shell where all of the dependencies of both Guile
5205 and Emacs are available:
5208 guix environment guile emacs
5211 Sometimes an interactive shell session is not desired. An arbitrary
5212 command may be invoked by placing the @code{--} token to separate the
5213 command from the rest of the arguments:
5216 guix environment guile -- make -j4
5219 In other situations, it is more convenient to specify the list of
5220 packages needed in the environment. For example, the following command
5221 runs @command{python} from an environment containing Python@tie{}2.7 and
5225 guix environment --ad-hoc python2-numpy python-2.7 -- python
5228 Furthermore, one might want the dependencies of a package and also some
5229 additional packages that are not build-time or runtime dependencies, but
5230 are useful when developing nonetheless. Because of this, the
5231 @option{--ad-hoc} flag is positional. Packages appearing before
5232 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5233 added to the environment. Packages appearing after are interpreted as
5234 packages that will be added to the environment directly. For example,
5235 the following command creates a Guix development environment that
5236 additionally includes Git and strace:
5239 guix environment --pure guix --ad-hoc git strace
5243 Sometimes it is desirable to isolate the environment as much as
5244 possible, for maximal purity and reproducibility. In particular, when
5245 using Guix on a host distro that is not Guix System, it is desirable to
5246 prevent access to @file{/usr/bin} and other system-wide resources from
5247 the development environment. For example, the following command spawns
5248 a Guile REPL in a ``container'' where only the store and the current
5249 working directory are mounted:
5252 guix environment --ad-hoc --container guile -- guile
5256 The @option{--container} option requires Linux-libre 3.19 or newer.
5259 @cindex certificates
5260 Another typical use case for containers is to run security-sensitive
5261 applications such as a web browser. To run Eolie, we must expose and
5262 share some files and directories; we include @code{nss-certs} and expose
5263 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5264 the @env{DISPLAY} environment variable since containerized graphical
5265 applications won't display without it.
5268 guix environment --preserve='^DISPLAY$' --container --network \
5269 --expose=/etc/machine-id \
5270 --expose=/etc/ssl/certs/ \
5271 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5272 --ad-hoc eolie nss-certs dbus -- eolie
5275 The available options are summarized below.
5278 @item --root=@var{file}
5279 @itemx -r @var{file}
5280 @cindex persistent environment
5281 @cindex garbage collector root, for environments
5282 Make @var{file} a symlink to the profile for this environment, and
5283 register it as a garbage collector root.
5285 This is useful if you want to protect your environment from garbage
5286 collection, to make it ``persistent''.
5288 When this option is omitted, the environment is protected from garbage
5289 collection only for the duration of the @command{guix environment}
5290 session. This means that next time you recreate the same environment,
5291 you could have to rebuild or re-download packages. @xref{Invoking guix
5292 gc}, for more on GC roots.
5294 @item --expression=@var{expr}
5295 @itemx -e @var{expr}
5296 Create an environment for the package or list of packages that
5297 @var{expr} evaluates to.
5299 For example, running:
5302 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5305 starts a shell with the environment for this specific variant of the
5311 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5314 starts a shell with all the base system packages available.
5316 The above commands only use the default output of the given packages.
5317 To select other outputs, two element tuples can be specified:
5320 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5323 @item --load=@var{file}
5324 @itemx -l @var{file}
5325 Create an environment for the package or list of packages that the code
5326 within @var{file} evaluates to.
5328 As an example, @var{file} might contain a definition like this
5329 (@pxref{Defining Packages}):
5332 @verbatiminclude environment-gdb.scm
5335 @item --manifest=@var{file}
5336 @itemx -m @var{file}
5337 Create an environment for the packages contained in the manifest object
5338 returned by the Scheme code in @var{file}. This option can be repeated
5339 several times, in which case the manifests are concatenated.
5341 This is similar to the same-named option in @command{guix package}
5342 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5346 Include all specified packages in the resulting environment, as if an
5347 @i{ad hoc} package were defined with them as inputs. This option is
5348 useful for quickly creating an environment without having to write a
5349 package expression to contain the desired inputs.
5351 For instance, the command:
5354 guix environment --ad-hoc guile guile-sdl -- guile
5357 runs @command{guile} in an environment where Guile and Guile-SDL are
5360 Note that this example implicitly asks for the default output of
5361 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5362 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5363 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5365 This option may be composed with the default behavior of @command{guix
5366 environment}. Packages appearing before @option{--ad-hoc} are
5367 interpreted as packages whose dependencies will be added to the
5368 environment, the default behavior. Packages appearing after are
5369 interpreted as packages that will be added to the environment directly.
5372 Unset existing environment variables when building the new environment, except
5373 those specified with @option{--preserve} (see below). This has the effect of
5374 creating an environment in which search paths only contain package inputs.
5376 @item --preserve=@var{regexp}
5377 @itemx -E @var{regexp}
5378 When used alongside @option{--pure}, preserve the environment variables
5379 matching @var{regexp}---in other words, put them on a ``white list'' of
5380 environment variables that must be preserved. This option can be repeated
5384 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5388 This example runs @command{mpirun} in a context where the only environment
5389 variables defined are @env{PATH}, environment variables whose name starts
5390 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5393 @item --search-paths
5394 Display the environment variable definitions that make up the
5397 @item --system=@var{system}
5398 @itemx -s @var{system}
5399 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5404 Run @var{command} within an isolated container. The current working
5405 directory outside the container is mapped inside the container.
5406 Additionally, unless overridden with @option{--user}, a dummy home
5407 directory is created that matches the current user's home directory, and
5408 @file{/etc/passwd} is configured accordingly.
5410 The spawned process runs as the current user outside the container. Inside
5411 the container, it has the same UID and GID as the current user, unless
5412 @option{--user} is passed (see below).
5416 For containers, share the network namespace with the host system.
5417 Containers created without this flag only have access to the loopback
5420 @item --link-profile
5422 For containers, link the environment profile to @file{~/.guix-profile}
5423 within the container. This is equivalent to running the command
5424 @samp{ln -s $GUIX_ENVIRONMENT ~/.guix-profile} within the container.
5425 Linking will fail and abort the environment if the directory already
5426 exists, which will certainly be the case if @command{guix environment}
5427 was invoked in the user's home directory.
5429 Certain packages are configured to look in @file{~/.guix-profile} for
5430 configuration files and data;@footnote{For example, the
5431 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5432 for additional fonts.} @option{--link-profile} allows these programs to
5433 behave as expected within the environment.
5435 @item --user=@var{user}
5436 @itemx -u @var{user}
5437 For containers, use the username @var{user} in place of the current
5438 user. The generated @file{/etc/passwd} entry within the container will
5439 contain the name @var{user}, the home directory will be
5440 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5441 the UID and GID inside the container are 1000. @var{user}
5442 need not exist on the system.
5444 Additionally, any shared or exposed path (see @option{--share} and
5445 @option{--expose} respectively) whose target is within the current user's
5446 home directory will be remapped relative to @file{/home/USER}; this
5447 includes the automatic mapping of the current working directory.
5450 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5452 guix environment --container --user=foo \
5453 --expose=$HOME/test \
5454 --expose=/tmp/target=$HOME/target
5457 While this will limit the leaking of user identity through home paths
5458 and each of the user fields, this is only one useful component of a
5459 broader privacy/anonymity solution---not one in and of itself.
5462 For containers, the default behavior is to share the current working
5463 directory with the isolated container and immediately change to that
5464 directory within the container. If this is undesirable,
5465 @option{--no-cwd} will cause the current working directory to @emph{not}
5466 be automatically shared and will change to the user's home directory
5467 within the container instead. See also @option{--user}.
5469 @item --expose=@var{source}[=@var{target}]
5470 @itemx --share=@var{source}[=@var{target}]
5471 For containers, @option{--expose} (resp. @option{--share}) exposes the
5472 file system @var{source} from the host system as the read-only
5473 (resp. writable) file system @var{target} within the container. If
5474 @var{target} is not specified, @var{source} is used as the target mount
5475 point in the container.
5477 The example below spawns a Guile REPL in a container in which the user's
5478 home directory is accessible read-only via the @file{/exchange}
5482 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5487 @command{guix environment}
5488 also supports all of the common build options that @command{guix
5489 build} supports (@pxref{Common Build Options}) as well as package
5490 transformation options (@pxref{Package Transformation Options}).
5492 @node Invoking guix pack
5493 @section Invoking @command{guix pack}
5495 Occasionally you want to pass software to people who are not (yet!)
5496 lucky enough to be using Guix. You'd tell them to run @command{guix
5497 package -i @var{something}}, but that's not possible in this case. This
5498 is where @command{guix pack} comes in.
5501 If you are looking for ways to exchange binaries among machines that
5502 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5503 publish}, and @ref{Invoking guix archive}.
5508 @cindex application bundle
5509 @cindex software bundle
5510 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5511 @dfn{software bundle}: it creates a tarball or some other archive
5512 containing the binaries of the software you're interested in, and all
5513 its dependencies. The resulting archive can be used on any machine that
5514 does not have Guix, and people can run the exact same binaries as those
5515 you have with Guix. The pack itself is created in a bit-reproducible
5516 fashion, so anyone can verify that it really contains the build results
5517 that you pretend to be shipping.
5519 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5520 their dependencies, you can run:
5523 $ guix pack guile emacs geiser
5525 /gnu/store/@dots{}-pack.tar.gz
5528 The result here is a tarball containing a @file{/gnu/store} directory
5529 with all the relevant packages. The resulting tarball contains a
5530 @dfn{profile} with the three packages of interest; the profile is the
5531 same as would be created by @command{guix package -i}. It is this
5532 mechanism that is used to create Guix's own standalone binary tarball
5533 (@pxref{Binary Installation}).
5535 Users of this pack would have to run
5536 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5537 find inconvenient. To work around it, you can create, say, a
5538 @file{/opt/gnu/bin} symlink to the profile:
5541 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5545 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5547 @cindex relocatable binaries, with @command{guix pack}
5548 What if the recipient of your pack does not have root privileges on
5549 their machine, and thus cannot unpack it in the root file system? In
5550 that case, you will want to use the @option{--relocatable} option (see
5551 below). This option produces @dfn{relocatable binaries}, meaning they
5552 they can be placed anywhere in the file system hierarchy: in the example
5553 above, users can unpack your tarball in their home directory and
5554 directly run @file{./opt/gnu/bin/guile}.
5556 @cindex Docker, build an image with guix pack
5557 Alternatively, you can produce a pack in the Docker image format using
5558 the following command:
5561 guix pack -f docker -S /bin=bin guile guile-readline
5565 The result is a tarball that can be passed to the @command{docker load}
5566 command, followed by @code{docker run}:
5569 docker load < @var{file}
5570 docker run -ti guile-guile-readline /bin/guile
5574 where @var{file} is the image returned by @var{guix pack}, and
5575 @code{guile-guile-readline} is its ``image tag''. See the
5576 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5577 documentation} for more information.
5579 @cindex Singularity, build an image with guix pack
5580 @cindex SquashFS, build an image with guix pack
5581 Yet another option is to produce a SquashFS image with the following
5585 guix pack -f squashfs bash guile emacs geiser
5589 The result is a SquashFS file system image that can either be mounted or
5590 directly be used as a file system container image with the
5591 @uref{https://www.sylabs.io/docs/, Singularity container execution
5592 environment}, using commands like @command{singularity shell} or
5593 @command{singularity exec}.
5595 Several command-line options allow you to customize your pack:
5598 @item --format=@var{format}
5599 @itemx -f @var{format}
5600 Produce a pack in the given @var{format}.
5602 The available formats are:
5606 This is the default format. It produces a tarball containing all the
5607 specified binaries and symlinks.
5610 This produces a tarball that follows the
5611 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5612 Docker Image Specification}. The ``repository name'' as it appears in
5613 the output of the @command{docker images} command is computed from
5614 package names passed on the command line or in the manifest file.
5617 This produces a SquashFS image containing all the specified binaries and
5618 symlinks, as well as empty mount points for virtual file systems like
5622 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5623 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5624 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5625 with something like:
5628 guix pack -f squashfs bash @dots{}
5631 If you forget the @code{bash} (or similar) package, @command{singularity
5632 run} and @command{singularity exec} will fail with an unhelpful ``no
5633 such file or directory'' message.
5637 @cindex relocatable binaries
5640 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5641 anywhere in the file system hierarchy and run from there.
5643 When this option is passed once, the resulting binaries require support for
5644 @dfn{user namespaces} in the kernel Linux; when passed
5645 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5646 PRoot support, can be thought of as the abbreviation of ``Really
5647 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5648 other techniques if user namespaces are unavailable, and essentially
5649 work anywhere---see below for the implications.
5651 For example, if you create a pack containing Bash with:
5654 guix pack -RR -S /mybin=bin bash
5658 ...@: you can copy that pack to a machine that lacks Guix, and from your
5659 home directory as a normal user, run:
5667 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5668 @file{/gnu/store} shows up and contains all the dependencies of
5669 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5670 altogether! That is probably the simplest way to deploy Guix-built
5671 software on a non-Guix machine.
5674 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5675 the kernel Linux, which allows unprivileged users to mount or change root.
5676 Old versions of Linux did not support it, and some GNU/Linux distributions
5679 To produce relocatable binaries that work even in the absence of user
5680 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5681 case, binaries will try user namespace support and fall back to another
5682 @dfn{execution engine} if user namespaces are not supported. The
5683 following execution engines are supported:
5687 Try user namespaces and fall back to PRoot if user namespaces are not
5688 supported (see below).
5691 Try user namespaces and fall back to Fakechroot if user namespaces are
5692 not supported (see below).
5695 Run the program through user namespaces and abort if they are not
5699 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5700 provides the necessary
5701 support for file system virtualization. It achieves that by using the
5702 @code{ptrace} system call on the running program. This approach has the
5703 advantage to work without requiring special kernel support, but it incurs
5704 run-time overhead every time a system call is made.
5707 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5708 Fakechroot} virtualizes file system accesses by intercepting calls to C
5709 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5710 on. Unlike PRoot, it incurs very little overhead. However, it does not
5711 always work: for example, some file system accesses made from within the
5712 C library are not intercepted, and file system accesses made @i{via}
5713 direct syscalls are not intercepted either, leading to erratic behavior.
5716 @vindex GUIX_EXECUTION_ENGINE
5717 When running a wrapped program, you can explicitly request one of the
5718 execution engines listed above by setting the
5719 @code{GUIX_EXECUTION_ENGINE} environment variable accordingly.
5722 @cindex entry point, for Docker images
5723 @item --entry-point=@var{command}
5724 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
5725 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
5726 support it. @var{command} must be relative to the profile contained in the
5729 The entry point specifies the command that tools like @code{docker run} or
5730 @code{singularity run} automatically start by default. For example, you can
5734 guix pack -f docker --entry-point=bin/guile guile
5737 The resulting pack can easily be loaded and @code{docker run} with no extra
5738 arguments will spawn @code{bin/guile}:
5741 docker load -i pack.tar.gz
5742 docker run @var{image-id}
5745 @item --expression=@var{expr}
5746 @itemx -e @var{expr}
5747 Consider the package @var{expr} evaluates to.
5749 This has the same purpose as the same-named option in @command{guix
5750 build} (@pxref{Additional Build Options, @option{--expression} in
5751 @command{guix build}}).
5753 @item --manifest=@var{file}
5754 @itemx -m @var{file}
5755 Use the packages contained in the manifest object returned by the Scheme
5756 code in @var{file}. This option can be repeated several times, in which
5757 case the manifests are concatenated.
5759 This has a similar purpose as the same-named option in @command{guix
5760 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
5761 same manifest files. It allows you to define a collection of packages
5762 once and use it both for creating profiles and for creating archives
5763 for use on machines that do not have Guix installed. Note that you can
5764 specify @emph{either} a manifest file @emph{or} a list of packages,
5767 @item --system=@var{system}
5768 @itemx -s @var{system}
5769 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
5770 the system type of the build host.
5772 @item --target=@var{triplet}
5773 @cindex cross-compilation
5774 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
5775 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
5776 configuration triplets,, autoconf, Autoconf}).
5778 @item --compression=@var{tool}
5779 @itemx -C @var{tool}
5780 Compress the resulting tarball using @var{tool}---one of @code{gzip},
5781 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
5784 @item --symlink=@var{spec}
5785 @itemx -S @var{spec}
5786 Add the symlinks specified by @var{spec} to the pack. This option can
5787 appear several times.
5789 @var{spec} has the form @code{@var{source}=@var{target}}, where
5790 @var{source} is the symlink that will be created and @var{target} is the
5793 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
5794 symlink pointing to the @file{bin} sub-directory of the profile.
5796 @item --save-provenance
5797 Save provenance information for the packages passed on the command line.
5798 Provenance information includes the URL and commit of the channels in use
5801 Provenance information is saved in the
5802 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
5803 usual package metadata---the name and version of each package, their
5804 propagated inputs, and so on. It is useful information to the recipient of
5805 the pack, who then knows how the pack was (supposedly) obtained.
5807 This option is not enabled by default because, like timestamps, provenance
5808 information contributes nothing to the build process. In other words, there
5809 is an infinity of channel URLs and commit IDs that can lead to the same pack.
5810 Recording such ``silent'' metadata in the output thus potentially breaks the
5811 source-to-binary bitwise reproducibility property.
5813 @item --root=@var{file}
5814 @itemx -r @var{file}
5815 @cindex garbage collector root, for packs
5816 Make @var{file} a symlink to the resulting pack, and register it as a garbage
5819 @item --localstatedir
5820 @itemx --profile-name=@var{name}
5821 Include the ``local state directory'', @file{/var/guix}, in the resulting
5822 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
5823 profile---by default @var{name} is @code{guix-profile}, which corresponds to
5824 @file{~root/.guix-profile}.
5826 @file{/var/guix} contains the store database (@pxref{The Store}) as well
5827 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
5828 the pack means that the store is ``complete'' and manageable by Guix;
5829 not providing it pack means that the store is ``dead'': items cannot be
5830 added to it or removed from it after extraction of the pack.
5832 One use case for this is the Guix self-contained binary tarball
5833 (@pxref{Binary Installation}).
5837 Print the name of the derivation that builds the pack.
5840 Use the bootstrap binaries to build the pack. This option is only
5841 useful to Guix developers.
5844 In addition, @command{guix pack} supports all the common build options
5845 (@pxref{Common Build Options}) and all the package transformation
5846 options (@pxref{Package Transformation Options}).
5849 @node The GCC toolchain
5850 @section The GCC toolchain
5854 @cindex linker wrapper
5855 @cindex toolchain, for C development
5856 @cindex toolchain, for Fortran development
5858 If you need a complete toolchain for compiling and linking C or C++
5859 source code, use the @code{gcc-toolchain} package. This package
5860 provides a complete GCC toolchain for C/C++ development, including GCC
5861 itself, the GNU C Library (headers and binaries, plus debugging symbols
5862 in the @code{debug} output), Binutils, and a linker wrapper.
5864 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
5865 passed to the linker, add corresponding @code{-rpath} arguments, and
5866 invoke the actual linker with this new set of arguments. You can instruct the
5867 wrapper to refuse to link against libraries not in the store by setting the
5868 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
5870 The package @code{gfortran-toolchain} provides a complete GCC toolchain
5871 for Fortran development. For other languages, please use
5872 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
5875 @node Invoking guix git authenticate
5876 @section Invoking @command{guix git authenticate}
5878 The @command{guix git authenticate} command authenticates a Git checkout
5879 following the same rule as for channels (@pxref{channel-authentication,
5880 channel authentication}). That is, starting from a given commit, it
5881 ensures that all subsequent commits are signed by an OpenPGP key whose
5882 fingerprint appears in the @file{.guix-authorizations} file of its
5885 You will find this command useful if you maintain a channel. But in
5886 fact, this authentication mechanism is useful in a broader context, so
5887 you might want to use it for Git repositories that have nothing to do
5890 The general syntax is:
5893 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
5896 By default, this command authenticates the Git checkout in the current
5897 directory; it outputs nothing and exits with exit code zero on success
5898 and non-zero on failure. @var{commit} above denotes the first commit
5899 where authentication takes place, and @var{signer} is the OpenPGP
5900 fingerprint of public key used to sign @var{commit}. Together, they
5901 form a ``channel introduction'' (@pxref{channel-authentication, channel
5902 introduction}). The options below allow you to fine-tune the process.
5905 @item --repository=@var{directory}
5906 @itemx -r @var{directory}
5907 Open the Git repository in @var{directory} instead of the current
5910 @item --keyring=@var{reference}
5911 @itemx -k @var{reference}
5912 Load OpenPGP keyring from @var{reference}, the reference of a branch
5913 such as @code{origin/keyring} or @code{my-keyring}. The branch must
5914 contain OpenPGP public keys in @file{.key} files, either in binary form
5915 or ``ASCII-armored''. By default the keyring is loaded from the branch
5916 named @code{keyring}.
5919 Display commit signing statistics upon completion.
5921 @item --cache-key=@var{key}
5922 Previously-authenticated commits are cached in a file under
5923 @file{~/.cache/guix/authentication}. This option forces the cache to be
5924 stored in file @var{key} in that directory.
5926 @item --historical-authorizations=@var{file}
5927 By default, any commit whose parent commit(s) lack the
5928 @file{.guix-authorizations} file is considered inauthentic. In
5929 contrast, this option considers the authorizations in @var{file} for any
5930 commit that lacks @file{.guix-authorizations}. The format of @var{file}
5931 is the same as that of @file{.guix-authorizations}
5932 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
5936 @c *********************************************************************
5937 @node Programming Interface
5938 @chapter Programming Interface
5940 GNU Guix provides several Scheme programming interfaces (APIs) to
5941 define, build, and query packages. The first interface allows users to
5942 write high-level package definitions. These definitions refer to
5943 familiar packaging concepts, such as the name and version of a package,
5944 its build system, and its dependencies. These definitions can then be
5945 turned into concrete build actions.
5947 Build actions are performed by the Guix daemon, on behalf of users. In a
5948 standard setup, the daemon has write access to the store---the
5949 @file{/gnu/store} directory---whereas users do not. The recommended
5950 setup also has the daemon perform builds in chroots, under specific
5951 build users, to minimize interference with the rest of the system.
5954 Lower-level APIs are available to interact with the daemon and the
5955 store. To instruct the daemon to perform a build action, users actually
5956 provide it with a @dfn{derivation}. A derivation is a low-level
5957 representation of the build actions to be taken, and the environment in
5958 which they should occur---derivations are to package definitions what
5959 assembly is to C programs. The term ``derivation'' comes from the fact
5960 that build results @emph{derive} from them.
5962 This chapter describes all these APIs in turn, starting from high-level
5963 package definitions.
5966 * Package Modules:: Packages from the programmer's viewpoint.
5967 * Defining Packages:: Defining new packages.
5968 * Build Systems:: Specifying how packages are built.
5969 * The Store:: Manipulating the package store.
5970 * Derivations:: Low-level interface to package derivations.
5971 * The Store Monad:: Purely functional interface to the store.
5972 * G-Expressions:: Manipulating build expressions.
5973 * Invoking guix repl:: Programming Guix in Guile
5976 @node Package Modules
5977 @section Package Modules
5979 From a programming viewpoint, the package definitions of the
5980 GNU distribution are provided by Guile modules in the @code{(gnu packages
5981 @dots{})} name space@footnote{Note that packages under the @code{(gnu
5982 packages @dots{})} module name space are not necessarily ``GNU
5983 packages''. This module naming scheme follows the usual Guile module
5984 naming convention: @code{gnu} means that these modules are distributed
5985 as part of the GNU system, and @code{packages} identifies modules that
5986 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
5987 Reference Manual}). For instance, the @code{(gnu packages emacs)}
5988 module exports a variable named @code{emacs}, which is bound to a
5989 @code{<package>} object (@pxref{Defining Packages}).
5991 The @code{(gnu packages @dots{})} module name space is
5992 automatically scanned for packages by the command-line tools. For
5993 instance, when running @code{guix install emacs}, all the @code{(gnu
5994 packages @dots{})} modules are scanned until one that exports a package
5995 object whose name is @code{emacs} is found. This package search
5996 facility is implemented in the @code{(gnu packages)} module.
5998 @cindex customization, of packages
5999 @cindex package module search path
6000 Users can store package definitions in modules with different
6001 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6002 name and module name must match. For instance, the @code{(my-packages
6003 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6004 relative to the load path specified with @option{--load-path} or
6005 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6006 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6007 these package definitions visible to the user interfaces:
6011 By adding the directory containing your package modules to the search path
6012 with the @code{-L} flag of @command{guix package} and other commands
6013 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6014 environment variable described below.
6017 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6018 pulls from it. A channel is essentially a Git repository containing package
6019 modules. @xref{Channels}, for more information on how to define and use
6023 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6025 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6026 This is a colon-separated list of directories to search for additional
6027 package modules. Directories listed in this variable take precedence
6028 over the own modules of the distribution.
6031 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6032 each package is built based solely on other packages in the
6033 distribution. The root of this dependency graph is a small set of
6034 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6035 bootstrap)} module. For more information on bootstrapping,
6036 @pxref{Bootstrapping}.
6038 @node Defining Packages
6039 @section Defining Packages
6041 The high-level interface to package definitions is implemented in the
6042 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6043 example, the package definition, or @dfn{recipe}, for the GNU Hello
6044 package looks like this:
6047 (define-module (gnu packages hello)
6048 #:use-module (guix packages)
6049 #:use-module (guix download)
6050 #:use-module (guix build-system gnu)
6051 #:use-module (guix licenses)
6052 #:use-module (gnu packages gawk))
6054 (define-public hello
6060 (uri (string-append "mirror://gnu/hello/hello-" version
6064 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6065 (build-system gnu-build-system)
6066 (arguments '(#:configure-flags '("--enable-silent-rules")))
6067 (inputs `(("gawk" ,gawk)))
6068 (synopsis "Hello, GNU world: An example GNU package")
6069 (description "Guess what GNU Hello prints!")
6070 (home-page "https://www.gnu.org/software/hello/")
6075 Without being a Scheme expert, the reader may have guessed the meaning
6076 of the various fields here. This expression binds the variable
6077 @code{hello} to a @code{<package>} object, which is essentially a record
6078 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6079 This package object can be inspected using procedures found in the
6080 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6081 returns---surprise!---@code{"hello"}.
6083 With luck, you may be able to import part or all of the definition of
6084 the package you are interested in from another repository, using the
6085 @code{guix import} command (@pxref{Invoking guix import}).
6087 In the example above, @var{hello} is defined in a module of its own,
6088 @code{(gnu packages hello)}. Technically, this is not strictly
6089 necessary, but it is convenient to do so: all the packages defined in
6090 modules under @code{(gnu packages @dots{})} are automatically known to
6091 the command-line tools (@pxref{Package Modules}).
6093 There are a few points worth noting in the above package definition:
6097 The @code{source} field of the package is an @code{<origin>} object
6098 (@pxref{origin Reference}, for the complete reference).
6099 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6100 meaning that the source is a file to be downloaded over FTP or HTTP.
6102 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6103 the GNU mirrors defined in @code{(guix download)}.
6105 The @code{sha256} field specifies the expected SHA256 hash of the file
6106 being downloaded. It is mandatory, and allows Guix to check the
6107 integrity of the file. The @code{(base32 @dots{})} form introduces the
6108 base32 representation of the hash. You can obtain this information with
6109 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6110 hash} (@pxref{Invoking guix hash}).
6113 When needed, the @code{origin} form can also have a @code{patches} field
6114 listing patches to be applied, and a @code{snippet} field giving a
6115 Scheme expression to modify the source code.
6118 @cindex GNU Build System
6119 The @code{build-system} field specifies the procedure to build the
6120 package (@pxref{Build Systems}). Here, @var{gnu-build-system}
6121 represents the familiar GNU Build System, where packages may be
6122 configured, built, and installed with the usual @code{./configure &&
6123 make && make check && make install} command sequence.
6126 The @code{arguments} field specifies options for the build system
6127 (@pxref{Build Systems}). Here it is interpreted by
6128 @var{gnu-build-system} as a request run @file{configure} with the
6129 @option{--enable-silent-rules} flag.
6135 What about these quote (@code{'}) characters? They are Scheme syntax to
6136 introduce a literal list; @code{'} is synonymous with @code{quote}.
6137 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6138 for details. Here the value of the @code{arguments} field is a list of
6139 arguments passed to the build system down the road, as with @code{apply}
6140 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6143 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6144 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6145 @code{#:configure-flags} is a keyword used to pass a keyword argument
6146 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6150 The @code{inputs} field specifies inputs to the build process---i.e.,
6151 build-time or run-time dependencies of the package. Here, we define an
6152 input called @code{"gawk"} whose value is that of the @var{gawk}
6153 variable; @var{gawk} is itself bound to a @code{<package>} object.
6155 @cindex backquote (quasiquote)
6158 @cindex comma (unquote)
6162 @findex unquote-splicing
6163 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6164 us to introduce a literal list in the @code{inputs} field, while
6165 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6166 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6169 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6170 be specified as inputs here. Instead, @var{gnu-build-system} takes care
6171 of ensuring that they are present (@pxref{Build Systems}).
6173 However, any other dependencies need to be specified in the
6174 @code{inputs} field. Any dependency not specified here will simply be
6175 unavailable to the build process, possibly leading to a build failure.
6178 @xref{package Reference}, for a full description of possible fields.
6180 Once a package definition is in place, the
6181 package may actually be built using the @code{guix build} command-line
6182 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6183 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6184 package definition using the @command{guix edit} command
6185 (@pxref{Invoking guix edit}).
6186 @xref{Packaging Guidelines}, for
6187 more information on how to test package definitions, and
6188 @ref{Invoking guix lint}, for information on how to check a definition
6189 for style conformance.
6190 @vindex GUIX_PACKAGE_PATH
6191 Lastly, @pxref{Channels}, for information
6192 on how to extend the distribution by adding your own package definitions
6195 Finally, updating the package definition to a new upstream version
6196 can be partly automated by the @command{guix refresh} command
6197 (@pxref{Invoking guix refresh}).
6199 Behind the scenes, a derivation corresponding to the @code{<package>}
6200 object is first computed by the @code{package-derivation} procedure.
6201 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6202 The build actions it prescribes may then be realized by using the
6203 @code{build-derivations} procedure (@pxref{The Store}).
6205 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6206 Return the @code{<derivation>} object of @var{package} for @var{system}
6207 (@pxref{Derivations}).
6209 @var{package} must be a valid @code{<package>} object, and @var{system}
6210 must be a string denoting the target system type---e.g.,
6211 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6212 must be a connection to the daemon, which operates on the store
6213 (@pxref{The Store}).
6217 @cindex cross-compilation
6218 Similarly, it is possible to compute a derivation that cross-builds a
6219 package for some other system:
6221 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6222 @var{package} @var{target} [@var{system}]
6223 Return the @code{<derivation>} object of @var{package} cross-built from
6224 @var{system} to @var{target}.
6226 @var{target} must be a valid GNU triplet denoting the target hardware
6227 and operating system, such as @code{"aarch64-linux-gnu"}
6228 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6231 @cindex package transformations
6232 @cindex input rewriting
6233 @cindex dependency tree rewriting
6234 Packages can be manipulated in arbitrary ways. An example of a useful
6235 transformation is @dfn{input rewriting}, whereby the dependency tree of
6236 a package is rewritten by replacing specific inputs by others:
6238 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
6239 [@var{rewrite-name}]
6240 Return a procedure that, when passed a package, replaces its direct and
6241 indirect dependencies (but not its implicit inputs) according to
6242 @var{replacements}. @var{replacements} is a list of package pairs; the
6243 first element of each pair is the package to replace, and the second one
6246 Optionally, @var{rewrite-name} is a one-argument procedure that takes
6247 the name of a package and returns its new name after rewrite.
6251 Consider this example:
6254 (define libressl-instead-of-openssl
6255 ;; This is a procedure to replace OPENSSL by LIBRESSL,
6257 (package-input-rewriting `((,openssl . ,libressl))))
6259 (define git-with-libressl
6260 (libressl-instead-of-openssl git))
6264 Here we first define a rewriting procedure that replaces @var{openssl}
6265 with @var{libressl}. Then we use it to define a @dfn{variant} of the
6266 @var{git} package that uses @var{libressl} instead of @var{openssl}.
6267 This is exactly what the @option{--with-input} command-line option does
6268 (@pxref{Package Transformation Options, @option{--with-input}}).
6270 The following variant of @code{package-input-rewriting} can match packages to
6271 be replaced by name rather than by identity.
6273 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements}
6274 Return a procedure that, given a package, applies the given @var{replacements} to
6275 all the package graph (excluding implicit inputs). @var{replacements} is a list of
6276 spec/procedures pair; each spec is a package specification such as @code{"gcc"} or
6277 @code{"guile@@2"}, and each procedure takes a matching package and returns a
6278 replacement for that package.
6281 The example above could be rewritten this way:
6284 (define libressl-instead-of-openssl
6285 ;; Replace all the packages called "openssl" with LibreSSL.
6286 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
6289 The key difference here is that, this time, packages are matched by spec and
6290 not by identity. In other words, any package in the graph that is called
6291 @code{openssl} will be replaced.
6293 A more generic procedure to rewrite a package dependency graph is
6294 @code{package-mapping}: it supports arbitrary changes to nodes in the
6297 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}]
6298 Return a procedure that, given a package, applies @var{proc} to all the packages
6299 depended on and returns the resulting package. The procedure stops recursion
6300 when @var{cut?} returns true for a given package.
6304 * package Reference:: The package data type.
6305 * origin Reference:: The origin data type.
6309 @node package Reference
6310 @subsection @code{package} Reference
6312 This section summarizes all the options available in @code{package}
6313 declarations (@pxref{Defining Packages}).
6315 @deftp {Data Type} package
6316 This is the data type representing a package recipe.
6320 The name of the package, as a string.
6322 @item @code{version}
6323 The version of the package, as a string.
6326 An object telling how the source code for the package should be
6327 acquired. Most of the time, this is an @code{origin} object, which
6328 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6329 can also be any other ``file-like'' object such as a @code{local-file},
6330 which denotes a file from the local file system (@pxref{G-Expressions,
6331 @code{local-file}}).
6333 @item @code{build-system}
6334 The build system that should be used to build the package (@pxref{Build
6337 @item @code{arguments} (default: @code{'()})
6338 The arguments that should be passed to the build system. This is a
6339 list, typically containing sequential keyword-value pairs.
6341 @item @code{inputs} (default: @code{'()})
6342 @itemx @code{native-inputs} (default: @code{'()})
6343 @itemx @code{propagated-inputs} (default: @code{'()})
6344 @cindex inputs, of packages
6345 These fields list dependencies of the package. Each one is a list of
6346 tuples, where each tuple has a label for the input (a string) as its
6347 first element, a package, origin, or derivation as its second element,
6348 and optionally the name of the output thereof that should be used, which
6349 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6350 more on package outputs). For example, the list below specifies three
6354 `(("libffi" ,libffi)
6355 ("libunistring" ,libunistring)
6356 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6359 @cindex cross compilation, package dependencies
6360 The distinction between @code{native-inputs} and @code{inputs} is
6361 necessary when considering cross-compilation. When cross-compiling,
6362 dependencies listed in @code{inputs} are built for the @emph{target}
6363 architecture; conversely, dependencies listed in @code{native-inputs}
6364 are built for the architecture of the @emph{build} machine.
6366 @code{native-inputs} is typically used to list tools needed at
6367 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6368 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6369 this area (@pxref{Invoking guix lint}).
6371 @anchor{package-propagated-inputs}
6372 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6373 specified packages will be automatically installed to profiles
6374 (@pxref{Features, the role of profiles in Guix}) alongside the package
6375 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6376 package}}, for information on how @command{guix package} deals with
6379 For example this is necessary when packaging a C/C++ library that needs
6380 headers of another library to compile, or when a pkg-config file refers
6381 to another one @i{via} its @code{Requires} field.
6383 Another example where @code{propagated-inputs} is useful is for languages
6384 that lack a facility to record the run-time search path akin to the
6385 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6386 more. When packaging libraries written in those languages, ensure they
6387 can find library code they depend on at run time by listing run-time
6388 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6390 @item @code{outputs} (default: @code{'("out")})
6391 The list of output names of the package. @xref{Packages with Multiple
6392 Outputs}, for typical uses of additional outputs.
6394 @item @code{native-search-paths} (default: @code{'()})
6395 @itemx @code{search-paths} (default: @code{'()})
6396 A list of @code{search-path-specification} objects describing
6397 search-path environment variables honored by the package.
6399 @item @code{replacement} (default: @code{#f})
6400 This must be either @code{#f} or a package object that will be used as a
6401 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6404 @item @code{synopsis}
6405 A one-line description of the package.
6407 @item @code{description}
6408 A more elaborate description of the package.
6410 @item @code{license}
6411 @cindex license, of packages
6412 The license of the package; a value from @code{(guix licenses)},
6413 or a list of such values.
6415 @item @code{home-page}
6416 The URL to the home-page of the package, as a string.
6418 @item @code{supported-systems} (default: @code{%supported-systems})
6419 The list of systems supported by the package, as strings of the form
6420 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6422 @item @code{location} (default: source location of the @code{package} form)
6423 The source location of the package. It is useful to override this when
6424 inheriting from another package, in which case this field is not
6425 automatically corrected.
6429 @deffn {Scheme Syntax} this-package
6430 When used in the @emph{lexical scope} of a package field definition, this
6431 identifier resolves to the package being defined.
6433 The example below shows how to add a package as a native input of itself when
6441 ;; When cross-compiled, Guile, for example, depends on
6442 ;; a native version of itself. Add it here.
6443 (native-inputs (if (%current-target-system)
6444 `(("self" ,this-package))
6448 It is an error to refer to @code{this-package} outside a package definition.
6451 @node origin Reference
6452 @subsection @code{origin} Reference
6454 This section summarizes all the options available in @code{origin}
6455 declarations (@pxref{Defining Packages}).
6457 @deftp {Data Type} origin
6458 This is the data type representing a source code origin.
6462 An object containing the URI of the source. The object type depends on
6463 the @code{method} (see below). For example, when using the
6464 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6465 values are: a URL represented as a string, or a list thereof.
6468 A procedure that handles the URI.
6473 @item @var{url-fetch} from @code{(guix download)}
6474 download a file from the HTTP, HTTPS, or FTP URL specified in the
6478 @item @var{git-fetch} from @code{(guix git-download)}
6479 clone the Git version control repository, and check out the revision
6480 specified in the @code{uri} field as a @code{git-reference} object; a
6481 @code{git-reference} looks like this:
6485 (url "https://git.savannah.gnu.org/git/hello.git")
6491 A bytevector containing the SHA-256 hash of the source. This is
6492 equivalent to providing a @code{content-hash} SHA256 object in the
6493 @code{hash} field described below.
6496 The @code{content-hash} object of the source---see below for how to use
6497 @code{content-hash}.
6499 You can obtain this information using @code{guix download}
6500 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6503 @item @code{file-name} (default: @code{#f})
6504 The file name under which the source code should be saved. When this is
6505 @code{#f}, a sensible default value will be used in most cases. In case
6506 the source is fetched from a URL, the file name from the URL will be
6507 used. For version control checkouts, it is recommended to provide the
6508 file name explicitly because the default is not very descriptive.
6510 @item @code{patches} (default: @code{'()})
6511 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6512 file-like objects}) pointing to patches to be applied to the source.
6514 This list of patches must be unconditional. In particular, it cannot
6515 depend on the value of @code{%current-system} or
6516 @code{%current-target-system}.
6518 @item @code{snippet} (default: @code{#f})
6519 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6520 in the source directory. This is a convenient way to modify the source,
6521 sometimes more convenient than a patch.
6523 @item @code{patch-flags} (default: @code{'("-p1")})
6524 A list of command-line flags that should be passed to the @code{patch}
6527 @item @code{patch-inputs} (default: @code{#f})
6528 Input packages or derivations to the patching process. When this is
6529 @code{#f}, the usual set of inputs necessary for patching are provided,
6530 such as GNU@tie{}Patch.
6532 @item @code{modules} (default: @code{'()})
6533 A list of Guile modules that should be loaded during the patching
6534 process and while running the code in the @code{snippet} field.
6536 @item @code{patch-guile} (default: @code{#f})
6537 The Guile package that should be used in the patching process. When
6538 this is @code{#f}, a sensible default is used.
6542 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6543 Construct a content hash object for the given @var{algorithm}, and with
6544 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6545 it is @code{sha256}.
6547 @var{value} can be a literal string, in which case it is base32-decoded,
6548 or it can be a bytevector.
6550 The following forms are all equivalent:
6553 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6554 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6556 (content-hash (base32
6557 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6558 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6562 Technically, @code{content-hash} is currently implemented as a macro.
6563 It performs sanity checks at macro-expansion time, when possible, such
6564 as ensuring that @var{value} has the right size for @var{algorithm}.
6568 @section Build Systems
6570 @cindex build system
6571 Each package definition specifies a @dfn{build system} and arguments for
6572 that build system (@pxref{Defining Packages}). This @code{build-system}
6573 field represents the build procedure of the package, as well as implicit
6574 dependencies of that build procedure.
6576 Build systems are @code{<build-system>} objects. The interface to
6577 create and manipulate them is provided by the @code{(guix build-system)}
6578 module, and actual build systems are exported by specific modules.
6580 @cindex bag (low-level package representation)
6581 Under the hood, build systems first compile package objects to
6582 @dfn{bags}. A @dfn{bag} is like a package, but with less
6583 ornamentation---in other words, a bag is a lower-level representation of
6584 a package, which includes all the inputs of that package, including some
6585 that were implicitly added by the build system. This intermediate
6586 representation is then compiled to a derivation (@pxref{Derivations}).
6588 Build systems accept an optional list of @dfn{arguments}. In package
6589 definitions, these are passed @i{via} the @code{arguments} field
6590 (@pxref{Defining Packages}). They are typically keyword arguments
6591 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
6592 Guile Reference Manual}). The value of these arguments is usually
6593 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
6594 by the daemon (@pxref{Derivations}).
6596 The main build system is @code{gnu-build-system}, which implements the
6597 standard build procedure for GNU and many other packages. It
6598 is provided by the @code{(guix build-system gnu)} module.
6600 @defvr {Scheme Variable} gnu-build-system
6601 @code{gnu-build-system} represents the GNU Build System, and variants
6602 thereof (@pxref{Configuration, configuration and makefile conventions,,
6603 standards, GNU Coding Standards}).
6605 @cindex build phases
6606 In a nutshell, packages using it are configured, built, and installed with
6607 the usual @code{./configure && make && make check && make install}
6608 command sequence. In practice, a few additional steps are often needed.
6609 All these steps are split up in separate @dfn{phases},
6610 notably@footnote{Please see the @code{(guix build gnu-build-system)}
6611 modules for more details about the build phases.}:
6615 Unpack the source tarball, and change the current directory to the
6616 extracted source tree. If the source is actually a directory, copy it
6617 to the build tree, and enter that directory.
6619 @item patch-source-shebangs
6620 Patch shebangs encountered in source files so they refer to the right
6621 store file names. For instance, this changes @code{#!/bin/sh} to
6622 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
6625 Run the @file{configure} script with a number of default options, such
6626 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
6627 by the @code{#:configure-flags} argument.
6630 Run @code{make} with the list of flags specified with
6631 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
6632 (the default), build with @code{make -j}.
6635 Run @code{make check}, or some other target specified with
6636 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
6637 @code{#:parallel-tests?} argument is true (the default), run @code{make
6641 Run @code{make install} with the flags listed in @code{#:make-flags}.
6643 @item patch-shebangs
6644 Patch shebangs on the installed executable files.
6647 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
6648 is false), copying them to the @code{debug} output when available
6649 (@pxref{Installing Debugging Files}).
6652 @vindex %standard-phases
6653 The build-side module @code{(guix build gnu-build-system)} defines
6654 @code{%standard-phases} as the default list of build phases.
6655 @code{%standard-phases} is a list of symbol/procedure pairs, where the
6656 procedure implements the actual phase.
6658 The list of phases used for a particular package can be changed with the
6659 @code{#:phases} parameter. For instance, passing:
6662 #:phases (modify-phases %standard-phases (delete 'configure))
6665 means that all the phases described above will be used, except the
6666 @code{configure} phase.
6668 In addition, this build system ensures that the ``standard'' environment
6669 for GNU packages is available. This includes tools such as GCC, libc,
6670 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
6671 build-system gnu)} module for a complete list). We call these the
6672 @dfn{implicit inputs} of a package, because package definitions do not
6673 have to mention them.
6676 Other @code{<build-system>} objects are defined to support other
6677 conventions and tools used by free software packages. They inherit most
6678 of @code{gnu-build-system}, and differ mainly in the set of inputs
6679 implicitly added to the build process, and in the list of phases
6680 executed. Some of these build systems are listed below.
6682 @defvr {Scheme Variable} ant-build-system
6683 This variable is exported by @code{(guix build-system ant)}. It
6684 implements the build procedure for Java packages that can be built with
6685 @url{https://ant.apache.org/, Ant build tool}.
6687 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
6688 provided by the @code{icedtea} package to the set of inputs. Different
6689 packages can be specified with the @code{#:ant} and @code{#:jdk}
6690 parameters, respectively.
6692 When the original package does not provide a suitable Ant build file,
6693 the parameter @code{#:jar-name} can be used to generate a minimal Ant
6694 build file @file{build.xml} with tasks to build the specified jar
6695 archive. In this case the parameter @code{#:source-dir} can be used to
6696 specify the source sub-directory, defaulting to ``src''.
6698 The @code{#:main-class} parameter can be used with the minimal ant
6699 buildfile to specify the main class of the resulting jar. This makes the
6700 jar file executable. The @code{#:test-include} parameter can be used to
6701 specify the list of junit tests to run. It defaults to
6702 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
6703 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
6704 because abstract classes cannot be run as tests.
6706 The parameter @code{#:build-target} can be used to specify the Ant task
6707 that should be run during the @code{build} phase. By default the
6708 ``jar'' task will be run.
6712 @defvr {Scheme Variable} android-ndk-build-system
6713 @cindex Android distribution
6714 @cindex Android NDK build system
6715 This variable is exported by @code{(guix build-system android-ndk)}. It
6716 implements a build procedure for Android NDK (native development kit)
6717 packages using a Guix-specific build process.
6719 The build system assumes that packages install their public interface
6720 (header) files to the subdirectory @file{include} of the @code{out} output and
6721 their libraries to the subdirectory @file{lib} the @code{out} output.
6723 It's also assumed that the union of all the dependencies of a package
6724 has no conflicting files.
6726 For the time being, cross-compilation is not supported - so right now
6727 the libraries and header files are assumed to be host tools.
6731 @defvr {Scheme Variable} asdf-build-system/source
6732 @defvrx {Scheme Variable} asdf-build-system/sbcl
6733 @defvrx {Scheme Variable} asdf-build-system/ecl
6735 These variables, exported by @code{(guix build-system asdf)}, implement
6736 build procedures for Common Lisp packages using
6737 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
6738 definition facility for Common Lisp programs and libraries.
6740 The @code{asdf-build-system/source} system installs the packages in
6741 source form, and can be loaded using any common lisp implementation, via
6742 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
6743 systems in the format which a particular implementation understands.
6744 These build systems can also be used to produce executable programs, or
6745 lisp images which contain a set of packages pre-loaded.
6747 The build system uses naming conventions. For binary packages, the
6748 package name should be prefixed with the lisp implementation, such as
6749 @code{sbcl-} for @code{asdf-build-system/sbcl}.
6751 Additionally, the corresponding source package should be labeled using
6752 the same convention as python packages (see @ref{Python Modules}), using
6753 the @code{cl-} prefix.
6755 For binary packages, each system should be defined as a Guix package.
6756 If one package @code{origin} contains several systems, package variants
6757 can be created in order to build all the systems. Source packages,
6758 which use @code{asdf-build-system/source}, may contain several systems.
6760 In order to create executable programs and images, the build-side
6761 procedures @code{build-program} and @code{build-image} can be used.
6762 They should be called in a build phase after the @code{create-symlinks}
6763 phase, so that the system which was just built can be used within the
6764 resulting image. @code{build-program} requires a list of Common Lisp
6765 expressions to be passed as the @code{#:entry-program} argument.
6767 If the system is not defined within its own @file{.asd} file of the same
6768 name, then the @code{#:asd-file} parameter should be used to specify
6769 which file the system is defined in. Furthermore, if the package
6770 defines a system for its tests in a separate file, it will be loaded
6771 before the tests are run if it is specified by the
6772 @code{#:test-asd-file} parameter. If it is not set, the files
6773 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
6774 and @code{test.asd} will be tried if they exist.
6776 If for some reason the package must be named in a different way than the
6777 naming conventions suggest, the @code{#:asd-system-name} parameter can
6778 be used to specify the name of the system.
6782 @defvr {Scheme Variable} cargo-build-system
6783 @cindex Rust programming language
6784 @cindex Cargo (Rust build system)
6785 This variable is exported by @code{(guix build-system cargo)}. It
6786 supports builds of packages using Cargo, the build tool of the
6787 @uref{https://www.rust-lang.org, Rust programming language}.
6789 It adds @code{rustc} and @code{cargo} to the set of inputs.
6790 A different Rust package can be specified with the @code{#:rust} parameter.
6792 Regular cargo dependencies should be added to the package definition via the
6793 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
6794 spec can be a package or a source definition. Note that the spec must
6795 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
6796 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
6797 should be added to the package definition via the
6798 @code{#:cargo-development-inputs} parameter.
6800 In its @code{configure} phase, this build system will make any source inputs
6801 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
6802 parameters available to cargo. It will also remove an included
6803 @code{Cargo.lock} file to be recreated by @code{cargo} during the
6804 @code{build} phase. The @code{install} phase installs any crate the binaries
6805 if they are defined by the crate.
6809 @defvr {Scheme Variable} copy-build-system
6810 This variable is exported by @code{(guix build-system copy)}. It
6811 supports builds of simple packages that don't require much compiling,
6812 mostly just moving files around.
6814 It adds much of the @code{gnu-build-system} packages to the set of
6815 inputs. Because of this, the @code{copy-build-system} does not require
6816 all the boilerplate code often needed for the
6817 @code{trivial-build-system}.
6819 To further simplify the file installation process, an
6820 @code{#:install-plan} argument is exposed to let the packager specify
6821 which files go where. The install plan is a list of @code{(@var{source}
6822 @var{target} [@var{filters}])}. @var{filters} are optional.
6825 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
6827 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
6828 @item Otherwise install @var{source} as @var{target}.
6831 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
6832 the trailing slash of @var{target} is implied with the same meaning
6835 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
6836 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
6837 @code{#:exclude-regexp}, only select files are installed depending on
6838 the filters. Each filters is specified by a list of strings.
6840 @item With @code{#:include}, install all the files which the path suffix matches
6841 at least one of the elements in the given list.
6842 @item With @code{#:include-regexp}, install all the files which the
6843 subpaths match at least one of the regular expressions in the given
6845 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
6846 are the complement of their inclusion counterpart. Without @code{#:include} flags,
6847 install all files but those matching the exclusion filters.
6848 If both inclusions and exclusions are specified, the exclusions are done
6849 on top of the inclusions.
6852 In all cases, the paths relative to @var{source} are preserved within
6859 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
6860 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
6861 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
6862 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
6863 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
6864 @file{share/my-app/sub/file}.
6865 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
6866 @file{share/my-app/file}.
6871 @cindex Clojure (programming language)
6872 @cindex simple Clojure build system
6873 @defvr {Scheme Variable} clojure-build-system
6874 This variable is exported by @code{(guix build-system clojure)}. It implements
6875 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
6876 using plain old @code{compile} in Clojure. Cross-compilation is not supported
6879 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
6880 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
6881 @code{#:zip} parameters, respectively.
6883 A list of source directories, test directories and jar names can be specified
6884 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
6885 parameters, respectively. Compile directory and main class can be specified
6886 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
6887 Other parameters are documented below.
6889 This build system is an extension of @code{ant-build-system}, but with the
6890 following phases changed:
6895 This phase calls @code{compile} in Clojure to compile source files and runs
6896 @command{jar} to create jars from both source files and compiled files
6897 according to the include list and exclude list specified in
6898 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
6899 has priority over the include list. These lists consist of symbols
6900 representing Clojure libraries or the special keyword @code{#:all} representing
6901 all Clojure libraries found under the source directories. The parameter
6902 @code{#:omit-source?} decides if source should be included into the jars.
6905 This phase runs tests according to the include list and exclude list specified
6906 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
6907 meanings are analogous to that of @code{#:aot-include} and
6908 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
6909 stands for all Clojure libraries found under the test directories. The
6910 parameter @code{#:tests?} decides if tests should be run.
6913 This phase installs all jars built previously.
6916 Apart from the above, this build system also contains an additional phase:
6921 This phase installs all top-level files with base name matching
6922 @code{%doc-regex}. A different regex can be specified with the
6923 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
6924 directories specified in @code{#:doc-dirs} are installed as well.
6928 @defvr {Scheme Variable} cmake-build-system
6929 This variable is exported by @code{(guix build-system cmake)}. It
6930 implements the build procedure for packages using the
6931 @url{https://www.cmake.org, CMake build tool}.
6933 It automatically adds the @code{cmake} package to the set of inputs.
6934 Which package is used can be specified with the @code{#:cmake}
6937 The @code{#:configure-flags} parameter is taken as a list of flags
6938 passed to the @command{cmake} command. The @code{#:build-type}
6939 parameter specifies in abstract terms the flags passed to the compiler;
6940 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
6941 debugging information''), which roughly means that code is compiled with
6942 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
6945 @defvr {Scheme Variable} dune-build-system
6946 This variable is exported by @code{(guix build-system dune)}. It
6947 supports builds of packages using @uref{https://dune.build/, Dune}, a build
6948 tool for the OCaml programming language. It is implemented as an extension
6949 of the @code{ocaml-build-system} which is described below. As such, the
6950 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
6953 It automatically adds the @code{dune} package to the set of inputs.
6954 Which package is used can be specified with the @code{#:dune}
6957 There is no @code{configure} phase because dune packages typically don't
6958 need to be configured. The @code{#:build-flags} parameter is taken as a
6959 list of flags passed to the @code{dune} command during the build.
6961 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
6962 command instead of the more recent @code{dune} command while building
6963 a package. Its default value is @code{#f}.
6965 The @code{#:package} parameter can be passed to specify a package name, which
6966 is useful when a package contains multiple packages and you want to build
6967 only one of them. This is equivalent to passing the @code{-p} argument to
6971 @defvr {Scheme Variable} go-build-system
6972 This variable is exported by @code{(guix build-system go)}. It
6973 implements a build procedure for Go packages using the standard
6974 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
6975 Go build mechanisms}.
6977 The user is expected to provide a value for the key @code{#:import-path}
6978 and, in some cases, @code{#:unpack-path}. The
6979 @url{https://golang.org/doc/code.html#ImportPaths, import path}
6980 corresponds to the file system path expected by the package's build
6981 scripts and any referring packages, and provides a unique way to
6982 refer to a Go package. It is typically based on a combination of the
6983 package source code's remote URI and file system hierarchy structure. In
6984 some cases, you will need to unpack the package's source code to a
6985 different directory structure than the one indicated by the import path,
6986 and @code{#:unpack-path} should be used in such cases.
6988 Packages that provide Go libraries should install their source code into
6989 the built output. The key @code{#:install-source?}, which defaults to
6990 @code{#t}, controls whether or not the source code is installed. It can
6991 be set to @code{#f} for packages that only provide executable files.
6994 @defvr {Scheme Variable} glib-or-gtk-build-system
6995 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
6996 is intended for use with packages making use of GLib or GTK+.
6998 This build system adds the following two phases to the ones defined by
6999 @code{gnu-build-system}:
7002 @item glib-or-gtk-wrap
7003 The phase @code{glib-or-gtk-wrap} ensures that programs in
7004 @file{bin/} are able to find GLib ``schemas'' and
7005 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7006 modules}. This is achieved by wrapping the programs in launch scripts
7007 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7008 environment variables.
7010 It is possible to exclude specific package outputs from that wrapping
7011 process by listing their names in the
7012 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7013 when an output is known not to contain any GLib or GTK+ binaries, and
7014 where wrapping would gratuitously add a dependency of that output on
7017 @item glib-or-gtk-compile-schemas
7018 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7019 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7020 GSettings schemas} of GLib are compiled. Compilation is performed by the
7021 @command{glib-compile-schemas} program. It is provided by the package
7022 @code{glib:bin} which is automatically imported by the build system.
7023 The @code{glib} package providing @command{glib-compile-schemas} can be
7024 specified with the @code{#:glib} parameter.
7027 Both phases are executed after the @code{install} phase.
7030 @defvr {Scheme Variable} guile-build-system
7031 This build system is for Guile packages that consist exclusively of Scheme
7032 code and that are so lean that they don't even have a makefile, let alone a
7033 @file{configure} script. It compiles Scheme code using @command{guild
7034 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7035 installs the @file{.scm} and @file{.go} files in the right place. It also
7036 installs documentation.
7038 This build system supports cross-compilation by using the
7039 @option{--target} option of @samp{guild compile}.
7041 Packages built with @code{guile-build-system} must provide a Guile package in
7042 their @code{native-inputs} field.
7045 @defvr {Scheme Variable} julia-build-system
7046 This variable is exported by @code{(guix build-system julia)}. It
7047 implements the build procedure used by @uref{https://julialang.org/,
7048 julia} packages, which essentially is similar to running @samp{julia -e
7049 'using Pkg; Pkg.add(package)'} in an environment where
7050 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7051 Tests are run not run.
7053 Julia packages require the source @code{file-name} to be the real name of the
7054 package, correctly capitalized.
7056 For packages requiring shared library dependencies, you may need to write the
7057 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7058 variable = /gnu/store/library.so} for each dependency, plus a void function
7059 @code{check_deps() = nothing}.
7061 Some older packages that aren't using @file{Package.toml} yet, will require
7062 this file to be created, too. The function @code{julia-create-package-toml}
7063 helps creating the file. You need to pass the outputs and the source of the
7064 package, it's name (the same as the @code{file-name} parameter), the package
7065 uuid, the package version, and a list of dependencies specified by their name
7069 @defvr {Scheme Variable} maven-build-system
7070 This variable is exported by @code{(guix build-system maven)}. It implements
7071 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7072 is a dependency and lifecycle management tool for Java. A user of Maven
7073 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7074 When Maven does not have one of the dependencies or plugins in its repository,
7075 it will download them and use them to build the package.
7077 The maven build system ensures that maven will not try to download any
7078 dependency by running in offline mode. Maven will fail if a dependency is
7079 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7080 modified to specify the version of dependencies and plugins that match the
7081 versions available in the guix build environment. Dependencies and plugins
7082 must be installed in the fake maven repository at @file{lib/m2}, and are
7083 symlinked into a proper repository before maven is run. Maven is instructed
7084 to use that repository for the build and installs built artifacts there.
7085 Changed files are copied to the @file{lib/m2} directory of the package output.
7087 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7088 or let the build system use the default @file{pom.xml} file in the sources.
7090 In case you need to specify a dependency's version manually, you can use the
7091 @code{#:local-packages} argument. It takes an association list where the key
7092 is the groupId of the package and its value is an association list where the
7093 key is the artifactId of the package and its value is the version you want to
7094 override in the @file{pom.xml}.
7096 Some packages use dependencies or plugins that are not useful at runtime nor
7097 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7098 using the @code{#:exclude} argument. Its value is an association list where
7099 the key is the groupId of the plugin or dependency you want to remove, and
7100 the value is a list of artifactId you want to remove.
7102 You can override the default @code{jdk} and @code{maven} packages with the
7103 corresponding argument, @code{#:jdk} and @code{#:maven}.
7105 The @code{#:maven-plugins} argument is a list of maven plugins used during
7106 the build, with the same format as the @code{inputs} fields of the package
7107 declaration. Its default value is @code{(default-maven-plugins)} which is
7111 @defvr {Scheme Variable} minify-build-system
7112 This variable is exported by @code{(guix build-system minify)}. It
7113 implements a minification procedure for simple JavaScript packages.
7115 It adds @code{uglify-js} to the set of inputs and uses it to compress
7116 all JavaScript files in the @file{src} directory. A different minifier
7117 package can be specified with the @code{#:uglify-js} parameter, but it
7118 is expected that the package writes the minified code to the standard
7121 When the input JavaScript files are not all located in the @file{src}
7122 directory, the parameter @code{#:javascript-files} can be used to
7123 specify a list of file names to feed to the minifier.
7126 @defvr {Scheme Variable} ocaml-build-system
7127 This variable is exported by @code{(guix build-system ocaml)}. It implements
7128 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7129 of choosing the correct set of commands to run for each package. OCaml
7130 packages can expect many different commands to be run. This build system will
7133 When the package has a @file{setup.ml} file present at the top-level, it will
7134 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7135 @code{ocaml setup.ml -install}. The build system will assume that this file
7136 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7137 care of setting the prefix and enabling tests if they are not disabled. You
7138 can pass configure and build flags with the @code{#:configure-flags} and
7139 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7140 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7141 bypass this system in the build and install phases.
7143 When the package has a @file{configure} file, it is assumed that it is a
7144 hand-made configure script that requires a different argument format than
7145 in the @code{gnu-build-system}. You can add more flags with the
7146 @code{#:configure-flags} key.
7148 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7149 @code{#t}), it will be used and more flags can be passed to the build and
7150 install phases with the @code{#:make-flags} key.
7152 Finally, some packages do not have these files and use a somewhat standard
7153 location for its build system. In that case, the build system will run
7154 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7155 providing the path to the required findlib module. Additional flags can
7156 be passed via the @code{#:build-flags} key. Install is taken care of by
7157 @command{opam-installer}. In this case, the @code{opam} package must
7158 be added to the @code{native-inputs} field of the package definition.
7160 Note that most OCaml packages assume they will be installed in the same
7161 directory as OCaml, which is not what we want in guix. In particular, they
7162 will install @file{.so} files in their module's directory, which is usually
7163 fine because it is in the OCaml compiler directory. In guix though, these
7164 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7165 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7166 @file{.so} libraries should be installed.
7169 @defvr {Scheme Variable} python-build-system
7170 This variable is exported by @code{(guix build-system python)}. It
7171 implements the more or less standard build procedure used by Python
7172 packages, which consists in running @code{python setup.py build} and
7173 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7175 For packages that install stand-alone Python programs under @code{bin/},
7176 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7177 environment variable points to all the Python libraries they depend on.
7179 Which Python package is used to perform the build can be specified with
7180 the @code{#:python} parameter. This is a useful way to force a package
7181 to be built for a specific version of the Python interpreter, which
7182 might be necessary if the package is only compatible with a single
7183 interpreter version.
7185 By default guix calls @code{setup.py} under control of
7186 @code{setuptools}, much like @command{pip} does. Some packages are not
7187 compatible with setuptools (and pip), thus you can disable this by
7188 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7191 @defvr {Scheme Variable} perl-build-system
7192 This variable is exported by @code{(guix build-system perl)}. It
7193 implements the standard build procedure for Perl packages, which either
7194 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7195 followed by @code{Build} and @code{Build install}; or in running
7196 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7197 @code{make} and @code{make install}, depending on which of
7198 @code{Build.PL} or @code{Makefile.PL} is present in the package
7199 distribution. Preference is given to the former if both @code{Build.PL}
7200 and @code{Makefile.PL} exist in the package distribution. This
7201 preference can be reversed by specifying @code{#t} for the
7202 @code{#:make-maker?} parameter.
7204 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7205 passes flags specified by the @code{#:make-maker-flags} or
7206 @code{#:module-build-flags} parameter, respectively.
7208 Which Perl package is used can be specified with @code{#:perl}.
7211 @defvr {Scheme Variable} qt-build-system
7212 This variable is exported by @code{(guix build-system qt)}. It
7213 is intended for use with applications using Qt or KDE.
7215 This build system adds the following two phases to the ones defined by
7216 @code{cmake-build-system}:
7220 The phase @code{check-setup} prepares the environment for running
7221 the checks as commonly used by Qt test programs.
7222 For now this only sets some environment variables:
7223 @code{QT_QPA_PLATFORM=offscreen},
7224 @code{DBUS_FATAL_WARNINGS=0} and
7225 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7227 This phase is added before the @code{check} phase.
7228 It's a separate phase to ease adjusting if necessary.
7231 The phase @code{qt-wrap}
7232 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7233 and output. In case some path is found, all programs in the output's
7234 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7235 are wrapped in scripts defining the necessary environment variables.
7237 It is possible to exclude specific package outputs from that wrapping process
7238 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7239 This is useful when an output is known not to contain any Qt binaries, and
7240 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7243 This phase is added after the @code{install} phase.
7247 @defvr {Scheme Variable} r-build-system
7248 This variable is exported by @code{(guix build-system r)}. It
7249 implements the build procedure used by @uref{https://r-project.org, R}
7250 packages, which essentially is little more than running @samp{R CMD
7251 INSTALL --library=/gnu/store/@dots{}} in an environment where
7252 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7253 run after installation using the R function
7254 @code{tools::testInstalledPackage}.
7257 @defvr {Scheme Variable} rakudo-build-system
7258 This variable is exported by @code{(guix build-system rakudo)}. It
7259 implements the build procedure used by @uref{https://rakudo.org/,
7260 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7261 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7262 installs the binaries, library files and the resources, as well as wrap
7263 the files under the @code{bin/} directory. Tests can be skipped by
7264 passing @code{#f} to the @code{tests?} parameter.
7266 Which rakudo package is used can be specified with @code{rakudo}.
7267 Which perl6-tap-harness package used for the tests can be specified with
7268 @code{#:prove6} or removed by passing @code{#f} to the
7269 @code{with-prove6?} parameter.
7270 Which perl6-zef package used for tests and installing can be specified
7271 with @code{#:zef} or removed by passing @code{#f} to the
7272 @code{with-zef?} parameter.
7275 @defvr {Scheme Variable} texlive-build-system
7276 This variable is exported by @code{(guix build-system texlive)}. It is
7277 used to build TeX packages in batch mode with a specified engine. The
7278 build system sets the @env{TEXINPUTS} variable to find all TeX source
7279 files in the inputs.
7281 By default it runs @code{luatex} on all files ending on @code{ins}. A
7282 different engine and format can be specified with the
7283 @code{#:tex-format} argument. Different build targets can be specified
7284 with the @code{#:build-targets} argument, which expects a list of file
7285 names. The build system adds only @code{texlive-bin} and
7286 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7287 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7288 and @code{#:texlive-latex-base}, respectively.
7290 The @code{#:tex-directory} parameter tells the build system where to
7291 install the built files under the texmf tree.
7294 @defvr {Scheme Variable} ruby-build-system
7295 This variable is exported by @code{(guix build-system ruby)}. It
7296 implements the RubyGems build procedure used by Ruby packages, which
7297 involves running @code{gem build} followed by @code{gem install}.
7299 The @code{source} field of a package that uses this build system
7300 typically references a gem archive, since this is the format that Ruby
7301 developers use when releasing their software. The build system unpacks
7302 the gem archive, potentially patches the source, runs the test suite,
7303 repackages the gem, and installs it. Additionally, directories and
7304 tarballs may be referenced to allow building unreleased gems from Git or
7305 a traditional source release tarball.
7307 Which Ruby package is used can be specified with the @code{#:ruby}
7308 parameter. A list of additional flags to be passed to the @command{gem}
7309 command can be specified with the @code{#:gem-flags} parameter.
7312 @defvr {Scheme Variable} waf-build-system
7313 This variable is exported by @code{(guix build-system waf)}. It
7314 implements a build procedure around the @code{waf} script. The common
7315 phases---@code{configure}, @code{build}, and @code{install}---are
7316 implemented by passing their names as arguments to the @code{waf}
7319 The @code{waf} script is executed by the Python interpreter. Which
7320 Python package is used to run the script can be specified with the
7321 @code{#:python} parameter.
7324 @defvr {Scheme Variable} scons-build-system
7325 This variable is exported by @code{(guix build-system scons)}. It
7326 implements the build procedure used by the SCons software construction
7327 tool. This build system runs @code{scons} to build the package,
7328 @code{scons test} to run tests, and then @code{scons install} to install
7331 Additional flags to be passed to @code{scons} can be specified with the
7332 @code{#:scons-flags} parameter. The default build and install targets
7333 can be overridden with @code{#:build-targets} and
7334 @code{#:install-targets} respectively. The version of Python used to
7335 run SCons can be specified by selecting the appropriate SCons package
7336 with the @code{#:scons} parameter.
7339 @defvr {Scheme Variable} haskell-build-system
7340 This variable is exported by @code{(guix build-system haskell)}. It
7341 implements the Cabal build procedure used by Haskell packages, which
7342 involves running @code{runhaskell Setup.hs configure
7343 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7344 Instead of installing the package by running @code{runhaskell Setup.hs
7345 install}, to avoid trying to register libraries in the read-only
7346 compiler store directory, the build system uses @code{runhaskell
7347 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7348 addition, the build system generates the package documentation by
7349 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7350 is passed. Optional Haddock parameters can be passed with the help of
7351 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7352 not found, the build system looks for @code{Setup.lhs} instead.
7354 Which Haskell compiler is used can be specified with the @code{#:haskell}
7355 parameter which defaults to @code{ghc}.
7358 @defvr {Scheme Variable} dub-build-system
7359 This variable is exported by @code{(guix build-system dub)}. It
7360 implements the Dub build procedure used by D packages, which
7361 involves running @code{dub build} and @code{dub run}.
7362 Installation is done by copying the files manually.
7364 Which D compiler is used can be specified with the @code{#:ldc}
7365 parameter which defaults to @code{ldc}.
7368 @defvr {Scheme Variable} emacs-build-system
7369 This variable is exported by @code{(guix build-system emacs)}. It
7370 implements an installation procedure similar to the packaging system
7371 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7373 It first creates the @code{@code{package}-autoloads.el} file, then it
7374 byte compiles all Emacs Lisp files. Differently from the Emacs
7375 packaging system, the Info documentation files are moved to the standard
7376 documentation directory and the @file{dir} file is deleted. The Elisp
7377 package files are installed directly under @file{share/emacs/site-lisp}.
7380 @defvr {Scheme Variable} font-build-system
7381 This variable is exported by @code{(guix build-system font)}. It
7382 implements an installation procedure for font packages where upstream
7383 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7384 need to be copied into place. It copies font files to standard
7385 locations in the output directory.
7388 @defvr {Scheme Variable} meson-build-system
7389 This variable is exported by @code{(guix build-system meson)}. It
7390 implements the build procedure for packages that use
7391 @url{https://mesonbuild.com, Meson} as their build system.
7393 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7394 of inputs, and they can be changed with the parameters @code{#:meson}
7395 and @code{#:ninja} if needed. The default Meson is
7396 @code{meson-for-build}, which is special because it doesn't clear the
7397 @code{RUNPATH} of binaries and libraries when they are installed.
7399 This build system is an extension of @code{gnu-build-system}, but with the
7400 following phases changed to some specific for Meson:
7405 The phase runs @code{meson} with the flags specified in
7406 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7407 @code{debugoptimized} unless something else is specified in
7408 @code{#:build-type}.
7411 The phase runs @code{ninja} to build the package in parallel by default, but
7412 this can be changed with @code{#:parallel-build?}.
7415 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7416 which is @code{"test"} by default.
7419 The phase runs @code{ninja install} and can not be changed.
7422 Apart from that, the build system also adds the following phases:
7427 This phase ensures that all binaries can find the libraries they need.
7428 It searches for required libraries in subdirectories of the package being
7429 built, and adds those to @code{RUNPATH} where needed. It also removes
7430 references to libraries left over from the build phase by
7431 @code{meson-for-build}, such as test dependencies, that aren't actually
7432 required for the program to run.
7434 @item glib-or-gtk-wrap
7435 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7436 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7438 @item glib-or-gtk-compile-schemas
7439 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
7440 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
7444 @defvr {Scheme Variable} linux-module-build-system
7445 @code{linux-module-build-system} allows building Linux kernel modules.
7447 @cindex build phases
7448 This build system is an extension of @code{gnu-build-system}, but with the
7449 following phases changed:
7454 This phase configures the environment so that the Linux kernel's Makefile
7455 can be used to build the external kernel module.
7458 This phase uses the Linux kernel's Makefile in order to build the external
7462 This phase uses the Linux kernel's Makefile in order to install the external
7466 It is possible and useful to specify the Linux kernel to use for building
7467 the module (in the @code{arguments} form of a package using the
7468 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
7471 @defvr {Scheme Variable} node-build-system
7472 This variable is exported by @code{(guix build-system node)}. It
7473 implements the build procedure used by @uref{https://nodejs.org,
7474 Node.js}, which implements an approximation of the @code{npm install}
7475 command, followed by an @code{npm test} command.
7477 Which Node.js package is used to interpret the @code{npm} commands can
7478 be specified with the @code{#:node} parameter which defaults to
7482 Lastly, for packages that do not need anything as sophisticated, a
7483 ``trivial'' build system is provided. It is trivial in the sense that
7484 it provides basically no support: it does not pull any implicit inputs,
7485 and does not have a notion of build phases.
7487 @defvr {Scheme Variable} trivial-build-system
7488 This variable is exported by @code{(guix build-system trivial)}.
7490 This build system requires a @code{#:builder} argument. This argument
7491 must be a Scheme expression that builds the package output(s)---as
7492 with @code{build-expression->derivation} (@pxref{Derivations,
7493 @code{build-expression->derivation}}).
7503 Conceptually, the @dfn{store} is the place where derivations that have
7504 been built successfully are stored---by default, @file{/gnu/store}.
7505 Sub-directories in the store are referred to as @dfn{store items} or
7506 sometimes @dfn{store paths}. The store has an associated database that
7507 contains information such as the store paths referred to by each store
7508 path, and the list of @emph{valid} store items---results of successful
7509 builds. This database resides in @file{@var{localstatedir}/guix/db},
7510 where @var{localstatedir} is the state directory specified @i{via}
7511 @option{--localstatedir} at configure time, usually @file{/var}.
7513 The store is @emph{always} accessed by the daemon on behalf of its clients
7514 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
7515 connect to the daemon over a Unix-domain socket, send requests to it,
7516 and read the result---these are remote procedure calls, or RPCs.
7519 Users must @emph{never} modify files under @file{/gnu/store} directly.
7520 This would lead to inconsistencies and break the immutability
7521 assumptions of Guix's functional model (@pxref{Introduction}).
7523 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
7524 how to check the integrity of the store and attempt recovery from
7525 accidental modifications.
7528 The @code{(guix store)} module provides procedures to connect to the
7529 daemon, and to perform RPCs. These are described below. By default,
7530 @code{open-connection}, and thus all the @command{guix} commands,
7531 connect to the local daemon or to the URI specified by the
7532 @env{GUIX_DAEMON_SOCKET} environment variable.
7534 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
7535 When set, the value of this variable should be a file name or a URI
7536 designating the daemon endpoint. When it is a file name, it denotes a
7537 Unix-domain socket to connect to. In addition to file names, the
7538 supported URI schemes are:
7543 These are for Unix-domain sockets.
7544 @code{file:///var/guix/daemon-socket/socket} is equivalent to
7545 @file{/var/guix/daemon-socket/socket}.
7548 @cindex daemon, remote access
7549 @cindex remote access to the daemon
7550 @cindex daemon, cluster setup
7551 @cindex clusters, daemon setup
7552 These URIs denote connections over TCP/IP, without encryption nor
7553 authentication of the remote host. The URI must specify the host name
7554 and optionally a port number (by default port 44146 is used):
7557 guix://master.guix.example.org:1234
7560 This setup is suitable on local networks, such as clusters, where only
7561 trusted nodes may connect to the build daemon at
7562 @code{master.guix.example.org}.
7564 The @option{--listen} option of @command{guix-daemon} can be used to
7565 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
7566 @option{--listen}}).
7569 @cindex SSH access to build daemons
7570 These URIs allow you to connect to a remote daemon over SSH. This
7571 feature requires Guile-SSH (@pxref{Requirements}) and a working
7572 @command{guile} binary in @env{PATH} on the destination machine. It
7573 supports public key and GSSAPI authentication. A typical URL might look
7577 ssh://charlie@@guix.example.org:22
7580 As for @command{guix copy}, the usual OpenSSH client configuration files
7581 are honored (@pxref{Invoking guix copy}).
7584 Additional URI schemes may be supported in the future.
7586 @c XXX: Remove this note when the protocol incurs fewer round trips
7587 @c and when (guix derivations) no longer relies on file system access.
7589 The ability to connect to remote build daemons is considered
7590 experimental as of @value{VERSION}. Please get in touch with us to
7591 share any problems or suggestions you may have (@pxref{Contributing}).
7595 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
7596 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
7597 @var{reserve-space?} is true, instruct it to reserve a little bit of
7598 extra space on the file system so that the garbage collector can still
7599 operate should the disk become full. Return a server object.
7601 @var{file} defaults to @code{%default-socket-path}, which is the normal
7602 location given the options that were passed to @command{configure}.
7605 @deffn {Scheme Procedure} close-connection @var{server}
7606 Close the connection to @var{server}.
7609 @defvr {Scheme Variable} current-build-output-port
7610 This variable is bound to a SRFI-39 parameter, which refers to the port
7611 where build and error logs sent by the daemon should be written.
7614 Procedures that make RPCs all take a server object as their first
7617 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
7618 @cindex invalid store items
7619 Return @code{#t} when @var{path} designates a valid store item and
7620 @code{#f} otherwise (an invalid item may exist on disk but still be
7621 invalid, for instance because it is the result of an aborted or failed
7624 A @code{&store-protocol-error} condition is raised if @var{path} is not
7625 prefixed by the store directory (@file{/gnu/store}).
7628 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
7629 Add @var{text} under file @var{name} in the store, and return its store
7630 path. @var{references} is the list of store paths referred to by the
7631 resulting store path.
7634 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
7636 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
7637 file names, or derivation/output pairs, using the specified
7638 @var{mode}---@code{(build-mode normal)} by default.
7641 Note that the @code{(guix monads)} module provides a monad as well as
7642 monadic versions of the above procedures, with the goal of making it
7643 more convenient to work with code that accesses the store (@pxref{The
7647 @i{This section is currently incomplete.}
7650 @section Derivations
7653 Low-level build actions and the environment in which they are performed
7654 are represented by @dfn{derivations}. A derivation contains the
7655 following pieces of information:
7659 The outputs of the derivation---derivations produce at least one file or
7660 directory in the store, but may produce more.
7663 @cindex build-time dependencies
7664 @cindex dependencies, build-time
7665 The inputs of the derivations---i.e., its build-time dependencies---which may
7666 be other derivations or plain files in the store (patches, build scripts,
7670 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
7673 The file name of a build script in the store, along with the arguments
7677 A list of environment variables to be defined.
7681 @cindex derivation path
7682 Derivations allow clients of the daemon to communicate build actions to
7683 the store. They exist in two forms: as an in-memory representation,
7684 both on the client- and daemon-side, and as files in the store whose
7685 name end in @file{.drv}---these files are referred to as @dfn{derivation
7686 paths}. Derivations paths can be passed to the @code{build-derivations}
7687 procedure to perform the build actions they prescribe (@pxref{The
7690 @cindex fixed-output derivations
7691 Operations such as file downloads and version-control checkouts for
7692 which the expected content hash is known in advance are modeled as
7693 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
7694 of a fixed-output derivation are independent of its inputs---e.g., a
7695 source code download produces the same result regardless of the download
7696 method and tools being used.
7699 @cindex run-time dependencies
7700 @cindex dependencies, run-time
7701 The outputs of derivations---i.e., the build results---have a set of
7702 @dfn{references}, as reported by the @code{references} RPC or the
7703 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
7704 are the set of run-time dependencies of the build results. References are a
7705 subset of the inputs of the derivation; this subset is automatically computed
7706 by the build daemon by scanning all the files in the outputs.
7708 The @code{(guix derivations)} module provides a representation of
7709 derivations as Scheme objects, along with procedures to create and
7710 otherwise manipulate derivations. The lowest-level primitive to create
7711 a derivation is the @code{derivation} procedure:
7713 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
7714 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7715 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
7716 [#:system (%current-system)] [#:references-graphs #f] @
7717 [#:allowed-references #f] [#:disallowed-references #f] @
7718 [#:leaked-env-vars #f] [#:local-build? #f] @
7719 [#:substitutable? #t] [#:properties '()]
7720 Build a derivation with the given arguments, and return the resulting
7721 @code{<derivation>} object.
7723 When @var{hash} and @var{hash-algo} are given, a
7724 @dfn{fixed-output derivation} is created---i.e., one whose result is
7725 known in advance, such as a file download. If, in addition,
7726 @var{recursive?} is true, then that fixed output may be an executable
7727 file or a directory and @var{hash} must be the hash of an archive
7728 containing this output.
7730 When @var{references-graphs} is true, it must be a list of file
7731 name/store path pairs. In that case, the reference graph of each store
7732 path is exported in the build environment in the corresponding file, in
7733 a simple text format.
7735 When @var{allowed-references} is true, it must be a list of store items
7736 or outputs that the derivation's output may refer to. Likewise,
7737 @var{disallowed-references}, if true, must be a list of things the
7738 outputs may @emph{not} refer to.
7740 When @var{leaked-env-vars} is true, it must be a list of strings
7741 denoting environment variables that are allowed to ``leak'' from the
7742 daemon's environment to the build environment. This is only applicable
7743 to fixed-output derivations---i.e., when @var{hash} is true. The main
7744 use is to allow variables such as @code{http_proxy} to be passed to
7745 derivations that download files.
7747 When @var{local-build?} is true, declare that the derivation is not a
7748 good candidate for offloading and should rather be built locally
7749 (@pxref{Daemon Offload Setup}). This is the case for small derivations
7750 where the costs of data transfers would outweigh the benefits.
7752 When @var{substitutable?} is false, declare that substitutes of the
7753 derivation's output should not be used (@pxref{Substitutes}). This is
7754 useful, for instance, when building packages that capture details of the
7755 host CPU instruction set.
7757 @var{properties} must be an association list describing ``properties'' of the
7758 derivation. It is kept as-is, uninterpreted, in the derivation.
7762 Here's an example with a shell script as its builder, assuming
7763 @var{store} is an open connection to the daemon, and @var{bash} points
7764 to a Bash executable in the store:
7767 (use-modules (guix utils)
7771 (let ((builder ; add the Bash script to the store
7772 (add-text-to-store store "my-builder.sh"
7773 "echo hello world > $out\n" '())))
7774 (derivation store "foo"
7775 bash `("-e" ,builder)
7776 #:inputs `((,bash) (,builder))
7777 #:env-vars '(("HOME" . "/homeless"))))
7778 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
7781 As can be guessed, this primitive is cumbersome to use directly. A
7782 better approach is to write build scripts in Scheme, of course! The
7783 best course of action for that is to write the build code as a
7784 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
7785 information, @pxref{G-Expressions}.
7787 Once upon a time, @code{gexp->derivation} did not exist and constructing
7788 derivations with build code written in Scheme was achieved with
7789 @code{build-expression->derivation}, documented below. This procedure
7790 is now deprecated in favor of the much nicer @code{gexp->derivation}.
7792 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
7793 @var{name} @var{exp} @
7794 [#:system (%current-system)] [#:inputs '()] @
7795 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
7796 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
7797 [#:references-graphs #f] [#:allowed-references #f] @
7798 [#:disallowed-references #f] @
7799 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
7800 Return a derivation that executes Scheme expression @var{exp} as a
7801 builder for derivation @var{name}. @var{inputs} must be a list of
7802 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
7803 @code{"out"} is assumed. @var{modules} is a list of names of Guile
7804 modules from the current search path to be copied in the store,
7805 compiled, and made available in the load path during the execution of
7806 @var{exp}---e.g., @code{((guix build utils) (guix build
7807 gnu-build-system))}.
7809 @var{exp} is evaluated in an environment where @code{%outputs} is bound
7810 to a list of output/path pairs, and where @code{%build-inputs} is bound
7811 to a list of string/output-path pairs made from @var{inputs}.
7812 Optionally, @var{env-vars} is a list of string pairs specifying the name
7813 and value of environment variables visible to the builder. The builder
7814 terminates by passing the result of @var{exp} to @code{exit}; thus, when
7815 @var{exp} returns @code{#f}, the build is considered to have failed.
7817 @var{exp} is built using @var{guile-for-build} (a derivation). When
7818 @var{guile-for-build} is omitted or is @code{#f}, the value of the
7819 @code{%guile-for-build} fluid is used instead.
7821 See the @code{derivation} procedure for the meaning of
7822 @var{references-graphs}, @var{allowed-references},
7823 @var{disallowed-references}, @var{local-build?}, and
7824 @var{substitutable?}.
7828 Here's an example of a single-output derivation that creates a directory
7829 containing one file:
7832 (let ((builder '(let ((out (assoc-ref %outputs "out")))
7833 (mkdir out) ; create /gnu/store/@dots{}-goo
7834 (call-with-output-file (string-append out "/test")
7836 (display '(hello guix) p))))))
7837 (build-expression->derivation store "goo" builder))
7839 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
7843 @node The Store Monad
7844 @section The Store Monad
7848 The procedures that operate on the store described in the previous
7849 sections all take an open connection to the build daemon as their first
7850 argument. Although the underlying model is functional, they either have
7851 side effects or depend on the current state of the store.
7853 The former is inconvenient: the connection to the build daemon has to be
7854 carried around in all those functions, making it impossible to compose
7855 functions that do not take that parameter with functions that do. The
7856 latter can be problematic: since store operations have side effects
7857 and/or depend on external state, they have to be properly sequenced.
7859 @cindex monadic values
7860 @cindex monadic functions
7861 This is where the @code{(guix monads)} module comes in. This module
7862 provides a framework for working with @dfn{monads}, and a particularly
7863 useful monad for our uses, the @dfn{store monad}. Monads are a
7864 construct that allows two things: associating ``context'' with values
7865 (in our case, the context is the store), and building sequences of
7866 computations (here computations include accesses to the store). Values
7867 in a monad---values that carry this additional context---are called
7868 @dfn{monadic values}; procedures that return such values are called
7869 @dfn{monadic procedures}.
7871 Consider this ``normal'' procedure:
7874 (define (sh-symlink store)
7875 ;; Return a derivation that symlinks the 'bash' executable.
7876 (let* ((drv (package-derivation store bash))
7877 (out (derivation->output-path drv))
7878 (sh (string-append out "/bin/bash")))
7879 (build-expression->derivation store "sh"
7880 `(symlink ,sh %output))))
7883 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
7884 as a monadic function:
7887 (define (sh-symlink)
7888 ;; Same, but return a monadic value.
7889 (mlet %store-monad ((drv (package->derivation bash)))
7890 (gexp->derivation "sh"
7891 #~(symlink (string-append #$drv "/bin/bash")
7895 There are several things to note in the second version: the @code{store}
7896 parameter is now implicit and is ``threaded'' in the calls to the
7897 @code{package->derivation} and @code{gexp->derivation} monadic
7898 procedures, and the monadic value returned by @code{package->derivation}
7899 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
7901 As it turns out, the call to @code{package->derivation} can even be
7902 omitted since it will take place implicitly, as we will see later
7903 (@pxref{G-Expressions}):
7906 (define (sh-symlink)
7907 (gexp->derivation "sh"
7908 #~(symlink (string-append #$bash "/bin/bash")
7913 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
7914 @c for the funny quote.
7915 Calling the monadic @code{sh-symlink} has no effect. As someone once
7916 said, ``you exit a monad like you exit a building on fire: by running''.
7917 So, to exit the monad and get the desired effect, one must use
7918 @code{run-with-store}:
7921 (run-with-store (open-connection) (sh-symlink))
7922 @result{} /gnu/store/...-sh-symlink
7925 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
7926 new ``meta-commands'' to make it easier to deal with monadic procedures:
7927 @code{run-in-store}, and @code{enter-store-monad}. The former is used
7928 to ``run'' a single monadic value through the store:
7931 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
7932 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7935 The latter enters a recursive REPL, where all the return values are
7936 automatically run through the store:
7939 scheme@@(guile-user)> ,enter-store-monad
7940 store-monad@@(guile-user) [1]> (package->derivation hello)
7941 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
7942 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
7943 $3 = "/gnu/store/@dots{}-foo"
7944 store-monad@@(guile-user) [1]> ,q
7945 scheme@@(guile-user)>
7949 Note that non-monadic values cannot be returned in the
7950 @code{store-monad} REPL.
7952 The main syntactic forms to deal with monads in general are provided by
7953 the @code{(guix monads)} module and are described below.
7955 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
7956 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
7960 @deffn {Scheme Syntax} return @var{val}
7961 Return a monadic value that encapsulates @var{val}.
7964 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
7965 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
7966 procedures @var{mproc}@dots{}@footnote{This operation is commonly
7967 referred to as ``bind'', but that name denotes an unrelated procedure in
7968 Guile. Thus we use this somewhat cryptic symbol inherited from the
7969 Haskell language.}. There can be one @var{mproc} or several of them, as
7974 (with-monad %state-monad
7976 (lambda (x) (return (+ 1 x)))
7977 (lambda (x) (return (* 2 x)))))
7981 @result{} some-state
7985 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
7987 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
7989 Bind the variables @var{var} to the monadic values @var{mval} in
7990 @var{body}, which is a sequence of expressions. As with the bind
7991 operator, this can be thought of as ``unpacking'' the raw, non-monadic
7992 value ``contained'' in @var{mval} and making @var{var} refer to that
7993 raw, non-monadic value within the scope of the @var{body}. The form
7994 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
7995 @var{val}, as per @code{let}. The binding operations occur in sequence
7996 from left to right. The last expression of @var{body} must be a monadic
7997 expression, and its result will become the result of the @code{mlet} or
7998 @code{mlet*} when run in the @var{monad}.
8000 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
8001 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
8004 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
8005 Bind @var{mexp} and the following monadic expressions in sequence,
8006 returning the result of the last expression. Every expression in the
8007 sequence must be a monadic expression.
8009 This is akin to @code{mlet}, except that the return values of the
8010 monadic expressions are ignored. In that sense, it is analogous to
8011 @code{begin}, but applied to monadic expressions.
8014 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
8015 When @var{condition} is true, evaluate the sequence of monadic
8016 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8017 @var{condition} is false, return @code{*unspecified*} in the current
8018 monad. Every expression in the sequence must be a monadic expression.
8021 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
8022 When @var{condition} is false, evaluate the sequence of monadic
8023 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
8024 @var{condition} is true, return @code{*unspecified*} in the current
8025 monad. Every expression in the sequence must be a monadic expression.
8029 The @code{(guix monads)} module provides the @dfn{state monad}, which
8030 allows an additional value---the state---to be @emph{threaded} through
8031 monadic procedure calls.
8033 @defvr {Scheme Variable} %state-monad
8034 The state monad. Procedures in the state monad can access and change
8035 the state that is threaded.
8037 Consider the example below. The @code{square} procedure returns a value
8038 in the state monad. It returns the square of its argument, but also
8039 increments the current state value:
8043 (mlet %state-monad ((count (current-state)))
8044 (mbegin %state-monad
8045 (set-current-state (+ 1 count))
8048 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
8053 When ``run'' through @code{%state-monad}, we obtain that additional state
8054 value, which is the number of @code{square} calls.
8057 @deffn {Monadic Procedure} current-state
8058 Return the current state as a monadic value.
8061 @deffn {Monadic Procedure} set-current-state @var{value}
8062 Set the current state to @var{value} and return the previous state as a
8066 @deffn {Monadic Procedure} state-push @var{value}
8067 Push @var{value} to the current state, which is assumed to be a list,
8068 and return the previous state as a monadic value.
8071 @deffn {Monadic Procedure} state-pop
8072 Pop a value from the current state and return it as a monadic value.
8073 The state is assumed to be a list.
8076 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
8077 Run monadic value @var{mval} starting with @var{state} as the initial
8078 state. Return two values: the resulting value, and the resulting state.
8081 The main interface to the store monad, provided by the @code{(guix
8082 store)} module, is as follows.
8084 @defvr {Scheme Variable} %store-monad
8085 The store monad---an alias for @code{%state-monad}.
8087 Values in the store monad encapsulate accesses to the store. When its
8088 effect is needed, a value of the store monad must be ``evaluated'' by
8089 passing it to the @code{run-with-store} procedure (see below).
8092 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
8093 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
8094 open store connection.
8097 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
8098 Return as a monadic value the absolute file name in the store of the file
8099 containing @var{text}, a string. @var{references} is a list of store items that the
8100 resulting text file refers to; it defaults to the empty list.
8103 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
8104 Return as a monadic value the absolute file name in the store of the file
8105 containing @var{data}, a bytevector. @var{references} is a list of store
8106 items that the resulting binary file refers to; it defaults to the empty list.
8109 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
8110 [#:recursive? #t] [#:select? (const #t)]
8111 Return the name of @var{file} once interned in the store. Use
8112 @var{name} as its store name, or the basename of @var{file} if
8113 @var{name} is omitted.
8115 When @var{recursive?} is true, the contents of @var{file} are added
8116 recursively; if @var{file} designates a flat file and @var{recursive?}
8117 is true, its contents are added, and its permission bits are kept.
8119 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8120 @var{stat})} for each directory entry, where @var{file} is the entry's
8121 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8122 entries for which @var{select?} does not return true.
8124 The example below adds a file to the store, under two different names:
8127 (run-with-store (open-connection)
8128 (mlet %store-monad ((a (interned-file "README"))
8129 (b (interned-file "README" "LEGU-MIN")))
8130 (return (list a b))))
8132 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
8137 The @code{(guix packages)} module exports the following package-related
8140 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
8141 [#:system (%current-system)] [#:target #f] @
8144 value in the absolute file name of @var{file} within the @var{output}
8145 directory of @var{package}. When @var{file} is omitted, return the name
8146 of the @var{output} directory of @var{package}. When @var{target} is
8147 true, use it as a cross-compilation target triplet.
8149 Note that this procedure does @emph{not} build @var{package}. Thus, the
8150 result might or might not designate an existing file. We recommend not
8151 using this procedure unless you know what you are doing.
8154 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
8155 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
8156 @var{target} [@var{system}]
8157 Monadic version of @code{package-derivation} and
8158 @code{package-cross-derivation} (@pxref{Defining Packages}).
8163 @section G-Expressions
8165 @cindex G-expression
8166 @cindex build code quoting
8167 So we have ``derivations'', which represent a sequence of build actions
8168 to be performed to produce an item in the store (@pxref{Derivations}).
8169 These build actions are performed when asking the daemon to actually
8170 build the derivations; they are run by the daemon in a container
8171 (@pxref{Invoking guix-daemon}).
8173 @cindex strata of code
8174 It should come as no surprise that we like to write these build actions
8175 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
8176 code@footnote{The term @dfn{stratum} in this context was coined by
8177 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
8178 Kiselyov, who has written insightful
8179 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
8180 on this topic}, refers to this kind of code generation as
8181 @dfn{staging}.}: the ``host code''---code that defines packages, talks
8182 to the daemon, etc.---and the ``build code''---code that actually
8183 performs build actions, such as making directories, invoking
8184 @command{make}, etc.
8186 To describe a derivation and its build actions, one typically needs to
8187 embed build code inside host code. It boils down to manipulating build
8188 code as data, and the homoiconicity of Scheme---code has a direct
8189 representation as data---comes in handy for that. But we need more than
8190 the normal @code{quasiquote} mechanism in Scheme to construct build
8193 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
8194 S-expressions adapted to build expressions. G-expressions, or
8195 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
8196 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
8197 @code{#$}, and @code{#$@@}), which are comparable to
8198 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
8199 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
8200 GNU Guile Reference Manual}). However, there are major differences:
8204 Gexps are meant to be written to a file and run or manipulated by other
8208 When a high-level object such as a package or derivation is unquoted
8209 inside a gexp, the result is as if its output file name had been
8213 Gexps carry information about the packages or derivations they refer to,
8214 and these dependencies are automatically added as inputs to the build
8215 processes that use them.
8218 @cindex lowering, of high-level objects in gexps
8219 This mechanism is not limited to package and derivation
8220 objects: @dfn{compilers} able to ``lower'' other high-level objects to
8221 derivations or files in the store can be defined,
8222 such that these objects can also be inserted
8223 into gexps. For example, a useful type of high-level objects that can be
8224 inserted in a gexp is ``file-like objects'', which make it easy to
8225 add files to the store and to refer to them in
8226 derivations and such (see @code{local-file} and @code{plain-file}
8229 To illustrate the idea, here is an example of a gexp:
8236 (symlink (string-append #$coreutils "/bin/ls")
8240 This gexp can be passed to @code{gexp->derivation}; we obtain a
8241 derivation that builds a directory containing exactly one symlink to
8242 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
8245 (gexp->derivation "the-thing" build-exp)
8248 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
8249 substituted to the reference to the @var{coreutils} package in the
8250 actual build code, and @var{coreutils} is automatically made an input to
8251 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
8252 output)}) is replaced by a string containing the directory name of the
8253 output of the derivation.
8255 @cindex cross compilation
8256 In a cross-compilation context, it is useful to distinguish between
8257 references to the @emph{native} build of a package---that can run on the
8258 host---versus references to cross builds of a package. To that end, the
8259 @code{#+} plays the same role as @code{#$}, but is a reference to a
8260 native package build:
8263 (gexp->derivation "vi"
8266 (mkdir (string-append #$output "/bin"))
8267 (system* (string-append #+coreutils "/bin/ln")
8269 (string-append #$emacs "/bin/emacs")
8270 (string-append #$output "/bin/vi")))
8271 #:target "aarch64-linux-gnu")
8275 In the example above, the native build of @var{coreutils} is used, so
8276 that @command{ln} can actually run on the host; but then the
8277 cross-compiled build of @var{emacs} is referenced.
8279 @cindex imported modules, for gexps
8280 @findex with-imported-modules
8281 Another gexp feature is @dfn{imported modules}: sometimes you want to be
8282 able to use certain Guile modules from the ``host environment'' in the
8283 gexp, so those modules should be imported in the ``build environment''.
8284 The @code{with-imported-modules} form allows you to express that:
8287 (let ((build (with-imported-modules '((guix build utils))
8289 (use-modules (guix build utils))
8290 (mkdir-p (string-append #$output "/bin"))))))
8291 (gexp->derivation "empty-dir"
8294 (display "success!\n")
8299 In this example, the @code{(guix build utils)} module is automatically
8300 pulled into the isolated build environment of our gexp, such that
8301 @code{(use-modules (guix build utils))} works as expected.
8303 @cindex module closure
8304 @findex source-module-closure
8305 Usually you want the @emph{closure} of the module to be imported---i.e.,
8306 the module itself and all the modules it depends on---rather than just
8307 the module; failing to do that, attempts to use the module will fail
8308 because of missing dependent modules. The @code{source-module-closure}
8309 procedure computes the closure of a module by looking at its source file
8310 headers, which comes in handy in this case:
8313 (use-modules (guix modules)) ;for 'source-module-closure'
8315 (with-imported-modules (source-module-closure
8316 '((guix build utils)
8318 (gexp->derivation "something-with-vms"
8320 (use-modules (guix build utils)
8325 @cindex extensions, for gexps
8326 @findex with-extensions
8327 In the same vein, sometimes you want to import not just pure-Scheme
8328 modules, but also ``extensions'' such as Guile bindings to C libraries
8329 or other ``full-blown'' packages. Say you need the @code{guile-json}
8330 package available on the build side, here's how you would do it:
8333 (use-modules (gnu packages guile)) ;for 'guile-json'
8335 (with-extensions (list guile-json)
8336 (gexp->derivation "something-with-json"
8338 (use-modules (json))
8342 The syntactic form to construct gexps is summarized below.
8344 @deffn {Scheme Syntax} #~@var{exp}
8345 @deffnx {Scheme Syntax} (gexp @var{exp})
8346 Return a G-expression containing @var{exp}. @var{exp} may contain one
8347 or more of the following forms:
8351 @itemx (ungexp @var{obj})
8352 Introduce a reference to @var{obj}. @var{obj} may have one of the
8353 supported types, for example a package or a
8354 derivation, in which case the @code{ungexp} form is replaced by its
8355 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
8357 If @var{obj} is a list, it is traversed and references to supported
8358 objects are substituted similarly.
8360 If @var{obj} is another gexp, its contents are inserted and its
8361 dependencies are added to those of the containing gexp.
8363 If @var{obj} is another kind of object, it is inserted as is.
8365 @item #$@var{obj}:@var{output}
8366 @itemx (ungexp @var{obj} @var{output})
8367 This is like the form above, but referring explicitly to the
8368 @var{output} of @var{obj}---this is useful when @var{obj} produces
8369 multiple outputs (@pxref{Packages with Multiple Outputs}).
8372 @itemx #+@var{obj}:output
8373 @itemx (ungexp-native @var{obj})
8374 @itemx (ungexp-native @var{obj} @var{output})
8375 Same as @code{ungexp}, but produces a reference to the @emph{native}
8376 build of @var{obj} when used in a cross compilation context.
8378 @item #$output[:@var{output}]
8379 @itemx (ungexp output [@var{output}])
8380 Insert a reference to derivation output @var{output}, or to the main
8381 output when @var{output} is omitted.
8383 This only makes sense for gexps passed to @code{gexp->derivation}.
8386 @itemx (ungexp-splicing @var{lst})
8387 Like the above, but splices the contents of @var{lst} inside the
8391 @itemx (ungexp-native-splicing @var{lst})
8392 Like the above, but refers to native builds of the objects listed in
8397 G-expressions created by @code{gexp} or @code{#~} are run-time objects
8398 of the @code{gexp?} type (see below).
8401 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
8402 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
8403 in their execution environment.
8405 Each item in @var{modules} can be the name of a module, such as
8406 @code{(guix build utils)}, or it can be a module name, followed by an
8407 arrow, followed by a file-like object:
8410 `((guix build utils)
8412 ((guix config) => ,(scheme-file "config.scm"
8413 #~(define-module @dots{}))))
8417 In the example above, the first two modules are taken from the search
8418 path, and the last one is created from the given file-like object.
8420 This form has @emph{lexical} scope: it has an effect on the gexps
8421 directly defined in @var{body}@dots{}, but not on those defined, say, in
8422 procedures called from @var{body}@dots{}.
8425 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
8426 Mark the gexps defined in @var{body}@dots{} as requiring
8427 @var{extensions} in their build and execution environment.
8428 @var{extensions} is typically a list of package objects such as those
8429 defined in the @code{(gnu packages guile)} module.
8431 Concretely, the packages listed in @var{extensions} are added to the
8432 load path while compiling imported modules in @var{body}@dots{}; they
8433 are also added to the load path of the gexp returned by
8437 @deffn {Scheme Procedure} gexp? @var{obj}
8438 Return @code{#t} if @var{obj} is a G-expression.
8441 G-expressions are meant to be written to disk, either as code building
8442 some derivation, or as plain files in the store. The monadic procedures
8443 below allow you to do that (@pxref{The Store Monad}, for more
8444 information about monads).
8446 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
8447 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
8448 [#:hash #f] [#:hash-algo #f] @
8449 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8450 [#:module-path @code{%load-path}] @
8451 [#:effective-version "2.2"] @
8452 [#:references-graphs #f] [#:allowed-references #f] @
8453 [#:disallowed-references #f] @
8454 [#:leaked-env-vars #f] @
8455 [#:script-name (string-append @var{name} "-builder")] @
8456 [#:deprecation-warnings #f] @
8457 [#:local-build? #f] [#:substitutable? #t] @
8458 [#:properties '()] [#:guile-for-build #f]
8459 Return a derivation @var{name} that runs @var{exp} (a gexp) with
8460 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
8461 stored in a file called @var{script-name}. When @var{target} is true,
8462 it is used as the cross-compilation target triplet for packages referred
8465 @var{modules} is deprecated in favor of @code{with-imported-modules}.
8467 make @var{modules} available in the evaluation context of @var{exp};
8468 @var{modules} is a list of names of Guile modules searched in
8469 @var{module-path} to be copied in the store, compiled, and made available in
8470 the load path during the execution of @var{exp}---e.g., @code{((guix
8471 build utils) (guix build gnu-build-system))}.
8473 @var{effective-version} determines the string to use when adding extensions of
8474 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
8476 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
8479 When @var{references-graphs} is true, it must be a list of tuples of one of the
8483 (@var{file-name} @var{package})
8484 (@var{file-name} @var{package} @var{output})
8485 (@var{file-name} @var{derivation})
8486 (@var{file-name} @var{derivation} @var{output})
8487 (@var{file-name} @var{store-item})
8490 The right-hand-side of each element of @var{references-graphs} is automatically made
8491 an input of the build process of @var{exp}. In the build environment, each
8492 @var{file-name} contains the reference graph of the corresponding item, in a simple
8495 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
8496 In the latter case, the list denotes store items that the result is allowed to
8497 refer to. Any reference to another store item will lead to a build error.
8498 Similarly for @var{disallowed-references}, which can list items that must not be
8499 referenced by the outputs.
8501 @var{deprecation-warnings} determines whether to show deprecation warnings while
8502 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
8504 The other arguments are as for @code{derivation} (@pxref{Derivations}).
8507 @cindex file-like objects
8508 The @code{local-file}, @code{plain-file}, @code{computed-file},
8509 @code{program-file}, and @code{scheme-file} procedures below return
8510 @dfn{file-like objects}. That is, when unquoted in a G-expression,
8511 these objects lead to a file in the store. Consider this G-expression:
8514 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
8515 #$(local-file "/tmp/my-nscd.conf"))
8518 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
8519 to the store. Once expanded, for instance @i{via}
8520 @code{gexp->derivation}, the G-expression refers to that copy under
8521 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
8522 does not have any effect on what the G-expression does.
8523 @code{plain-file} can be used similarly; it differs in that the file
8524 content is directly passed as a string.
8526 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
8527 [#:recursive? #f] [#:select? (const #t)]
8528 Return an object representing local file @var{file} to add to the store;
8529 this object can be used in a gexp. If @var{file} is a literal string
8530 denoting a relative file name, it is looked up relative to the source
8531 file where it appears; if @var{file} is not a literal string, it is
8532 looked up relative to the current working directory at run time.
8533 @var{file} will be added to the store under @var{name}--by default the
8534 base name of @var{file}.
8536 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
8537 designates a flat file and @var{recursive?} is true, its contents are added, and its
8538 permission bits are kept.
8540 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
8541 @var{stat})} for each directory entry, where @var{file} is the entry's
8542 absolute file name and @var{stat} is the result of @code{lstat}; exclude
8543 entries for which @var{select?} does not return true.
8545 This is the declarative counterpart of the @code{interned-file} monadic
8546 procedure (@pxref{The Store Monad, @code{interned-file}}).
8549 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
8550 Return an object representing a text file called @var{name} with the given
8551 @var{content} (a string or a bytevector) to be added to the store.
8553 This is the declarative counterpart of @code{text-file}.
8556 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
8559 Return an object representing the store item @var{name}, a file or
8560 directory computed by @var{gexp}. When @var{local-build?} is true (the
8561 default), the derivation is built locally. @var{options} is a list of
8562 additional arguments to pass to @code{gexp->derivation}.
8564 This is the declarative counterpart of @code{gexp->derivation}.
8567 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
8568 [#:guile (default-guile)] [#:module-path %load-path] @
8569 [#:system (%current-system)] [#:target #f]
8570 Return an executable script @var{name} that runs @var{exp} using
8571 @var{guile}, with @var{exp}'s imported modules in its search path.
8572 Look up @var{exp}'s modules in @var{module-path}.
8574 The example below builds a script that simply invokes the @command{ls}
8578 (use-modules (guix gexp) (gnu packages base))
8580 (gexp->script "list-files"
8581 #~(execl #$(file-append coreutils "/bin/ls")
8585 When ``running'' it through the store (@pxref{The Store Monad,
8586 @code{run-with-store}}), we obtain a derivation that produces an
8587 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
8590 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
8592 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
8596 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
8597 [#:guile #f] [#:module-path %load-path]
8598 Return an object representing the executable store item @var{name} that
8599 runs @var{gexp}. @var{guile} is the Guile package used to execute that
8600 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
8602 This is the declarative counterpart of @code{gexp->script}.
8605 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
8606 [#:set-load-path? #t] [#:module-path %load-path] @
8608 [#:guile (default-guile)]
8609 Return a derivation that builds a file @var{name} containing @var{exp}.
8610 When @var{splice?} is true, @var{exp} is considered to be a list of
8611 expressions that will be spliced in the resulting file.
8613 When @var{set-load-path?} is true, emit code in the resulting file to
8614 set @code{%load-path} and @code{%load-compiled-path} to honor
8615 @var{exp}'s imported modules. Look up @var{exp}'s modules in
8618 The resulting file holds references to all the dependencies of @var{exp}
8619 or a subset thereof.
8622 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
8623 [#:splice? #f] [#:set-load-path? #t]
8624 Return an object representing the Scheme file @var{name} that contains
8627 This is the declarative counterpart of @code{gexp->file}.
8630 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
8631 Return as a monadic value a derivation that builds a text file
8632 containing all of @var{text}. @var{text} may list, in addition to
8633 strings, objects of any type that can be used in a gexp: packages,
8634 derivations, local file objects, etc. The resulting store file holds
8635 references to all these.
8637 This variant should be preferred over @code{text-file} anytime the file
8638 to create will reference items from the store. This is typically the
8639 case when building a configuration file that embeds store file names,
8643 (define (profile.sh)
8644 ;; Return the name of a shell script in the store that
8645 ;; initializes the 'PATH' environment variable.
8646 (text-file* "profile.sh"
8647 "export PATH=" coreutils "/bin:"
8648 grep "/bin:" sed "/bin\n"))
8651 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
8652 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
8653 preventing them from being garbage-collected during its lifetime.
8656 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
8657 Return an object representing store file @var{name} containing
8658 @var{text}. @var{text} is a sequence of strings and file-like objects,
8662 (mixed-text-file "profile"
8663 "export PATH=" coreutils "/bin:" grep "/bin")
8666 This is the declarative counterpart of @code{text-file*}.
8669 @deffn {Scheme Procedure} file-union @var{name} @var{files}
8670 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
8671 Each item in @var{files} must be a two-element list where the first element is the
8672 file name to use in the new directory, and the second element is a gexp
8673 denoting the target file. Here's an example:
8677 `(("hosts" ,(plain-file "hosts"
8678 "127.0.0.1 localhost"))
8679 ("bashrc" ,(plain-file "bashrc"
8680 "alias ls='ls --color=auto'"))))
8683 This yields an @code{etc} directory containing these two files.
8686 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
8687 Return a directory that is the union of @var{things}, where @var{things} is a list of
8688 file-like objects denoting directories. For example:
8691 (directory-union "guile+emacs" (list guile emacs))
8694 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
8697 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
8698 Return a file-like object that expands to the concatenation of @var{obj}
8699 and @var{suffix}, where @var{obj} is a lowerable object and each
8700 @var{suffix} is a string.
8702 As an example, consider this gexp:
8705 (gexp->script "run-uname"
8706 #~(system* #$(file-append coreutils
8710 The same effect could be achieved with:
8713 (gexp->script "run-uname"
8714 #~(system* (string-append #$coreutils
8718 There is one difference though: in the @code{file-append} case, the
8719 resulting script contains the absolute file name as a string, whereas in
8720 the second case, the resulting script contains a @code{(string-append
8721 @dots{})} expression to construct the file name @emph{at run time}.
8724 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
8725 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
8726 Bind @var{system} to the currently targeted system---e.g.,
8727 @code{"x86_64-linux"}---within @var{body}.
8729 In the second case, additionally bind @var{target} to the current
8730 cross-compilation target---a GNU triplet such as
8731 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
8734 @code{let-system} is useful in the occasional case where the object
8735 spliced into the gexp depends on the target system, as in this example:
8739 #+(let-system system
8740 (cond ((string-prefix? "armhf-" system)
8741 (file-append qemu "/bin/qemu-system-arm"))
8742 ((string-prefix? "x86_64-" system)
8743 (file-append qemu "/bin/qemu-system-x86_64"))
8746 "-net" "user" #$image)
8750 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
8751 This macro is similar to the @code{parameterize} form for
8752 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
8753 Guile Reference Manual}). The key difference is that it takes effect
8754 when the file-like object returned by @var{exp} is lowered to a
8755 derivation or store item.
8757 A typical use of @code{with-parameters} is to force the system in effect
8761 (with-parameters ((%current-system "i686-linux"))
8765 The example above returns an object that corresponds to the i686 build
8766 of Coreutils, regardless of the current value of @code{%current-system}.
8770 Of course, in addition to gexps embedded in ``host'' code, there are
8771 also modules containing build tools. To make it clear that they are
8772 meant to be used in the build stratum, these modules are kept in the
8773 @code{(guix build @dots{})} name space.
8775 @cindex lowering, of high-level objects in gexps
8776 Internally, high-level objects are @dfn{lowered}, using their compiler,
8777 to either derivations or store items. For instance, lowering a package
8778 yields a derivation, and lowering a @code{plain-file} yields a store
8779 item. This is achieved using the @code{lower-object} monadic procedure.
8781 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
8783 Return as a value in @code{%store-monad} the derivation or store item
8784 corresponding to @var{obj} for @var{system}, cross-compiling for
8785 @var{target} if @var{target} is true. @var{obj} must be an object that
8786 has an associated gexp compiler, such as a @code{<package>}.
8789 @node Invoking guix repl
8790 @section Invoking @command{guix repl}
8792 @cindex REPL, read-eval-print loop, script
8793 The @command{guix repl} command makes it easier to program Guix in Guile
8794 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
8795 programming (@pxref{Using Guile Interactively,,, guile,
8796 GNU Guile Reference Manual}), or by running Guile scripts
8797 (@pxref{Running Guile Scripts,,, guile,
8798 GNU Guile Reference Manual}).
8799 Compared to just launching the @command{guile}
8800 command, @command{guix repl} guarantees that all the Guix modules and all its
8801 dependencies are available in the search path.
8803 The general syntax is:
8806 guix repl @var{options} [@var{file} @var{args}]
8809 When a @var{file} argument is provided, @var{file} is
8810 executed as a Guile scripts:
8813 guix repl my-script.scm
8816 To pass arguments to the script, use @code{--} to prevent them from
8817 being interpreted as arguments to @command{guix repl} itself:
8820 guix repl -- my-script.scm --input=foo.txt
8823 To make a script executable directly from the shell, using the guix
8824 executable that is on the user's search path, add the following two
8825 lines at the top of the script:
8828 @code{#!/usr/bin/env -S guix repl --}
8832 Without a file name argument, a Guile REPL is started:
8836 scheme@@(guile-user)> ,use (gnu packages base)
8837 scheme@@(guile-user)> coreutils
8838 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
8842 In addition, @command{guix repl} implements a simple machine-readable REPL
8843 protocol for use by @code{(guix inferior)}, a facility to interact with
8844 @dfn{inferiors}, separate processes running a potentially different revision
8847 The available options are as follows:
8850 @item --type=@var{type}
8851 @itemx -t @var{type}
8852 Start a REPL of the given @var{TYPE}, which can be one of the following:
8856 This is default, and it spawns a standard full-featured Guile REPL.
8858 Spawn a REPL that uses the machine-readable protocol. This is the protocol
8859 that the @code{(guix inferior)} module speaks.
8862 @item --listen=@var{endpoint}
8863 By default, @command{guix repl} reads from standard input and writes to
8864 standard output. When this option is passed, it will instead listen for
8865 connections on @var{endpoint}. Here are examples of valid options:
8868 @item --listen=tcp:37146
8869 Accept connections on localhost on port 37146.
8871 @item --listen=unix:/tmp/socket
8872 Accept connections on the Unix-domain socket @file{/tmp/socket}.
8875 @item --load-path=@var{directory}
8876 @itemx -L @var{directory}
8877 Add @var{directory} to the front of the package module search path
8878 (@pxref{Package Modules}).
8880 This allows users to define their own packages and make them visible to
8884 Inhibit loading of the @file{~/.guile} file. By default, that
8885 configuration file is loaded when spawning a @code{guile} REPL.
8888 @c *********************************************************************
8892 This section describes Guix command-line utilities. Some of them are
8893 primarily targeted at developers and users who write new package
8894 definitions, while others are more generally useful. They complement
8895 the Scheme programming interface of Guix in a convenient way.
8898 * Invoking guix build:: Building packages from the command line.
8899 * Invoking guix edit:: Editing package definitions.
8900 * Invoking guix download:: Downloading a file and printing its hash.
8901 * Invoking guix hash:: Computing the cryptographic hash of a file.
8902 * Invoking guix import:: Importing package definitions.
8903 * Invoking guix refresh:: Updating package definitions.
8904 * Invoking guix lint:: Finding errors in package definitions.
8905 * Invoking guix size:: Profiling disk usage.
8906 * Invoking guix graph:: Visualizing the graph of packages.
8907 * Invoking guix publish:: Sharing substitutes.
8908 * Invoking guix challenge:: Challenging substitute servers.
8909 * Invoking guix copy:: Copying to and from a remote store.
8910 * Invoking guix container:: Process isolation.
8911 * Invoking guix weather:: Assessing substitute availability.
8912 * Invoking guix processes:: Listing client processes.
8915 @node Invoking guix build
8916 @section Invoking @command{guix build}
8918 @cindex package building
8919 @cindex @command{guix build}
8920 The @command{guix build} command builds packages or derivations and
8921 their dependencies, and prints the resulting store paths. Note that it
8922 does not modify the user's profile---this is the job of the
8923 @command{guix package} command (@pxref{Invoking guix package}). Thus,
8924 it is mainly useful for distribution developers.
8926 The general syntax is:
8929 guix build @var{options} @var{package-or-derivation}@dots{}
8932 As an example, the following command builds the latest versions of Emacs
8933 and of Guile, displays their build logs, and finally displays the
8934 resulting directories:
8937 guix build emacs guile
8940 Similarly, the following command builds all the available packages:
8943 guix build --quiet --keep-going \
8944 `guix package -A | cut -f1,2 --output-delimiter=@@`
8947 @var{package-or-derivation} may be either the name of a package found in
8948 the software distribution such as @code{coreutils} or
8949 @code{coreutils@@8.20}, or a derivation such as
8950 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
8951 package with the corresponding name (and optionally version) is searched
8952 for among the GNU distribution modules (@pxref{Package Modules}).
8954 Alternatively, the @option{--expression} option may be used to specify a
8955 Scheme expression that evaluates to a package; this is useful when
8956 disambiguating among several same-named packages or package variants is
8959 There may be zero or more @var{options}. The available options are
8960 described in the subsections below.
8963 * Common Build Options:: Build options for most commands.
8964 * Package Transformation Options:: Creating variants of packages.
8965 * Additional Build Options:: Options specific to 'guix build'.
8966 * Debugging Build Failures:: Real life packaging experience.
8969 @node Common Build Options
8970 @subsection Common Build Options
8972 A number of options that control the build process are common to
8973 @command{guix build} and other commands that can spawn builds, such as
8974 @command{guix package} or @command{guix archive}. These are the
8979 @item --load-path=@var{directory}
8980 @itemx -L @var{directory}
8981 Add @var{directory} to the front of the package module search path
8982 (@pxref{Package Modules}).
8984 This allows users to define their own packages and make them visible to
8985 the command-line tools.
8989 Keep the build tree of failed builds. Thus, if a build fails, its build
8990 tree is kept under @file{/tmp}, in a directory whose name is shown at
8991 the end of the build log. This is useful when debugging build issues.
8992 @xref{Debugging Build Failures}, for tips and tricks on how to debug
8995 This option implies @option{--no-offload}, and it has no effect when
8996 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
8997 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
9001 Keep going when some of the derivations fail to build; return only once
9002 all the builds have either completed or failed.
9004 The default behavior is to stop as soon as one of the specified
9005 derivations has failed.
9009 Do not build the derivations.
9011 @anchor{fallback-option}
9013 When substituting a pre-built binary fails, fall back to building
9014 packages locally (@pxref{Substitution Failure}).
9016 @item --substitute-urls=@var{urls}
9017 @anchor{client-substitute-urls}
9018 Consider @var{urls} the whitespace-separated list of substitute source
9019 URLs, overriding the default list of URLs of @command{guix-daemon}
9020 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
9022 This means that substitutes may be downloaded from @var{urls}, provided
9023 they are signed by a key authorized by the system administrator
9024 (@pxref{Substitutes}).
9026 When @var{urls} is the empty string, substitutes are effectively
9029 @item --no-substitutes
9030 Do not use substitutes for build products. That is, always build things
9031 locally instead of allowing downloads of pre-built binaries
9032 (@pxref{Substitutes}).
9035 Do not ``graft'' packages. In practice, this means that package updates
9036 available as grafts are not applied. @xref{Security Updates}, for more
9037 information on grafts.
9039 @item --rounds=@var{n}
9040 Build each derivation @var{n} times in a row, and raise an error if
9041 consecutive build results are not bit-for-bit identical.
9043 This is a useful way to detect non-deterministic builds processes.
9044 Non-deterministic build processes are a problem because they make it
9045 practically impossible for users to @emph{verify} whether third-party
9046 binaries are genuine. @xref{Invoking guix challenge}, for more.
9048 Note that, currently, the differing build results are not kept around,
9049 so you will have to manually investigate in case of an error---e.g., by
9050 stashing one of the build results with @code{guix archive --export}
9051 (@pxref{Invoking guix archive}), then rebuilding, and finally comparing
9055 Do not use offload builds to other machines (@pxref{Daemon Offload
9056 Setup}). That is, always build things locally instead of offloading
9057 builds to remote machines.
9059 @item --max-silent-time=@var{seconds}
9060 When the build or substitution process remains silent for more than
9061 @var{seconds}, terminate it and report a build failure.
9063 By default, the daemon's setting is honored (@pxref{Invoking
9064 guix-daemon, @option{--max-silent-time}}).
9066 @item --timeout=@var{seconds}
9067 Likewise, when the build or substitution process lasts for more than
9068 @var{seconds}, terminate it and report a build failure.
9070 By default, the daemon's setting is honored (@pxref{Invoking
9071 guix-daemon, @option{--timeout}}).
9073 @c Note: This option is actually not part of %standard-build-options but
9074 @c most programs honor it.
9075 @cindex verbosity, of the command-line tools
9076 @cindex build logs, verbosity
9077 @item -v @var{level}
9078 @itemx --verbosity=@var{level}
9079 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
9080 output is produced, 1 is for quiet output, and 2 shows all the build log
9081 output on standard error.
9083 @item --cores=@var{n}
9085 Allow the use of up to @var{n} CPU cores for the build. The special
9086 value @code{0} means to use as many CPU cores as available.
9088 @item --max-jobs=@var{n}
9090 Allow at most @var{n} build jobs in parallel. @xref{Invoking
9091 guix-daemon, @option{--max-jobs}}, for details about this option and the
9092 equivalent @command{guix-daemon} option.
9094 @item --debug=@var{level}
9095 Produce debugging output coming from the build daemon. @var{level} must be an
9096 integer between 0 and 5; higher means more verbose output. Setting a level of
9097 4 or more may be helpful when debugging setup issues with the build daemon.
9101 Behind the scenes, @command{guix build} is essentially an interface to
9102 the @code{package-derivation} procedure of the @code{(guix packages)}
9103 module, and to the @code{build-derivations} procedure of the @code{(guix
9104 derivations)} module.
9106 In addition to options explicitly passed on the command line,
9107 @command{guix build} and other @command{guix} commands that support
9108 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
9110 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
9111 Users can define this variable to a list of command line options that
9112 will automatically be used by @command{guix build} and other
9113 @command{guix} commands that can perform builds, as in the example
9117 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
9120 These options are parsed independently, and the result is appended to
9121 the parsed command-line options.
9125 @node Package Transformation Options
9126 @subsection Package Transformation Options
9128 @cindex package variants
9129 Another set of command-line options supported by @command{guix build}
9130 and also @command{guix package} are @dfn{package transformation
9131 options}. These are options that make it possible to define @dfn{package
9132 variants}---for instance, packages built from different source code.
9133 This is a convenient way to create customized packages on the fly
9134 without having to type in the definitions of package variants
9135 (@pxref{Defining Packages}).
9139 @item --with-source=@var{source}
9140 @itemx --with-source=@var{package}=@var{source}
9141 @itemx --with-source=@var{package}@@@var{version}=@var{source}
9142 Use @var{source} as the source of @var{package}, and @var{version} as
9144 @var{source} must be a file name or a URL, as for @command{guix
9145 download} (@pxref{Invoking guix download}).
9147 When @var{package} is omitted,
9148 it is taken to be the package name specified on the
9149 command line that matches the base of @var{source}---e.g.,
9150 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
9151 package is @code{guile}.
9153 Likewise, when @var{version} is omitted, the version string is inferred from
9154 @var{source}; in the previous example, it is @code{2.0.10}.
9156 This option allows users to try out versions of packages other than the
9157 one provided by the distribution. The example below downloads
9158 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
9159 the @code{ed} package:
9162 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
9165 As a developer, @option{--with-source} makes it easy to test release
9169 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
9172 @dots{} or to build from a checkout in a pristine environment:
9175 $ git clone git://git.sv.gnu.org/guix.git
9176 $ guix build guix --with-source=guix@@1.0=./guix
9179 @item --with-input=@var{package}=@var{replacement}
9180 Replace dependency on @var{package} by a dependency on
9181 @var{replacement}. @var{package} must be a package name, and
9182 @var{replacement} must be a package specification such as @code{guile}
9183 or @code{guile@@1.8}.
9185 For instance, the following command builds Guix, but replaces its
9186 dependency on the current stable version of Guile with a dependency on
9187 the legacy version of Guile, @code{guile@@2.0}:
9190 guix build --with-input=guile=guile@@2.0 guix
9193 This is a recursive, deep replacement. So in this example, both
9194 @code{guix} and its dependency @code{guile-json} (which also depends on
9195 @code{guile}) get rebuilt against @code{guile@@2.0}.
9197 This is implemented using the @code{package-input-rewriting} Scheme
9198 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
9200 @item --with-graft=@var{package}=@var{replacement}
9201 This is similar to @option{--with-input} but with an important difference:
9202 instead of rebuilding the whole dependency chain, @var{replacement} is
9203 built and then @dfn{grafted} onto the binaries that were initially
9204 referring to @var{package}. @xref{Security Updates}, for more
9205 information on grafts.
9207 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
9208 and all its dependencies, replacing references to the version of GnuTLS
9209 they currently refer to:
9212 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
9215 This has the advantage of being much faster than rebuilding everything.
9216 But there is a caveat: it works if and only if @var{package} and
9217 @var{replacement} are strictly compatible---for example, if they provide
9218 a library, the application binary interface (ABI) of those libraries
9219 must be compatible. If @var{replacement} is somehow incompatible with
9220 @var{package}, then the resulting package may be unusable. Use with
9223 @item --with-git-url=@var{package}=@var{url}
9224 @cindex Git, using the latest commit
9225 @cindex latest commit, building
9226 Build @var{package} from the latest commit of the @code{master} branch of the
9227 Git repository at @var{url}. Git sub-modules of the repository are fetched,
9230 For example, the following command builds the NumPy Python library against the
9231 latest commit of the master branch of Python itself:
9234 guix build python-numpy \
9235 --with-git-url=python=https://github.com/python/cpython
9238 This option can also be combined with @option{--with-branch} or
9239 @option{--with-commit} (see below).
9241 @cindex continuous integration
9242 Obviously, since it uses the latest commit of the given branch, the result of
9243 such a command varies over time. Nevertheless it is a convenient way to
9244 rebuild entire software stacks against the latest commit of one or more
9245 packages. This is particularly useful in the context of continuous
9248 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
9249 consecutive accesses to the same repository. You may want to clean it up once
9250 in a while to save disk space.
9252 @item --with-branch=@var{package}=@var{branch}
9253 Build @var{package} from the latest commit of @var{branch}. If the
9254 @code{source} field of @var{package} is an origin with the @code{git-fetch}
9255 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
9256 repository URL is taken from that @code{source}. Otherwise you have to use
9257 @option{--with-git-url} to specify the URL of the Git repository.
9259 For instance, the following command builds @code{guile-sqlite3} from the
9260 latest commit of its @code{master} branch, and then builds @code{guix} (which
9261 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
9262 specific @code{guile-sqlite3} build:
9265 guix build --with-branch=guile-sqlite3=master cuirass
9268 @item --with-commit=@var{package}=@var{commit}
9269 This is similar to @option{--with-branch}, except that it builds from
9270 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
9271 Git commit SHA1 identifier or a tag.
9274 @node Additional Build Options
9275 @subsection Additional Build Options
9277 The command-line options presented below are specific to @command{guix
9284 Build quietly, without displaying the build log; this is equivalent to
9285 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
9286 (or similar) and can always be retrieved using the @option{--log-file} option.
9288 @item --file=@var{file}
9289 @itemx -f @var{file}
9290 Build the package, derivation, or other file-like object that the code within
9291 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
9293 As an example, @var{file} might contain a package definition like this
9294 (@pxref{Defining Packages}):
9297 @include package-hello.scm
9300 The @var{file} may also contain a JSON representation of one or more
9301 package definitions. Running @code{guix build -f} on @file{hello.json}
9302 with the following contents would result in building the packages
9303 @code{myhello} and @code{greeter}:
9306 @verbatiminclude package-hello.json
9309 @item --manifest=@var{manifest}
9310 @itemx -m @var{manifest}
9311 Build all packages listed in the given @var{manifest}
9312 (@pxref{profile-manifest, @option{--manifest}}).
9314 @item --expression=@var{expr}
9315 @itemx -e @var{expr}
9316 Build the package or derivation @var{expr} evaluates to.
9318 For example, @var{expr} may be @code{(@@ (gnu packages guile)
9319 guile-1.8)}, which unambiguously designates this specific variant of
9320 version 1.8 of Guile.
9322 Alternatively, @var{expr} may be a G-expression, in which case it is used
9323 as a build program passed to @code{gexp->derivation}
9324 (@pxref{G-Expressions}).
9326 Lastly, @var{expr} may refer to a zero-argument monadic procedure
9327 (@pxref{The Store Monad}). The procedure must return a derivation as a
9328 monadic value, which is then passed through @code{run-with-store}.
9332 Build the source derivations of the packages, rather than the packages
9335 For instance, @code{guix build -S gcc} returns something like
9336 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
9339 The returned source tarball is the result of applying any patches and
9340 code snippets specified in the package @code{origin} (@pxref{Defining
9343 Note that @command{guix build -S} compiles the sources only of the
9344 specified packages. They do not include the sources of statically
9345 linked dependencies and by themselves are insufficient for reproducing
9349 Fetch and return the source of @var{package-or-derivation} and all their
9350 dependencies, recursively. This is a handy way to obtain a local copy
9351 of all the source code needed to build @var{packages}, allowing you to
9352 eventually build them even without network access. It is an extension
9353 of the @option{--source} option and can accept one of the following
9354 optional argument values:
9358 This value causes the @option{--sources} option to behave in the same way
9359 as the @option{--source} option.
9362 Build the source derivations of all packages, including any source that
9363 might be listed as @code{inputs}. This is the default value.
9366 $ guix build --sources tzdata
9367 The following derivations will be built:
9368 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
9369 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9373 Build the source derivations of all packages, as well of all transitive
9374 inputs to the packages. This can be used e.g.@: to
9375 prefetch package source for later offline building.
9378 $ guix build --sources=transitive tzdata
9379 The following derivations will be built:
9380 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
9381 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
9382 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
9383 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
9384 /gnu/store/@dots{}-make-4.1.tar.xz.drv
9385 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
9391 @item --system=@var{system}
9392 @itemx -s @var{system}
9393 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
9394 the system type of the build host. The @command{guix build} command allows
9395 you to repeat this option several times, in which case it builds for all the
9396 specified systems; other commands ignore extraneous @option{-s} options.
9399 The @option{--system} flag is for @emph{native} compilation and must not
9400 be confused with cross-compilation. See @option{--target} below for
9401 information on cross-compilation.
9404 An example use of this is on Linux-based systems, which can emulate
9405 different personalities. For instance, passing
9406 @option{--system=i686-linux} on an @code{x86_64-linux} system or
9407 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
9408 you to build packages in a complete 32-bit environment.
9411 Building for an @code{armhf-linux} system is unconditionally enabled on
9412 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
9413 allow for this functionality, notably the ThunderX.
9416 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
9417 is enabled (@pxref{Virtualization Services,
9418 @code{qemu-binfmt-service-type}}), you can build for any system for
9419 which a QEMU @code{binfmt_misc} handler is installed.
9421 Builds for a system other than that of the machine you are using can
9422 also be offloaded to a remote machine of the right architecture.
9423 @xref{Daemon Offload Setup}, for more information on offloading.
9425 @item --target=@var{triplet}
9426 @cindex cross-compilation
9427 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
9428 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
9429 configuration triplets,, autoconf, Autoconf}).
9431 @anchor{build-check}
9433 @cindex determinism, checking
9434 @cindex reproducibility, checking
9435 Rebuild @var{package-or-derivation}, which are already available in the
9436 store, and raise an error if the build results are not bit-for-bit
9439 This mechanism allows you to check whether previously installed
9440 substitutes are genuine (@pxref{Substitutes}), or whether the build result
9441 of a package is deterministic. @xref{Invoking guix challenge}, for more
9442 background information and tools.
9444 When used in conjunction with @option{--keep-failed}, the differing
9445 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
9446 This makes it easy to look for differences between the two results.
9449 @cindex repairing store items
9450 @cindex corruption, recovering from
9451 Attempt to repair the specified store items, if they are corrupt, by
9452 re-downloading or rebuilding them.
9454 This operation is not atomic and thus restricted to @code{root}.
9458 Return the derivation paths, not the output paths, of the given
9461 @item --root=@var{file}
9462 @itemx -r @var{file}
9463 @cindex GC roots, adding
9464 @cindex garbage collector roots, adding
9465 Make @var{file} a symlink to the result, and register it as a garbage
9468 Consequently, the results of this @command{guix build} invocation are
9469 protected from garbage collection until @var{file} is removed. When
9470 that option is omitted, build results are eligible for garbage
9471 collection as soon as the build completes. @xref{Invoking guix gc}, for
9475 @cindex build logs, access
9476 Return the build log file names or URLs for the given
9477 @var{package-or-derivation}, or raise an error if build logs are
9480 This works regardless of how packages or derivations are specified. For
9481 instance, the following invocations are equivalent:
9484 guix build --log-file `guix build -d guile`
9485 guix build --log-file `guix build guile`
9486 guix build --log-file guile
9487 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
9490 If a log is unavailable locally, and unless @option{--no-substitutes} is
9491 passed, the command looks for a corresponding log on one of the
9492 substitute servers (as specified with @option{--substitute-urls}).
9494 So for instance, imagine you want to see the build log of GDB on MIPS,
9495 but you are actually on an @code{x86_64} machine:
9498 $ guix build --log-file gdb -s aarch64-linux
9499 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
9502 You can freely access a huge library of build logs!
9505 @node Debugging Build Failures
9506 @subsection Debugging Build Failures
9508 @cindex build failures, debugging
9509 When defining a new package (@pxref{Defining Packages}), you will
9510 probably find yourself spending some time debugging and tweaking the
9511 build until it succeeds. To do that, you need to operate the build
9512 commands yourself in an environment as close as possible to the one the
9515 To that end, the first thing to do is to use the @option{--keep-failed}
9516 or @option{-K} option of @command{guix build}, which will keep the
9517 failed build tree in @file{/tmp} or whatever directory you specified as
9518 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
9520 From there on, you can @command{cd} to the failed build tree and source
9521 the @file{environment-variables} file, which contains all the
9522 environment variable definitions that were in place when the build
9523 failed. So let's say you're debugging a build failure in package
9524 @code{foo}; a typical session would look like this:
9528 @dots{} @i{build fails}
9529 $ cd /tmp/guix-build-foo.drv-0
9530 $ source ./environment-variables
9534 Now, you can invoke commands as if you were the daemon (almost) and
9535 troubleshoot your build process.
9537 Sometimes it happens that, for example, a package's tests pass when you
9538 run them manually but they fail when the daemon runs them. This can
9539 happen because the daemon runs builds in containers where, unlike in our
9540 environment above, network access is missing, @file{/bin/sh} does not
9541 exist, etc. (@pxref{Build Environment Setup}).
9543 In such cases, you may need to run inspect the build process from within
9544 a container similar to the one the build daemon creates:
9549 $ cd /tmp/guix-build-foo.drv-0
9550 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
9551 [env]# source ./environment-variables
9555 Here, @command{guix environment -C} creates a container and spawns a new
9556 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
9557 strace gdb} part adds the @command{strace} and @command{gdb} commands to
9558 the container, which you may find handy while debugging. The
9559 @option{--no-grafts} option makes sure we get the exact same
9560 environment, with ungrafted packages (@pxref{Security Updates}, for more
9563 To get closer to a container like that used by the build daemon, we can
9564 remove @file{/bin/sh}:
9570 (Don't worry, this is harmless: this is all happening in the throw-away
9571 container created by @command{guix environment}.)
9573 The @command{strace} command is probably not in the search path, but we
9577 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
9580 In this way, not only you will have reproduced the environment variables
9581 the daemon uses, you will also be running the build process in a container
9582 similar to the one the daemon uses.
9585 @node Invoking guix edit
9586 @section Invoking @command{guix edit}
9588 @cindex @command{guix edit}
9589 @cindex package definition, editing
9590 So many packages, so many source files! The @command{guix edit} command
9591 facilitates the life of users and packagers by pointing their editor at
9592 the source file containing the definition of the specified packages.
9596 guix edit gcc@@4.9 vim
9600 launches the program specified in the @env{VISUAL} or in the
9601 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
9604 If you are using a Guix Git checkout (@pxref{Building from Git}), or
9605 have created your own packages on @env{GUIX_PACKAGE_PATH}
9606 (@pxref{Package Modules}), you will be able to edit the package
9607 recipes. In other cases, you will be able to examine the read-only recipes
9608 for packages currently in the store.
9610 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
9611 @option{--load-path=@var{directory}} (or in short @option{-L
9612 @var{directory}}) allows you to add @var{directory} to the front of the
9613 package module search path and so make your own packages visible.
9615 @node Invoking guix download
9616 @section Invoking @command{guix download}
9618 @cindex @command{guix download}
9619 @cindex downloading package sources
9620 When writing a package definition, developers typically need to download
9621 a source tarball, compute its SHA256 hash, and write that
9622 hash in the package definition (@pxref{Defining Packages}). The
9623 @command{guix download} tool helps with this task: it downloads a file
9624 from the given URI, adds it to the store, and prints both its file name
9625 in the store and its SHA256 hash.
9627 The fact that the downloaded file is added to the store saves bandwidth:
9628 when the developer eventually tries to build the newly defined package
9629 with @command{guix build}, the source tarball will not have to be
9630 downloaded again because it is already in the store. It is also a
9631 convenient way to temporarily stash files, which may be deleted
9632 eventually (@pxref{Invoking guix gc}).
9634 The @command{guix download} command supports the same URIs as used in
9635 package definitions. In particular, it supports @code{mirror://} URIs.
9636 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
9637 Guile bindings for GnuTLS are available in the user's environment; when
9638 they are not available, an error is raised. @xref{Guile Preparations,
9639 how to install the GnuTLS bindings for Guile,, gnutls-guile,
9640 GnuTLS-Guile}, for more information.
9642 @command{guix download} verifies HTTPS server certificates by loading
9643 the certificates of X.509 authorities from the directory pointed to by
9644 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
9645 Certificates}), unless @option{--no-check-certificate} is used.
9647 The following options are available:
9650 @item --hash=@var{algorithm}
9651 @itemx -H @var{algorithm}
9652 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
9653 hash}, for more information.
9655 @item --format=@var{fmt}
9657 Write the hash in the format specified by @var{fmt}. For more
9658 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
9660 @item --no-check-certificate
9661 Do not validate the X.509 certificates of HTTPS servers.
9663 When using this option, you have @emph{absolutely no guarantee} that you
9664 are communicating with the authentic server responsible for the given
9665 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
9667 @item --output=@var{file}
9668 @itemx -o @var{file}
9669 Save the downloaded file to @var{file} instead of adding it to the
9673 @node Invoking guix hash
9674 @section Invoking @command{guix hash}
9676 @cindex @command{guix hash}
9677 The @command{guix hash} command computes the hash of a file.
9678 It is primarily a convenience tool for anyone contributing to the
9679 distribution: it computes the cryptographic hash of a file, which can be
9680 used in the definition of a package (@pxref{Defining Packages}).
9682 The general syntax is:
9685 guix hash @var{option} @var{file}
9688 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
9689 hash of data read from standard input. @command{guix hash} has the
9694 @item --hash=@var{algorithm}
9695 @itemx -H @var{algorithm}
9696 Compute a hash using the specified @var{algorithm}, @code{sha256} by
9699 @var{algorithm} must the name of a cryptographic hash algorithm
9700 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
9701 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
9704 @item --format=@var{fmt}
9706 Write the hash in the format specified by @var{fmt}.
9708 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
9709 (@code{hex} and @code{hexadecimal} can be used as well).
9711 If the @option{--format} option is not specified, @command{guix hash}
9712 will output the hash in @code{nix-base32}. This representation is used
9713 in the definitions of packages.
9717 Compute the hash on @var{file} recursively.
9719 In this case, the hash is computed on an archive containing @var{file},
9720 including its children if it is a directory. Some of the metadata of
9721 @var{file} is part of the archive; for instance, when @var{file} is a
9722 regular file, the hash is different depending on whether @var{file} is
9723 executable or not. Metadata such as time stamps has no impact on the
9724 hash (@pxref{Invoking guix archive}).
9725 @c FIXME: Replace xref above with xref to an ``Archive'' section when
9730 When combined with @option{--recursive}, exclude version control system
9731 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
9734 As an example, here is how you would compute the hash of a Git checkout,
9735 which is useful when using the @code{git-fetch} method (@pxref{origin
9739 $ git clone http://example.org/foo.git
9745 @node Invoking guix import
9746 @section Invoking @command{guix import}
9748 @cindex importing packages
9749 @cindex package import
9750 @cindex package conversion
9751 @cindex Invoking @command{guix import}
9752 The @command{guix import} command is useful for people who would like to
9753 add a package to the distribution with as little work as
9754 possible---a legitimate demand. The command knows of a few
9755 repositories from which it can ``import'' package metadata. The result
9756 is a package definition, or a template thereof, in the format we know
9757 (@pxref{Defining Packages}).
9759 The general syntax is:
9762 guix import @var{importer} @var{options}@dots{}
9765 @var{importer} specifies the source from which to import package
9766 metadata, and @var{options} specifies a package identifier and other
9767 options specific to @var{importer}.
9769 Some of the importers rely on the ability to run the @command{gpgv} command.
9770 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
9773 Currently, the available ``importers'' are:
9777 Import metadata for the given GNU package. This provides a template
9778 for the latest version of that GNU package, including the hash of its
9779 source tarball, and its canonical synopsis and description.
9781 Additional information such as the package dependencies and its
9782 license needs to be figured out manually.
9784 For example, the following command returns a package definition for
9788 guix import gnu hello
9791 Specific command-line options are:
9794 @item --key-download=@var{policy}
9795 As for @command{guix refresh}, specify the policy to handle missing
9796 OpenPGP keys when verifying the package signature. @xref{Invoking guix
9797 refresh, @option{--key-download}}.
9802 Import metadata from the @uref{https://pypi.python.org/, Python Package
9803 Index}. Information is taken from the JSON-formatted description
9804 available at @code{pypi.python.org} and usually includes all the relevant
9805 information, including package dependencies. For maximum efficiency, it
9806 is recommended to install the @command{unzip} utility, so that the
9807 importer can unzip Python wheels and gather data from them.
9809 The command below imports metadata for the @code{itsdangerous} Python
9813 guix import pypi itsdangerous
9819 Traverse the dependency graph of the given upstream package recursively
9820 and generate package expressions for all those packages that are not yet
9826 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
9827 is taken from the JSON-formatted description available at
9828 @code{rubygems.org} and includes most relevant information, including
9829 runtime dependencies. There are some caveats, however. The metadata
9830 doesn't distinguish between synopses and descriptions, so the same string
9831 is used for both fields. Additionally, the details of non-Ruby
9832 dependencies required to build native extensions is unavailable and left
9833 as an exercise to the packager.
9835 The command below imports metadata for the @code{rails} Ruby package:
9838 guix import gem rails
9844 Traverse the dependency graph of the given upstream package recursively
9845 and generate package expressions for all those packages that are not yet
9851 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
9852 Information is taken from the JSON-formatted metadata provided through
9853 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
9854 relevant information, such as module dependencies. License information
9855 should be checked closely. If Perl is available in the store, then the
9856 @code{corelist} utility will be used to filter core modules out of the
9857 list of dependencies.
9859 The command command below imports metadata for the Acme::Boolean Perl
9863 guix import cpan Acme::Boolean
9868 @cindex Bioconductor
9869 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
9870 central repository for the @uref{https://r-project.org, GNU@tie{}R
9871 statistical and graphical environment}.
9873 Information is extracted from the @file{DESCRIPTION} file of the package.
9875 The command command below imports metadata for the Cairo R package:
9878 guix import cran Cairo
9881 When @option{--recursive} is added, the importer will traverse the
9882 dependency graph of the given upstream package recursively and generate
9883 package expressions for all those packages that are not yet in Guix.
9885 When @option{--archive=bioconductor} is added, metadata is imported from
9886 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
9887 packages for for the analysis and comprehension of high-throughput
9888 genomic data in bioinformatics.
9890 Information is extracted from the @file{DESCRIPTION} file contained in the
9893 The command below imports metadata for the GenomicRanges R package:
9896 guix import cran --archive=bioconductor GenomicRanges
9899 Finally, you can also import R packages that have not yet been published on
9900 CRAN or Bioconductor as long as they are in a git repository. Use
9901 @option{--archive=git} followed by the URL of the git repository:
9904 guix import cran --archive=git https://github.com/immunogenomics/harmony
9910 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
9911 comprehensive TeX archive network for TeX packages that are part of the
9912 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
9914 Information about the package is obtained through the XML API provided
9915 by CTAN, while the source code is downloaded from the SVN repository of
9916 the Tex Live project. This is done because the CTAN does not keep
9919 The command command below imports metadata for the @code{fontspec}
9923 guix import texlive fontspec
9926 When @option{--archive=@var{directory}} is added, the source code is
9927 downloaded not from the @file{latex} sub-directory of the
9928 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
9929 the specified sibling @var{directory} under the same root.
9931 The command below imports metadata for the @code{ifxetex} package from
9932 CTAN while fetching the sources from the directory
9933 @file{texmf/source/generic}:
9936 guix import texlive --archive=generic ifxetex
9940 @cindex JSON, import
9941 Import package metadata from a local JSON file. Consider the following
9942 example package definition in JSON format:
9948 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
9949 "build-system": "gnu",
9950 "home-page": "https://www.gnu.org/software/hello/",
9951 "synopsis": "Hello, GNU world: An example GNU package",
9952 "description": "GNU Hello prints a greeting.",
9953 "license": "GPL-3.0+",
9954 "native-inputs": ["gettext"]
9958 The field names are the same as for the @code{<package>} record
9959 (@xref{Defining Packages}). References to other packages are provided
9960 as JSON lists of quoted package specification strings such as
9961 @code{guile} or @code{guile@@2.0}.
9963 The importer also supports a more explicit source definition using the
9964 common fields for @code{<origin>} records:
9970 "method": "url-fetch",
9971 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
9973 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
9980 The command below reads metadata from the JSON file @code{hello.json}
9981 and outputs a package expression:
9984 guix import json hello.json
9988 Import metadata from a local copy of the source of the
9989 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
9990 relies on the @command{nix-instantiate} command of
9991 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
9992 typically written in a mixture of Nix-language and Bash code. This
9993 command only imports the high-level package structure that is written in
9994 the Nix language. It normally includes all the basic fields of a
9997 When importing a GNU package, the synopsis and descriptions are replaced
9998 by their canonical upstream variant.
10000 Usually, you will first need to do:
10003 export NIX_REMOTE=daemon
10007 so that @command{nix-instantiate} does not try to open the Nix database.
10009 As an example, the command below imports the package definition of
10010 LibreOffice (more precisely, it imports the definition of the package
10011 bound to the @code{libreoffice} top-level attribute):
10014 guix import nix ~/path/to/nixpkgs libreoffice
10019 Import metadata from the Haskell community's central package archive
10020 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
10021 Cabal files and includes all the relevant information, including package
10024 Specific command-line options are:
10029 Read a Cabal file from standard input.
10030 @item --no-test-dependencies
10032 Do not include dependencies required only by the test suites.
10033 @item --cabal-environment=@var{alist}
10034 @itemx -e @var{alist}
10035 @var{alist} is a Scheme alist defining the environment in which the
10036 Cabal conditionals are evaluated. The accepted keys are: @code{os},
10037 @code{arch}, @code{impl} and a string representing the name of a flag.
10038 The value associated with a flag has to be either the symbol
10039 @code{true} or @code{false}. The value associated with other keys
10040 has to conform to the Cabal file format definition. The default value
10041 associated with the keys @code{os}, @code{arch} and @code{impl} is
10042 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
10045 Traverse the dependency graph of the given upstream package recursively
10046 and generate package expressions for all those packages that are not yet
10050 The command below imports metadata for the latest version of the
10051 HTTP Haskell package without including test dependencies and
10052 specifying the value of the flag @samp{network-uri} as @code{false}:
10055 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
10058 A specific package version may optionally be specified by following the
10059 package name by an at-sign and a version number as in the following example:
10062 guix import hackage mtl@@2.1.3.1
10067 The @code{stackage} importer is a wrapper around the @code{hackage} one.
10068 It takes a package name, looks up the package version included in a
10069 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
10070 release and uses the @code{hackage} importer to retrieve its metadata.
10071 Note that it is up to you to select an LTS release compatible with the
10072 GHC compiler used by Guix.
10074 Specific command-line options are:
10077 @item --no-test-dependencies
10079 Do not include dependencies required only by the test suites.
10080 @item --lts-version=@var{version}
10081 @itemx -l @var{version}
10082 @var{version} is the desired LTS release version. If omitted the latest
10086 Traverse the dependency graph of the given upstream package recursively
10087 and generate package expressions for all those packages that are not yet
10091 The command below imports metadata for the HTTP Haskell package
10092 included in the LTS Stackage release version 7.18:
10095 guix import stackage --lts-version=7.18 HTTP
10100 Import metadata from an Emacs Lisp Package Archive (ELPA) package
10101 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
10103 Specific command-line options are:
10106 @item --archive=@var{repo}
10107 @itemx -a @var{repo}
10108 @var{repo} identifies the archive repository from which to retrieve the
10109 information. Currently the supported repositories and their identifiers
10113 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
10114 identifier. This is the default.
10116 Packages from @code{elpa.gnu.org} are signed with one of the keys
10117 contained in the GnuPG keyring at
10118 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
10119 @code{emacs} package (@pxref{Package Installation, ELPA package
10120 signatures,, emacs, The GNU Emacs Manual}).
10123 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
10124 @code{melpa-stable} identifier.
10127 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
10133 Traverse the dependency graph of the given upstream package recursively
10134 and generate package expressions for all those packages that are not yet
10140 Import metadata from the crates.io Rust package repository
10141 @uref{https://crates.io, crates.io}, as in this example:
10144 guix import crate blake2-rfc
10147 The crate importer also allows you to specify a version string:
10150 guix import crate constant-time-eq@@0.1.0
10153 Additional options include:
10158 Traverse the dependency graph of the given upstream package recursively
10159 and generate package expressions for all those packages that are not yet
10166 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
10167 repository used by the OCaml community.
10170 The structure of the @command{guix import} code is modular. It would be
10171 useful to have more importers for other package formats, and your help
10172 is welcome here (@pxref{Contributing}).
10174 @node Invoking guix refresh
10175 @section Invoking @command{guix refresh}
10177 @cindex @command {guix refresh}
10178 The primary audience of the @command{guix refresh} command is developers
10179 of the GNU software distribution. By default, it reports any packages
10180 provided by the distribution that are outdated compared to the latest
10181 upstream version, like this:
10185 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
10186 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
10189 Alternatively, one can specify packages to consider, in which case a
10190 warning is emitted for packages that lack an updater:
10193 $ guix refresh coreutils guile guile-ssh
10194 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
10195 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
10198 @command{guix refresh} browses the upstream repository of each package and determines
10199 the highest version number of the releases therein. The command
10200 knows how to update specific types of packages: GNU packages, ELPA
10201 packages, etc.---see the documentation for @option{--type} below. There
10202 are many packages, though, for which it lacks a method to determine
10203 whether a new upstream release is available. However, the mechanism is
10204 extensible, so feel free to get in touch with us to add a new method!
10209 Consider the packages specified, and all the packages upon which they depend.
10212 $ guix refresh --recursive coreutils
10213 gnu/packages/acl.scm:35:2: warning: no updater for acl
10214 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
10215 gnu/packages/xml.scm:68:2: warning: no updater for expat
10216 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
10222 Sometimes the upstream name differs from the package name used in Guix,
10223 and @command{guix refresh} needs a little help. Most updaters honor the
10224 @code{upstream-name} property in package definitions, which can be used
10228 (define-public network-manager
10230 (name "network-manager")
10232 (properties '((upstream-name . "NetworkManager")))))
10235 When passed @option{--update}, it modifies distribution source files to
10236 update the version numbers and source tarball hashes of those package
10237 recipes (@pxref{Defining Packages}). This is achieved by downloading
10238 each package's latest source tarball and its associated OpenPGP
10239 signature, authenticating the downloaded tarball against its signature
10240 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
10241 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
10244 key used to sign the tarball is missing from the user's keyring, an
10245 attempt is made to automatically retrieve it from a public key server;
10246 when this is successful, the key is added to the user's keyring; otherwise,
10247 @command{guix refresh} reports an error.
10249 The following options are supported:
10253 @item --expression=@var{expr}
10254 @itemx -e @var{expr}
10255 Consider the package @var{expr} evaluates to.
10257 This is useful to precisely refer to a package, as in this example:
10260 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
10263 This command lists the dependents of the ``final'' libc (essentially all
10268 Update distribution source files (package recipes) in place. This is
10269 usually run from a checkout of the Guix source tree (@pxref{Running
10270 Guix Before It Is Installed}):
10273 $ ./pre-inst-env guix refresh -s non-core -u
10276 @xref{Defining Packages}, for more information on package definitions.
10278 @item --select=[@var{subset}]
10279 @itemx -s @var{subset}
10280 Select all the packages in @var{subset}, one of @code{core} or
10283 The @code{core} subset refers to all the packages at the core of the
10284 distribution---i.e., packages that are used to build ``everything
10285 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
10286 changing one of these packages in the distribution entails a rebuild of
10287 all the others. Thus, such updates are an inconvenience to users in
10288 terms of build time or bandwidth used to achieve the upgrade.
10290 The @code{non-core} subset refers to the remaining packages. It is
10291 typically useful in cases where an update of the core packages would be
10294 @item --manifest=@var{file}
10295 @itemx -m @var{file}
10296 Select all the packages from the manifest in @var{file}. This is useful to
10297 check if any packages of the user manifest can be updated.
10299 @item --type=@var{updater}
10300 @itemx -t @var{updater}
10301 Select only packages handled by @var{updater} (may be a comma-separated
10302 list of updaters). Currently, @var{updater} may be one of:
10306 the updater for GNU packages;
10308 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
10310 the updater for GNOME packages;
10312 the updater for KDE packages;
10314 the updater for X.org packages;
10316 the updater for packages hosted on kernel.org;
10318 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
10320 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
10322 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
10324 the updater for @uref{https://www.cpan.org/, CPAN} packages;
10326 the updater for @uref{https://pypi.python.org, PyPI} packages.
10328 the updater for @uref{https://rubygems.org, RubyGems} packages.
10330 the updater for @uref{https://github.com, GitHub} packages.
10332 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
10334 the updater for @uref{https://www.stackage.org, Stackage} packages.
10336 the updater for @uref{https://crates.io, Crates} packages.
10338 the updater for @uref{https://launchpad.net, Launchpad} packages.
10341 For instance, the following command only checks for updates of Emacs
10342 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
10345 $ guix refresh --type=elpa,cran
10346 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
10347 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
10352 In addition, @command{guix refresh} can be passed one or more package
10353 names, as in this example:
10356 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
10360 The command above specifically updates the @code{emacs} and
10361 @code{idutils} packages. The @option{--select} option would have no
10362 effect in this case.
10364 When considering whether to upgrade a package, it is sometimes
10365 convenient to know which packages would be affected by the upgrade and
10366 should be checked for compatibility. For this the following option may
10367 be used when passing @command{guix refresh} one or more package names:
10371 @item --list-updaters
10373 List available updaters and exit (see @option{--type} above).
10375 For each updater, display the fraction of packages it covers; at the
10376 end, display the fraction of packages covered by all these updaters.
10378 @item --list-dependent
10380 List top-level dependent packages that would need to be rebuilt as a
10381 result of upgrading one or more packages.
10383 @xref{Invoking guix graph, the @code{reverse-package} type of
10384 @command{guix graph}}, for information on how to visualize the list of
10385 dependents of a package.
10389 Be aware that the @option{--list-dependent} option only
10390 @emph{approximates} the rebuilds that would be required as a result of
10391 an upgrade. More rebuilds might be required under some circumstances.
10394 $ guix refresh --list-dependent flex
10395 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
10396 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
10399 The command above lists a set of packages that could be built to check
10400 for compatibility with an upgraded @code{flex} package.
10404 @item --list-transitive
10405 List all the packages which one or more packages depend upon.
10408 $ guix refresh --list-transitive flex
10409 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
10410 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{}
10415 The command above lists a set of packages which, when changed, would cause
10416 @code{flex} to be rebuilt.
10418 The following options can be used to customize GnuPG operation:
10422 @item --gpg=@var{command}
10423 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
10424 for in @code{$PATH}.
10426 @item --keyring=@var{file}
10427 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
10428 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
10429 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
10430 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
10431 information on a tool to manipulate keybox files).
10433 When this option is omitted, @command{guix refresh} uses
10434 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
10435 signing keys. OpenPGP signatures are checked against keys from this keyring;
10436 missing keys are downloaded to this keyring as well (see
10437 @option{--key-download} below).
10439 You can export keys from your default GPG keyring into a keybox file using
10440 commands like this one:
10443 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
10446 Likewise, you can fetch keys to a specific keybox file like this:
10449 gpg --no-default-keyring --keyring mykeyring.kbx \
10450 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
10453 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
10454 Privacy Guard}, for more information on GPG's @option{--keyring} option.
10456 @item --key-download=@var{policy}
10457 Handle missing OpenPGP keys according to @var{policy}, which may be one
10462 Always download missing OpenPGP keys from the key server, and add them
10463 to the user's GnuPG keyring.
10466 Never try to download missing OpenPGP keys. Instead just bail out.
10469 When a package signed with an unknown OpenPGP key is encountered, ask
10470 the user whether to download it or not. This is the default behavior.
10473 @item --key-server=@var{host}
10474 Use @var{host} as the OpenPGP key server when importing a public key.
10476 @item --load-path=@var{directory}
10477 Add @var{directory} to the front of the package module search path
10478 (@pxref{Package Modules}).
10480 This allows users to define their own packages and make them visible to
10481 the command-line tools.
10485 The @code{github} updater uses the
10486 @uref{https://developer.github.com/v3/, GitHub API} to query for new
10487 releases. When used repeatedly e.g.@: when refreshing all packages,
10488 GitHub will eventually refuse to answer any further API requests. By
10489 default 60 API requests per hour are allowed, and a full refresh on all
10490 GitHub packages in Guix requires more than this. Authentication with
10491 GitHub through the use of an API token alleviates these limits. To use
10492 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
10493 token procured from @uref{https://github.com/settings/tokens} or
10497 @node Invoking guix lint
10498 @section Invoking @command{guix lint}
10500 @cindex @command{guix lint}
10501 @cindex package, checking for errors
10502 The @command{guix lint} command is meant to help package developers avoid
10503 common errors and use a consistent style. It runs a number of checks on
10504 a given set of packages in order to find common mistakes in their
10505 definitions. Available @dfn{checkers} include (see
10506 @option{--list-checkers} for a complete list):
10511 Validate certain typographical and stylistic rules about package
10512 descriptions and synopses.
10514 @item inputs-should-be-native
10515 Identify inputs that should most likely be native inputs.
10521 @itemx source-file-name
10522 Probe @code{home-page} and @code{source} URLs and report those that are
10523 invalid. Suggest a @code{mirror://} URL when applicable. If the
10524 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
10525 URL. Check that the source file name is meaningful, e.g.@: is not just a
10526 version number or ``git-checkout'', without a declared @code{file-name}
10527 (@pxref{origin Reference}).
10529 @item source-unstable-tarball
10530 Parse the @code{source} URL to determine if a tarball from GitHub is
10531 autogenerated or if it is a release tarball. Unfortunately GitHub's
10532 autogenerated tarballs are sometimes regenerated.
10535 Check that the derivation of the given packages can be successfully
10536 computed for all the supported systems (@pxref{Derivations}).
10538 @item profile-collisions
10539 Check whether installing the given packages in a profile would lead to
10540 collisions. Collisions occur when several packages with the same name
10541 but a different version or a different store file name are propagated.
10542 @xref{package Reference, @code{propagated-inputs}}, for more information
10543 on propagated inputs.
10546 @cindex Software Heritage, source code archive
10547 @cindex archival of source code, Software Heritage
10548 Checks whether the package's source code is archived at
10549 @uref{https://www.softwareheritage.org, Software Heritage}.
10551 When the source code that is not archived comes from a version-control system
10552 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
10553 ``save'' request so that it eventually archives it. This ensures that the
10554 source will remain available in the long term, and that Guix can fall back to
10555 Software Heritage should the source code disappear from its original host.
10556 The status of recent ``save'' requests can be
10557 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
10559 When source code is a tarball obtained with @code{url-fetch}, simply print a
10560 message when it is not archived. As of this writing, Software Heritage does
10561 not allow requests to save arbitrary tarballs; we are working on ways to
10562 ensure that non-VCS source code is also archived.
10565 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
10566 request rate per IP address}. When the limit is reached, @command{guix lint}
10567 prints a message and the @code{archival} checker stops doing anything until
10568 that limit has been reset.
10571 @cindex security vulnerabilities
10572 @cindex CVE, Common Vulnerabilities and Exposures
10573 Report known vulnerabilities found in the Common Vulnerabilities and
10574 Exposures (CVE) databases of the current and past year
10575 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
10578 To view information about a particular vulnerability, visit pages such as:
10582 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
10584 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
10588 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
10589 @code{CVE-2015-7554}.
10591 Package developers can specify in package recipes the
10592 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
10593 name and version of the package when they differ from the name or version
10594 that Guix uses, as in this example:
10600 ;; CPE calls this package "grub2".
10601 (properties '((cpe-name . "grub2")
10602 (cpe-version . "2.3"))))
10605 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
10606 Some entries in the CVE database do not specify which version of a
10607 package they apply to, and would thus ``stick around'' forever. Package
10608 developers who found CVE alerts and verified they can be ignored can
10609 declare them as in this example:
10615 ;; These CVEs no longer apply and can be safely ignored.
10616 (properties `((lint-hidden-cve . ("CVE-2011-0433"
10619 "CVE-2011-5244")))))
10623 Warn about obvious source code formatting issues: trailing white space,
10624 use of tabulations, etc.
10627 The general syntax is:
10630 guix lint @var{options} @var{package}@dots{}
10633 If no package is given on the command line, then all packages are checked.
10634 The @var{options} may be zero or more of the following:
10637 @item --list-checkers
10639 List and describe all the available checkers that will be run on packages
10644 Only enable the checkers specified in a comma-separated list using the
10645 names returned by @option{--list-checkers}.
10647 @item --load-path=@var{directory}
10648 @itemx -L @var{directory}
10649 Add @var{directory} to the front of the package module search path
10650 (@pxref{Package Modules}).
10652 This allows users to define their own packages and make them visible to
10653 the command-line tools.
10657 @node Invoking guix size
10658 @section Invoking @command{guix size}
10661 @cindex package size
10663 @cindex @command{guix size}
10664 The @command{guix size} command helps package developers profile the
10665 disk usage of packages. It is easy to overlook the impact of an
10666 additional dependency added to a package, or the impact of using a
10667 single output for a package that could easily be split (@pxref{Packages
10668 with Multiple Outputs}). Such are the typical issues that
10669 @command{guix size} can highlight.
10671 The command can be passed one or more package specifications
10672 such as @code{gcc@@4.8}
10673 or @code{guile:debug}, or a file name in the store. Consider this
10677 $ guix size coreutils
10678 store item total self
10679 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
10680 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
10681 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
10682 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
10683 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
10684 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
10685 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
10686 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
10691 The store items listed here constitute the @dfn{transitive closure} of
10692 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
10693 would be returned by:
10696 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
10699 Here the output shows three columns next to store items. The first column,
10700 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
10701 the store item---that is, its own size plus the size of all its
10702 dependencies. The next column, labeled ``self'', shows the size of the
10703 item itself. The last column shows the ratio of the size of the item
10704 itself to the space occupied by all the items listed here.
10706 In this example, we see that the closure of Coreutils weighs in at
10707 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
10708 libraries. (That libc and GCC's libraries represent a large fraction of
10709 the closure is not a problem @i{per se} because they are always available
10710 on the system anyway.)
10712 Since the command also accepts store file names, assessing the size of
10713 a build result is straightforward:
10716 guix size $(guix system build config.scm)
10719 When the package(s) passed to @command{guix size} are available in the
10720 store@footnote{More precisely, @command{guix size} looks for the
10721 @emph{ungrafted} variant of the given package(s), as returned by
10722 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
10723 for information on grafts.}, @command{guix size} queries the daemon to determine its
10724 dependencies, and measures its size in the store, similar to @command{du
10725 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
10728 When the given packages are @emph{not} in the store, @command{guix size}
10729 reports information based on the available substitutes
10730 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
10731 store items that are not even on disk, only available remotely.
10733 You can also specify several package names:
10736 $ guix size coreutils grep sed bash
10737 store item total self
10738 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
10739 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
10740 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
10741 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
10747 In this example we see that the combination of the four packages takes
10748 102.3@tie{}MiB in total, which is much less than the sum of each closure
10749 since they have a lot of dependencies in common.
10751 When looking at the profile returned by @command{guix size}, you may
10752 find yourself wondering why a given package shows up in the profile at
10753 all. To understand it, you can use @command{guix graph --path -t
10754 references} to display the shortest path between the two packages
10755 (@pxref{Invoking guix graph}).
10757 The available options are:
10761 @item --substitute-urls=@var{urls}
10762 Use substitute information from @var{urls}.
10763 @xref{client-substitute-urls, the same option for @code{guix build}}.
10765 @item --sort=@var{key}
10766 Sort lines according to @var{key}, one of the following options:
10770 the size of each item (the default);
10772 the total size of the item's closure.
10775 @item --map-file=@var{file}
10776 Write a graphical map of disk usage in PNG format to @var{file}.
10778 For the example above, the map looks like this:
10780 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
10781 produced by @command{guix size}}
10783 This option requires that
10784 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
10785 installed and visible in Guile's module search path. When that is not
10786 the case, @command{guix size} fails as it tries to load it.
10788 @item --system=@var{system}
10789 @itemx -s @var{system}
10790 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
10792 @item --load-path=@var{directory}
10793 @itemx -L @var{directory}
10794 Add @var{directory} to the front of the package module search path
10795 (@pxref{Package Modules}).
10797 This allows users to define their own packages and make them visible to
10798 the command-line tools.
10801 @node Invoking guix graph
10802 @section Invoking @command{guix graph}
10805 @cindex @command{guix graph}
10806 @cindex package dependencies
10807 Packages and their dependencies form a @dfn{graph}, specifically a
10808 directed acyclic graph (DAG). It can quickly become difficult to have a
10809 mental model of the package DAG, so the @command{guix graph} command
10810 provides a visual representation of the DAG. By default,
10811 @command{guix graph} emits a DAG representation in the input format of
10812 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
10813 directly to the @command{dot} command of Graphviz. It can also emit an
10814 HTML page with embedded JavaScript code to display a ``chord diagram''
10815 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
10816 emit Cypher queries to construct a graph in a graph database supporting
10817 the @uref{https://www.opencypher.org/, openCypher} query language. With
10818 @option{--path}, it simply displays the shortest path between two
10819 packages. The general syntax is:
10822 guix graph @var{options} @var{package}@dots{}
10825 For example, the following command generates a PDF file representing the
10826 package DAG for the GNU@tie{}Core Utilities, showing its build-time
10830 guix graph coreutils | dot -Tpdf > dag.pdf
10833 The output looks like this:
10835 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
10837 Nice little graph, no?
10839 You may find it more pleasant to navigate the graph interactively with
10840 @command{xdot} (from the @code{xdot} package):
10843 guix graph coreutils | xdot -
10846 But there is more than one graph! The one above is concise: it is the
10847 graph of package objects, omitting implicit inputs such as GCC, libc,
10848 grep, etc. It is often useful to have such a concise graph, but
10849 sometimes one may want to see more details. @command{guix graph} supports
10850 several types of graphs, allowing you to choose the level of detail:
10854 This is the default type used in the example above. It shows the DAG of
10855 package objects, excluding implicit dependencies. It is concise, but
10856 filters out many details.
10858 @item reverse-package
10859 This shows the @emph{reverse} DAG of packages. For example:
10862 guix graph --type=reverse-package ocaml
10865 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
10866 you are also interested in cases where OCaml is an implicit dependency, see
10867 @code{reverse-bag} below).
10869 Note that for core packages this can yield huge graphs. If all you want
10870 is to know the number of packages that depend on a given package, use
10871 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
10872 @option{--list-dependent}}).
10875 This is the package DAG, @emph{including} implicit inputs.
10877 For instance, the following command:
10880 guix graph --type=bag-emerged coreutils
10883 ...@: yields this bigger graph:
10885 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
10887 At the bottom of the graph, we see all the implicit inputs of
10888 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
10890 Now, note that the dependencies of these implicit inputs---that is, the
10891 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
10892 here, for conciseness.
10895 Similar to @code{bag-emerged}, but this time including all the bootstrap
10898 @item bag-with-origins
10899 Similar to @code{bag}, but also showing origins and their dependencies.
10902 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
10903 it also takes implicit dependencies into account. For example:
10906 guix graph -t reverse-bag dune
10910 ...@: yields the graph of all packages that depend on Dune, directly or
10911 indirectly. Since Dune is an @emph{implicit} dependency of many packages
10912 @i{via} @code{dune-build-system}, this shows a large number of packages,
10913 whereas @code{reverse-package} would show very few if any.
10916 This is the most detailed representation: It shows the DAG of
10917 derivations (@pxref{Derivations}) and plain store items. Compared to
10918 the above representation, many additional nodes are visible, including
10919 build scripts, patches, Guile modules, etc.
10921 For this type of graph, it is also possible to pass a @file{.drv} file
10922 name instead of a package name, as in:
10925 guix graph -t derivation `guix system build -d my-config.scm`
10929 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
10930 For example, the following command shows the graph for the package
10931 module that defines the @code{guile} package:
10934 guix graph -t module guile | xdot -
10938 All the types above correspond to @emph{build-time dependencies}. The
10939 following graph type represents the @emph{run-time dependencies}:
10943 This is the graph of @dfn{references} of a package output, as returned
10944 by @command{guix gc --references} (@pxref{Invoking guix gc}).
10946 If the given package output is not available in the store, @command{guix
10947 graph} attempts to obtain dependency information from substitutes.
10949 Here you can also pass a store file name instead of a package name. For
10950 example, the command below produces the reference graph of your profile
10951 (which can be big!):
10954 guix graph -t references `readlink -f ~/.guix-profile`
10958 This is the graph of the @dfn{referrers} of a store item, as returned by
10959 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
10961 This relies exclusively on local information from your store. For
10962 instance, let us suppose that the current Inkscape is available in 10
10963 profiles on your machine; @command{guix graph -t referrers inkscape}
10964 will show a graph rooted at Inkscape and with those 10 profiles linked
10967 It can help determine what is preventing a store item from being garbage
10972 @cindex shortest path, between packages
10973 Often, the graph of the package you are interested in does not fit on
10974 your screen, and anyway all you want to know is @emph{why} that package
10975 actually depends on some seemingly unrelated package. The
10976 @option{--path} option instructs @command{guix graph} to display the
10977 shortest path between two packages (or derivations, or store items,
10981 $ guix graph --path emacs libunistring
10984 libunistring@@0.9.10
10985 $ guix graph --path -t derivation emacs libunistring
10986 /gnu/store/@dots{}-emacs-26.3.drv
10987 /gnu/store/@dots{}-mailutils-3.9.drv
10988 /gnu/store/@dots{}-libunistring-0.9.10.drv
10989 $ guix graph --path -t references emacs libunistring
10990 /gnu/store/@dots{}-emacs-26.3
10991 /gnu/store/@dots{}-libidn2-2.2.0
10992 /gnu/store/@dots{}-libunistring-0.9.10
10995 The available options are the following:
10998 @item --type=@var{type}
10999 @itemx -t @var{type}
11000 Produce a graph output of @var{type}, where @var{type} must be one of
11001 the values listed above.
11004 List the supported graph types.
11006 @item --backend=@var{backend}
11007 @itemx -b @var{backend}
11008 Produce a graph using the selected @var{backend}.
11010 @item --list-backends
11011 List the supported graph backends.
11013 Currently, the available backends are Graphviz and d3.js.
11016 Display the shortest path between two nodes of the type specified by
11017 @option{--type}. The example below shows the shortest path between
11018 @code{libreoffice} and @code{llvm} according to the references of
11019 @code{libreoffice}:
11022 $ guix graph --path -t references libreoffice llvm
11023 /gnu/store/@dots{}-libreoffice-6.4.2.2
11024 /gnu/store/@dots{}-libepoxy-1.5.4
11025 /gnu/store/@dots{}-mesa-19.3.4
11026 /gnu/store/@dots{}-llvm-9.0.1
11029 @item --expression=@var{expr}
11030 @itemx -e @var{expr}
11031 Consider the package @var{expr} evaluates to.
11033 This is useful to precisely refer to a package, as in this example:
11036 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
11039 @item --system=@var{system}
11040 @itemx -s @var{system}
11041 Display the graph for @var{system}---e.g., @code{i686-linux}.
11043 The package dependency graph is largely architecture-independent, but there
11044 are some architecture-dependent bits that this option allows you to visualize.
11046 @item --load-path=@var{directory}
11047 @itemx -L @var{directory}
11048 Add @var{directory} to the front of the package module search path
11049 (@pxref{Package Modules}).
11051 This allows users to define their own packages and make them visible to
11052 the command-line tools.
11055 On top of that, @command{guix graph} supports all the usual package
11056 transformation options (@pxref{Package Transformation Options}). This
11057 makes it easy to view the effect of a graph-rewriting transformation
11058 such as @option{--with-input}. For example, the command below outputs
11059 the graph of @code{git} once @code{openssl} has been replaced by
11060 @code{libressl} everywhere in the graph:
11063 guix graph git --with-input=openssl=libressl
11066 So many possibilities, so much fun!
11068 @node Invoking guix publish
11069 @section Invoking @command{guix publish}
11071 @cindex @command{guix publish}
11072 The purpose of @command{guix publish} is to enable users to easily share
11073 their store with others, who can then use it as a substitute server
11074 (@pxref{Substitutes}).
11076 When @command{guix publish} runs, it spawns an HTTP server which allows
11077 anyone with network access to obtain substitutes from it. This means
11078 that any machine running Guix can also act as if it were a build farm,
11079 since the HTTP interface is compatible with Cuirass, the software behind
11080 the @code{@value{SUBSTITUTE-SERVER}} build farm.
11082 For security, each substitute is signed, allowing recipients to check
11083 their authenticity and integrity (@pxref{Substitutes}). Because
11084 @command{guix publish} uses the signing key of the system, which is only
11085 readable by the system administrator, it must be started as root; the
11086 @option{--user} option makes it drop root privileges early on.
11088 The signing key pair must be generated before @command{guix publish} is
11089 launched, using @command{guix archive --generate-key} (@pxref{Invoking
11092 The general syntax is:
11095 guix publish @var{options}@dots{}
11098 Running @command{guix publish} without any additional arguments will
11099 spawn an HTTP server on port 8080:
11105 Once a publishing server has been authorized (@pxref{Invoking guix
11106 archive}), the daemon may download substitutes from it:
11109 guix-daemon --substitute-urls=http://example.org:8080
11112 By default, @command{guix publish} compresses archives on the fly as it
11113 serves them. This ``on-the-fly'' mode is convenient in that it requires
11114 no setup and is immediately available. However, when serving lots of
11115 clients, we recommend using the @option{--cache} option, which enables
11116 caching of the archives before they are sent to clients---see below for
11117 details. The @command{guix weather} command provides a handy way to
11118 check what a server provides (@pxref{Invoking guix weather}).
11120 As a bonus, @command{guix publish} also serves as a content-addressed
11121 mirror for source files referenced in @code{origin} records
11122 (@pxref{origin Reference}). For instance, assuming @command{guix
11123 publish} is running on @code{example.org}, the following URL returns the
11124 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
11125 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
11128 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
11131 Obviously, these URLs only work for files that are in the store; in
11132 other cases, they return 404 (``Not Found'').
11134 @cindex build logs, publication
11135 Build logs are available from @code{/log} URLs like:
11138 http://example.org/log/gwspk@dots{}-guile-2.2.3
11142 When @command{guix-daemon} is configured to save compressed build logs,
11143 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
11144 URLs return the compressed log as-is, with an appropriate
11145 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
11146 running @command{guix-daemon} with @option{--log-compression=gzip} since
11147 Web browsers can automatically decompress it, which is not the case with
11150 The following options are available:
11153 @item --port=@var{port}
11154 @itemx -p @var{port}
11155 Listen for HTTP requests on @var{port}.
11157 @item --listen=@var{host}
11158 Listen on the network interface for @var{host}. The default is to
11159 accept connections from any interface.
11161 @item --user=@var{user}
11162 @itemx -u @var{user}
11163 Change privileges to @var{user} as soon as possible---i.e., once the
11164 server socket is open and the signing key has been read.
11166 @item --compression[=@var{method}[:@var{level}]]
11167 @itemx -C [@var{method}[:@var{level}]]
11168 Compress data using the given @var{method} and @var{level}. @var{method} is
11169 one of @code{lzip} and @code{gzip}; when @var{method} is omitted, @code{gzip}
11172 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
11173 to different compression levels: 1 is the fastest, and 9 is the best
11174 (CPU-intensive). The default is 3.
11176 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a small
11177 increase in CPU usage; see
11178 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip Web
11181 Unless @option{--cache} is used, compression occurs on the fly and
11182 the compressed streams are not
11183 cached. Thus, to reduce load on the machine that runs @command{guix
11184 publish}, it may be a good idea to choose a low compression level, to
11185 run @command{guix publish} behind a caching proxy, or to use
11186 @option{--cache}. Using @option{--cache} has the advantage that it
11187 allows @command{guix publish} to add @code{Content-Length} HTTP header
11190 This option can be repeated, in which case every substitute gets compressed
11191 using all the selected methods, and all of them are advertised. This is
11192 useful when users may not support all the compression methods: they can select
11193 the one they support.
11195 @item --cache=@var{directory}
11196 @itemx -c @var{directory}
11197 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
11198 and only serve archives that are in cache.
11200 When this option is omitted, archives and meta-data are created
11201 on-the-fly. This can reduce the available bandwidth, especially when
11202 compression is enabled, since this may become CPU-bound. Another
11203 drawback of the default mode is that the length of archives is not known
11204 in advance, so @command{guix publish} does not add a
11205 @code{Content-Length} HTTP header to its responses, which in turn
11206 prevents clients from knowing the amount of data being downloaded.
11208 Conversely, when @option{--cache} is used, the first request for a store
11209 item (@i{via} a @code{.narinfo} URL) returns 404 and triggers a
11210 background process to @dfn{bake} the archive---computing its
11211 @code{.narinfo} and compressing the archive, if needed. Once the
11212 archive is cached in @var{directory}, subsequent requests succeed and
11213 are served directly from the cache, which guarantees that clients get
11214 the best possible bandwidth.
11216 The ``baking'' process is performed by worker threads. By default, one
11217 thread per CPU core is created, but this can be customized. See
11218 @option{--workers} below.
11220 When @option{--ttl} is used, cached entries are automatically deleted
11221 when they have expired.
11223 @item --workers=@var{N}
11224 When @option{--cache} is used, request the allocation of @var{N} worker
11225 threads to ``bake'' archives.
11227 @item --ttl=@var{ttl}
11228 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
11229 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
11230 days, @code{1m} means 1 month, and so on.
11232 This allows the user's Guix to keep substitute information in cache for
11233 @var{ttl}. However, note that @code{guix publish} does not itself
11234 guarantee that the store items it provides will indeed remain available
11235 for as long as @var{ttl}.
11237 Additionally, when @option{--cache} is used, cached entries that have
11238 not been accessed for @var{ttl} and that no longer have a corresponding
11239 item in the store, may be deleted.
11241 @item --nar-path=@var{path}
11242 Use @var{path} as the prefix for the URLs of ``nar'' files
11243 (@pxref{Invoking guix archive, normalized archives}).
11245 By default, nars are served at a URL such as
11246 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
11247 change the @code{/nar} part to @var{path}.
11249 @item --public-key=@var{file}
11250 @itemx --private-key=@var{file}
11251 Use the specific @var{file}s as the public/private key pair used to sign
11252 the store items being published.
11254 The files must correspond to the same key pair (the private key is used
11255 for signing and the public key is merely advertised in the signature
11256 metadata). They must contain keys in the canonical s-expression format
11257 as produced by @command{guix archive --generate-key} (@pxref{Invoking
11258 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
11259 @file{/etc/guix/signing-key.sec} are used.
11261 @item --repl[=@var{port}]
11262 @itemx -r [@var{port}]
11263 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
11264 Reference Manual}) on @var{port} (37146 by default). This is used
11265 primarily for debugging a running @command{guix publish} server.
11268 Enabling @command{guix publish} on Guix System is a one-liner: just
11269 instantiate a @code{guix-publish-service-type} service in the @code{services} field
11270 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
11271 @code{guix-publish-service-type}}).
11273 If you are instead running Guix on a ``foreign distro'', follow these
11278 If your host distro uses the systemd init system:
11281 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
11282 /etc/systemd/system/
11283 # systemctl start guix-publish && systemctl enable guix-publish
11287 If your host distro uses the Upstart init system:
11290 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
11291 # start guix-publish
11295 Otherwise, proceed similarly with your distro's init system.
11298 @node Invoking guix challenge
11299 @section Invoking @command{guix challenge}
11301 @cindex reproducible builds
11302 @cindex verifiable builds
11303 @cindex @command{guix challenge}
11305 Do the binaries provided by this server really correspond to the source
11306 code it claims to build? Is a package build process deterministic?
11307 These are the questions the @command{guix challenge} command attempts to
11310 The former is obviously an important question: Before using a substitute
11311 server (@pxref{Substitutes}), one had better @emph{verify} that it
11312 provides the right binaries, and thus @emph{challenge} it. The latter
11313 is what enables the former: If package builds are deterministic, then
11314 independent builds of the package should yield the exact same result,
11315 bit for bit; if a server provides a binary different from the one
11316 obtained locally, it may be either corrupt or malicious.
11318 We know that the hash that shows up in @file{/gnu/store} file names is
11319 the hash of all the inputs of the process that built the file or
11320 directory---compilers, libraries, build scripts,
11321 etc. (@pxref{Introduction}). Assuming deterministic build processes,
11322 one store file name should map to exactly one build output.
11323 @command{guix challenge} checks whether there is, indeed, a single
11324 mapping by comparing the build outputs of several independent builds of
11325 any given store item.
11327 The command output looks like this:
11330 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11331 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
11332 updating list of substitutes from 'https://guix.example.org'... 100.0%
11333 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
11334 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11335 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
11336 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
11338 /lib/libcrypto.so.1.1
11341 /gnu/store/@dots{}-git-2.5.0 contents differ:
11342 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
11343 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
11344 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
11346 /libexec/git-core/git-fsck
11348 /gnu/store/@dots{}-pius-2.1.1 contents differ:
11349 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11350 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
11351 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
11353 /share/man/man1/pius.1.gz
11357 6,406 store items were analyzed:
11358 - 4,749 (74.1%) were identical
11359 - 525 (8.2%) differed
11360 - 1,132 (17.7%) were inconclusive
11364 In this example, @command{guix challenge} first scans the store to
11365 determine the set of locally-built derivations---as opposed to store
11366 items that were downloaded from a substitute server---and then queries
11367 all the substitute servers. It then reports those store items for which
11368 the servers obtained a result different from the local build.
11370 @cindex non-determinism, in package builds
11371 As an example, @code{guix.example.org} always gets a different answer.
11372 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
11373 case of Git. This might indicate that the build process of Git is
11374 non-deterministic, meaning that its output varies as a function of
11375 various things that Guix does not fully control, in spite of building
11376 packages in isolated environments (@pxref{Features}). Most common
11377 sources of non-determinism include the addition of timestamps in build
11378 results, the inclusion of random numbers, and directory listings sorted
11379 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
11382 To find out what is wrong with this Git binary, the easiest approach is
11386 guix challenge git \
11387 --diff=diffoscope \
11388 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
11391 This automatically invokes @command{diffoscope}, which displays detailed
11392 information about files that differ.
11394 Alternatively, we can do something along these lines (@pxref{Invoking guix
11398 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
11399 | lzip -d | guix archive -x /tmp/git
11400 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
11403 This command shows the difference between the files resulting from the
11404 local build, and the files resulting from the build on
11405 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
11406 diffutils, Comparing and Merging Files}). The @command{diff} command
11407 works great for text files. When binary files differ, a better option
11408 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
11409 visualize differences for all kinds of files.
11411 Once you have done that work, you can tell whether the differences are due
11412 to a non-deterministic build process or to a malicious server. We try
11413 hard to remove sources of non-determinism in packages to make it easier
11414 to verify substitutes, but of course, this is a process that
11415 involves not just Guix, but a large part of the free software community.
11416 In the meantime, @command{guix challenge} is one tool to help address
11419 If you are writing packages for Guix, you are encouraged to check
11420 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
11421 same build result as you did with:
11424 $ guix challenge @var{package}
11428 where @var{package} is a package specification such as
11429 @code{guile@@2.0} or @code{glibc:debug}.
11431 The general syntax is:
11434 guix challenge @var{options} [@var{packages}@dots{}]
11437 When a difference is found between the hash of a locally-built item and
11438 that of a server-provided substitute, or among substitutes provided by
11439 different servers, the command displays it as in the example above and
11440 its exit code is 2 (other non-zero exit codes denote other kinds of
11443 The one option that matters is:
11447 @item --substitute-urls=@var{urls}
11448 Consider @var{urls} the whitespace-separated list of substitute source
11449 URLs to compare to.
11451 @item --diff=@var{mode}
11452 Upon mismatches, show differences according to @var{mode}, one of:
11455 @item @code{simple} (the default)
11456 Show the list of files that differ.
11458 @item @code{diffoscope}
11459 @itemx @var{command}
11460 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
11461 two directories whose contents do not match.
11463 When @var{command} is an absolute file name, run @var{command} instead
11467 Do not show further details about the differences.
11470 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
11471 downloads the store items from the given substitute servers so that it
11476 Show details about matches (identical contents) in addition to
11477 information about mismatches.
11481 @node Invoking guix copy
11482 @section Invoking @command{guix copy}
11484 @cindex copy, of store items, over SSH
11485 @cindex SSH, copy of store items
11486 @cindex sharing store items across machines
11487 @cindex transferring store items across machines
11488 The @command{guix copy} command copies items from the store of one
11489 machine to that of another machine over a secure shell (SSH)
11490 connection@footnote{This command is available only when Guile-SSH was
11491 found. @xref{Requirements}, for details.}. For example, the following
11492 command copies the @code{coreutils} package, the user's profile, and all
11493 their dependencies over to @var{host}, logged in as @var{user}:
11496 guix copy --to=@var{user}@@@var{host} \
11497 coreutils `readlink -f ~/.guix-profile`
11500 If some of the items to be copied are already present on @var{host},
11501 they are not actually sent.
11503 The command below retrieves @code{libreoffice} and @code{gimp} from
11504 @var{host}, assuming they are available there:
11507 guix copy --from=@var{host} libreoffice gimp
11510 The SSH connection is established using the Guile-SSH client, which is
11511 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
11512 @file{~/.ssh/config}, and uses the SSH agent for authentication.
11514 The key used to sign items that are sent must be accepted by the remote
11515 machine. Likewise, the key used by the remote machine to sign items you
11516 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
11517 own daemon. @xref{Invoking guix archive}, for more information about
11518 store item authentication.
11520 The general syntax is:
11523 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
11526 You must always specify one of the following options:
11529 @item --to=@var{spec}
11530 @itemx --from=@var{spec}
11531 Specify the host to send to or receive from. @var{spec} must be an SSH
11532 spec such as @code{example.org}, @code{charlie@@example.org}, or
11533 @code{charlie@@example.org:2222}.
11536 The @var{items} can be either package names, such as @code{gimp}, or
11537 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
11539 When specifying the name of a package to send, it is first built if
11540 needed, unless @option{--dry-run} was specified. Common build options
11541 are supported (@pxref{Common Build Options}).
11544 @node Invoking guix container
11545 @section Invoking @command{guix container}
11547 @cindex @command{guix container}
11549 As of version @value{VERSION}, this tool is experimental. The interface
11550 is subject to radical change in the future.
11553 The purpose of @command{guix container} is to manipulate processes
11554 running within an isolated environment, commonly known as a
11555 ``container'', typically created by the @command{guix environment}
11556 (@pxref{Invoking guix environment}) and @command{guix system container}
11557 (@pxref{Invoking guix system}) commands.
11559 The general syntax is:
11562 guix container @var{action} @var{options}@dots{}
11565 @var{action} specifies the operation to perform with a container, and
11566 @var{options} specifies the context-specific arguments for the action.
11568 The following actions are available:
11572 Execute a command within the context of a running container.
11577 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
11580 @var{pid} specifies the process ID of the running container.
11581 @var{program} specifies an executable file name within the root file
11582 system of the container. @var{arguments} are the additional options that
11583 will be passed to @var{program}.
11585 The following command launches an interactive login shell inside a
11586 Guix system container, started by @command{guix system container}, and whose
11587 process ID is 9001:
11590 guix container exec 9001 /run/current-system/profile/bin/bash --login
11593 Note that the @var{pid} cannot be the parent process of a container. It
11594 must be PID 1 of the container or one of its child processes.
11598 @node Invoking guix weather
11599 @section Invoking @command{guix weather}
11601 Occasionally you're grumpy because substitutes are lacking and you end
11602 up building packages by yourself (@pxref{Substitutes}). The
11603 @command{guix weather} command reports on substitute availability on the
11604 specified servers so you can have an idea of whether you'll be grumpy
11605 today. It can sometimes be useful info as a user, but it is primarily
11606 useful to people running @command{guix publish} (@pxref{Invoking guix
11609 @cindex statistics, for substitutes
11610 @cindex availability of substitutes
11611 @cindex substitute availability
11612 @cindex weather, substitute availability
11613 Here's a sample run:
11616 $ guix weather --substitute-urls=https://guix.example.org
11617 computing 5,872 package derivations for x86_64-linux...
11618 looking for 6,128 store items on https://guix.example.org..
11619 updating list of substitutes from 'https://guix.example.org'... 100.0%
11620 https://guix.example.org
11621 43.4% substitutes available (2,658 out of 6,128)
11622 7,032.5 MiB of nars (compressed)
11623 19,824.2 MiB on disk (uncompressed)
11624 0.030 seconds per request (182.9 seconds in total)
11625 33.5 requests per second
11627 9.8% (342 out of 3,470) of the missing items are queued
11629 x86_64-linux: 518 (59.7%)
11630 i686-linux: 221 (25.5%)
11631 aarch64-linux: 128 (14.8%)
11632 build rate: 23.41 builds per hour
11633 x86_64-linux: 11.16 builds per hour
11634 i686-linux: 6.03 builds per hour
11635 aarch64-linux: 6.41 builds per hour
11638 @cindex continuous integration, statistics
11639 As you can see, it reports the fraction of all the packages for which
11640 substitutes are available on the server---regardless of whether
11641 substitutes are enabled, and regardless of whether this server's signing
11642 key is authorized. It also reports the size of the compressed archives
11643 (``nars'') provided by the server, the size the corresponding store
11644 items occupy in the store (assuming deduplication is turned off), and
11645 the server's throughput. The second part gives continuous integration
11646 (CI) statistics, if the server supports it. In addition, using the
11647 @option{--coverage} option, @command{guix weather} can list ``important''
11648 package substitutes missing on the server (see below).
11650 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
11651 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
11652 challenge}, it ignores signatures on those substitutes, which is
11653 innocuous since the command only gathers statistics and cannot install
11656 The general syntax is:
11659 guix weather @var{options}@dots{} [@var{packages}@dots{}]
11662 When @var{packages} is omitted, @command{guix weather} checks the availability
11663 of substitutes for @emph{all} the packages, or for those specified with
11664 @option{--manifest}; otherwise it only considers the specified packages. It
11665 is also possible to query specific system types with @option{--system}.
11666 @command{guix weather} exits with a non-zero code when the fraction of
11667 available substitutes is below 100%.
11669 The available options are listed below.
11672 @item --substitute-urls=@var{urls}
11673 @var{urls} is the space-separated list of substitute server URLs to
11674 query. When this option is omitted, the default set of substitute
11675 servers is queried.
11677 @item --system=@var{system}
11678 @itemx -s @var{system}
11679 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
11680 option can be repeated, in which case @command{guix weather} will query
11681 substitutes for several system types.
11683 @item --manifest=@var{file}
11684 Instead of querying substitutes for all the packages, only ask for those
11685 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
11686 with the @code{-m} option of @command{guix package} (@pxref{Invoking
11689 This option can be repeated several times, in which case the manifests
11692 @item --coverage[=@var{count}]
11693 @itemx -c [@var{count}]
11694 Report on substitute coverage for packages: list packages with at least
11695 @var{count} dependents (zero by default) for which substitutes are
11696 unavailable. Dependent packages themselves are not listed: if @var{b} depends
11697 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
11698 @var{b} usually lacks substitutes as well. The result looks like this:
11701 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
11702 computing 8,983 package derivations for x86_64-linux...
11703 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
11704 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
11705 @value{SUBSTITUTE-URL}
11706 64.7% substitutes available (6,047 out of 9,343)
11708 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
11709 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
11710 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
11711 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
11715 What this example shows is that @code{kcoreaddons} and presumably the 58
11716 packages that depend on it have no substitutes at @code{ci.guix.info};
11717 likewise for @code{qgpgme} and the 46 packages that depend on it.
11719 If you are a Guix developer, or if you are taking care of this build farm,
11720 you'll probably want to have a closer look at these packages: they may simply
11723 @item --display-missing
11724 Display the list of store items for which substitutes are missing.
11727 @node Invoking guix processes
11728 @section Invoking @command{guix processes}
11730 The @command{guix processes} command can be useful to developers and system
11731 administrators, especially on multi-user machines and on build farms: it lists
11732 the current sessions (connections to the daemon), as well as information about
11733 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
11734 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
11735 listed.}. Here's an example of the information it returns:
11738 $ sudo guix processes
11741 ClientCommand: guix environment --ad-hoc python
11745 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
11749 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11750 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
11751 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
11752 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
11753 ChildProcess: 20495: guix offload x86_64-linux 7200 1 28800
11754 ChildProcess: 27733: guix offload x86_64-linux 7200 1 28800
11755 ChildProcess: 27793: guix offload x86_64-linux 7200 1 28800
11758 In this example we see that @command{guix-daemon} has three clients:
11759 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
11760 integration tool; their process identifier (PID) is given by the
11761 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
11762 @command{guix-daemon} sub-process of this particular session.
11764 The @code{LockHeld} fields show which store items are currently locked by this
11765 session, which corresponds to store items being built or substituted (the
11766 @code{LockHeld} field is not displayed when @command{guix processes} is not
11767 running as root). Last, by looking at the @code{ChildProcess} field, we
11768 understand that these three builds are being offloaded (@pxref{Daemon Offload
11771 The output is in Recutils format so we can use the handy @command{recsel}
11772 command to select sessions of interest (@pxref{Selection Expressions,,,
11773 recutils, GNU recutils manual}). As an example, the command shows the command
11774 line and PID of the client that triggered the build of a Perl package:
11777 $ sudo guix processes | \
11778 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
11780 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
11783 @node System Configuration
11784 @chapter System Configuration
11786 @cindex system configuration
11787 Guix System supports a consistent whole-system configuration
11788 mechanism. By that we mean that all aspects of the global system
11789 configuration---such as the available system services, timezone and
11790 locale settings, user accounts---are declared in a single place. Such
11791 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
11793 One of the advantages of putting all the system configuration under the
11794 control of Guix is that it supports transactional system upgrades, and
11795 makes it possible to roll back to a previous system instantiation,
11796 should something go wrong with the new one (@pxref{Features}). Another
11797 advantage is that it makes it easy to replicate the exact same configuration
11798 across different machines, or at different points in time, without
11799 having to resort to additional administration tools layered on top of
11800 the own tools of the system.
11801 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
11803 This section describes this mechanism. First we focus on the system
11804 administrator's viewpoint---explaining how the system is configured and
11805 instantiated. Then we show how this mechanism can be extended, for
11806 instance to support new system services.
11809 * Using the Configuration System:: Customizing your GNU system.
11810 * operating-system Reference:: Detail of operating-system declarations.
11811 * File Systems:: Configuring file system mounts.
11812 * Mapped Devices:: Block device extra processing.
11813 * User Accounts:: Specifying user accounts.
11814 * Keyboard Layout:: How the system interprets key strokes.
11815 * Locales:: Language and cultural convention settings.
11816 * Services:: Specifying system services.
11817 * Setuid Programs:: Programs running with root privileges.
11818 * X.509 Certificates:: Authenticating HTTPS servers.
11819 * Name Service Switch:: Configuring libc's name service switch.
11820 * Initial RAM Disk:: Linux-Libre bootstrapping.
11821 * Bootloader Configuration:: Configuring the boot loader.
11822 * Invoking guix system:: Instantiating a system configuration.
11823 * Invoking guix deploy:: Deploying a system configuration to a remote host.
11824 * Running Guix in a VM:: How to run Guix System in a virtual machine.
11825 * Defining Services:: Adding new service definitions.
11828 @node Using the Configuration System
11829 @section Using the Configuration System
11831 The operating system is configured by providing an
11832 @code{operating-system} declaration in a file that can then be passed to
11833 the @command{guix system} command (@pxref{Invoking guix system}). A
11834 simple setup, with the default system services, the default Linux-Libre
11835 kernel, initial RAM disk, and boot loader looks like this:
11837 @findex operating-system
11839 @include os-config-bare-bones.texi
11842 This example should be self-describing. Some of the fields defined
11843 above, such as @code{host-name} and @code{bootloader}, are mandatory.
11844 Others, such as @code{packages} and @code{services}, can be omitted, in
11845 which case they get a default value.
11847 Below we discuss the effect of some of the most important fields
11848 (@pxref{operating-system Reference}, for details about all the available
11849 fields), and how to @dfn{instantiate} the operating system using
11850 @command{guix system}.
11852 @unnumberedsubsec Bootloader
11854 @cindex legacy boot, on Intel machines
11855 @cindex BIOS boot, on Intel machines
11858 The @code{bootloader} field describes the method that will be used to boot
11859 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
11860 mode, as in the example above. However, more recent machines rely instead on
11861 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
11862 the @code{bootloader} field should contain something along these lines:
11865 (bootloader-configuration
11866 (bootloader grub-efi-bootloader)
11867 (target "/boot/efi"))
11870 @xref{Bootloader Configuration}, for more information on the available
11871 configuration options.
11873 @unnumberedsubsec Globally-Visible Packages
11875 @vindex %base-packages
11876 The @code{packages} field lists packages that will be globally visible
11877 on the system, for all user accounts---i.e., in every user's @env{PATH}
11878 environment variable---in addition to the per-user profiles
11879 (@pxref{Invoking guix package}). The @code{%base-packages} variable
11880 provides all the tools one would expect for basic user and administrator
11881 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
11882 the GNU Zile lightweight text editor, @command{find}, @command{grep},
11883 etc. The example above adds GNU@tie{}Screen to those,
11884 taken from the @code{(gnu packages screen)}
11885 module (@pxref{Package Modules}). The
11886 @code{(list package output)} syntax can be used to add a specific output
11890 (use-modules (gnu packages))
11891 (use-modules (gnu packages dns))
11895 (packages (cons (list bind "utils")
11899 @findex specification->package
11900 Referring to packages by variable name, like @code{bind} above, has
11901 the advantage of being unambiguous; it also allows typos and such to be
11902 diagnosed right away as ``unbound variables''. The downside is that one
11903 needs to know which module defines which package, and to augment the
11904 @code{use-package-modules} line accordingly. To avoid that, one can use
11905 the @code{specification->package} procedure of the @code{(gnu packages)}
11906 module, which returns the best package for a given name or name and
11910 (use-modules (gnu packages))
11914 (packages (append (map specification->package
11915 '("tcpdump" "htop" "gnupg@@2.0"))
11919 @unnumberedsubsec System Services
11922 @vindex %base-services
11923 The @code{services} field lists @dfn{system services} to be made
11924 available when the system starts (@pxref{Services}).
11925 The @code{operating-system} declaration above specifies that, in
11926 addition to the basic services, we want the OpenSSH secure shell
11927 daemon listening on port 2222 (@pxref{Networking Services,
11928 @code{openssh-service-type}}). Under the hood,
11929 @code{openssh-service-type} arranges so that @command{sshd} is started with the
11930 right command-line options, possibly with supporting configuration files
11931 generated as needed (@pxref{Defining Services}).
11933 @cindex customization, of services
11934 @findex modify-services
11935 Occasionally, instead of using the base services as is, you will want to
11936 customize them. To do this, use @code{modify-services} (@pxref{Service
11937 Reference, @code{modify-services}}) to modify the list.
11939 For example, suppose you want to modify @code{guix-daemon} and Mingetty
11940 (the console log-in) in the @code{%base-services} list (@pxref{Base
11941 Services, @code{%base-services}}). To do that, you can write the
11942 following in your operating system declaration:
11945 (define %my-services
11946 ;; My very own list of services.
11947 (modify-services %base-services
11948 (guix-service-type config =>
11949 (guix-configuration
11951 (use-substitutes? #f)
11952 (extra-options '("--gc-keep-derivations"))))
11953 (mingetty-service-type config =>
11954 (mingetty-configuration
11955 (inherit config)))))
11959 (services %my-services))
11962 This changes the configuration---i.e., the service parameters---of the
11963 @code{guix-service-type} instance, and that of all the
11964 @code{mingetty-service-type} instances in the @code{%base-services} list.
11965 Observe how this is accomplished: first, we arrange for the original
11966 configuration to be bound to the identifier @code{config} in the
11967 @var{body}, and then we write the @var{body} so that it evaluates to the
11968 desired configuration. In particular, notice how we use @code{inherit}
11969 to create a new configuration which has the same values as the old
11970 configuration, but with a few modifications.
11972 @cindex encrypted disk
11973 The configuration for a typical ``desktop'' usage, with an encrypted
11974 root partition, the X11 display
11975 server, GNOME and Xfce (users can choose which of these desktop
11976 environments to use at the log-in screen by pressing @kbd{F1}), network
11977 management, power management, and more, would look like this:
11980 @include os-config-desktop.texi
11983 A graphical system with a choice of lightweight window managers
11984 instead of full-blown desktop environments would look like this:
11987 @include os-config-lightweight-desktop.texi
11990 This example refers to the @file{/boot/efi} file system by its UUID,
11991 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
11992 as returned by the @command{blkid} command.
11994 @xref{Desktop Services}, for the exact list of services provided by
11995 @code{%desktop-services}. @xref{X.509 Certificates}, for background
11996 information about the @code{nss-certs} package that is used here.
11998 Again, @code{%desktop-services} is just a list of service objects. If
11999 you want to remove services from there, you can do so using the
12000 procedures for list filtering (@pxref{SRFI-1 Filtering and
12001 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
12002 following expression returns a list that contains all the services in
12003 @code{%desktop-services} minus the Avahi service:
12006 (remove (lambda (service)
12007 (eq? (service-kind service) avahi-service-type))
12011 @unnumberedsubsec Instantiating the System
12013 Assuming the @code{operating-system} declaration
12014 is stored in the @file{my-system-config.scm}
12015 file, the @command{guix system reconfigure my-system-config.scm} command
12016 instantiates that configuration, and makes it the default GRUB boot
12017 entry (@pxref{Invoking guix system}).
12019 The normal way to change the system configuration is by updating this
12020 file and re-running @command{guix system reconfigure}. One should never
12021 have to touch files in @file{/etc} or to run commands that modify the
12022 system state such as @command{useradd} or @command{grub-install}. In
12023 fact, you must avoid that since that would not only void your warranty
12024 but also prevent you from rolling back to previous versions of your
12025 system, should you ever need to.
12027 @cindex roll-back, of the operating system
12028 Speaking of roll-back, each time you run @command{guix system
12029 reconfigure}, a new @dfn{generation} of the system is created---without
12030 modifying or deleting previous generations. Old system generations get
12031 an entry in the bootloader boot menu, allowing you to boot them in case
12032 something went wrong with the latest generation. Reassuring, no? The
12033 @command{guix system list-generations} command lists the system
12034 generations available on disk. It is also possible to roll back the
12035 system via the commands @command{guix system roll-back} and
12036 @command{guix system switch-generation}.
12038 Although the @command{guix system reconfigure} command will not modify
12039 previous generations, you must take care when the current generation is not
12040 the latest (e.g., after invoking @command{guix system roll-back}), since
12041 the operation might overwrite a later generation (@pxref{Invoking guix
12044 @unnumberedsubsec The Programming Interface
12046 At the Scheme level, the bulk of an @code{operating-system} declaration
12047 is instantiated with the following monadic procedure (@pxref{The Store
12050 @deffn {Monadic Procedure} operating-system-derivation os
12051 Return a derivation that builds @var{os}, an @code{operating-system}
12052 object (@pxref{Derivations}).
12054 The output of the derivation is a single directory that refers to all
12055 the packages, configuration files, and other supporting files needed to
12056 instantiate @var{os}.
12059 This procedure is provided by the @code{(gnu system)} module. Along
12060 with @code{(gnu services)} (@pxref{Services}), this module contains the
12061 guts of Guix System. Make sure to visit it!
12064 @node operating-system Reference
12065 @section @code{operating-system} Reference
12067 This section summarizes all the options available in
12068 @code{operating-system} declarations (@pxref{Using the Configuration
12071 @deftp {Data Type} operating-system
12072 This is the data type representing an operating system configuration.
12073 By that, we mean all the global system configuration, not per-user
12074 configuration (@pxref{Using the Configuration System}).
12077 @item @code{kernel} (default: @code{linux-libre})
12078 The package object of the operating system kernel to
12079 use@footnote{Currently only the Linux-libre kernel is fully supported.
12080 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
12081 available when building a virtual machine disk image.}.
12084 @item @code{hurd} (default: @code{#f})
12085 The package object of the hurd to be started by the kernel. When this
12086 field is set, produce a GNU/Hurd operating system. In that case,
12087 @code{kernel} must also be set to the @code{gnumach} package---the
12088 microkernel the Hurd runs on.
12091 This feature is experimental and only supported for disk images.
12094 @item @code{kernel-loadable-modules} (default: '())
12095 A list of objects (usually packages) to collect loadable kernel modules
12096 from--e.g. @code{(list ddcci-driver-linux)}.
12098 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
12099 List of strings or gexps representing additional arguments to pass on
12100 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
12102 @item @code{bootloader}
12103 The system bootloader configuration object. @xref{Bootloader Configuration}.
12106 This is the label (a string) as it appears in the bootloader's menu entry.
12107 The default label includes the kernel name and version.
12109 @item @code{keyboard-layout} (default: @code{#f})
12110 This field specifies the keyboard layout to use in the console. It can be
12111 either @code{#f}, in which case the default keyboard layout is used (usually
12112 US English), or a @code{<keyboard-layout>} record.
12114 This keyboard layout is in effect as soon as the kernel has booted. For
12115 instance, it is the keyboard layout in effect when you type a passphrase if
12116 your root file system is on a @code{luks-device-mapping} mapped device
12117 (@pxref{Mapped Devices}).
12120 This does @emph{not} specify the keyboard layout used by the bootloader, nor
12121 that used by the graphical display server. @xref{Bootloader Configuration},
12122 for information on how to specify the bootloader's keyboard layout. @xref{X
12123 Window}, for information on how to specify the keyboard layout used by the X
12127 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
12129 @cindex initial RAM disk
12130 The list of Linux kernel modules that need to be available in the
12131 initial RAM disk. @xref{Initial RAM Disk}.
12133 @item @code{initrd} (default: @code{base-initrd})
12134 A procedure that returns an initial RAM disk for the Linux
12135 kernel. This field is provided to support low-level customization and
12136 should rarely be needed for casual use. @xref{Initial RAM Disk}.
12138 @item @code{firmware} (default: @code{%base-firmware})
12140 List of firmware packages loadable by the operating system kernel.
12142 The default includes firmware needed for Atheros- and Broadcom-based
12143 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
12144 respectively). @xref{Hardware Considerations}, for more info on
12145 supported hardware.
12147 @item @code{host-name}
12150 @item @code{hosts-file}
12152 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
12153 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
12154 Reference Manual}). The default is a file with entries for
12155 @code{localhost} and @var{host-name}.
12157 @item @code{mapped-devices} (default: @code{'()})
12158 A list of mapped devices. @xref{Mapped Devices}.
12160 @item @code{file-systems}
12161 A list of file systems. @xref{File Systems}.
12163 @item @code{swap-devices} (default: @code{'()})
12164 @cindex swap devices
12165 A list of strings identifying devices or files to be used for ``swap
12166 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
12167 Manual}). For example, @code{'("/dev/sda3")} or @code{'("/swapfile")}.
12168 It is possible to specify a swap file in a file system on a mapped
12169 device, provided that the necessary device mapping and file system are
12170 also specified. @xref{Mapped Devices} and @ref{File Systems}.
12172 @item @code{users} (default: @code{%base-user-accounts})
12173 @itemx @code{groups} (default: @code{%base-groups})
12174 List of user accounts and groups. @xref{User Accounts}.
12176 If the @code{users} list lacks a user account with UID@tie{}0, a
12177 ``root'' account with UID@tie{}0 is automatically added.
12179 @item @code{skeletons} (default: @code{(default-skeletons)})
12180 A list of target file name/file-like object tuples (@pxref{G-Expressions,
12181 file-like objects}). These are the skeleton files that will be added to
12182 the home directory of newly-created user accounts.
12184 For instance, a valid value may look like this:
12187 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
12188 (".guile" ,(plain-file "guile"
12189 "(use-modules (ice-9 readline))
12190 (activate-readline)")))
12193 @item @code{issue} (default: @code{%default-issue})
12194 A string denoting the contents of the @file{/etc/issue} file, which is
12195 displayed when users log in on a text console.
12197 @item @code{packages} (default: @code{%base-packages})
12198 A list of packages to be installed in the global profile, which is accessible
12199 at @file{/run/current-system/profile}. Each element is either a package
12200 variable or a package/output tuple. Here's a simple example of both:
12203 (cons* git ; the default "out" output
12204 (list git "send-email") ; another output of git
12205 %base-packages) ; the default set
12208 The default set includes core utilities and it is good practice to
12209 install non-core utilities in user profiles (@pxref{Invoking guix
12212 @item @code{timezone}
12213 A timezone identifying string---e.g., @code{"Europe/Paris"}.
12215 You can run the @command{tzselect} command to find out which timezone
12216 string corresponds to your region. Choosing an invalid timezone name
12217 causes @command{guix system} to fail.
12219 @item @code{locale} (default: @code{"en_US.utf8"})
12220 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
12221 Library Reference Manual}). @xref{Locales}, for more information.
12223 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
12224 The list of locale definitions to be compiled and that may be used at
12225 run time. @xref{Locales}.
12227 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
12228 The list of GNU@tie{}libc packages whose locale data and tools are used
12229 to build the locale definitions. @xref{Locales}, for compatibility
12230 considerations that justify this option.
12232 @item @code{name-service-switch} (default: @code{%default-nss})
12233 Configuration of the libc name service switch (NSS)---a
12234 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
12237 @item @code{services} (default: @code{%base-services})
12238 A list of service objects denoting system services. @xref{Services}.
12240 @cindex essential services
12241 @item @code{essential-services} (default: ...)
12242 The list of ``essential services''---i.e., things like instances of
12243 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
12244 Reference}), which are derived from the operating system definition itself.
12245 As a user you should @emph{never} need to touch this field.
12247 @item @code{pam-services} (default: @code{(base-pam-services)})
12249 @cindex pluggable authentication modules
12250 Linux @dfn{pluggable authentication module} (PAM) services.
12251 @c FIXME: Add xref to PAM services section.
12253 @item @code{setuid-programs} (default: @code{%setuid-programs})
12254 List of string-valued G-expressions denoting setuid programs.
12255 @xref{Setuid Programs}.
12257 @item @code{sudoers-file} (default: @code{%sudoers-specification})
12258 @cindex sudoers file
12259 The contents of the @file{/etc/sudoers} file as a file-like object
12260 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
12262 This file specifies which users can use the @command{sudo} command, what
12263 they are allowed to do, and what privileges they may gain. The default
12264 is that only @code{root} and members of the @code{wheel} group may use
12269 @deffn {Scheme Syntax} this-operating-system
12270 When used in the @emph{lexical scope} of an operating system field definition,
12271 this identifier resolves to the operating system being defined.
12273 The example below shows how to refer to the operating system being defined in
12274 the definition of the @code{label} field:
12277 (use-modules (gnu) (guix))
12281 (label (package-full-name
12282 (operating-system-kernel this-operating-system))))
12285 It is an error to refer to @code{this-operating-system} outside an operating
12292 @section File Systems
12294 The list of file systems to be mounted is specified in the
12295 @code{file-systems} field of the operating system declaration
12296 (@pxref{Using the Configuration System}). Each file system is declared
12297 using the @code{file-system} form, like this:
12301 (mount-point "/home")
12302 (device "/dev/sda3")
12306 As usual, some of the fields are mandatory---those shown in the example
12307 above---while others can be omitted. These are described below.
12309 @deftp {Data Type} file-system
12310 Objects of this type represent file systems to be mounted. They
12311 contain the following members:
12315 This is a string specifying the type of the file system---e.g.,
12318 @item @code{mount-point}
12319 This designates the place where the file system is to be mounted.
12321 @item @code{device}
12322 This names the ``source'' of the file system. It can be one of three
12323 things: a file system label, a file system UUID, or the name of a
12324 @file{/dev} node. Labels and UUIDs offer a way to refer to file
12325 systems without having to hard-code their actual device
12326 name@footnote{Note that, while it is tempting to use
12327 @file{/dev/disk/by-uuid} and similar device names to achieve the same
12328 result, this is not recommended: These special device nodes are created
12329 by the udev daemon and may be unavailable at the time the device is
12332 @findex file-system-label
12333 File system labels are created using the @code{file-system-label}
12334 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
12335 plain strings. Here's an example of a file system referred to by its
12336 label, as shown by the @command{e2label} command:
12340 (mount-point "/home")
12342 (device (file-system-label "my-home")))
12346 UUIDs are converted from their string representation (as shown by the
12347 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
12348 @code{uuid} form expects 16-byte UUIDs as defined in
12349 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
12350 form of UUID used by the ext2 family of file systems and others, but it
12351 is different from ``UUIDs'' found in FAT file systems, for instance.},
12356 (mount-point "/home")
12358 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
12361 When the source of a file system is a mapped device (@pxref{Mapped
12362 Devices}), its @code{device} field @emph{must} refer to the mapped
12363 device name---e.g., @file{"/dev/mapper/root-partition"}.
12364 This is required so that
12365 the system knows that mounting the file system depends on having the
12366 corresponding device mapping established.
12368 @item @code{flags} (default: @code{'()})
12369 This is a list of symbols denoting mount flags. Recognized flags
12370 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
12371 access to special files), @code{no-suid} (ignore setuid and setgid
12372 bits), @code{no-atime} (do not update file access times),
12373 @code{strict-atime} (update file access time), @code{lazy-time} (only
12374 update time on the in-memory version of the file inode), and
12375 @code{no-exec} (disallow program execution).
12376 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
12377 Manual}, for more information on these flags.
12379 @item @code{options} (default: @code{#f})
12380 This is either @code{#f}, or a string denoting mount options passed to
12381 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
12382 Library Reference Manual}, for details and run @command{man 8 mount} for
12383 options for various file systems. Note that the
12384 @code{file-system-options->alist} and @code{alist->file-system-options}
12385 procedures from @code{(gnu system file-systems)} can be used to convert
12386 file system options given as an association list to the string
12387 representation, and vice-versa.
12389 @item @code{mount?} (default: @code{#t})
12390 This value indicates whether to automatically mount the file system when
12391 the system is brought up. When set to @code{#f}, the file system gets
12392 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
12393 is not automatically mounted.
12395 @item @code{needed-for-boot?} (default: @code{#f})
12396 This Boolean value indicates whether the file system is needed when
12397 booting. If that is true, then the file system is mounted when the
12398 initial RAM disk (initrd) is loaded. This is always the case, for
12399 instance, for the root file system.
12401 @item @code{check?} (default: @code{#t})
12402 This Boolean indicates whether the file system needs to be checked for
12403 errors before being mounted.
12405 @item @code{create-mount-point?} (default: @code{#f})
12406 When true, the mount point is created if it does not exist yet.
12408 @item @code{mount-may-fail?} (default: @code{#f})
12409 When true, this indicates that mounting this file system can fail but
12410 that should not be considered an error. This is useful in unusual
12411 cases; an example of this is @code{efivarfs}, a file system that can
12412 only be mounted on EFI/UEFI systems.
12414 @item @code{dependencies} (default: @code{'()})
12415 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
12416 representing file systems that must be mounted or mapped devices that
12417 must be opened before (and unmounted or closed after) this one.
12419 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
12420 a dependency of @file{/sys/fs/cgroup/cpu} and
12421 @file{/sys/fs/cgroup/memory}.
12423 Another example is a file system that depends on a mapped device, for
12424 example for an encrypted partition (@pxref{Mapped Devices}).
12428 @deffn {Scheme Procedure} file-system-label @var{str}
12429 This procedure returns an opaque file system label from @var{str}, a
12433 (file-system-label "home")
12434 @result{} #<file-system-label "home">
12437 File system labels are used to refer to file systems by label rather
12438 than by device name. See above for examples.
12441 The @code{(gnu system file-systems)} exports the following useful
12444 @defvr {Scheme Variable} %base-file-systems
12445 These are essential file systems that are required on normal systems,
12446 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
12447 below). Operating system declarations should always contain at least
12451 @defvr {Scheme Variable} %pseudo-terminal-file-system
12452 This is the file system to be mounted as @file{/dev/pts}. It supports
12453 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
12454 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
12455 Manual}). Pseudo-terminals are used by terminal emulators such as
12459 @defvr {Scheme Variable} %shared-memory-file-system
12460 This file system is mounted as @file{/dev/shm} and is used to support
12461 memory sharing across processes (@pxref{Memory-mapped I/O,
12462 @code{shm_open},, libc, The GNU C Library Reference Manual}).
12465 @defvr {Scheme Variable} %immutable-store
12466 This file system performs a read-only ``bind mount'' of
12467 @file{/gnu/store}, making it read-only for all the users including
12468 @code{root}. This prevents against accidental modification by software
12469 running as @code{root} or by system administrators.
12471 The daemon itself is still able to write to the store: it remounts it
12472 read-write in its own ``name space.''
12475 @defvr {Scheme Variable} %binary-format-file-system
12476 The @code{binfmt_misc} file system, which allows handling of arbitrary
12477 executable file types to be delegated to user space. This requires the
12478 @code{binfmt.ko} kernel module to be loaded.
12481 @defvr {Scheme Variable} %fuse-control-file-system
12482 The @code{fusectl} file system, which allows unprivileged users to mount
12483 and unmount user-space FUSE file systems. This requires the
12484 @code{fuse.ko} kernel module to be loaded.
12487 The @code{(gnu system uuid)} module provides tools to deal with file
12488 system ``unique identifiers'' (UUIDs).
12490 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
12491 Return an opaque UUID (unique identifier) object of the given @var{type}
12492 (a symbol) by parsing @var{str} (a string):
12495 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
12496 @result{} #<<uuid> type: dce bv: @dots{}>
12498 (uuid "1234-ABCD" 'fat)
12499 @result{} #<<uuid> type: fat bv: @dots{}>
12502 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
12503 @code{ntfs}, or one of the commonly found synonyms for these.
12505 UUIDs are another way to unambiguously refer to file systems in
12506 operating system configuration. See the examples above.
12510 @node Btrfs file system
12511 @subsection Btrfs file system
12513 The Btrfs has special features, such as subvolumes, that merit being
12514 explained in more details. The following section attempts to cover
12515 basic as well as complex uses of a Btrfs file system with the Guix
12518 In its simplest usage, a Btrfs file system can be described, for
12523 (mount-point "/home")
12525 (device (file-system-label "my-home")))
12528 The example below is more complex, as it makes use of a Btrfs
12529 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
12530 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
12531 dependency on @code{mapped-devices}):
12535 (device (file-system-label "my-btrfs-pool"))
12538 (options "subvol=rootfs")
12539 (dependencies mapped-devices))
12542 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
12543 top level during the early boot, and rely on their configuration to
12544 refer to the correct subvolume path within that top level. The
12545 bootloaders operating in this way typically produce their configuration
12546 on a running system where the Btrfs partitions are already mounted and
12547 where the subvolume information is readily available. As an example,
12548 @command{grub-mkconfig}, the configuration generator command shipped
12549 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
12550 path of a subvolume.
12552 The Guix System produces a bootloader configuration using the operating
12553 system configuration as its sole input; it is therefore necessary to
12554 extract the subvolume name on which @file{/gnu/store} lives (if any)
12555 from that operating system configuration. To better illustrate,
12556 consider a subvolume named 'rootfs' which contains the root file system
12557 data. In such situation, the GRUB bootloader would only see the top
12558 level of the root Btrfs partition, e.g.:
12562 ├── rootfs (subvolume directory)
12563 ├── gnu (normal directory)
12564 ├── store (normal directory)
12568 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
12569 of the kernel, initrd binaries and any other files referred to in the
12570 GRUB configuration that must be found during the early boot.
12572 The next example shows a nested hierarchy of subvolumes and
12577 ├── rootfs (subvolume)
12578 ├── gnu (normal directory)
12579 ├── store (subvolume)
12583 This scenario would work without mounting the 'store' subvolume.
12584 Mounting 'rootfs' is sufficient, since the subvolume name matches its
12585 intended mount point in the file system hierarchy. Alternatively, the
12586 'store' subvolume could be referred to by setting the @code{subvol}
12587 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
12589 Finally, a more contrived example of nested subvolumes:
12593 ├── root-snapshots (subvolume)
12594 ├── root-current (subvolume)
12595 ├── guix-store (subvolume)
12599 Here, the 'guix-store' subvolume doesn't match its intended mount point,
12600 so it is necessary to mount it. The subvolume must be fully specified,
12601 by passing its file name to the @code{subvol} option. To illustrate,
12602 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
12603 a file system declaration such as:
12607 (device (file-system-label "btrfs-pool-1"))
12608 (mount-point "/gnu/store")
12610 (options "subvol=root-snapshots/root-current/guix-store,\
12611 compress-force=zstd,space_cache=v2"))
12614 @node Mapped Devices
12615 @section Mapped Devices
12617 @cindex device mapping
12618 @cindex mapped devices
12619 The Linux kernel has a notion of @dfn{device mapping}: a block device,
12620 such as a hard disk partition, can be @dfn{mapped} into another device,
12621 usually in @code{/dev/mapper/},
12622 with additional processing over the data that flows through
12623 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
12624 concept of a ``mapped device'' and that of a file system: both boil down
12625 to @emph{translating} input/output operations made on a file to
12626 operations on its backing store. Thus, the Hurd implements mapped
12627 devices, like file systems, using the generic @dfn{translator} mechanism
12628 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
12629 typical example is encryption device mapping: all writes to the mapped
12630 device are encrypted, and all reads are deciphered, transparently.
12631 Guix extends this notion by considering any device or set of devices that
12632 are @dfn{transformed} in some way to create a new device; for instance,
12633 RAID devices are obtained by @dfn{assembling} several other devices, such
12634 as hard disks or partitions, into a new one that behaves as one partition.
12635 Other examples, not yet implemented, are LVM logical volumes.
12637 Mapped devices are declared using the @code{mapped-device} form,
12638 defined as follows; for examples, see below.
12640 @deftp {Data Type} mapped-device
12641 Objects of this type represent device mappings that will be made when
12642 the system boots up.
12646 This is either a string specifying the name of the block device to be mapped,
12647 such as @code{"/dev/sda3"}, or a list of such strings when several devices
12648 need to be assembled for creating a new one.
12651 This string specifies the name of the resulting mapped device. For
12652 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
12653 specifying @code{"my-partition"} leads to the creation of
12654 the @code{"/dev/mapper/my-partition"} device.
12655 For RAID devices of type @code{raid-device-mapping}, the full device name
12656 such as @code{"/dev/md0"} needs to be given.
12659 This must be a @code{mapped-device-kind} object, which specifies how
12660 @var{source} is mapped to @var{target}.
12664 @defvr {Scheme Variable} luks-device-mapping
12665 This defines LUKS block device encryption using the @command{cryptsetup}
12666 command from the package with the same name. It relies on the
12667 @code{dm-crypt} Linux kernel module.
12670 @defvr {Scheme Variable} raid-device-mapping
12671 This defines a RAID device, which is assembled using the @code{mdadm}
12672 command from the package with the same name. It requires a Linux kernel
12673 module for the appropriate RAID level to be loaded, such as @code{raid456}
12674 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
12677 @cindex disk encryption
12679 The following example specifies a mapping from @file{/dev/sda3} to
12680 @file{/dev/mapper/home} using LUKS---the
12681 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
12682 standard mechanism for disk encryption.
12683 The @file{/dev/mapper/home}
12684 device can then be used as the @code{device} of a @code{file-system}
12685 declaration (@pxref{File Systems}).
12689 (source "/dev/sda3")
12691 (type luks-device-mapping))
12694 Alternatively, to become independent of device numbering, one may obtain
12695 the LUKS UUID (@dfn{unique identifier}) of the source device by a
12699 cryptsetup luksUUID /dev/sda3
12702 and use it as follows:
12706 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
12708 (type luks-device-mapping))
12711 @cindex swap encryption
12712 It is also desirable to encrypt swap space, since swap space may contain
12713 sensitive data. One way to accomplish that is to use a swap file in a
12714 file system on a device mapped via LUKS encryption. In this way, the
12715 swap file is encrypted because the entire device is encrypted.
12716 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
12718 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
12719 may be declared as follows:
12723 (source (list "/dev/sda1" "/dev/sdb1"))
12724 (target "/dev/md0")
12725 (type raid-device-mapping))
12728 The @file{/dev/md0} device can then be used as the @code{device} of a
12729 @code{file-system} declaration (@pxref{File Systems}).
12730 Note that the RAID level need not be given; it is chosen during the
12731 initial creation and formatting of the RAID device and is determined
12732 automatically later.
12735 @node User Accounts
12736 @section User Accounts
12740 @cindex user accounts
12741 User accounts and groups are entirely managed through the
12742 @code{operating-system} declaration. They are specified with the
12743 @code{user-account} and @code{user-group} forms:
12749 (supplementary-groups '("wheel" ;allow use of sudo, etc.
12750 "audio" ;sound card
12751 "video" ;video devices such as webcams
12752 "cdrom")) ;the good ol' CD-ROM
12753 (comment "Bob's sister")
12754 (home-directory "/home/alice"))
12757 When booting or upon completion of @command{guix system reconfigure},
12758 the system ensures that only the user accounts and groups specified in
12759 the @code{operating-system} declaration exist, and with the specified
12760 properties. Thus, account or group creations or modifications made by
12761 directly invoking commands such as @command{useradd} are lost upon
12762 reconfiguration or reboot. This ensures that the system remains exactly
12765 @deftp {Data Type} user-account
12766 Objects of this type represent user accounts. The following members may
12771 The name of the user account.
12775 This is the name (a string) or identifier (a number) of the user group
12776 this account belongs to.
12778 @item @code{supplementary-groups} (default: @code{'()})
12779 Optionally, this can be defined as a list of group names that this
12780 account belongs to.
12782 @item @code{uid} (default: @code{#f})
12783 This is the user ID for this account (a number), or @code{#f}. In the
12784 latter case, a number is automatically chosen by the system when the
12785 account is created.
12787 @item @code{comment} (default: @code{""})
12788 A comment about the account, such as the account owner's full name.
12790 @item @code{home-directory}
12791 This is the name of the home directory for the account.
12793 @item @code{create-home-directory?} (default: @code{#t})
12794 Indicates whether the home directory of this account should be created
12795 if it does not exist yet.
12797 @item @code{shell} (default: Bash)
12798 This is a G-expression denoting the file name of a program to be used as
12799 the shell (@pxref{G-Expressions}).
12801 @item @code{system?} (default: @code{#f})
12802 This Boolean value indicates whether the account is a ``system''
12803 account. System accounts are sometimes treated specially; for instance,
12804 graphical login managers do not list them.
12806 @anchor{user-account-password}
12807 @cindex password, for user accounts
12808 @item @code{password} (default: @code{#f})
12809 You would normally leave this field to @code{#f}, initialize user
12810 passwords as @code{root} with the @command{passwd} command, and then let
12811 users change it with @command{passwd}. Passwords set with
12812 @command{passwd} are of course preserved across reboot and
12815 If you @emph{do} want to set an initial password for an account, then
12816 this field must contain the encrypted password, as a string. You can use the
12817 @code{crypt} procedure for this purpose:
12824 ;; Specify a SHA-512-hashed initial password.
12825 (password (crypt "InitialPassword!" "$6$abc")))
12829 The hash of this initial password will be available in a file in
12830 @file{/gnu/store}, readable by all the users, so this method must be used with
12834 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
12835 more information on password encryption, and @ref{Encryption,,, guile, GNU
12836 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
12842 User group declarations are even simpler:
12845 (user-group (name "students"))
12848 @deftp {Data Type} user-group
12849 This type is for, well, user groups. There are just a few fields:
12853 The name of the group.
12855 @item @code{id} (default: @code{#f})
12856 The group identifier (a number). If @code{#f}, a new number is
12857 automatically allocated when the group is created.
12859 @item @code{system?} (default: @code{#f})
12860 This Boolean value indicates whether the group is a ``system'' group.
12861 System groups have low numerical IDs.
12863 @item @code{password} (default: @code{#f})
12864 What, user groups can have a password? Well, apparently yes. Unless
12865 @code{#f}, this field specifies the password of the group.
12870 For convenience, a variable lists all the basic user groups one may
12873 @defvr {Scheme Variable} %base-groups
12874 This is the list of basic user groups that users and/or packages expect
12875 to be present on the system. This includes groups such as ``root'',
12876 ``wheel'', and ``users'', as well as groups used to control access to
12877 specific devices such as ``audio'', ``disk'', and ``cdrom''.
12880 @defvr {Scheme Variable} %base-user-accounts
12881 This is the list of basic system accounts that programs may expect to
12882 find on a GNU/Linux system, such as the ``nobody'' account.
12884 Note that the ``root'' account is not included here. It is a
12885 special-case and is automatically added whether or not it is specified.
12888 @node Keyboard Layout
12889 @section Keyboard Layout
12891 @cindex keyboard layout
12893 To specify what each key of your keyboard does, you need to tell the operating
12894 system what @dfn{keyboard layout} you want to use. The default, when nothing
12895 is specified, is the US English QWERTY layout for 105-key PC keyboards.
12896 However, German speakers will usually prefer the German QWERTZ layout, French
12897 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
12898 or bépo, and they might even want to further customize the effect of some of
12899 the keys. This section explains how to get that done.
12901 @cindex keyboard layout, definition
12902 There are three components that will want to know about your keyboard layout:
12906 The @emph{bootloader} may want to know what keyboard layout you want to use
12907 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
12908 you want, for instance, to make sure that you can type the passphrase of your
12909 encrypted root partition using the right layout.
12912 The @emph{operating system kernel}, Linux, will need that so that the console
12913 is properly configured (@pxref{operating-system Reference,
12914 @code{keyboard-layout}}).
12917 The @emph{graphical display server}, usually Xorg, also has its own idea of
12918 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
12921 Guix allows you to configure all three separately but, fortunately, it allows
12922 you to share the same keyboard layout for all three components.
12924 @cindex XKB, keyboard layouts
12925 Keyboard layouts are represented by records created by the
12926 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
12927 the X Keyboard extension (XKB), each layout has four attributes: a name (often
12928 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
12929 optional variant name, an optional keyboard model name, and a possibly empty
12930 list of additional options. In most cases the layout name is all you care
12931 about. Here are a few example:
12934 ;; The German QWERTZ layout. Here we assume a standard
12935 ;; "pc105" keyboard model.
12936 (keyboard-layout "de")
12938 ;; The bépo variant of the French layout.
12939 (keyboard-layout "fr" "bepo")
12941 ;; The Catalan layout.
12942 (keyboard-layout "es" "cat")
12944 ;; Arabic layout with "Alt-Shift" to switch to US layout.
12945 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
12947 ;; The Latin American Spanish layout. In addition, the
12948 ;; "Caps Lock" key is used as an additional "Ctrl" key,
12949 ;; and the "Menu" key is used as a "Compose" key to enter
12950 ;; accented letters.
12951 (keyboard-layout "latam"
12952 #:options '("ctrl:nocaps" "compose:menu"))
12954 ;; The Russian layout for a ThinkPad keyboard.
12955 (keyboard-layout "ru" #:model "thinkpad")
12957 ;; The "US international" layout, which is the US layout plus
12958 ;; dead keys to enter accented characters. This is for an
12959 ;; Apple MacBook keyboard.
12960 (keyboard-layout "us" "intl" #:model "macbook78")
12963 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
12964 for a complete list of supported layouts, variants, and models.
12966 @cindex keyboard layout, configuration
12967 Let's say you want your system to use the Turkish keyboard layout throughout
12968 your system---bootloader, console, and Xorg. Here's what your system
12969 configuration would look like:
12971 @findex set-xorg-configuration
12973 ;; Using the Turkish layout for the bootloader, the console,
12978 (keyboard-layout (keyboard-layout "tr")) ;for the console
12979 (bootloader (bootloader-configuration
12980 (bootloader grub-efi-bootloader)
12981 (target "/boot/efi")
12982 (keyboard-layout keyboard-layout))) ;for GRUB
12983 (services (cons (set-xorg-configuration
12984 (xorg-configuration ;for Xorg
12985 (keyboard-layout keyboard-layout)))
12986 %desktop-services)))
12989 In the example above, for GRUB and for Xorg, we just refer to the
12990 @code{keyboard-layout} field defined above, but we could just as well refer to
12991 a different layout. The @code{set-xorg-configuration} procedure communicates
12992 the desired Xorg configuration to the graphical log-in manager, by default
12995 We've discussed how to specify the @emph{default} keyboard layout of your
12996 system when it starts, but you can also adjust it at run time:
13000 If you're using GNOME, its settings panel has a ``Region & Language'' entry
13001 where you can select one or more keyboard layouts.
13004 Under Xorg, the @command{setxkbmap} command (from the same-named package)
13005 allows you to change the current layout. For example, this is how you would
13006 change the layout to US Dvorak:
13009 setxkbmap us dvorak
13013 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
13014 console. However, note that @code{loadkeys} does @emph{not} use the XKB
13015 keyboard layout categorization described above. The command below loads the
13016 French bépo layout:
13027 A @dfn{locale} defines cultural conventions for a particular language
13028 and region of the world (@pxref{Locales,,, libc, The GNU C Library
13029 Reference Manual}). Each locale has a name that typically has the form
13030 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
13031 @code{fr_LU.utf8} designates the locale for the French language, with
13032 cultural conventions from Luxembourg, and using the UTF-8 encoding.
13034 @cindex locale definition
13035 Usually, you will want to specify the default locale for the machine
13036 using the @code{locale} field of the @code{operating-system} declaration
13037 (@pxref{operating-system Reference, @code{locale}}).
13039 The selected locale is automatically added to the @dfn{locale
13040 definitions} known to the system if needed, with its codeset inferred
13041 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
13042 @code{UTF-8} codeset. Additional locale definitions can be specified in
13043 the @code{locale-definitions} slot of @code{operating-system}---this is
13044 useful, for instance, if the codeset could not be inferred from the
13045 locale name. The default set of locale definitions includes some widely
13046 used locales, but not all the available locales, in order to save space.
13048 For instance, to add the North Frisian locale for Germany, the value of
13052 (cons (locale-definition
13053 (name "fy_DE.utf8") (source "fy_DE"))
13054 %default-locale-definitions)
13057 Likewise, to save space, one might want @code{locale-definitions} to
13058 list only the locales that are actually used, as in:
13061 (list (locale-definition
13062 (name "ja_JP.eucjp") (source "ja_JP")
13063 (charset "EUC-JP")))
13067 The compiled locale definitions are available at
13068 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
13069 version, which is the default location where the GNU@tie{}libc provided
13070 by Guix looks for locale data. This can be overridden using the
13071 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
13072 @env{LOCPATH} and locale packages}).
13074 The @code{locale-definition} form is provided by the @code{(gnu system
13075 locale)} module. Details are given below.
13077 @deftp {Data Type} locale-definition
13078 This is the data type of a locale definition.
13083 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
13084 Reference Manual}, for more information on locale names.
13086 @item @code{source}
13087 The name of the source for that locale. This is typically the
13088 @code{@var{language}_@var{territory}} part of the locale name.
13090 @item @code{charset} (default: @code{"UTF-8"})
13091 The ``character set'' or ``code set'' for that locale,
13092 @uref{https://www.iana.org/assignments/character-sets, as defined by
13098 @defvr {Scheme Variable} %default-locale-definitions
13099 A list of commonly used UTF-8 locales, used as the default
13100 value of the @code{locale-definitions} field of @code{operating-system}
13103 @cindex locale name
13104 @cindex normalized codeset in locale names
13105 These locale definitions use the @dfn{normalized codeset} for the part
13106 that follows the dot in the name (@pxref{Using gettextized software,
13107 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
13108 instance it has @code{uk_UA.utf8} but @emph{not}, say,
13109 @code{uk_UA.UTF-8}.
13112 @subsection Locale Data Compatibility Considerations
13114 @cindex incompatibility, of locale data
13115 @code{operating-system} declarations provide a @code{locale-libcs} field
13116 to specify the GNU@tie{}libc packages that are used to compile locale
13117 declarations (@pxref{operating-system Reference}). ``Why would I
13118 care?'', you may ask. Well, it turns out that the binary format of
13119 locale data is occasionally incompatible from one libc version to
13122 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
13123 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
13124 For instance, a program linked against libc version 2.21 is unable to
13125 read locale data produced with libc 2.22; worse, that program
13126 @emph{aborts} instead of simply ignoring the incompatible locale
13127 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
13128 the incompatible locale data, which is already an improvement.}.
13129 Similarly, a program linked against libc 2.22 can read most, but not
13130 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
13131 data is incompatible); thus calls to @code{setlocale} may fail, but
13132 programs will not abort.
13134 The ``problem'' with Guix is that users have a lot of freedom: They can
13135 choose whether and when to upgrade software in their profiles, and might
13136 be using a libc version different from the one the system administrator
13137 used to build the system-wide locale data.
13139 Fortunately, unprivileged users can also install their own locale data
13140 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
13141 @env{GUIX_LOCPATH} and locale packages}).
13143 Still, it is best if the system-wide locale data at
13144 @file{/run/current-system/locale} is built for all the libc versions
13145 actually in use on the system, so that all the programs can access
13146 it---this is especially crucial on a multi-user system. To do that, the
13147 administrator can specify several libc packages in the
13148 @code{locale-libcs} field of @code{operating-system}:
13151 (use-package-modules base)
13155 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
13158 This example would lead to a system containing locale definitions for
13159 both libc 2.21 and the current version of libc in
13160 @file{/run/current-system/locale}.
13166 @cindex system services
13167 An important part of preparing an @code{operating-system} declaration is
13168 listing @dfn{system services} and their configuration (@pxref{Using the
13169 Configuration System}). System services are typically daemons launched
13170 when the system boots, or other actions needed at that time---e.g.,
13171 configuring network access.
13173 Guix has a broad definition of ``service'' (@pxref{Service
13174 Composition}), but many services are managed by the GNU@tie{}Shepherd
13175 (@pxref{Shepherd Services}). On a running system, the @command{herd}
13176 command allows you to list the available services, show their status,
13177 start and stop them, or do other specific operations (@pxref{Jump
13178 Start,,, shepherd, The GNU Shepherd Manual}). For example:
13184 The above command, run as @code{root}, lists the currently defined
13185 services. The @command{herd doc} command shows a synopsis of the given
13186 service and its associated actions:
13190 Run libc's name service cache daemon (nscd).
13192 # herd doc nscd action invalidate
13193 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
13196 The @command{start}, @command{stop}, and @command{restart} sub-commands
13197 have the effect you would expect. For instance, the commands below stop
13198 the nscd service and restart the Xorg display server:
13202 Service nscd has been stopped.
13203 # herd restart xorg-server
13204 Service xorg-server has been stopped.
13205 Service xorg-server has been started.
13208 The following sections document the available services, starting with
13209 the core services, that may be used in an @code{operating-system}
13213 * Base Services:: Essential system services.
13214 * Scheduled Job Execution:: The mcron service.
13215 * Log Rotation:: The rottlog service.
13216 * Networking Services:: Network setup, SSH daemon, etc.
13217 * Unattended Upgrades:: Automated system upgrades.
13218 * X Window:: Graphical display.
13219 * Printing Services:: Local and remote printer support.
13220 * Desktop Services:: D-Bus and desktop services.
13221 * Sound Services:: ALSA and Pulseaudio services.
13222 * Database Services:: SQL databases, key-value stores, etc.
13223 * Mail Services:: IMAP, POP3, SMTP, and all that.
13224 * Messaging Services:: Messaging services.
13225 * Telephony Services:: Telephony services.
13226 * Monitoring Services:: Monitoring services.
13227 * Kerberos Services:: Kerberos services.
13228 * LDAP Services:: LDAP services.
13229 * Web Services:: Web servers.
13230 * Certificate Services:: TLS certificates via Let's Encrypt.
13231 * DNS Services:: DNS daemons.
13232 * VPN Services:: VPN daemons.
13233 * Network File System:: NFS related services.
13234 * Continuous Integration:: The Cuirass service.
13235 * Power Management Services:: Extending battery life.
13236 * Audio Services:: The MPD.
13237 * Virtualization Services:: Virtualization services.
13238 * Version Control Services:: Providing remote access to Git repositories.
13239 * Game Services:: Game servers.
13240 * PAM Mount Service:: Service to mount volumes when logging in.
13241 * Guix Services:: Services relating specifically to Guix.
13242 * Linux Services:: Services tied to the Linux kernel.
13243 * Hurd Services:: Services specific for a Hurd System.
13244 * Miscellaneous Services:: Other services.
13247 @node Base Services
13248 @subsection Base Services
13250 The @code{(gnu services base)} module provides definitions for the basic
13251 services that one expects from the system. The services exported by
13252 this module are listed below.
13254 @defvr {Scheme Variable} %base-services
13255 This variable contains a list of basic services (@pxref{Service Types
13256 and Services}, for more information on service objects) one would
13257 expect from the system: a login service (mingetty) on each tty, syslogd,
13258 the libc name service cache daemon (nscd), the udev device manager, and
13261 This is the default value of the @code{services} field of
13262 @code{operating-system} declarations. Usually, when customizing a
13263 system, you will want to append services to @code{%base-services}, like
13267 (append (list (service avahi-service-type)
13268 (service openssh-service-type))
13273 @defvr {Scheme Variable} special-files-service-type
13274 This is the service that sets up ``special files'' such as
13275 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
13277 The value associated with @code{special-files-service-type} services
13278 must be a list of tuples where the first element is the ``special file''
13279 and the second element is its target. By default it is:
13281 @cindex @file{/bin/sh}
13282 @cindex @file{sh}, in @file{/bin}
13284 `(("/bin/sh" ,(file-append bash "/bin/sh")))
13287 @cindex @file{/usr/bin/env}
13288 @cindex @file{env}, in @file{/usr/bin}
13289 If you want to add, say, @code{/usr/bin/env} to your system, you can
13293 `(("/bin/sh" ,(file-append bash "/bin/sh"))
13294 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
13297 Since this is part of @code{%base-services}, you can use
13298 @code{modify-services} to customize the set of special files
13299 (@pxref{Service Reference, @code{modify-services}}). But the simple way
13300 to add a special file is @i{via} the @code{extra-special-file} procedure
13304 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
13305 Use @var{target} as the ``special file'' @var{file}.
13307 For example, adding the following lines to the @code{services} field of
13308 your operating system declaration leads to a @file{/usr/bin/env}
13312 (extra-special-file "/usr/bin/env"
13313 (file-append coreutils "/bin/env"))
13317 @deffn {Scheme Procedure} host-name-service @var{name}
13318 Return a service that sets the host name to @var{name}.
13321 @defvr {Scheme Variable} console-font-service-type
13322 Install the given fonts on the specified ttys (fonts are per
13323 virtual console on the kernel Linux). The value of this service is a list of
13324 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
13325 package or any valid argument to @command{setfont}, as in this example:
13328 `(("tty1" . "LatGrkCyr-8x16")
13329 ("tty2" . ,(file-append
13331 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
13332 ("tty3" . ,(file-append
13334 "/share/consolefonts/ter-132n"))) ; for HDPI
13338 @deffn {Scheme Procedure} login-service @var{config}
13339 Return a service to run login according to @var{config}, a
13340 @code{<login-configuration>} object, which specifies the message of the day,
13341 among other things.
13344 @deftp {Data Type} login-configuration
13345 This is the data type representing the configuration of login.
13350 @cindex message of the day
13351 A file-like object containing the ``message of the day''.
13353 @item @code{allow-empty-passwords?} (default: @code{#t})
13354 Allow empty passwords by default so that first-time users can log in when
13355 the 'root' account has just been created.
13360 @deffn {Scheme Procedure} mingetty-service @var{config}
13361 Return a service to run mingetty according to @var{config}, a
13362 @code{<mingetty-configuration>} object, which specifies the tty to run, among
13366 @deftp {Data Type} mingetty-configuration
13367 This is the data type representing the configuration of Mingetty, which
13368 provides the default implementation of virtual console log-in.
13373 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
13375 @item @code{auto-login} (default: @code{#f})
13376 When true, this field must be a string denoting the user name under
13377 which the system automatically logs in. When it is @code{#f}, a
13378 user name and password must be entered to log in.
13380 @item @code{login-program} (default: @code{#f})
13381 This must be either @code{#f}, in which case the default log-in program
13382 is used (@command{login} from the Shadow tool suite), or a gexp denoting
13383 the name of the log-in program.
13385 @item @code{login-pause?} (default: @code{#f})
13386 When set to @code{#t} in conjunction with @var{auto-login}, the user
13387 will have to press a key before the log-in shell is launched.
13389 @item @code{mingetty} (default: @var{mingetty})
13390 The Mingetty package to use.
13395 @deffn {Scheme Procedure} agetty-service @var{config}
13396 Return a service to run agetty according to @var{config}, an
13397 @code{<agetty-configuration>} object, which specifies the tty to run,
13398 among other things.
13401 @deftp {Data Type} agetty-configuration
13402 This is the data type representing the configuration of agetty, which
13403 implements virtual and serial console log-in. See the @code{agetty(8)}
13404 man page for more information.
13409 The name of the console this agetty runs on, as a string---e.g.,
13410 @code{"ttyS0"}. This argument is optional, it will default to
13411 a reasonable default serial port used by the kernel Linux.
13413 For this, if there is a value for an option @code{agetty.tty} in the kernel
13414 command line, agetty will extract the device name of the serial port
13415 from it and use that.
13417 If not and if there is a value for an option @code{console} with a tty in
13418 the Linux command line, agetty will extract the device name of the
13419 serial port from it and use that.
13421 In both cases, agetty will leave the other serial device settings
13422 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
13425 @item @code{baud-rate} (default: @code{#f})
13426 A string containing a comma-separated list of one or more baud rates, in
13429 @item @code{term} (default: @code{#f})
13430 A string containing the value used for the @env{TERM} environment
13433 @item @code{eight-bits?} (default: @code{#f})
13434 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
13437 @item @code{auto-login} (default: @code{#f})
13438 When passed a login name, as a string, the specified user will be logged
13439 in automatically without prompting for their login name or password.
13441 @item @code{no-reset?} (default: @code{#f})
13442 When @code{#t}, don't reset terminal cflags (control modes).
13444 @item @code{host} (default: @code{#f})
13445 This accepts a string containing the ``login_host'', which will be written
13446 into the @file{/var/run/utmpx} file.
13448 @item @code{remote?} (default: @code{#f})
13449 When set to @code{#t} in conjunction with @var{host}, this will add an
13450 @code{-r} fakehost option to the command line of the login program
13451 specified in @var{login-program}.
13453 @item @code{flow-control?} (default: @code{#f})
13454 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
13456 @item @code{no-issue?} (default: @code{#f})
13457 When set to @code{#t}, the contents of the @file{/etc/issue} file will
13458 not be displayed before presenting the login prompt.
13460 @item @code{init-string} (default: @code{#f})
13461 This accepts a string that will be sent to the tty or modem before
13462 sending anything else. It can be used to initialize a modem.
13464 @item @code{no-clear?} (default: @code{#f})
13465 When set to @code{#t}, agetty will not clear the screen before showing
13468 @item @code{login-program} (default: (file-append shadow "/bin/login"))
13469 This must be either a gexp denoting the name of a log-in program, or
13470 unset, in which case the default value is the @command{login} from the
13473 @item @code{local-line} (default: @code{#f})
13474 Control the CLOCAL line flag. This accepts one of three symbols as
13475 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
13476 the default value chosen by agetty is @code{'auto}.
13478 @item @code{extract-baud?} (default: @code{#f})
13479 When set to @code{#t}, instruct agetty to try to extract the baud rate
13480 from the status messages produced by certain types of modems.
13482 @item @code{skip-login?} (default: @code{#f})
13483 When set to @code{#t}, do not prompt the user for a login name. This
13484 can be used with @var{login-program} field to use non-standard login
13487 @item @code{no-newline?} (default: @code{#f})
13488 When set to @code{#t}, do not print a newline before printing the
13489 @file{/etc/issue} file.
13491 @c Is this dangerous only when used with login-program, or always?
13492 @item @code{login-options} (default: @code{#f})
13493 This option accepts a string containing options that are passed to the
13494 login program. When used with the @var{login-program}, be aware that a
13495 malicious user could try to enter a login name containing embedded
13496 options that could be parsed by the login program.
13498 @item @code{login-pause} (default: @code{#f})
13499 When set to @code{#t}, wait for any key before showing the login prompt.
13500 This can be used in conjunction with @var{auto-login} to save memory by
13501 lazily spawning shells.
13503 @item @code{chroot} (default: @code{#f})
13504 Change root to the specified directory. This option accepts a directory
13507 @item @code{hangup?} (default: @code{#f})
13508 Use the Linux system call @code{vhangup} to do a virtual hangup of the
13509 specified terminal.
13511 @item @code{keep-baud?} (default: @code{#f})
13512 When set to @code{#t}, try to keep the existing baud rate. The baud
13513 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
13516 @item @code{timeout} (default: @code{#f})
13517 When set to an integer value, terminate if no user name could be read
13518 within @var{timeout} seconds.
13520 @item @code{detect-case?} (default: @code{#f})
13521 When set to @code{#t}, turn on support for detecting an uppercase-only
13522 terminal. This setting will detect a login name containing only
13523 uppercase letters as indicating an uppercase-only terminal and turn on
13524 some upper-to-lower case conversions. Note that this will not support
13525 Unicode characters.
13527 @item @code{wait-cr?} (default: @code{#f})
13528 When set to @code{#t}, wait for the user or modem to send a
13529 carriage-return or linefeed character before displaying
13530 @file{/etc/issue} or login prompt. This is typically used with the
13531 @var{init-string} option.
13533 @item @code{no-hints?} (default: @code{#f})
13534 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
13537 @item @code{no-hostname?} (default: @code{#f})
13538 By default, the hostname is printed. When this option is set to
13539 @code{#t}, no hostname will be shown at all.
13541 @item @code{long-hostname?} (default: @code{#f})
13542 By default, the hostname is only printed until the first dot. When this
13543 option is set to @code{#t}, the fully qualified hostname by
13544 @code{gethostname} or @code{getaddrinfo} is shown.
13546 @item @code{erase-characters} (default: @code{#f})
13547 This option accepts a string of additional characters that should be
13548 interpreted as backspace when the user types their login name.
13550 @item @code{kill-characters} (default: @code{#f})
13551 This option accepts a string that should be interpreted to mean ``ignore
13552 all previous characters'' (also called a ``kill'' character) when the user
13553 types their login name.
13555 @item @code{chdir} (default: @code{#f})
13556 This option accepts, as a string, a directory path that will be changed
13559 @item @code{delay} (default: @code{#f})
13560 This options accepts, as an integer, the number of seconds to sleep
13561 before opening the tty and displaying the login prompt.
13563 @item @code{nice} (default: @code{#f})
13564 This option accepts, as an integer, the nice value with which to run the
13565 @command{login} program.
13567 @item @code{extra-options} (default: @code{'()})
13568 This option provides an ``escape hatch'' for the user to provide arbitrary
13569 command-line arguments to @command{agetty} as a list of strings.
13574 @deffn {Scheme Procedure} kmscon-service-type @var{config}
13575 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
13576 according to @var{config}, a @code{<kmscon-configuration>} object, which
13577 specifies the tty to run, among other things.
13580 @deftp {Data Type} kmscon-configuration
13581 This is the data type representing the configuration of Kmscon, which
13582 implements virtual console log-in.
13586 @item @code{virtual-terminal}
13587 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
13589 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
13590 A gexp denoting the name of the log-in program. The default log-in program is
13591 @command{login} from the Shadow tool suite.
13593 @item @code{login-arguments} (default: @code{'("-p")})
13594 A list of arguments to pass to @command{login}.
13596 @item @code{auto-login} (default: @code{#f})
13597 When passed a login name, as a string, the specified user will be logged
13598 in automatically without prompting for their login name or password.
13600 @item @code{hardware-acceleration?} (default: #f)
13601 Whether to use hardware acceleration.
13603 @item @code{kmscon} (default: @var{kmscon})
13604 The Kmscon package to use.
13609 @cindex name service cache daemon
13611 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
13612 [#:name-services '()]
13613 Return a service that runs the libc name service cache daemon (nscd) with the
13614 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
13615 Service Switch}, for an example.
13617 For convenience, the Shepherd service for nscd provides the following actions:
13621 @cindex cache invalidation, nscd
13622 @cindex nscd, cache invalidation
13623 This invalidate the given cache. For instance, running:
13626 herd invalidate nscd hosts
13630 invalidates the host name lookup cache of nscd.
13633 Running @command{herd statistics nscd} displays information about nscd usage
13639 @defvr {Scheme Variable} %nscd-default-configuration
13640 This is the default @code{<nscd-configuration>} value (see below) used
13641 by @code{nscd-service}. It uses the caches defined by
13642 @code{%nscd-default-caches}; see below.
13645 @deftp {Data Type} nscd-configuration
13646 This is the data type representing the name service cache daemon (nscd)
13651 @item @code{name-services} (default: @code{'()})
13652 List of packages denoting @dfn{name services} that must be visible to
13653 the nscd---e.g., @code{(list @var{nss-mdns})}.
13655 @item @code{glibc} (default: @var{glibc})
13656 Package object denoting the GNU C Library providing the @command{nscd}
13659 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
13660 Name of the nscd log file. This is where debugging output goes when
13661 @code{debug-level} is strictly positive.
13663 @item @code{debug-level} (default: @code{0})
13664 Integer denoting the debugging levels. Higher numbers mean that more
13665 debugging output is logged.
13667 @item @code{caches} (default: @code{%nscd-default-caches})
13668 List of @code{<nscd-cache>} objects denoting things to be cached; see
13674 @deftp {Data Type} nscd-cache
13675 Data type representing a cache database of nscd and its parameters.
13679 @item @code{database}
13680 This is a symbol representing the name of the database to be cached.
13681 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
13682 @code{services}, which designate the corresponding NSS database
13683 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
13685 @item @code{positive-time-to-live}
13686 @itemx @code{negative-time-to-live} (default: @code{20})
13687 A number representing the number of seconds during which a positive or
13688 negative lookup result remains in cache.
13690 @item @code{check-files?} (default: @code{#t})
13691 Whether to check for updates of the files corresponding to
13694 For instance, when @var{database} is @code{hosts}, setting this flag
13695 instructs nscd to check for updates in @file{/etc/hosts} and to take
13698 @item @code{persistent?} (default: @code{#t})
13699 Whether the cache should be stored persistently on disk.
13701 @item @code{shared?} (default: @code{#t})
13702 Whether the cache should be shared among users.
13704 @item @code{max-database-size} (default: 32@tie{}MiB)
13705 Maximum size in bytes of the database cache.
13707 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
13708 @c settings, so leave them out.
13713 @defvr {Scheme Variable} %nscd-default-caches
13714 List of @code{<nscd-cache>} objects used by default by
13715 @code{nscd-configuration} (see above).
13717 It enables persistent and aggressive caching of service and host name
13718 lookups. The latter provides better host name lookup performance,
13719 resilience in the face of unreliable name servers, and also better
13720 privacy---often the result of host name lookups is in local cache, so
13721 external name servers do not even need to be queried.
13724 @anchor{syslog-configuration-type}
13727 @deftp {Data Type} syslog-configuration
13728 This data type represents the configuration of the syslog daemon.
13731 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
13732 The syslog daemon to use.
13734 @item @code{config-file} (default: @code{%default-syslog.conf})
13735 The syslog configuration file to use.
13740 @anchor{syslog-service}
13742 @deffn {Scheme Procedure} syslog-service @var{config}
13743 Return a service that runs a syslog daemon according to @var{config}.
13745 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
13746 information on the configuration file syntax.
13749 @defvr {Scheme Variable} guix-service-type
13750 This is the type of the service that runs the build daemon,
13751 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
13752 @code{guix-configuration} record as described below.
13755 @anchor{guix-configuration-type}
13756 @deftp {Data Type} guix-configuration
13757 This data type represents the configuration of the Guix build daemon.
13758 @xref{Invoking guix-daemon}, for more information.
13761 @item @code{guix} (default: @var{guix})
13762 The Guix package to use.
13764 @item @code{build-group} (default: @code{"guixbuild"})
13765 Name of the group for build user accounts.
13767 @item @code{build-accounts} (default: @code{10})
13768 Number of build user accounts to create.
13770 @item @code{authorize-key?} (default: @code{#t})
13771 @cindex substitutes, authorization thereof
13772 Whether to authorize the substitute keys listed in
13773 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
13774 (@pxref{Substitutes}).
13776 @vindex %default-authorized-guix-keys
13777 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
13778 The list of authorized key files for archive imports, as a list of
13779 string-valued gexps (@pxref{Invoking guix archive}). By default, it
13780 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
13782 @item @code{use-substitutes?} (default: @code{#t})
13783 Whether to use substitutes.
13785 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
13786 The list of URLs where to look for substitutes by default.
13788 @item @code{max-silent-time} (default: @code{0})
13789 @itemx @code{timeout} (default: @code{0})
13790 The number of seconds of silence and the number of seconds of activity,
13791 respectively, after which a build process times out. A value of zero
13792 disables the timeout.
13794 @item @code{log-compression} (default: @code{'bzip2})
13795 The type of compression used for build logs---one of @code{gzip},
13796 @code{bzip2}, or @code{none}.
13798 @item @code{extra-options} (default: @code{'()})
13799 List of extra command-line options for @command{guix-daemon}.
13801 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
13802 File where @command{guix-daemon}'s standard output and standard error
13805 @cindex HTTP proxy, for @code{guix-daemon}
13806 @cindex proxy, for @code{guix-daemon} HTTP access
13807 @item @code{http-proxy} (default: @code{#f})
13808 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
13809 derivations and substitutes.
13811 It is also possible to change the daemon's proxy at run time through the
13812 @code{set-http-proxy} action, which restarts it:
13815 herd set-http-proxy guix-daemon http://localhost:8118
13818 To clear the proxy settings, run:
13821 herd set-http-proxy guix-daemon
13824 @item @code{tmpdir} (default: @code{#f})
13825 A directory path where the @command{guix-daemon} will perform builds.
13830 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
13831 Run @var{udev}, which populates the @file{/dev} directory dynamically.
13832 udev rules can be provided as a list of files through the @var{rules}
13833 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
13834 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
13835 creation of such rule files.
13837 The @command{herd rules udev} command, as root, returns the name of the
13838 directory containing all the active udev rules.
13841 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
13842 Return a udev-rule file named @var{file-name} containing the rules
13843 defined by the @var{contents} literal.
13845 In the following example, a rule for a USB device is defined to be
13846 stored in the file @file{90-usb-thing.rules}. The rule runs a script
13847 upon detecting a USB device with a given product identifier.
13850 (define %example-udev-rule
13852 "90-usb-thing.rules"
13853 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
13854 "ATTR@{product@}==\"Example\", "
13855 "RUN+=\"/path/to/script\"")))
13859 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
13860 [#:groups @var{groups}]
13861 Return a service that extends @code{udev-service-type } with @var{rules}
13862 and @code{account-service-type} with @var{groups} as system groups.
13863 This works by creating a singleton service type
13864 @code{@var{name}-udev-rules}, of which the returned service is an
13867 Here we show how it can be used to extend @code{udev-service-type} with the
13868 previously defined rule @code{%example-udev-rule}.
13874 (cons (udev-rules-service 'usb-thing %example-udev-rule)
13875 %desktop-services)))
13879 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
13880 Return a udev file named @var{file-name} containing the rules defined
13881 within @var{file}, a file-like object.
13883 The following example showcases how we can use an existing rule file.
13886 (use-modules (guix download) ;for url-fetch
13887 (guix packages) ;for origin
13890 (define %android-udev-rules
13892 "51-android-udev.rules"
13893 (let ((version "20170910"))
13896 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
13897 "android-udev-rules/" version "/51-android.rules"))
13899 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
13903 Additionally, Guix package definitions can be included in @var{rules} in
13904 order to extend the udev rules with the definitions found under their
13905 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
13906 @var{file->udev-rule} example, we could have used the
13907 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
13908 packages android)} module.
13910 The following example shows how to use the @var{android-udev-rules}
13911 package so that the Android tool @command{adb} can detect devices
13912 without root privileges. It also details how to create the
13913 @code{adbusers} group, which is required for the proper functioning of
13914 the rules defined within the @code{android-udev-rules} package. To
13915 create such a group, we must define it both as part of the
13916 @code{supplementary-groups} of our @code{user-account} declaration, as
13917 well as in the @var{groups} of the @code{udev-rules-service} procedure.
13920 (use-modules (gnu packages android) ;for android-udev-rules
13921 (gnu system shadow) ;for user-group
13926 (users (cons (user-account
13928 (supplementary-groups
13929 '("adbusers" ;for adb
13930 "wheel" "netdev" "audio" "video")))))
13933 (cons (udev-rules-service 'android android-udev-rules
13934 #:groups '("adbusers"))
13935 %desktop-services)))
13938 @defvr {Scheme Variable} urandom-seed-service-type
13939 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
13940 when rebooting. It also tries to seed @file{/dev/urandom} from
13941 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
13945 @defvr {Scheme Variable} %random-seed-file
13946 This is the name of the file where some random bytes are saved by
13947 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
13948 It defaults to @file{/var/lib/random-seed}.
13953 @defvr {Scheme Variable} gpm-service-type
13954 This is the type of the service that runs GPM, the @dfn{general-purpose
13955 mouse daemon}, which provides mouse support to the Linux console. GPM
13956 allows users to use the mouse in the console, notably to select, copy,
13959 The value for services of this type must be a @code{gpm-configuration}
13960 (see below). This service is not part of @code{%base-services}.
13963 @deftp {Data Type} gpm-configuration
13964 Data type representing the configuration of GPM.
13967 @item @code{options} (default: @code{%default-gpm-options})
13968 Command-line options passed to @command{gpm}. The default set of
13969 options instruct @command{gpm} to listen to mouse events on
13970 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
13973 @item @code{gpm} (default: @code{gpm})
13974 The GPM package to use.
13979 @anchor{guix-publish-service-type}
13980 @deffn {Scheme Variable} guix-publish-service-type
13981 This is the service type for @command{guix publish} (@pxref{Invoking
13982 guix publish}). Its value must be a @code{guix-publish-configuration}
13983 object, as described below.
13985 This assumes that @file{/etc/guix} already contains a signing key pair as
13986 created by @command{guix archive --generate-key} (@pxref{Invoking guix
13987 archive}). If that is not the case, the service will fail to start.
13990 @deftp {Data Type} guix-publish-configuration
13991 Data type representing the configuration of the @code{guix publish}
13995 @item @code{guix} (default: @code{guix})
13996 The Guix package to use.
13998 @item @code{port} (default: @code{80})
13999 The TCP port to listen for connections.
14001 @item @code{host} (default: @code{"localhost"})
14002 The host (and thus, network interface) to listen to. Use
14003 @code{"0.0.0.0"} to listen on all the network interfaces.
14005 @item @code{compression} (default: @code{'(("gzip" 3))})
14006 This is a list of compression method/level tuple used when compressing
14007 substitutes. For example, to compress all substitutes with @emph{both} lzip
14008 at level 7 and gzip at level 9, write:
14011 '(("lzip" 7) ("gzip" 9))
14014 Level 9 achieves the best compression ratio at the expense of increased CPU
14015 usage, whereas level 1 achieves fast compression.
14017 An empty list disables compression altogether.
14019 @item @code{nar-path} (default: @code{"nar"})
14020 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
14021 publish, @option{--nar-path}}, for details.
14023 @item @code{cache} (default: @code{#f})
14024 When it is @code{#f}, disable caching and instead generate archives on
14025 demand. Otherwise, this should be the name of a directory---e.g.,
14026 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
14027 archives and meta-data ready to be sent. @xref{Invoking guix publish,
14028 @option{--cache}}, for more information on the tradeoffs involved.
14030 @item @code{workers} (default: @code{#f})
14031 When it is an integer, this is the number of worker threads used for
14032 caching; when @code{#f}, the number of processors is used.
14033 @xref{Invoking guix publish, @option{--workers}}, for more information.
14035 @item @code{ttl} (default: @code{#f})
14036 When it is an integer, this denotes the @dfn{time-to-live} in seconds
14037 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
14038 for more information.
14042 @anchor{rngd-service}
14043 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
14044 [#:device "/dev/hwrng"]
14045 Return a service that runs the @command{rngd} program from @var{rng-tools}
14046 to add @var{device} to the kernel's entropy pool. The service will fail if
14047 @var{device} does not exist.
14050 @anchor{pam-limits-service}
14051 @cindex session limits
14056 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
14058 Return a service that installs a configuration file for the
14059 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
14060 @code{pam_limits} module}. The procedure optionally takes a list of
14061 @code{pam-limits-entry} values, which can be used to specify
14062 @code{ulimit} limits and nice priority limits to user sessions.
14064 The following limits definition sets two hard and soft limits for all
14065 login sessions of users in the @code{realtime} group:
14068 (pam-limits-service
14070 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
14071 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
14074 The first entry increases the maximum realtime priority for
14075 non-privileged processes; the second entry lifts any restriction of the
14076 maximum address space that can be locked in memory. These settings are
14077 commonly used for real-time audio systems.
14080 @node Scheduled Job Execution
14081 @subsection Scheduled Job Execution
14085 @cindex scheduling jobs
14086 The @code{(gnu services mcron)} module provides an interface to
14087 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
14088 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
14089 Unix @command{cron} daemon; the main difference is that it is
14090 implemented in Guile Scheme, which provides a lot of flexibility when
14091 specifying the scheduling of jobs and their actions.
14093 The example below defines an operating system that runs the
14094 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
14095 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
14096 well as the @command{mkid} command on behalf of an unprivileged user
14097 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
14098 gexps to introduce job definitions that are passed to mcron
14099 (@pxref{G-Expressions}).
14102 (use-modules (guix) (gnu) (gnu services mcron))
14103 (use-package-modules base idutils)
14105 (define updatedb-job
14106 ;; Run 'updatedb' at 3AM every day. Here we write the
14107 ;; job's action as a Scheme procedure.
14108 #~(job '(next-hour '(3))
14110 (execl (string-append #$findutils "/bin/updatedb")
14112 "--prunepaths=/tmp /var/tmp /gnu/store"))))
14114 (define garbage-collector-job
14115 ;; Collect garbage 5 minutes after midnight every day.
14116 ;; The job's action is a shell command.
14117 #~(job "5 0 * * *" ;Vixie cron syntax
14120 (define idutils-job
14121 ;; Update the index database as user "charlie" at 12:15PM
14122 ;; and 19:15PM. This runs from the user's home directory.
14123 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
14124 (string-append #$idutils "/bin/mkid src")
14129 (services (cons (service mcron-service-type
14130 (mcron-configuration
14131 (jobs (list garbage-collector-job
14137 For more complex jobs defined in Scheme where you need control over the top
14138 level, for instance to introduce a @code{use-modules} form, you can move your
14139 code to a separate program using the @code{program-file} procedure of the
14140 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
14144 (define %battery-alert-job
14145 ;; Beep when the battery percentage falls below %MIN-LEVEL.
14147 '(next-minute (range 0 60 1))
14149 "battery-alert.scm"
14150 (with-imported-modules (source-module-closure
14151 '((guix build utils)))
14153 (use-modules (guix build utils)
14156 (ice-9 textual-ports)
14159 (define %min-level 20)
14161 (setenv "LC_ALL" "C") ;ensure English output
14162 (and-let* ((input-pipe (open-pipe*
14164 #$(file-append acpi "/bin/acpi")))
14165 (output (get-string-all input-pipe))
14166 (m (string-match "Discharging, ([0-9]+)%" output))
14167 (level (string->number (match:substring m 1)))
14168 ((< level %min-level)))
14169 (format #t "warning: Battery level is low (~a%)~%" level)
14170 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
14173 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
14174 for more information on mcron job specifications. Below is the
14175 reference of the mcron service.
14177 On a running system, you can use the @code{schedule} action of the service to
14178 visualize the mcron jobs that will be executed next:
14181 # herd schedule mcron
14185 The example above lists the next five tasks that will be executed, but you can
14186 also specify the number of tasks to display:
14189 # herd schedule mcron 10
14192 @defvr {Scheme Variable} mcron-service-type
14193 This is the type of the @code{mcron} service, whose value is an
14194 @code{mcron-configuration} object.
14196 This service type can be the target of a service extension that provides
14197 it additional job specifications (@pxref{Service Composition}). In
14198 other words, it is possible to define services that provide additional
14202 @deftp {Data Type} mcron-configuration
14203 Data type representing the configuration of mcron.
14206 @item @code{mcron} (default: @var{mcron})
14207 The mcron package to use.
14210 This is a list of gexps (@pxref{G-Expressions}), where each gexp
14211 corresponds to an mcron job specification (@pxref{Syntax, mcron job
14212 specifications,, mcron, GNU@tie{}mcron}).
14218 @subsection Log Rotation
14221 @cindex log rotation
14223 Log files such as those found in @file{/var/log} tend to grow endlessly,
14224 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
14225 their contents in separate files, possibly compressed. The @code{(gnu
14226 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
14227 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
14229 This service is part of @code{%base-services}, and thus enabled by
14230 default, with the default settings, for commonly encountered log files.
14231 The example below shows how to extend it with an additional
14232 @dfn{rotation}, should you need to do that (usually, services that
14233 produce log files already take care of that):
14236 (use-modules (guix) (gnu))
14237 (use-service-modules admin)
14239 (define my-log-files
14240 ;; Log files that I want to rotate.
14241 '("/var/log/something.log" "/var/log/another.log"))
14245 (services (cons (simple-service 'rotate-my-stuff
14246 rottlog-service-type
14247 (list (log-rotation
14249 (files my-log-files))))
14253 @defvr {Scheme Variable} rottlog-service-type
14254 This is the type of the Rottlog service, whose value is a
14255 @code{rottlog-configuration} object.
14257 Other services can extend this one with new @code{log-rotation} objects
14258 (see below), thereby augmenting the set of files to be rotated.
14260 This service type can define mcron jobs (@pxref{Scheduled Job
14261 Execution}) to run the rottlog service.
14264 @deftp {Data Type} rottlog-configuration
14265 Data type representing the configuration of rottlog.
14268 @item @code{rottlog} (default: @code{rottlog})
14269 The Rottlog package to use.
14271 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
14272 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
14273 rottlog, GNU Rot[t]log Manual}).
14275 @item @code{rotations} (default: @code{%default-rotations})
14276 A list of @code{log-rotation} objects as defined below.
14279 This is a list of gexps where each gexp corresponds to an mcron job
14280 specification (@pxref{Scheduled Job Execution}).
14284 @deftp {Data Type} log-rotation
14285 Data type representing the rotation of a group of log files.
14287 Taking an example from the Rottlog manual (@pxref{Period Related File
14288 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
14294 (files '("/var/log/apache/*"))
14295 (options '("storedir apache-archives"
14301 The list of fields is as follows:
14304 @item @code{frequency} (default: @code{'weekly})
14305 The log rotation frequency, a symbol.
14308 The list of files or file glob patterns to rotate.
14310 @item @code{options} (default: @code{'()})
14311 The list of rottlog options for this rotation (@pxref{Configuration
14312 parameters,,, rottlog, GNU Rot[t]lg Manual}).
14314 @item @code{post-rotate} (default: @code{#f})
14315 Either @code{#f} or a gexp to execute once the rotation has completed.
14319 @defvr {Scheme Variable} %default-rotations
14320 Specifies weekly rotation of @code{%rotated-files} and of
14321 @file{/var/log/guix-daemon.log}.
14324 @defvr {Scheme Variable} %rotated-files
14325 The list of syslog-controlled files to be rotated. By default it is:
14326 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
14327 "/var/log/maillog")}.
14330 @node Networking Services
14331 @subsection Networking Services
14333 The @code{(gnu services networking)} module provides services to configure
14334 the network interface.
14336 @cindex DHCP, networking service
14337 @defvr {Scheme Variable} dhcp-client-service-type
14338 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
14339 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
14340 is the DHCP client package to use, @code{isc-dhcp} by default.
14343 @deffn {Scheme Procedure} dhcpd-service-type
14344 This type defines a service that runs a DHCP daemon. To create a
14345 service of this type, you must supply a @code{<dhcpd-configuration>}.
14349 (service dhcpd-service-type
14350 (dhcpd-configuration
14351 (config-file (local-file "my-dhcpd.conf"))
14352 (interfaces '("enp0s25"))))
14356 @deftp {Data Type} dhcpd-configuration
14358 @item @code{package} (default: @code{isc-dhcp})
14359 The package that provides the DHCP daemon. This package is expected to
14360 provide the daemon at @file{sbin/dhcpd} relative to its output
14361 directory. The default package is the
14362 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
14363 @item @code{config-file} (default: @code{#f})
14364 The configuration file to use. This is required. It will be passed to
14365 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
14366 object (@pxref{G-Expressions, file-like objects}). See @code{man
14367 dhcpd.conf} for details on the configuration file syntax.
14368 @item @code{version} (default: @code{"4"})
14369 The DHCP version to use. The ISC DHCP server supports the values ``4'',
14370 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
14371 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
14373 @item @code{run-directory} (default: @code{"/run/dhcpd"})
14374 The run directory to use. At service activation time, this directory
14375 will be created if it does not exist.
14376 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
14377 The PID file to use. This corresponds to the @code{-pf} option of
14378 @code{dhcpd}. See @code{man dhcpd} for details.
14379 @item @code{interfaces} (default: @code{'()})
14380 The names of the network interfaces on which dhcpd should listen for
14381 broadcasts. If this list is not empty, then its elements (which must be
14382 strings) will be appended to the @code{dhcpd} invocation when starting
14383 the daemon. It may not be necessary to explicitly specify any
14384 interfaces here; see @code{man dhcpd} for details.
14388 @defvr {Scheme Variable} static-networking-service-type
14389 This is the type for statically-configured network interfaces.
14390 @c TODO Document <static-networking> data structures.
14393 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
14394 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
14395 [#:requirement @code{'(udev)}]
14396 Return a service that starts @var{interface} with address @var{ip}. If
14397 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
14398 it must be a string specifying the default network gateway. @var{requirement}
14399 can be used to declare a dependency on another service before configuring the
14402 This procedure can be called several times, one for each network
14403 interface of interest. Behind the scenes what it does is extend
14404 @code{static-networking-service-type} with additional network interfaces
14410 (static-networking-service "eno1" "192.168.1.82"
14411 #:gateway "192.168.1.2"
14412 #:name-servers '("192.168.1.2"))
14419 @cindex network management
14420 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
14421 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
14422 management daemon that aims to simplify wired and wireless networking.
14424 This service adds the @var{wicd} package to the global profile, providing
14425 several commands to interact with the daemon and configure networking:
14426 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
14427 and @command{wicd-curses} user interfaces.
14430 @cindex ModemManager
14432 @defvr {Scheme Variable} modem-manager-service-type
14433 This is the service type for the
14434 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
14435 service. The value for this service type is a
14436 @code{modem-manager-configuration} record.
14438 This service is part of @code{%desktop-services} (@pxref{Desktop
14442 @deftp {Data Type} modem-manager-configuration
14443 Data type representing the configuration of ModemManager.
14446 @item @code{modem-manager} (default: @code{modem-manager})
14447 The ModemManager package to use.
14452 @cindex USB_ModeSwitch
14453 @cindex Modeswitching
14455 @defvr {Scheme Variable} usb-modeswitch-service-type
14456 This is the service type for the
14457 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch} service. The
14458 value for this service type is a @code{usb-modeswitch-configuration} record.
14460 When plugged in, some USB modems (and other USB devices) initially present
14461 themselves as a read-only storage medium and not as a modem. They need to be
14462 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
14463 installs udev rules to automatically modeswitch these devices when they are
14466 This service is part of @code{%desktop-services} (@pxref{Desktop
14470 @deftp {Data Type} usb-modeswitch-configuration
14471 Data type representing the configuration of USB_ModeSwitch.
14474 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
14475 The USB_ModeSwitch package providing the binaries for modeswitching.
14477 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
14478 The package providing the device data and udev rules file used by
14481 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
14482 Which config file to use for the USB_ModeSwitch dispatcher. By default the
14483 config file shipped with USB_ModeSwitch is used which disables logging to
14484 @file{/var/log} among other default settings. If set to @code{#f}, no config
14490 @cindex NetworkManager
14492 @defvr {Scheme Variable} network-manager-service-type
14493 This is the service type for the
14494 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
14495 service. The value for this service type is a
14496 @code{network-manager-configuration} record.
14498 This service is part of @code{%desktop-services} (@pxref{Desktop
14502 @deftp {Data Type} network-manager-configuration
14503 Data type representing the configuration of NetworkManager.
14506 @item @code{network-manager} (default: @code{network-manager})
14507 The NetworkManager package to use.
14509 @item @code{dns} (default: @code{"default"})
14510 Processing mode for DNS, which affects how NetworkManager uses the
14511 @code{resolv.conf} configuration file.
14515 NetworkManager will update @code{resolv.conf} to reflect the nameservers
14516 provided by currently active connections.
14519 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
14520 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
14521 then update @code{resolv.conf} to point to the local nameserver.
14523 With this setting, you can share your network connection. For example when
14524 you want to share your network connection to another laptop @i{via} an
14525 Ethernet cable, you can open @command{nm-connection-editor} and configure the
14526 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
14527 and reestablish the connection (or reboot).
14529 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
14530 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
14531 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
14532 browser on your host system, or connect to the VM @i{via} SSH
14533 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
14534 host-to-guest connection, run this command once:
14537 nmcli connection add type tun \
14538 connection.interface-name tap0 \
14539 tun.mode tap tun.owner $(id -u) \
14540 ipv4.method shared \
14541 ipv4.addresses 172.28.112.1/24
14544 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
14545 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
14546 @command{qemu-system-...}.
14549 NetworkManager will not modify @code{resolv.conf}.
14552 @item @code{vpn-plugins} (default: @code{'()})
14553 This is the list of available plugins for virtual private networks
14554 (VPNs). An example of this is the @code{network-manager-openvpn}
14555 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
14561 @deffn {Scheme Variable} connman-service-type
14562 This is the service type to run @url{https://01.org/connman,Connman},
14563 a network connection manager.
14565 Its value must be an
14566 @code{connman-configuration} record as in this example:
14569 (service connman-service-type
14570 (connman-configuration
14571 (disable-vpn? #t)))
14574 See below for details about @code{connman-configuration}.
14577 @deftp {Data Type} connman-configuration
14578 Data Type representing the configuration of connman.
14581 @item @code{connman} (default: @var{connman})
14582 The connman package to use.
14584 @item @code{disable-vpn?} (default: @code{#f})
14585 When true, disable connman's vpn plugin.
14589 @cindex WPA Supplicant
14590 @defvr {Scheme Variable} wpa-supplicant-service-type
14591 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
14592 supplicant}, an authentication daemon required to authenticate against
14593 encrypted WiFi or ethernet networks.
14596 @deftp {Data Type} wpa-supplicant-configuration
14597 Data type representing the configuration of WPA Supplicant.
14599 It takes the following parameters:
14602 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
14603 The WPA Supplicant package to use.
14605 @item @code{requirement} (default: @code{'(user-processes dbus-system loopback syslogd)}
14606 List of services that should be started before WPA Supplicant starts.
14608 @item @code{dbus?} (default: @code{#t})
14609 Whether to listen for requests on D-Bus.
14611 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
14612 Where to store the PID file.
14614 @item @code{interface} (default: @code{#f})
14615 If this is set, it must specify the name of a network interface that
14616 WPA supplicant will control.
14618 @item @code{config-file} (default: @code{#f})
14619 Optional configuration file to use.
14621 @item @code{extra-options} (default: @code{'()})
14622 List of additional command-line arguments to pass to the daemon.
14626 @cindex hostapd service, for Wi-Fi access points
14627 @cindex Wi-Fi access points, hostapd service
14628 @defvr {Scheme Variable} hostapd-service-type
14629 This is the service type to run the @uref{https://w1.fi/hostapd/,
14630 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
14631 authentication servers. Its associated value must be a
14632 @code{hostapd-configuration} as shown below:
14635 ;; Use wlan1 to run the access point for "My Network".
14636 (service hostapd-service-type
14637 (hostapd-configuration
14638 (interface "wlan1")
14639 (ssid "My Network")
14644 @deftp {Data Type} hostapd-configuration
14645 This data type represents the configuration of the hostapd service, with
14646 the following fields:
14649 @item @code{package} (default: @code{hostapd})
14650 The hostapd package to use.
14652 @item @code{interface} (default: @code{"wlan0"})
14653 The network interface to run the WiFi access point.
14656 The SSID (@dfn{service set identifier}), a string that identifies this
14659 @item @code{broadcast-ssid?} (default: @code{#t})
14660 Whether to broadcast this SSID.
14662 @item @code{channel} (default: @code{1})
14663 The WiFi channel to use.
14665 @item @code{driver} (default: @code{"nl80211"})
14666 The driver interface type. @code{"nl80211"} is used with all Linux
14667 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
14668 RADIUS server that does # not control any wireless/wired driver.
14670 @item @code{extra-settings} (default: @code{""})
14671 Extra settings to append as-is to the hostapd configuration file. See
14672 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
14673 configuration file reference.
14677 @defvr {Scheme Variable} simulated-wifi-service-type
14678 This is the type of a service to simulate WiFi networking, which can be
14679 useful in virtual machines for testing purposes. The service loads the
14681 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
14682 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
14683 network that can be seen on @code{wlan0}, by default.
14685 The service's value is a @code{hostapd-configuration} record.
14689 @defvr {Scheme Variable} iptables-service-type
14690 This is the service type to set up an iptables configuration. iptables is a
14691 packet filtering framework supported by the Linux kernel. This service
14692 supports configuring iptables for both IPv4 and IPv6. A simple example
14693 configuration rejecting all incoming connections except those to the ssh port
14697 (service iptables-service-type
14698 (iptables-configuration
14699 (ipv4-rules (plain-file "iptables.rules" "*filter
14703 -A INPUT -p tcp --dport 22 -j ACCEPT
14704 -A INPUT -j REJECT --reject-with icmp-port-unreachable
14707 (ipv6-rules (plain-file "ip6tables.rules" "*filter
14711 -A INPUT -p tcp --dport 22 -j ACCEPT
14712 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
14718 @deftp {Data Type} iptables-configuration
14719 The data type representing the configuration of iptables.
14722 @item @code{iptables} (default: @code{iptables})
14723 The iptables package that provides @code{iptables-restore} and
14724 @code{ip6tables-restore}.
14725 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
14726 The iptables rules to use. It will be passed to @code{iptables-restore}.
14727 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14729 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
14730 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
14731 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
14737 @defvr {Scheme Variable} nftables-service-type
14738 This is the service type to set up a nftables configuration. nftables is a
14739 netfilter project that aims to replace the existing iptables, ip6tables,
14740 arptables and ebtables framework. It provides a new packet filtering
14741 framework, a new user-space utility @command{nft}, and a compatibility layer
14742 for iptables. This service comes with a default ruleset
14743 @code{%default-nftables-ruleset} that rejecting all incomming connections
14744 except those to the ssh port 22. To use it, simply write:
14747 (service nftables-service-type)
14751 @deftp {Data Type} nftables-configuration
14752 The data type representing the configuration of nftables.
14755 @item @code{package} (default: @code{nftables})
14756 The nftables package that provides @command{nft}.
14757 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
14758 The nftables ruleset to use. This may be any ``file-like'' object
14759 (@pxref{G-Expressions, file-like objects}).
14763 @cindex NTP (Network Time Protocol), service
14764 @cindex ntpd, service for the Network Time Protocol daemon
14765 @cindex real time clock
14766 @defvr {Scheme Variable} ntp-service-type
14767 This is the type of the service running the @uref{https://www.ntp.org,
14768 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
14769 system clock synchronized with that of the specified NTP servers.
14771 The value of this service is an @code{ntpd-configuration} object, as described
14775 @deftp {Data Type} ntp-configuration
14776 This is the data type for the NTP service configuration.
14779 @item @code{servers} (default: @code{%ntp-servers})
14780 This is the list of servers (@code{<ntp-server>} records) with which
14781 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
14784 @item @code{allow-large-adjustment?} (default: @code{#t})
14785 This determines whether @command{ntpd} is allowed to make an initial
14786 adjustment of more than 1,000 seconds.
14788 @item @code{ntp} (default: @code{ntp})
14789 The NTP package to use.
14793 @defvr {Scheme Variable} %ntp-servers
14794 List of host names used as the default NTP servers. These are servers of the
14795 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
14798 @deftp {Data Type} ntp-server
14799 The data type representing the configuration of a NTP server.
14802 @item @code{type} (default: @code{'server})
14803 The type of the NTP server, given as a symbol. One of @code{'pool},
14804 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
14806 @item @code{address}
14807 The address of the server, as a string.
14809 @item @code{options}
14810 NTPD options to use with that specific server, given as a list of option names
14811 and/or of option names and values tuples. The following example define a server
14812 to use with the options @option{iburst} and @option{prefer}, as well as
14813 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
14818 (address "some.ntp.server.org")
14819 (options `(iburst (version 3) (maxpoll 16) prefer))))
14825 @deffn {Scheme Procedure} openntpd-service-type
14826 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
14827 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
14828 clock synchronized with that of the given servers.
14832 openntpd-service-type
14833 (openntpd-configuration
14834 (listen-on '("127.0.0.1" "::1"))
14835 (sensor '("udcf0 correction 70000"))
14836 (constraint-from '("www.gnu.org"))
14837 (constraints-from '("https://www.google.com/"))
14838 (allow-large-adjustment? #t)))
14843 @defvr {Scheme Variable} %openntpd-servers
14844 This variable is a list of the server addresses defined in
14845 @code{%ntp-servers}.
14848 @deftp {Data Type} openntpd-configuration
14850 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
14851 The openntpd executable to use.
14852 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
14853 A list of local IP addresses or hostnames the ntpd daemon should listen on.
14854 @item @code{query-from} (default: @code{'()})
14855 A list of local IP address the ntpd daemon should use for outgoing queries.
14856 @item @code{sensor} (default: @code{'()})
14857 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
14858 will listen to each sensor that actually exists and ignore non-existent ones.
14859 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
14861 @item @code{server} (default: @code{'()})
14862 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
14863 @item @code{servers} (default: @code{%openntp-servers})
14864 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
14865 @item @code{constraint-from} (default: @code{'()})
14866 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
14867 This time information is not used for precision but acts as an authenticated
14868 constraint, thereby reducing the impact of unauthenticated NTP
14869 man-in-the-middle attacks.
14870 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
14872 @item @code{constraints-from} (default: @code{'()})
14873 As with constraint from, specify a list of URLs, IP addresses or hostnames of
14874 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
14875 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
14876 @item @code{allow-large-adjustment?} (default: @code{#f})
14877 Determines if @code{ntpd} is allowed to make an initial adjustment of more
14883 @deffn {Scheme variable} inetd-service-type
14884 This service runs the @command{inetd} (@pxref{inetd invocation,,,
14885 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
14886 connections on internet sockets, and lazily starts the specified server
14887 program when a connection is made on one of these sockets.
14889 The value of this service is an @code{inetd-configuration} object. The
14890 following example configures the @command{inetd} daemon to provide the
14891 built-in @command{echo} service, as well as an smtp service which
14892 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
14893 gateway @code{hostname}:
14898 (inetd-configuration
14902 (socket-type 'stream)
14909 (socket-type 'stream)
14913 (program (file-append openssh "/bin/ssh"))
14915 '("ssh" "-qT" "-i" "/path/to/ssh_key"
14916 "-W" "smtp-server:25" "user@@hostname")))))))
14919 See below for more details about @code{inetd-configuration}.
14922 @deftp {Data Type} inetd-configuration
14923 Data type representing the configuration of @command{inetd}.
14926 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
14927 The @command{inetd} executable to use.
14929 @item @code{entries} (default: @code{'()})
14930 A list of @command{inetd} service entries. Each entry should be created
14931 by the @code{inetd-entry} constructor.
14935 @deftp {Data Type} inetd-entry
14936 Data type representing an entry in the @command{inetd} configuration.
14937 Each entry corresponds to a socket where @command{inetd} will listen for
14941 @item @code{node} (default: @code{#f})
14942 Optional string, a comma-separated list of local addresses
14943 @command{inetd} should use when listening for this service.
14944 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
14945 description of all options.
14947 A string, the name must correspond to an entry in @code{/etc/services}.
14948 @item @code{socket-type}
14949 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
14951 @item @code{protocol}
14952 A string, must correspond to an entry in @code{/etc/protocols}.
14953 @item @code{wait?} (default: @code{#t})
14954 Whether @command{inetd} should wait for the server to exit before
14955 listening to new service requests.
14957 A string containing the user (and, optionally, group) name of the user
14958 as whom the server should run. The group name can be specified in a
14959 suffix, separated by a colon or period, i.e.@: @code{"user"},
14960 @code{"user:group"} or @code{"user.group"}.
14961 @item @code{program} (default: @code{"internal"})
14962 The server program which will serve the requests, or @code{"internal"}
14963 if @command{inetd} should use a built-in service.
14964 @item @code{arguments} (default: @code{'()})
14965 A list strings or file-like objects, which are the server program's
14966 arguments, starting with the zeroth argument, i.e.@: the name of the
14967 program itself. For @command{inetd}'s internal services, this entry
14968 must be @code{'()} or @code{'("internal")}.
14971 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
14972 detailed discussion of each configuration field.
14976 @defvr {Scheme Variable} tor-service-type
14977 This is the type for a service that runs the @uref{https://torproject.org,
14978 Tor} anonymous networking daemon. The service is configured using a
14979 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
14980 @code{tor} unprivileged user, which is a member of the @code{tor} group.
14984 @deftp {Data Type} tor-configuration
14986 @item @code{tor} (default: @code{tor})
14987 The package that provides the Tor daemon. This package is expected to provide
14988 the daemon at @file{bin/tor} relative to its output directory. The default
14989 package is the @uref{https://www.torproject.org, Tor Project's}
14992 @item @code{config-file} (default: @code{(plain-file "empty" "")})
14993 The configuration file to use. It will be appended to a default configuration
14994 file, and the final configuration file will be passed to @code{tor} via its
14995 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
14996 file-like objects}). See @code{man tor} for details on the configuration file
14999 @item @code{hidden-services} (default: @code{'()})
15000 The list of @code{<hidden-service>} records to use. For any hidden service
15001 you include in this list, appropriate configuration to enable the hidden
15002 service will be automatically added to the default configuration file. You
15003 may conveniently create @code{<hidden-service>} records using the
15004 @code{tor-hidden-service} procedure described below.
15006 @item @code{socks-socket-type} (default: @code{'tcp})
15007 The default socket type that Tor should use for its SOCKS socket. This must
15008 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
15009 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
15010 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
15011 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
15014 If you want to customize the SOCKS socket in more detail, leave
15015 @code{socks-socket-type} at its default value of @code{'tcp} and use
15016 @code{config-file} to override the default by providing your own
15017 @code{SocksPort} option.
15021 @cindex hidden service
15022 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
15023 Define a new Tor @dfn{hidden service} called @var{name} and implementing
15024 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
15027 '((22 "127.0.0.1:22")
15028 (80 "127.0.0.1:8080"))
15031 In this example, port 22 of the hidden service is mapped to local port 22, and
15032 port 80 is mapped to local port 8080.
15034 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
15035 the @file{hostname} file contains the @code{.onion} host name for the hidden
15038 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
15039 project's documentation} for more information.
15042 The @code{(gnu services rsync)} module provides the following services:
15044 You might want an rsync daemon if you have files that you want available
15045 so anyone (or just yourself) can download existing files or upload new
15048 @deffn {Scheme Variable} rsync-service-type
15049 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
15050 The value for this service type is a
15051 @command{rsync-configuration} record as in this example:
15054 (service rsync-service-type)
15057 See below for details about @code{rsync-configuration}.
15060 @deftp {Data Type} rsync-configuration
15061 Data type representing the configuration for @code{rsync-service}.
15064 @item @code{package} (default: @var{rsync})
15065 @code{rsync} package to use.
15067 @item @code{port-number} (default: @code{873})
15068 TCP port on which @command{rsync} listens for incoming connections. If port
15069 is less than @code{1024} @command{rsync} needs to be started as the
15070 @code{root} user and group.
15072 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
15073 Name of the file where @command{rsync} writes its PID.
15075 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
15076 Name of the file where @command{rsync} writes its lock file.
15078 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
15079 Name of the file where @command{rsync} writes its log file.
15081 @item @code{use-chroot?} (default: @var{#t})
15082 Whether to use chroot for @command{rsync} shared directory.
15084 @item @code{share-path} (default: @file{/srv/rsync})
15085 Location of the @command{rsync} shared directory.
15087 @item @code{share-comment} (default: @code{"Rsync share"})
15088 Comment of the @command{rsync} shared directory.
15090 @item @code{read-only?} (default: @var{#f})
15091 Read-write permissions to shared directory.
15093 @item @code{timeout} (default: @code{300})
15094 I/O timeout in seconds.
15096 @item @code{user} (default: @var{"root"})
15097 Owner of the @code{rsync} process.
15099 @item @code{group} (default: @var{"root"})
15100 Group of the @code{rsync} process.
15102 @item @code{uid} (default: @var{"rsyncd"})
15103 User name or user ID that file transfers to and from that module should take
15104 place as when the daemon was run as @code{root}.
15106 @item @code{gid} (default: @var{"rsyncd"})
15107 Group name or group ID that will be used when accessing the module.
15112 Furthermore, @code{(gnu services ssh)} provides the following services.
15116 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
15117 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
15118 [#:allow-empty-passwords? #f] [#:root-login? #f] @
15119 [#:syslog-output? #t] [#:x11-forwarding? #t] @
15120 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
15121 [#:public-key-authentication? #t] [#:initialize? #t]
15122 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
15123 @var{host-key} must designate a file containing the host key, and readable
15126 When @var{daemonic?} is true, @command{lshd} will detach from the
15127 controlling terminal and log its output to syslogd, unless one sets
15128 @var{syslog-output?} to false. Obviously, it also makes lsh-service
15129 depend on existence of syslogd service. When @var{pid-file?} is true,
15130 @command{lshd} writes its PID to the file called @var{pid-file}.
15132 When @var{initialize?} is true, automatically create the seed and host key
15133 upon service activation if they do not exist yet. This may take long and
15134 require interaction.
15136 When @var{initialize?} is false, it is up to the user to initialize the
15137 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
15138 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
15139 basics,,, lsh, LSH Manual}).
15141 When @var{interfaces} is empty, lshd listens for connections on all the
15142 network interfaces; otherwise, @var{interfaces} must be a list of host names
15145 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
15146 passwords, and @var{root-login?} specifies whether to accept log-ins as
15149 The other options should be self-descriptive.
15154 @deffn {Scheme Variable} openssh-service-type
15155 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
15156 shell daemon, @command{sshd}. Its value must be an
15157 @code{openssh-configuration} record as in this example:
15160 (service openssh-service-type
15161 (openssh-configuration
15162 (x11-forwarding? #t)
15163 (permit-root-login 'without-password)
15165 `(("alice" ,(local-file "alice.pub"))
15166 ("bob" ,(local-file "bob.pub"))))))
15169 See below for details about @code{openssh-configuration}.
15171 This service can be extended with extra authorized keys, as in this
15175 (service-extension openssh-service-type
15176 (const `(("charlie"
15177 ,(local-file "charlie.pub")))))
15181 @deftp {Data Type} openssh-configuration
15182 This is the configuration record for OpenSSH's @command{sshd}.
15185 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
15186 Name of the file where @command{sshd} writes its PID.
15188 @item @code{port-number} (default: @code{22})
15189 TCP port on which @command{sshd} listens for incoming connections.
15191 @item @code{permit-root-login} (default: @code{#f})
15192 This field determines whether and when to allow logins as root. If
15193 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
15194 If it's the symbol @code{'without-password}, then root logins are
15195 permitted but not with password-based authentication.
15197 @item @code{allow-empty-passwords?} (default: @code{#f})
15198 When true, users with empty passwords may log in. When false, they may
15201 @item @code{password-authentication?} (default: @code{#t})
15202 When true, users may log in with their password. When false, they have
15203 other authentication methods.
15205 @item @code{public-key-authentication?} (default: @code{#t})
15206 When true, users may log in using public key authentication. When
15207 false, users have to use other authentication method.
15209 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
15210 This is used only by protocol version 2.
15212 @item @code{x11-forwarding?} (default: @code{#f})
15213 When true, forwarding of X11 graphical client connections is
15214 enabled---in other words, @command{ssh} options @option{-X} and
15215 @option{-Y} will work.
15217 @item @code{allow-agent-forwarding?} (default: @code{#t})
15218 Whether to allow agent forwarding.
15220 @item @code{allow-tcp-forwarding?} (default: @code{#t})
15221 Whether to allow TCP forwarding.
15223 @item @code{gateway-ports?} (default: @code{#f})
15224 Whether to allow gateway ports.
15226 @item @code{challenge-response-authentication?} (default: @code{#f})
15227 Specifies whether challenge response authentication is allowed (e.g.@: via
15230 @item @code{use-pam?} (default: @code{#t})
15231 Enables the Pluggable Authentication Module interface. If set to
15232 @code{#t}, this will enable PAM authentication using
15233 @code{challenge-response-authentication?} and
15234 @code{password-authentication?}, in addition to PAM account and session
15235 module processing for all authentication types.
15237 Because PAM challenge response authentication usually serves an
15238 equivalent role to password authentication, you should disable either
15239 @code{challenge-response-authentication?} or
15240 @code{password-authentication?}.
15242 @item @code{print-last-log?} (default: @code{#t})
15243 Specifies whether @command{sshd} should print the date and time of the
15244 last user login when a user logs in interactively.
15246 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
15247 Configures external subsystems (e.g.@: file transfer daemon).
15249 This is a list of two-element lists, each of which containing the
15250 subsystem name and a command (with optional arguments) to execute upon
15253 The command @command{internal-sftp} implements an in-process SFTP
15254 server. Alternatively, one can specify the @command{sftp-server} command:
15256 (service openssh-service-type
15257 (openssh-configuration
15259 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
15262 @item @code{accepted-environment} (default: @code{'()})
15263 List of strings describing which environment variables may be exported.
15265 Each string gets on its own line. See the @code{AcceptEnv} option in
15266 @code{man sshd_config}.
15268 This example allows ssh-clients to export the @env{COLORTERM} variable.
15269 It is set by terminal emulators, which support colors. You can use it in
15270 your shell's resource file to enable colors for the prompt and commands
15271 if this variable is set.
15274 (service openssh-service-type
15275 (openssh-configuration
15276 (accepted-environment '("COLORTERM"))))
15279 @item @code{authorized-keys} (default: @code{'()})
15280 @cindex authorized keys, SSH
15281 @cindex SSH authorized keys
15282 This is the list of authorized keys. Each element of the list is a user
15283 name followed by one or more file-like objects that represent SSH public
15287 (openssh-configuration
15289 `(("rekado" ,(local-file "rekado.pub"))
15290 ("chris" ,(local-file "chris.pub"))
15291 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
15295 registers the specified public keys for user accounts @code{rekado},
15296 @code{chris}, and @code{root}.
15298 Additional authorized keys can be specified @i{via}
15299 @code{service-extension}.
15301 Note that this does @emph{not} interfere with the use of
15302 @file{~/.ssh/authorized_keys}.
15304 @item @code{log-level} (default: @code{'info})
15305 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
15306 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
15307 page for @file{sshd_config} for the full list of level names.
15309 @item @code{extra-content} (default: @code{""})
15310 This field can be used to append arbitrary text to the configuration file. It
15311 is especially useful for elaborate configurations that cannot be expressed
15312 otherwise. This configuration, for example, would generally disable root
15313 logins, but permit them from one specific IP address:
15316 (openssh-configuration
15318 Match Address 192.168.0.1
15319 PermitRootLogin yes"))
15325 @deffn {Scheme Procedure} dropbear-service [@var{config}]
15326 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
15327 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
15330 For example, to specify a Dropbear service listening on port 1234, add
15331 this call to the operating system's @code{services} field:
15334 (dropbear-service (dropbear-configuration
15335 (port-number 1234)))
15339 @deftp {Data Type} dropbear-configuration
15340 This data type represents the configuration of a Dropbear SSH daemon.
15343 @item @code{dropbear} (default: @var{dropbear})
15344 The Dropbear package to use.
15346 @item @code{port-number} (default: 22)
15347 The TCP port where the daemon waits for incoming connections.
15349 @item @code{syslog-output?} (default: @code{#t})
15350 Whether to enable syslog output.
15352 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
15353 File name of the daemon's PID file.
15355 @item @code{root-login?} (default: @code{#f})
15356 Whether to allow @code{root} logins.
15358 @item @code{allow-empty-passwords?} (default: @code{#f})
15359 Whether to allow empty passwords.
15361 @item @code{password-authentication?} (default: @code{#t})
15362 Whether to enable password-based authentication.
15367 @deffn {Scheme Variable} autossh-service-type
15368 This is the type for the @uref{https://www.harding.motd.ca/autossh,
15369 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
15370 restarting it as necessary should it die or stop passing traffic.
15371 AutoSSH can be run manually from the command-line by passing arguments
15372 to the binary @command{autossh} from the package @code{autossh}, but it
15373 can also be run as a Guix service. This latter use case is documented
15376 AutoSSH can be used to forward local traffic to a remote machine using
15377 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
15380 For example, to specify a service running autossh as the user
15381 @code{pino} and forwarding all local connections to port @code{8081} to
15382 @code{remote:8081} using an SSH tunnel, add this call to the operating
15383 system's @code{services} field:
15386 (service autossh-service-type
15387 (autossh-configuration
15389 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
15393 @deftp {Data Type} autossh-configuration
15394 This data type represents the configuration of an AutoSSH service.
15398 @item @code{user} (default @code{"autossh"})
15399 The user as which the AutoSSH service is to be run.
15400 This assumes that the specified user exists.
15402 @item @code{poll} (default @code{600})
15403 Specifies the connection poll time in seconds.
15405 @item @code{first-poll} (default @code{#f})
15406 Specifies how many seconds AutoSSH waits before the first connection
15407 test. After this first test, polling is resumed at the pace defined in
15408 @code{poll}. When set to @code{#f}, the first poll is not treated
15409 specially and will also use the connection poll specified in
15412 @item @code{gate-time} (default @code{30})
15413 Specifies how many seconds an SSH connection must be active before it is
15414 considered successful.
15416 @item @code{log-level} (default @code{1})
15417 The log level, corresponding to the levels used by syslog---so @code{0}
15418 is the most silent while @code{7} is the chattiest.
15420 @item @code{max-start} (default @code{#f})
15421 The maximum number of times SSH may be (re)started before AutoSSH exits.
15422 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
15424 @item @code{message} (default @code{""})
15425 The message to append to the echo message sent when testing connections.
15427 @item @code{port} (default @code{"0"})
15428 The ports used for monitoring the connection. When set to @code{"0"},
15429 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
15430 a positive integer, ports @var{n} and @var{n}+1 are used for
15431 monitoring the connection, such that port @var{n} is the base
15432 monitoring port and @code{n+1} is the echo port. When set to
15433 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
15434 integers, the ports @var{n} and @var{m} are used for monitoring the
15435 connection, such that port @var{n} is the base monitoring port and
15436 @var{m} is the echo port.
15438 @item @code{ssh-options} (default @code{'()})
15439 The list of command-line arguments to pass to @command{ssh} when it is
15440 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
15441 may cause undefined behaviour.
15446 @defvr {Scheme Variable} %facebook-host-aliases
15447 This variable contains a string for use in @file{/etc/hosts}
15448 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
15449 line contains a entry that maps a known server name of the Facebook
15450 on-line service---e.g., @code{www.facebook.com}---to the local
15451 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
15453 This variable is typically used in the @code{hosts-file} field of an
15454 @code{operating-system} declaration (@pxref{operating-system Reference,
15455 @file{/etc/hosts}}):
15458 (use-modules (gnu) (guix))
15461 (host-name "mymachine")
15464 ;; Create a /etc/hosts file with aliases for "localhost"
15465 ;; and "mymachine", as well as for Facebook servers.
15466 (plain-file "hosts"
15467 (string-append (local-host-aliases host-name)
15468 %facebook-host-aliases))))
15471 This mechanism can prevent programs running locally, such as Web
15472 browsers, from accessing Facebook.
15475 The @code{(gnu services avahi)} provides the following definition.
15477 @defvr {Scheme Variable} avahi-service-type
15478 This is the service that runs @command{avahi-daemon}, a system-wide
15479 mDNS/DNS-SD responder that allows for service discovery and
15480 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
15481 Its value must be a @code{zero-configuration} record---see below.
15483 This service extends the name service cache daemon (nscd) so that it can
15484 resolve @code{.local} host names using
15485 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
15486 Service Switch}, for information on host name resolution.
15488 Additionally, add the @var{avahi} package to the system profile so that
15489 commands such as @command{avahi-browse} are directly usable.
15492 @deftp {Data Type} avahi-configuration
15493 Data type representation the configuration for Avahi.
15497 @item @code{host-name} (default: @code{#f})
15498 If different from @code{#f}, use that as the host name to
15499 publish for this machine; otherwise, use the machine's actual host name.
15501 @item @code{publish?} (default: @code{#t})
15502 When true, allow host names and services to be published (broadcast) over the
15505 @item @code{publish-workstation?} (default: @code{#t})
15506 When true, @command{avahi-daemon} publishes the machine's host name and IP
15507 address via mDNS on the local network. To view the host names published on
15508 your local network, you can run:
15511 avahi-browse _workstation._tcp
15514 @item @code{wide-area?} (default: @code{#f})
15515 When true, DNS-SD over unicast DNS is enabled.
15517 @item @code{ipv4?} (default: @code{#t})
15518 @itemx @code{ipv6?} (default: @code{#t})
15519 These fields determine whether to use IPv4/IPv6 sockets.
15521 @item @code{domains-to-browse} (default: @code{'()})
15522 This is a list of domains to browse.
15526 @deffn {Scheme Variable} openvswitch-service-type
15527 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
15528 service, whose value should be an @code{openvswitch-configuration}
15532 @deftp {Data Type} openvswitch-configuration
15533 Data type representing the configuration of Open vSwitch, a multilayer
15534 virtual switch which is designed to enable massive network automation
15535 through programmatic extension.
15538 @item @code{package} (default: @var{openvswitch})
15539 Package object of the Open vSwitch.
15544 @defvr {Scheme Variable} pagekite-service-type
15545 This is the service type for the @uref{https://pagekite.net, PageKite} service,
15546 a tunneling solution for making localhost servers publicly visible, even from
15547 behind restrictive firewalls or NAT without forwarded ports. The value for
15548 this service type is a @code{pagekite-configuration} record.
15550 Here's an example exposing the local HTTP and SSH daemons:
15553 (service pagekite-service-type
15554 (pagekite-configuration
15555 (kites '("http:@@kitename:localhost:80:@@kitesecret"
15556 "raw/22:@@kitename:localhost:22:@@kitesecret"))
15557 (extra-file "/etc/pagekite.rc")))
15561 @deftp {Data Type} pagekite-configuration
15562 Data type representing the configuration of PageKite.
15565 @item @code{package} (default: @var{pagekite})
15566 Package object of PageKite.
15568 @item @code{kitename} (default: @code{#f})
15569 PageKite name for authenticating to the frontend server.
15571 @item @code{kitesecret} (default: @code{#f})
15572 Shared secret for authenticating to the frontend server. You should probably
15573 put this inside @code{extra-file} instead.
15575 @item @code{frontend} (default: @code{#f})
15576 Connect to the named PageKite frontend server instead of the
15577 @uref{https://pagekite.net,,pagekite.net} service.
15579 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
15580 List of service kites to use. Exposes HTTP on port 80 by default. The format
15581 is @code{proto:kitename:host:port:secret}.
15583 @item @code{extra-file} (default: @code{#f})
15584 Extra configuration file to read, which you are expected to create manually.
15585 Use this to add additional options and manage shared secrets out-of-band.
15590 @node Unattended Upgrades
15591 @subsection Unattended Upgrades
15593 @cindex unattended upgrades
15594 @cindex upgrades, unattended
15595 Guix provides a service to perform @emph{unattended upgrades}:
15596 periodically, the system automatically reconfigures itself from the
15597 latest Guix. Guix System has several properties that make unattended
15602 upgrades are transactional (either the upgrade succeeds or it fails, but
15603 you cannot end up with an ``in-between'' system state);
15605 the upgrade log is kept---you can view it with @command{guix system
15606 list-generations}---and you can roll back to any previous generation,
15607 should the upgraded system fail to behave as intended;
15609 channel code is authenticated so you know you can only run genuine code
15610 (@pxref{Channels});
15612 @command{guix system reconfigure} prevents downgrades, which makes it
15613 immune to @dfn{downgrade attacks}.
15616 To set up unattended upgrades, add an instance of
15617 @code{unattended-upgrade-service-type} like the one below to the list of
15618 your operating system services:
15621 (service unattended-upgrade-service-type)
15624 The defaults above set up weekly upgrades: every Sunday at midnight.
15625 You do not need to provide the operating system configuration file: it
15626 uses @file{/run/current-system/configuration.scm}, which ensures it
15627 always uses your latest configuration---@pxref{provenance-service-type},
15628 for more information about this file.
15630 There are several things that can be configured, in particular the
15631 periodicity and services (daemons) to be restarted upon completion.
15632 When the upgrade is successful, the service takes care of deleting
15633 system generations older that some threshold, as per @command{guix
15634 system delete-generations}. See the reference below for details.
15636 To ensure that upgrades are actually happening, you can run
15637 @command{guix system describe}. To investigate upgrade failures, visit
15638 the unattended upgrade log file (see below).
15640 @defvr {Scheme Variable} unattended-upgrade-service-type
15641 This is the service type for unattended upgrades. It sets up an mcron
15642 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
15643 reconfigure} from the latest version of the specified channels.
15645 Its value must be a @code{unattended-upgrade-configuration} record (see
15649 @deftp {Data Type} unattended-upgrade-configuration
15650 This data type represents the configuration of the unattended upgrade
15651 service. The following fields are available:
15654 @item @code{schedule} (default: @code{"30 01 * * 0"})
15655 This is the schedule of upgrades, expressed as a gexp containing an
15656 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
15657 mcron, GNU@tie{}mcron}).
15659 @item @code{channels} (default: @code{#~%default-channels})
15660 This gexp specifies the channels to use for the upgrade
15661 (@pxref{Channels}). By default, the tip of the official @code{guix}
15664 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
15665 This field specifies the operating system configuration file to use.
15666 The default is to reuse the config file of the current configuration.
15668 There are cases, though, where referring to
15669 @file{/run/current-system/configuration.scm} is not enough, for instance
15670 because that file refers to extra files (SSH public keys, extra
15671 configuration files, etc.) @i{via} @code{local-file} and similar
15672 constructs. For those cases, we recommend something along these lines:
15675 (unattended-upgrade-configuration
15676 (operating-system-file
15677 (file-append (local-file "." "config-dir" #:recursive? #t)
15681 The effect here is to import all of the current directory into the
15682 store, and to refer to @file{config.scm} within that directory.
15683 Therefore, uses of @code{local-file} within @file{config.scm} will work
15684 as expected. @xref{G-Expressions}, for information about
15685 @code{local-file} and @code{file-append}.
15687 @item @code{services-to-restart} (default: @code{'(mcron)})
15688 This field specifies the Shepherd services to restart when the upgrade
15691 Those services are restarted right away upon completion, as with
15692 @command{herd restart}, which ensures that the latest version is
15693 running---remember that by default @command{guix system reconfigure}
15694 only restarts services that are not currently running, which is
15695 conservative: it minimizes disruption but leaves outdated services
15698 By default, the @code{mcron} service is restarted. This ensures that
15699 the latest version of the unattended upgrade job will be used next time.
15701 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
15702 This is the expiration time in seconds for system generations. System
15703 generations older that this amount of time are deleted with
15704 @command{guix system delete-generations} when an upgrade completes.
15707 The unattended upgrade service does not run the garbage collector. You
15708 will probably want to set up your own mcron job to run @command{guix gc}
15712 @item @code{maximum-duration} (default: @code{3600})
15713 Maximum duration in seconds for the upgrade; past that time, the upgrade
15716 This is primarily useful to ensure the upgrade does not end up
15717 rebuilding or re-downloading ``the world''.
15719 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
15720 File where unattended upgrades are logged.
15725 @subsection X Window
15728 @cindex X Window System
15729 @cindex login manager
15730 Support for the X Window graphical display system---specifically
15731 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
15732 there is no @code{xorg-service} procedure. Instead, the X server is
15733 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
15736 @cindex GNOME, login manager
15737 GDM of course allows users to log in into window managers and desktop
15738 environments other than GNOME; for those using GNOME, GDM is required for
15739 features such as automatic screen locking.
15741 @cindex window manager
15742 To use X11, you must install at least one @dfn{window manager}---for
15743 example the @code{windowmaker} or @code{openbox} packages---preferably
15744 by adding it to the @code{packages} field of your operating system
15745 definition (@pxref{operating-system Reference, system-wide packages}).
15747 @defvr {Scheme Variable} gdm-service-type
15748 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
15749 Desktop Manager} (GDM), a program that manages graphical display servers and
15750 handles graphical user logins. Its value must be a @code{gdm-configuration}
15753 @cindex session types (X11)
15754 @cindex X11 session types
15755 GDM looks for @dfn{session types} described by the @file{.desktop} files in
15756 @file{/run/current-system/profile/share/xsessions} and allows users to choose
15757 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
15758 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
15759 set of packages automatically makes them available at the log-in screen.
15761 In addition, @file{~/.xsession} files are honored. When available,
15762 @file{~/.xsession} must be an executable that starts a window manager
15763 and/or other X clients.
15766 @deftp {Data Type} gdm-configuration
15768 @item @code{auto-login?} (default: @code{#f})
15769 @itemx @code{default-user} (default: @code{#f})
15770 When @code{auto-login?} is false, GDM presents a log-in screen.
15772 When @code{auto-login?} is true, GDM logs in directly as
15773 @code{default-user}.
15775 @item @code{debug?} (default: @code{#f})
15776 When true, GDM writes debug messages to its log.
15778 @item @code{gnome-shell-assets} (default: ...)
15779 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
15781 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
15782 Configuration of the Xorg graphical server.
15784 @item @code{xsession} (default: @code{(xinitrc)})
15785 Script to run before starting a X session.
15787 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
15788 File name of the @code{dbus-daemon} executable.
15790 @item @code{gdm} (default: @code{gdm})
15791 The GDM package to use.
15795 @defvr {Scheme Variable} slim-service-type
15796 This is the type for the SLiM graphical login manager for X11.
15798 Like GDM, SLiM looks for session types described by @file{.desktop} files and
15799 allows users to choose a session from the log-in screen using @kbd{F1}. It
15800 also honors @file{~/.xsession} files.
15802 Unlike GDM, SLiM does not spawn the user session on a different VT after
15803 logging in, which means that you can only start one graphical session. If you
15804 want to be able to run multiple graphical sessions at the same time you have
15805 to add multiple SLiM services to your system services. The following example
15806 shows how to replace the default GDM service with two SLiM services on tty7
15810 (use-modules (gnu services)
15811 (gnu services desktop)
15812 (gnu services xorg)
15813 (srfi srfi-1)) ;for 'remove'
15817 (services (cons* (service slim-service-type (slim-configuration
15820 (service slim-service-type (slim-configuration
15823 (remove (lambda (service)
15824 (eq? (service-kind service) gdm-service-type))
15825 %desktop-services))))
15830 @deftp {Data Type} slim-configuration
15831 Data type representing the configuration of @code{slim-service-type}.
15834 @item @code{allow-empty-passwords?} (default: @code{#t})
15835 Whether to allow logins with empty passwords.
15837 @item @code{auto-login?} (default: @code{#f})
15838 @itemx @code{default-user} (default: @code{""})
15839 When @code{auto-login?} is false, SLiM presents a log-in screen.
15841 When @code{auto-login?} is true, SLiM logs in directly as
15842 @code{default-user}.
15844 @item @code{theme} (default: @code{%default-slim-theme})
15845 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
15846 The graphical theme to use and its name.
15848 @item @code{auto-login-session} (default: @code{#f})
15849 If true, this must be the name of the executable to start as the default
15850 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
15852 If false, a session described by one of the available @file{.desktop}
15853 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
15857 You must install at least one window manager in the system profile or in
15858 your user profile. Failing to do that, if @code{auto-login-session} is
15859 false, you will be unable to log in.
15862 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15863 Configuration of the Xorg graphical server.
15865 @item @code{display} (default @code{":0"})
15866 The display on which to start the Xorg graphical server.
15868 @item @code{vt} (default @code{"vt7"})
15869 The VT on which to start the Xorg graphical server.
15871 @item @code{xauth} (default: @code{xauth})
15872 The XAuth package to use.
15874 @item @code{shepherd} (default: @code{shepherd})
15875 The Shepherd package used when invoking @command{halt} and
15878 @item @code{sessreg} (default: @code{sessreg})
15879 The sessreg package used in order to register the session.
15881 @item @code{slim} (default: @code{slim})
15882 The SLiM package to use.
15886 @defvr {Scheme Variable} %default-theme
15887 @defvrx {Scheme Variable} %default-theme-name
15888 The default SLiM theme and its name.
15892 @deftp {Data Type} sddm-configuration
15893 This is the data type representing the SDDM service configuration.
15896 @item @code{display-server} (default: "x11")
15897 Select display server to use for the greeter. Valid values are
15898 @samp{"x11"} or @samp{"wayland"}.
15900 @item @code{numlock} (default: "on")
15901 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
15903 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
15904 Command to run when halting.
15906 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
15907 Command to run when rebooting.
15909 @item @code{theme} (default "maldives")
15910 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
15911 @samp{"maldives"} or @samp{"maya"}.
15913 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
15914 Directory to look for themes.
15916 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
15917 Directory to look for faces.
15919 @item @code{default-path} (default "/run/current-system/profile/bin")
15920 Default PATH to use.
15922 @item @code{minimum-uid} (default: 1000)
15923 Minimum UID displayed in SDDM and allowed for log-in.
15925 @item @code{maximum-uid} (default: 2000)
15926 Maximum UID to display in SDDM.
15928 @item @code{remember-last-user?} (default #t)
15929 Remember last user.
15931 @item @code{remember-last-session?} (default #t)
15932 Remember last session.
15934 @item @code{hide-users} (default "")
15935 Usernames to hide from SDDM greeter.
15937 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
15938 Users with shells listed will be hidden from the SDDM greeter.
15940 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
15941 Script to run before starting a wayland session.
15943 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
15944 Directory to look for desktop files starting wayland sessions.
15946 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
15947 Configuration of the Xorg graphical server.
15949 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
15952 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
15955 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
15956 Script to run after starting xorg-server.
15958 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
15959 Script to run before stopping xorg-server.
15961 @item @code{xsession-command} (default: @code{xinitrc})
15962 Script to run before starting a X session.
15964 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
15965 Directory to look for desktop files starting X sessions.
15967 @item @code{minimum-vt} (default: 7)
15970 @item @code{auto-login-user} (default "")
15971 User to use for auto-login.
15973 @item @code{auto-login-session} (default "")
15974 Desktop file to use for auto-login.
15976 @item @code{relogin?} (default #f)
15977 Relogin after logout.
15982 @cindex login manager
15984 @defvr {Scheme Variable} sddm-service-type
15985 This is the type of the service to run the
15986 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
15987 must be a @code{sddm-configuration} record (see below).
15989 Here's an example use:
15992 (service sddm-service-type
15993 (sddm-configuration
15994 (auto-login-user "alice")
15995 (auto-login-session "xfce.desktop")))
15999 @deftp {Data Type} sddm-configuration
16000 This data type represents the configuration of the SDDM login manager.
16001 The available fields are:
16004 @item @code{sddm} (default: @code{sddm})
16005 The SDDM package to use.
16007 @item @code{display-server} (default: @code{"x11"})
16008 This must be either @code{"x11"} or @code{"wayland"}.
16010 @c FIXME: Add more fields.
16012 @item @code{auto-login-user} (default: @code{""})
16013 If non-empty, this is the user account under which to log in
16016 @item @code{auto-login-session} (default: @code{""})
16017 If non-empty, this is the @file{.desktop} file name to use as the
16018 auto-login session.
16022 @cindex Xorg, configuration
16023 @deftp {Data Type} xorg-configuration
16024 This data type represents the configuration of the Xorg graphical display
16025 server. Note that there is no Xorg service; instead, the X server is started
16026 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
16027 of these display managers aggregates an @code{xorg-configuration} record.
16030 @item @code{modules} (default: @code{%default-xorg-modules})
16031 This is a list of @dfn{module packages} loaded by the Xorg
16032 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
16034 @item @code{fonts} (default: @code{%default-xorg-fonts})
16035 This is a list of font directories to add to the server's @dfn{font path}.
16037 @item @code{drivers} (default: @code{'()})
16038 This must be either the empty list, in which case Xorg chooses a graphics
16039 driver automatically, or a list of driver names that will be tried in this
16040 order---e.g., @code{("modesetting" "vesa")}.
16042 @item @code{resolutions} (default: @code{'()})
16043 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
16044 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
16047 @cindex keyboard layout, for Xorg
16048 @cindex keymap, for Xorg
16049 @item @code{keyboard-layout} (default: @code{#f})
16050 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
16051 English (``qwerty'') for a 105-key PC keyboard.
16053 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
16054 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
16055 information on how to specify the keyboard layout.
16057 @item @code{extra-config} (default: @code{'()})
16058 This is a list of strings or objects appended to the configuration file. It
16059 is used to pass extra text to be added verbatim to the configuration file.
16061 @item @code{server} (default: @code{xorg-server})
16062 This is the package providing the Xorg server.
16064 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
16065 This is the list of command-line arguments to pass to the X server. The
16066 default is @code{-nolisten tcp}.
16070 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
16071 [@var{login-manager-service-type}]
16072 Tell the log-in manager (of type @var{login-manager-service-type}) to use
16073 @var{config}, an @code{<xorg-configuration>} record.
16075 Since the Xorg configuration is embedded in the log-in manager's
16076 configuration---e.g., @code{gdm-configuration}---this procedure provides a
16077 shorthand to set the Xorg configuration.
16080 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
16081 Return a @code{startx} script in which the modules, fonts, etc. specified
16082 in @var{config}, are available. The result should be used in place of
16085 Usually the X server is started by a login manager.
16089 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
16090 Add @var{package}, a package for a screen locker or screen saver whose
16091 command is @var{program}, to the set of setuid programs and add a PAM entry
16092 for it. For example:
16095 (screen-locker-service xlockmore "xlock")
16098 makes the good ol' XlockMore usable.
16102 @node Printing Services
16103 @subsection Printing Services
16105 @cindex printer support with CUPS
16106 The @code{(gnu services cups)} module provides a Guix service definition
16107 for the CUPS printing service. To add printer support to a Guix
16108 system, add a @code{cups-service} to the operating system definition:
16110 @deffn {Scheme Variable} cups-service-type
16111 The service type for the CUPS print server. Its value should be a valid
16112 CUPS configuration (see below). To use the default settings, simply
16115 (service cups-service-type)
16119 The CUPS configuration controls the basic things about your CUPS
16120 installation: what interfaces it listens on, what to do if a print job
16121 fails, how much logging to do, and so on. To actually add a printer,
16122 you have to visit the @url{http://localhost:631} URL, or use a tool such
16123 as GNOME's printer configuration services. By default, configuring a
16124 CUPS service will generate a self-signed certificate if needed, for
16125 secure connections to the print server.
16127 Suppose you want to enable the Web interface of CUPS and also add
16128 support for Epson printers @i{via} the @code{escpr} package and for HP
16129 printers @i{via} the @code{hplip-minimal} package. You can do that directly,
16130 like this (you need to use the @code{(gnu packages cups)} module):
16133 (service cups-service-type
16134 (cups-configuration
16135 (web-interface? #t)
16137 (list cups-filters escpr hplip-minimal))))
16140 Note: If you wish to use the Qt5 based GUI which comes with the hplip
16141 package then it is suggested that you install the @code{hplip} package,
16142 either in your OS configuration file or as your user.
16144 The available configuration parameters follow. Each parameter
16145 definition is preceded by its type; for example, @samp{string-list foo}
16146 indicates that the @code{foo} parameter should be specified as a list of
16147 strings. There is also a way to specify the configuration as a string,
16148 if you have an old @code{cupsd.conf} file that you want to port over
16149 from some other system; see the end for more details.
16151 @c The following documentation was initially generated by
16152 @c (generate-documentation) in (gnu services cups). Manually maintained
16153 @c documentation is better, so we shouldn't hesitate to edit below as
16154 @c needed. However if the change you want to make to this documentation
16155 @c can be done in an automated way, it's probably easier to change
16156 @c (generate-documentation) than to make it below and have to deal with
16157 @c the churn as CUPS updates.
16160 Available @code{cups-configuration} fields are:
16162 @deftypevr {@code{cups-configuration} parameter} package cups
16166 @deftypevr {@code{cups-configuration} parameter} package-list extensions
16167 Drivers and other extensions to the CUPS package.
16170 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
16171 Configuration of where to write logs, what directories to use for print
16172 spools, and related privileged configuration parameters.
16174 Available @code{files-configuration} fields are:
16176 @deftypevr {@code{files-configuration} parameter} log-location access-log
16177 Defines the access log filename. Specifying a blank filename disables
16178 access log generation. The value @code{stderr} causes log entries to be
16179 sent to the standard error file when the scheduler is running in the
16180 foreground, or to the system log daemon when run in the background. The
16181 value @code{syslog} causes log entries to be sent to the system log
16182 daemon. The server name may be included in filenames using the string
16183 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
16185 Defaults to @samp{"/var/log/cups/access_log"}.
16188 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
16189 Where CUPS should cache data.
16191 Defaults to @samp{"/var/cache/cups"}.
16194 @deftypevr {@code{files-configuration} parameter} string config-file-perm
16195 Specifies the permissions for all configuration files that the scheduler
16198 Note that the permissions for the printers.conf file are currently
16199 masked to only allow access from the scheduler user (typically root).
16200 This is done because printer device URIs sometimes contain sensitive
16201 authentication information that should not be generally known on the
16202 system. There is no way to disable this security feature.
16204 Defaults to @samp{"0640"}.
16207 @deftypevr {@code{files-configuration} parameter} log-location error-log
16208 Defines the error log filename. Specifying a blank filename disables
16209 error log generation. The value @code{stderr} causes log entries to be
16210 sent to the standard error file when the scheduler is running in the
16211 foreground, or to the system log daemon when run in the background. The
16212 value @code{syslog} causes log entries to be sent to the system log
16213 daemon. The server name may be included in filenames using the string
16214 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
16216 Defaults to @samp{"/var/log/cups/error_log"}.
16219 @deftypevr {@code{files-configuration} parameter} string fatal-errors
16220 Specifies which errors are fatal, causing the scheduler to exit. The
16225 No errors are fatal.
16228 All of the errors below are fatal.
16231 Browsing initialization errors are fatal, for example failed connections
16232 to the DNS-SD daemon.
16235 Configuration file syntax errors are fatal.
16238 Listen or Port errors are fatal, except for IPv6 failures on the
16239 loopback or @code{any} addresses.
16242 Log file creation or write errors are fatal.
16245 Bad startup file permissions are fatal, for example shared TLS
16246 certificate and key files with world-read permissions.
16249 Defaults to @samp{"all -browse"}.
16252 @deftypevr {@code{files-configuration} parameter} boolean file-device?
16253 Specifies whether the file pseudo-device can be used for new printer
16254 queues. The URI @uref{file:///dev/null} is always allowed.
16256 Defaults to @samp{#f}.
16259 @deftypevr {@code{files-configuration} parameter} string group
16260 Specifies the group name or ID that will be used when executing external
16263 Defaults to @samp{"lp"}.
16266 @deftypevr {@code{files-configuration} parameter} string log-file-perm
16267 Specifies the permissions for all log files that the scheduler writes.
16269 Defaults to @samp{"0644"}.
16272 @deftypevr {@code{files-configuration} parameter} log-location page-log
16273 Defines the page log filename. Specifying a blank filename disables
16274 page log generation. The value @code{stderr} causes log entries to be
16275 sent to the standard error file when the scheduler is running in the
16276 foreground, or to the system log daemon when run in the background. The
16277 value @code{syslog} causes log entries to be sent to the system log
16278 daemon. The server name may be included in filenames using the string
16279 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
16281 Defaults to @samp{"/var/log/cups/page_log"}.
16284 @deftypevr {@code{files-configuration} parameter} string remote-root
16285 Specifies the username that is associated with unauthenticated accesses
16286 by clients claiming to be the root user. The default is @code{remroot}.
16288 Defaults to @samp{"remroot"}.
16291 @deftypevr {@code{files-configuration} parameter} file-name request-root
16292 Specifies the directory that contains print jobs and other HTTP request
16295 Defaults to @samp{"/var/spool/cups"}.
16298 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
16299 Specifies the level of security sandboxing that is applied to print
16300 filters, backends, and other child processes of the scheduler; either
16301 @code{relaxed} or @code{strict}. This directive is currently only
16302 used/supported on macOS.
16304 Defaults to @samp{strict}.
16307 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
16308 Specifies the location of TLS certificates and private keys. CUPS will
16309 look for public and private keys in this directory: @file{.crt} files
16310 for PEM-encoded certificates and corresponding @file{.key} files for
16311 PEM-encoded private keys.
16313 Defaults to @samp{"/etc/cups/ssl"}.
16316 @deftypevr {@code{files-configuration} parameter} file-name server-root
16317 Specifies the directory containing the server configuration files.
16319 Defaults to @samp{"/etc/cups"}.
16322 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
16323 Specifies whether the scheduler calls fsync(2) after writing
16324 configuration or state files.
16326 Defaults to @samp{#f}.
16329 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
16330 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
16333 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
16334 Specifies the directory where temporary files are stored.
16336 Defaults to @samp{"/var/spool/cups/tmp"}.
16339 @deftypevr {@code{files-configuration} parameter} string user
16340 Specifies the user name or ID that is used when running external
16343 Defaults to @samp{"lp"}.
16346 @deftypevr {@code{files-configuration} parameter} string set-env
16347 Set the specified environment variable to be passed to child processes.
16349 Defaults to @samp{"variable value"}.
16353 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
16354 Specifies the logging level for the AccessLog file. The @code{config}
16355 level logs when printers and classes are added, deleted, or modified and
16356 when configuration files are accessed or updated. The @code{actions}
16357 level logs when print jobs are submitted, held, released, modified, or
16358 canceled, and any of the conditions for @code{config}. The @code{all}
16359 level logs all requests.
16361 Defaults to @samp{actions}.
16364 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
16365 Specifies whether to purge job history data automatically when it is no
16366 longer required for quotas.
16368 Defaults to @samp{#f}.
16371 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
16372 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
16373 For example, @samp{"_cups" "_print"} will tell network clients that both
16374 CUPS sharing and IPP Everywhere are supported.
16376 Defaults to @samp{"_cups"}.
16379 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
16380 Specifies which protocols to use for local printer sharing.
16382 Defaults to @samp{dnssd}.
16385 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
16386 Specifies whether the CUPS web interface is advertised.
16388 Defaults to @samp{#f}.
16391 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
16392 Specifies whether shared printers are advertised.
16394 Defaults to @samp{#f}.
16397 @deftypevr {@code{cups-configuration} parameter} string classification
16398 Specifies the security classification of the server. Any valid banner
16399 name can be used, including @samp{"classified"}, @samp{"confidential"},
16400 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
16401 banner can be omitted to disable secure printing functions.
16403 Defaults to @samp{""}.
16406 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
16407 Specifies whether users may override the classification (cover page) of
16408 individual print jobs using the @code{job-sheets} option.
16410 Defaults to @samp{#f}.
16413 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
16414 Specifies the default type of authentication to use.
16416 Defaults to @samp{Basic}.
16419 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
16420 Specifies whether encryption will be used for authenticated requests.
16422 Defaults to @samp{Required}.
16425 @deftypevr {@code{cups-configuration} parameter} string default-language
16426 Specifies the default language to use for text and web content.
16428 Defaults to @samp{"en"}.
16431 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
16432 Specifies the default paper size for new print queues. @samp{"Auto"}
16433 uses a locale-specific default, while @samp{"None"} specifies there is
16434 no default paper size. Specific size names are typically
16435 @samp{"Letter"} or @samp{"A4"}.
16437 Defaults to @samp{"Auto"}.
16440 @deftypevr {@code{cups-configuration} parameter} string default-policy
16441 Specifies the default access policy to use.
16443 Defaults to @samp{"default"}.
16446 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
16447 Specifies whether local printers are shared by default.
16449 Defaults to @samp{#t}.
16452 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
16453 Specifies the delay for updating of configuration and state files, in
16454 seconds. A value of 0 causes the update to happen as soon as possible,
16455 typically within a few milliseconds.
16457 Defaults to @samp{30}.
16460 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
16461 Specifies what to do when an error occurs. Possible values are
16462 @code{abort-job}, which will discard the failed print job;
16463 @code{retry-job}, which will retry the job at a later time;
16464 @code{retry-current-job}, which retries the failed job immediately; and
16465 @code{stop-printer}, which stops the printer.
16467 Defaults to @samp{stop-printer}.
16470 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
16471 Specifies the maximum cost of filters that are run concurrently, which
16472 can be used to minimize disk, memory, and CPU resource problems. A
16473 limit of 0 disables filter limiting. An average print to a
16474 non-PostScript printer needs a filter limit of about 200. A PostScript
16475 printer needs about half that (100). Setting the limit below these
16476 thresholds will effectively limit the scheduler to printing a single job
16479 Defaults to @samp{0}.
16482 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
16483 Specifies the scheduling priority of filters that are run to print a
16484 job. The nice value ranges from 0, the highest priority, to 19, the
16487 Defaults to @samp{0}.
16490 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
16491 Specifies whether to do reverse lookups on connecting clients. The
16492 @code{double} setting causes @code{cupsd} to verify that the hostname
16493 resolved from the address matches one of the addresses returned for that
16494 hostname. Double lookups also prevent clients with unregistered
16495 addresses from connecting to your server. Only set this option to
16496 @code{#t} or @code{double} if absolutely required.
16498 Defaults to @samp{#f}.
16501 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
16502 Specifies the number of seconds to wait before killing the filters and
16503 backend associated with a canceled or held job.
16505 Defaults to @samp{30}.
16508 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
16509 Specifies the interval between retries of jobs in seconds. This is
16510 typically used for fax queues but can also be used with normal print
16511 queues whose error policy is @code{retry-job} or
16512 @code{retry-current-job}.
16514 Defaults to @samp{30}.
16517 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
16518 Specifies the number of retries that are done for jobs. This is
16519 typically used for fax queues but can also be used with normal print
16520 queues whose error policy is @code{retry-job} or
16521 @code{retry-current-job}.
16523 Defaults to @samp{5}.
16526 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
16527 Specifies whether to support HTTP keep-alive connections.
16529 Defaults to @samp{#t}.
16532 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
16533 Specifies how long an idle client connection remains open, in seconds.
16535 Defaults to @samp{30}.
16538 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
16539 Specifies the maximum size of print files, IPP requests, and HTML form
16540 data. A limit of 0 disables the limit check.
16542 Defaults to @samp{0}.
16545 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
16546 Listens on the specified interfaces for connections. Valid values are
16547 of the form @var{address}:@var{port}, where @var{address} is either an
16548 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
16549 indicate all addresses. Values can also be file names of local UNIX
16550 domain sockets. The Listen directive is similar to the Port directive
16551 but allows you to restrict access to specific interfaces or networks.
16554 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
16555 Specifies the number of pending connections that will be allowed. This
16556 normally only affects very busy servers that have reached the MaxClients
16557 limit, but can also be triggered by large numbers of simultaneous
16558 connections. When the limit is reached, the operating system will
16559 refuse additional connections until the scheduler can accept the pending
16562 Defaults to @samp{128}.
16565 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
16566 Specifies a set of additional access controls.
16568 Available @code{location-access-controls} fields are:
16570 @deftypevr {@code{location-access-controls} parameter} file-name path
16571 Specifies the URI path to which the access control applies.
16574 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
16575 Access controls for all access to this path, in the same format as the
16576 @code{access-controls} of @code{operation-access-control}.
16578 Defaults to @samp{()}.
16581 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
16582 Access controls for method-specific access to this path.
16584 Defaults to @samp{()}.
16586 Available @code{method-access-controls} fields are:
16588 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
16589 If @code{#t}, apply access controls to all methods except the listed
16590 methods. Otherwise apply to only the listed methods.
16592 Defaults to @samp{#f}.
16595 @deftypevr {@code{method-access-controls} parameter} method-list methods
16596 Methods to which this access control applies.
16598 Defaults to @samp{()}.
16601 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
16602 Access control directives, as a list of strings. Each string should be
16603 one directive, such as @samp{"Order allow,deny"}.
16605 Defaults to @samp{()}.
16610 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
16611 Specifies the number of debugging messages that are retained for logging
16612 if an error occurs in a print job. Debug messages are logged regardless
16613 of the LogLevel setting.
16615 Defaults to @samp{100}.
16618 @deftypevr {@code{cups-configuration} parameter} log-level log-level
16619 Specifies the level of logging for the ErrorLog file. The value
16620 @code{none} stops all logging while @code{debug2} logs everything.
16622 Defaults to @samp{info}.
16625 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
16626 Specifies the format of the date and time in the log files. The value
16627 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
16629 Defaults to @samp{standard}.
16632 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
16633 Specifies the maximum number of simultaneous clients that are allowed by
16636 Defaults to @samp{100}.
16639 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
16640 Specifies the maximum number of simultaneous clients that are allowed
16641 from a single address.
16643 Defaults to @samp{100}.
16646 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
16647 Specifies the maximum number of copies that a user can print of each
16650 Defaults to @samp{9999}.
16653 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
16654 Specifies the maximum time a job may remain in the @code{indefinite}
16655 hold state before it is canceled. A value of 0 disables cancellation of
16658 Defaults to @samp{0}.
16661 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
16662 Specifies the maximum number of simultaneous jobs that are allowed. Set
16663 to 0 to allow an unlimited number of jobs.
16665 Defaults to @samp{500}.
16668 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
16669 Specifies the maximum number of simultaneous jobs that are allowed per
16670 printer. A value of 0 allows up to MaxJobs jobs per printer.
16672 Defaults to @samp{0}.
16675 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
16676 Specifies the maximum number of simultaneous jobs that are allowed per
16677 user. A value of 0 allows up to MaxJobs jobs per user.
16679 Defaults to @samp{0}.
16682 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
16683 Specifies the maximum time a job may take to print before it is
16684 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
16686 Defaults to @samp{10800}.
16689 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
16690 Specifies the maximum size of the log files before they are rotated, in
16691 bytes. The value 0 disables log rotation.
16693 Defaults to @samp{1048576}.
16696 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
16697 Specifies the maximum amount of time to allow between files in a
16698 multiple file print job, in seconds.
16700 Defaults to @samp{300}.
16703 @deftypevr {@code{cups-configuration} parameter} string page-log-format
16704 Specifies the format of PageLog lines. Sequences beginning with percent
16705 (@samp{%}) characters are replaced with the corresponding information,
16706 while all other characters are copied literally. The following percent
16707 sequences are recognized:
16711 insert a single percent character
16714 insert the value of the specified IPP attribute
16717 insert the number of copies for the current page
16720 insert the current page number
16723 insert the current date and time in common log format
16729 insert the printer name
16732 insert the username
16735 A value of the empty string disables page logging. The string @code{%p
16736 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
16737 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
16740 Defaults to @samp{""}.
16743 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
16744 Passes the specified environment variable(s) to child processes; a list
16747 Defaults to @samp{()}.
16750 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
16751 Specifies named access control policies.
16753 Available @code{policy-configuration} fields are:
16755 @deftypevr {@code{policy-configuration} parameter} string name
16756 Name of the policy.
16759 @deftypevr {@code{policy-configuration} parameter} string job-private-access
16760 Specifies an access list for a job's private values. @code{@@ACL} maps
16761 to the printer's requesting-user-name-allowed or
16762 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16763 owner. @code{@@SYSTEM} maps to the groups listed for the
16764 @code{system-group} field of the @code{files-config} configuration,
16765 which is reified into the @code{cups-files.conf(5)} file. Other
16766 possible elements of the access list include specific user names, and
16767 @code{@@@var{group}} to indicate members of a specific group. The
16768 access list may also be simply @code{all} or @code{default}.
16770 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16773 @deftypevr {@code{policy-configuration} parameter} string job-private-values
16774 Specifies the list of job values to make private, or @code{all},
16775 @code{default}, or @code{none}.
16777 Defaults to @samp{"job-name job-originating-host-name
16778 job-originating-user-name phone"}.
16781 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
16782 Specifies an access list for a subscription's private values.
16783 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
16784 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
16785 owner. @code{@@SYSTEM} maps to the groups listed for the
16786 @code{system-group} field of the @code{files-config} configuration,
16787 which is reified into the @code{cups-files.conf(5)} file. Other
16788 possible elements of the access list include specific user names, and
16789 @code{@@@var{group}} to indicate members of a specific group. The
16790 access list may also be simply @code{all} or @code{default}.
16792 Defaults to @samp{"@@OWNER @@SYSTEM"}.
16795 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
16796 Specifies the list of job values to make private, or @code{all},
16797 @code{default}, or @code{none}.
16799 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
16800 notify-subscriber-user-name notify-user-data"}.
16803 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
16804 Access control by IPP operation.
16806 Defaults to @samp{()}.
16810 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
16811 Specifies whether job files (documents) are preserved after a job is
16812 printed. If a numeric value is specified, job files are preserved for
16813 the indicated number of seconds after printing. Otherwise a boolean
16814 value applies indefinitely.
16816 Defaults to @samp{86400}.
16819 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
16820 Specifies whether the job history is preserved after a job is printed.
16821 If a numeric value is specified, the job history is preserved for the
16822 indicated number of seconds after printing. If @code{#t}, the job
16823 history is preserved until the MaxJobs limit is reached.
16825 Defaults to @samp{#t}.
16828 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
16829 Specifies the amount of time to wait for job completion before
16830 restarting the scheduler.
16832 Defaults to @samp{30}.
16835 @deftypevr {@code{cups-configuration} parameter} string rip-cache
16836 Specifies the maximum amount of memory to use when converting documents
16837 into bitmaps for a printer.
16839 Defaults to @samp{"128m"}.
16842 @deftypevr {@code{cups-configuration} parameter} string server-admin
16843 Specifies the email address of the server administrator.
16845 Defaults to @samp{"root@@localhost.localdomain"}.
16848 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
16849 The ServerAlias directive is used for HTTP Host header validation when
16850 clients connect to the scheduler from external interfaces. Using the
16851 special name @code{*} can expose your system to known browser-based DNS
16852 rebinding attacks, even when accessing sites through a firewall. If the
16853 auto-discovery of alternate names does not work, we recommend listing
16854 each alternate name with a ServerAlias directive instead of using
16857 Defaults to @samp{*}.
16860 @deftypevr {@code{cups-configuration} parameter} string server-name
16861 Specifies the fully-qualified host name of the server.
16863 Defaults to @samp{"localhost"}.
16866 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
16867 Specifies what information is included in the Server header of HTTP
16868 responses. @code{None} disables the Server header. @code{ProductOnly}
16869 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
16870 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
16871 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
16872 the output of the @code{uname} command. @code{Full} reports @code{CUPS
16873 2.0.0 (@var{uname}) IPP/2.0}.
16875 Defaults to @samp{Minimal}.
16878 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
16879 Listens on the specified interfaces for encrypted connections. Valid
16880 values are of the form @var{address}:@var{port}, where @var{address} is
16881 either an IPv6 address enclosed in brackets, an IPv4 address, or
16882 @code{*} to indicate all addresses.
16884 Defaults to @samp{()}.
16887 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
16888 Sets encryption options. By default, CUPS only supports encryption
16889 using TLS v1.0 or higher using known secure cipher suites. Security is
16890 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
16891 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
16892 suites, which are required for some older clients. The @code{AllowSSL3} option
16893 enables SSL v3.0, which is required for some older clients that do not support
16894 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
16895 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
16896 protocol version to TLS v1.1.
16898 Defaults to @samp{()}.
16901 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
16902 Specifies whether the scheduler requires clients to strictly adhere to
16903 the IPP specifications.
16905 Defaults to @samp{#f}.
16908 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
16909 Specifies the HTTP request timeout, in seconds.
16911 Defaults to @samp{300}.
16915 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
16916 Specifies whether the web interface is enabled.
16918 Defaults to @samp{#f}.
16921 At this point you're probably thinking ``oh dear, Guix manual, I like
16922 you but you can stop already with the configuration options''. Indeed.
16923 However, one more point: it could be that you have an existing
16924 @code{cupsd.conf} that you want to use. In that case, you can pass an
16925 @code{opaque-cups-configuration} as the configuration of a
16926 @code{cups-service-type}.
16928 Available @code{opaque-cups-configuration} fields are:
16930 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
16934 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
16935 The contents of the @code{cupsd.conf}, as a string.
16938 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
16939 The contents of the @code{cups-files.conf} file, as a string.
16942 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
16943 strings of the same name, you could instantiate a CUPS service like
16947 (service cups-service-type
16948 (opaque-cups-configuration
16949 (cupsd.conf cupsd.conf)
16950 (cups-files.conf cups-files.conf)))
16954 @node Desktop Services
16955 @subsection Desktop Services
16957 The @code{(gnu services desktop)} module provides services that are
16958 usually useful in the context of a ``desktop'' setup---that is, on a
16959 machine running a graphical display server, possibly with graphical user
16960 interfaces, etc. It also defines services that provide specific desktop
16961 environments like GNOME, Xfce or MATE.
16963 To simplify things, the module defines a variable containing the set of
16964 services that users typically expect on a machine with a graphical
16965 environment and networking:
16967 @defvr {Scheme Variable} %desktop-services
16968 This is a list of services that builds upon @code{%base-services} and
16969 adds or adjusts services for a typical ``desktop'' setup.
16971 In particular, it adds a graphical login manager (@pxref{X Window,
16972 @code{gdm-service-type}}), screen lockers, a network management tool
16973 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
16974 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
16975 energy and color management services, the @code{elogind} login and seat
16976 manager, the Polkit privilege service, the GeoClue location service, the
16977 AccountsService daemon that allows authorized users change system passwords,
16978 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
16979 name service switch service configured to be able to use @code{nss-mdns}
16980 (@pxref{Name Service Switch, mDNS}).
16983 The @code{%desktop-services} variable can be used as the @code{services}
16984 field of an @code{operating-system} declaration (@pxref{operating-system
16985 Reference, @code{services}}).
16987 Additionally, the @code{gnome-desktop-service-type},
16988 @code{xfce-desktop-service}, @code{mate-desktop-service-type} and
16989 @code{enlightenment-desktop-service-type} procedures can add GNOME, Xfce, MATE
16990 and/or Enlightenment to a system. To ``add GNOME'' means that system-level
16991 services like the backlight adjustment helpers and the power management
16992 utilities are added to the system, extending @code{polkit} and @code{dbus}
16993 appropriately, allowing GNOME to operate with elevated privileges on a
16994 limited number of special-purpose system interfaces. Additionally,
16995 adding a service made by @code{gnome-desktop-service-type} adds the GNOME
16996 metapackage to the system profile. Likewise, adding the Xfce service
16997 not only adds the @code{xfce} metapackage to the system profile, but it
16998 also gives the Thunar file manager the ability to open a ``root-mode''
16999 file management window, if the user authenticates using the
17000 administrator's password via the standard polkit graphical interface.
17001 To ``add MATE'' means that @code{polkit} and @code{dbus} are extended
17002 appropriately, allowing MATE to operate with elevated privileges on a
17003 limited number of special-purpose system interfaces. Additionally,
17004 adding a service of type @code{mate-desktop-service-type} adds the MATE
17005 metapackage to the system profile. ``Adding Enlightenment'' means that
17006 @code{dbus} is extended appropriately, and several of Enlightenment's binaries
17007 are set as setuid, allowing Enlightenment's screen locker and other
17008 functionality to work as expected.
17010 The desktop environments in Guix use the Xorg display server by
17011 default. If you'd like to use the newer display server protocol
17012 called Wayland, you need to use the @code{sddm-service} instead of
17013 GDM as the graphical login manager. You should then
17014 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
17015 also try starting GNOME on Wayland manually from a TTY with the
17016 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
17017 gnome-session``. Currently only GNOME has support for Wayland.
17019 @defvr {Scheme Variable} gnome-desktop-service-type
17020 This is the type of the service that adds the @uref{https://www.gnome.org,
17021 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
17022 object (see below).
17024 This service adds the @code{gnome} package to the system profile, and extends
17025 polkit with the actions from @code{gnome-settings-daemon}.
17028 @deftp {Data Type} gnome-desktop-configuration
17029 Configuration record for the GNOME desktop environment.
17032 @item @code{gnome} (default: @code{gnome})
17033 The GNOME package to use.
17037 @defvr {Scheme Variable} xfce-desktop-service-type
17038 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
17039 desktop environment. Its value is an @code{xfce-desktop-configuration} object
17042 This service adds the @code{xfce} package to the system profile, and
17043 extends polkit with the ability for @code{thunar} to manipulate the file
17044 system as root from within a user session, after the user has authenticated
17045 with the administrator's password.
17048 @deftp {Data Type} xfce-desktop-configuration
17049 Configuration record for the Xfce desktop environment.
17052 @item @code{xfce} (default: @code{xfce})
17053 The Xfce package to use.
17057 @deffn {Scheme Variable} mate-desktop-service-type
17058 This is the type of the service that runs the @uref{https://mate-desktop.org/,
17059 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
17060 object (see below).
17062 This service adds the @code{mate} package to the system
17063 profile, and extends polkit with the actions from
17064 @code{mate-settings-daemon}.
17067 @deftp {Data Type} mate-desktop-configuration
17068 Configuration record for the MATE desktop environment.
17071 @item @code{mate} (default: @code{mate})
17072 The MATE package to use.
17076 @deffn {Scheme Variable} enlightenment-desktop-service-type
17077 Return a service that adds the @code{enlightenment} package to the system
17078 profile, and extends dbus with actions from @code{efl}.
17081 @deftp {Data Type} enlightenment-desktop-service-configuration
17083 @item @code{enlightenment} (default: @code{enlightenment})
17084 The enlightenment package to use.
17088 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
17089 the default @code{%desktop-services} variable doesn't include any of
17090 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
17091 @code{%desktop-services} in the @code{services} field of your
17092 @code{operating-system}:
17095 (use-modules (gnu))
17096 (use-service-modules desktop)
17099 ;; cons* adds items to the list given as its last argument.
17100 (services (cons* (service gnome-desktop-service-type)
17101 (service xfce-desktop-service)
17102 %desktop-services))
17106 These desktop environments will then be available as options in the
17107 graphical login window.
17109 The actual service definitions included in @code{%desktop-services} and
17110 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
17111 are described below.
17113 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
17114 Return a service that runs the ``system bus'', using @var{dbus}, with
17115 support for @var{services}.
17117 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
17118 facility. Its system bus is used to allow system services to communicate
17119 and to be notified of system-wide events.
17121 @var{services} must be a list of packages that provide an
17122 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
17123 and policy files. For example, to allow avahi-daemon to use the system bus,
17124 @var{services} must be equal to @code{(list avahi)}.
17127 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
17128 Return a service that runs the @code{elogind} login and
17129 seat management daemon. @uref{https://github.com/elogind/elogind,
17130 Elogind} exposes a D-Bus interface that can be used to know which users
17131 are logged in, know what kind of sessions they have open, suspend the
17132 system, inhibit system suspend, reboot the system, and other tasks.
17134 Elogind handles most system-level power events for a computer, for
17135 example suspending the system when a lid is closed, or shutting it down
17136 when the power button is pressed.
17138 The @var{config} keyword argument specifies the configuration for
17139 elogind, and should be the result of an @code{(elogind-configuration
17140 (@var{parameter} @var{value})...)} invocation. Available parameters and
17141 their default values are:
17144 @item kill-user-processes?
17146 @item kill-only-users
17148 @item kill-exclude-users
17150 @item inhibit-delay-max-seconds
17152 @item handle-power-key
17154 @item handle-suspend-key
17156 @item handle-hibernate-key
17158 @item handle-lid-switch
17160 @item handle-lid-switch-docked
17162 @item power-key-ignore-inhibited?
17164 @item suspend-key-ignore-inhibited?
17166 @item hibernate-key-ignore-inhibited?
17168 @item lid-switch-ignore-inhibited?
17170 @item holdoff-timeout-seconds
17174 @item idle-action-seconds
17176 @item runtime-directory-size-percent
17178 @item runtime-directory-size
17182 @item suspend-state
17183 @code{("mem" "standby" "freeze")}
17186 @item hibernate-state
17188 @item hibernate-mode
17189 @code{("platform" "shutdown")}
17190 @item hybrid-sleep-state
17192 @item hybrid-sleep-mode
17193 @code{("suspend" "platform" "shutdown")}
17197 @deffn {Scheme Procedure} accountsservice-service @
17198 [#:accountsservice @var{accountsservice}]
17199 Return a service that runs AccountsService, a system service that can
17200 list available accounts, change their passwords, and so on.
17201 AccountsService integrates with PolicyKit to enable unprivileged users
17202 to acquire the capability to modify their system configuration.
17203 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
17204 accountsservice web site} for more information.
17206 The @var{accountsservice} keyword argument is the @code{accountsservice}
17207 package to expose as a service.
17210 @deffn {Scheme Procedure} polkit-service @
17211 [#:polkit @var{polkit}]
17212 Return a service that runs the
17213 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
17214 management service}, which allows system administrators to grant access to
17215 privileged operations in a structured way. By querying the Polkit service, a
17216 privileged system component can know when it should grant additional
17217 capabilities to ordinary users. For example, an ordinary user can be granted
17218 the capability to suspend the system if the user is logged in locally.
17221 @defvr {Scheme Variable} polkit-wheel-service
17222 Service that adds the @code{wheel} group as admins to the Polkit
17223 service. This makes it so that users in the @code{wheel} group are queried
17224 for their own passwords when performing administrative actions instead of
17225 @code{root}'s, similar to the behaviour used by @code{sudo}.
17228 @defvr {Scheme Variable} upower-service-type
17229 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
17230 system-wide monitor for power consumption and battery levels, with the given
17231 configuration settings.
17233 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
17234 notably used by GNOME.
17237 @deftp {Data Type} upower-configuration
17238 Data type representation the configuration for UPower.
17242 @item @code{upower} (default: @var{upower})
17243 Package to use for @code{upower}.
17245 @item @code{watts-up-pro?} (default: @code{#f})
17246 Enable the Watts Up Pro device.
17248 @item @code{poll-batteries?} (default: @code{#t})
17249 Enable polling the kernel for battery level changes.
17251 @item @code{ignore-lid?} (default: @code{#f})
17252 Ignore the lid state, this can be useful if it's incorrect on a device.
17254 @item @code{use-percentage-for-policy?} (default: @code{#f})
17255 Whether battery percentage based policy should be used. The default is to use
17256 the time left, change to @code{#t} to use the percentage.
17258 @item @code{percentage-low} (default: @code{10})
17259 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17260 at which the battery is considered low.
17262 @item @code{percentage-critical} (default: @code{3})
17263 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17264 at which the battery is considered critical.
17266 @item @code{percentage-action} (default: @code{2})
17267 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
17268 at which action will be taken.
17270 @item @code{time-low} (default: @code{1200})
17271 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17272 seconds at which the battery is considered low.
17274 @item @code{time-critical} (default: @code{300})
17275 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17276 seconds at which the battery is considered critical.
17278 @item @code{time-action} (default: @code{120})
17279 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
17280 seconds at which action will be taken.
17282 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
17283 The action taken when @code{percentage-action} or @code{time-action} is
17284 reached (depending on the configuration of @code{use-percentage-for-policy?}).
17286 Possible values are:
17296 @code{'hybrid-sleep}.
17302 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
17303 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
17304 UDisks}, a @dfn{disk management} daemon that provides user interfaces
17305 with notifications and ways to mount/unmount disks. Programs that talk
17306 to UDisks include the @command{udisksctl} command, part of UDisks, and
17307 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
17308 it will only be able to use the file-system utilities installed in the
17309 system profile. For example if you want to be able to mount NTFS
17310 file-systems in read and write fashion, you'll need to have
17311 @code{ntfs-3g} installed system-wide.
17314 @deffn {Scheme Variable} colord-service-type
17315 This is the type of the service that runs @command{colord}, a system
17316 service with a D-Bus
17317 interface to manage the color profiles of input and output devices such as
17318 screens and scanners. It is notably used by the GNOME Color Manager graphical
17319 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
17320 site} for more information.
17323 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
17324 Return a configuration allowing an application to access GeoClue
17325 location data. @var{name} is the Desktop ID of the application, without
17326 the @code{.desktop} part. If @var{allowed?} is true, the application
17327 will have access to location information by default. The boolean
17328 @var{system?} value indicates whether an application is a system component
17329 or not. Finally @var{users} is a list of UIDs of all users for which
17330 this application is allowed location info access. An empty users list
17331 means that all users are allowed.
17334 @cindex scanner access
17335 @deffn {Scheme Procedure} sane-service-type
17336 This service provides access to scanners @i{via}
17337 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
17341 @defvr {Scheme Variable} %standard-geoclue-applications
17342 The standard list of well-known GeoClue application configurations,
17343 granting authority to the GNOME date-and-time utility to ask for the
17344 current location in order to set the time zone, and allowing the
17345 IceCat and Epiphany web browsers to request location information.
17346 IceCat and Epiphany both query the user before allowing a web page to
17347 know the user's location.
17350 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
17351 [#:whitelist '()] @
17352 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
17353 [#:submit-data? #f]
17354 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
17355 [#:submission-nick "geoclue"] @
17356 [#:applications %standard-geoclue-applications]
17357 Return a service that runs the GeoClue location service. This service
17358 provides a D-Bus interface to allow applications to request access to a
17359 user's physical location, and optionally to add information to online
17360 location databases. See
17361 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
17362 web site} for more information.
17365 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
17366 [@w{#:auto-enable? #f}]
17367 Return a service that runs the @command{bluetoothd} daemon, which
17368 manages all the Bluetooth devices and provides a number of D-Bus
17369 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
17370 powered automatically at boot, which can be useful when using a
17371 bluetooth keyboard or mouse.
17373 Users need to be in the @code{lp} group to access the D-Bus service.
17376 @defvr {Scheme Variable} gnome-keyring-service-type
17377 This is the type of the service that adds the
17378 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
17379 value is a @code{gnome-keyring-configuration} object (see below).
17381 This service adds the @code{gnome-keyring} package to the system profile
17382 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
17383 a user's login keyring when they log in or setting its password with passwd.
17386 @deftp {Data Type} gnome-keyring-configuration
17387 Configuration record for the GNOME Keyring service.
17390 @item @code{keyring} (default: @code{gnome-keyring})
17391 The GNOME keyring package to use.
17393 @item @code{pam-services}
17394 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
17395 services to extend, where @var{service} is the name of an existing
17396 service to extend and @var{kind} is one of @code{login} or
17399 If @code{login} is given, it adds an optional
17400 @code{pam_gnome_keyring.so} to the auth block without arguments and to
17401 the session block with @code{auto_start}. If @code{passwd} is given, it
17402 adds an optional @code{pam_gnome_keyring.so} to the password block
17405 By default, this field contains ``gdm-password'' with the value @code{login}
17406 and ``passwd'' is with the value @code{passwd}.
17411 @node Sound Services
17412 @subsection Sound Services
17414 @cindex sound support
17416 @cindex PulseAudio, sound support
17418 The @code{(gnu services sound)} module provides a service to configure the
17419 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
17420 preferred ALSA output driver.
17422 @deffn {Scheme Variable} alsa-service-type
17423 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
17424 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
17425 configuration file. The value for this type is a @command{alsa-configuration}
17426 record as in this example:
17429 (service alsa-service-type)
17432 See below for details about @code{alsa-configuration}.
17435 @deftp {Data Type} alsa-configuration
17436 Data type representing the configuration for @code{alsa-service}.
17439 @item @code{alsa-plugins} (default: @var{alsa-plugins})
17440 @code{alsa-plugins} package to use.
17442 @item @code{pulseaudio?} (default: @var{#t})
17443 Whether ALSA applications should transparently be made to use the
17444 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
17446 Using PulseAudio allows you to run several sound-producing applications
17447 at the same time and to individual control them @i{via}
17448 @command{pavucontrol}, among other things.
17450 @item @code{extra-options} (default: @var{""})
17451 String to append to the @file{/etc/asound.conf} file.
17456 Individual users who want to override the system configuration of ALSA can do
17457 it with the @file{~/.asoundrc} file:
17460 # In guix, we have to specify the absolute path for plugins.
17462 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
17465 # Routing ALSA to jack:
17466 # <http://jackaudio.org/faq/routing_alsa.html>.
17470 0 system:playback_1
17471 1 system:playback_2
17488 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
17491 @deffn {Scheme Variable} pulseaudio-service-type
17492 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
17493 sound server. It exists to allow system overrides of the default settings
17494 via @code{pulseaudio-configuration}, see below.
17497 This service overrides per-user configuration files. If you want
17498 PulseAudio to honor configuraton files in @file{~/.config/pulse} you
17499 have to unset the environment variables @env{PULSE_CONFIG} and
17500 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
17504 This service on its own does not ensure, that the @code{pulseaudio} package
17505 exists on your machine. It merely adds configuration files for it, as
17506 detailed below. In the (admittedly unlikely) case, that you find yourself
17507 without a @code{pulseaudio} package, consider enabling it through the
17508 @code{alsa-service-type} above.
17512 @deftp {Data Type} pulseaudio-configuration
17513 Data type representing the configuration for @code{pulseaudio-service}.
17516 @item @var{client-conf} (default: @code{'()})
17517 List of settings to set in @file{client.conf}.
17518 Accepts a list of strings or a symbol-value pairs. A string will be
17519 inserted as-is with a newline added. A pair will be formatted as
17520 ``key = value'', again with a newline added.
17522 @item @var{daemon-conf} (default: @code{'((flat-volumes . no))})
17523 List of settings to set in @file{daemon.conf}, formatted just like
17526 @item @var{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
17527 Script file to use as as @file{default.pa}.
17529 @item @var{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
17530 Script file to use as as @file{system.pa}.
17534 @deffn {Scheme Variable} ladspa-service-type
17535 This service sets the @var{LADSPA_PATH} variable, so that programs, which
17536 respect it, e.g. PulseAudio, can load LADSPA plugins.
17538 The following example will setup the service to enable modules from the
17539 @code{swh-plugins} package:
17542 (service ladspa-service-type
17543 (ladspa-configuration (plugins (list swh-plugins))))
17546 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
17551 @node Database Services
17552 @subsection Database Services
17556 The @code{(gnu services databases)} module provides the following services.
17558 @deffn {Scheme Procedure} postgresql-service [#:postgresql postgresql] @
17559 [#:config-file] [#:data-directory ``/var/lib/postgresql/data''] @
17560 [#:port 5432] [#:locale ``en_US.utf8''] [#:extension-packages '()]
17561 Return a service that runs @var{postgresql}, the PostgreSQL database
17564 The PostgreSQL daemon loads its runtime configuration from @var{config-file},
17565 creates a database cluster with @var{locale} as the default
17566 locale, stored in @var{data-directory}. It then listens on @var{port}.
17568 If the services fails to start, it may be due to an incompatible
17569 cluster already present in @var{data-directory}. Adjust it (or, if you
17570 don't need the cluster anymore, delete @var{data-directory}), then
17571 restart the service.
17573 Peer authentication is used by default and the @code{postgres} user
17574 account has no shell, which prevents the direct execution of @code{psql}
17575 commands as this user. To use @code{psql}, you can temporarily log in
17576 as @code{postgres} using a shell, create a PostgreSQL superuser with the
17577 same name as one of the system users and then create the associated
17581 sudo -u postgres -s /bin/sh
17582 createuser --interactive
17583 createdb $MY_USER_LOGIN # Replace appropriately.
17586 @cindex postgresql extension-packages
17587 Additional extensions are loaded from packages listed in
17588 @var{extension-packages}. Extensions are available at runtime. For instance,
17589 to create a geographic database using the @code{postgis} extension, a user can
17590 configure the postgresql-service as in this example:
17594 (use-package-modules databases geo)
17598 ;; postgresql is required to run `psql' but postgis is not required for
17599 ;; proper operation.
17600 (packages (cons* postgresql %base-packages))
17603 (postgresql-service #:extension-packages (list postgis))
17607 Then the extension becomes visible and you can initialise an empty geographic
17608 database in this way:
17612 > create database postgistest;
17613 > \connect postgistest;
17614 > create extension postgis;
17615 > create extension postgis_topology;
17618 There is no need to add this field for contrib extensions such as hstore or
17619 dblink as they are already loadable by postgresql. This field is only
17620 required to add extensions provided by other packages.
17623 @deffn {Scheme Procedure} mysql-service [#:config (mysql-configuration)]
17624 Return a service that runs @command{mysqld}, the MySQL or MariaDB
17627 The optional @var{config} argument specifies the configuration for
17628 @command{mysqld}, which should be a @code{<mysql-configuration>} object.
17631 @deftp {Data Type} mysql-configuration
17632 Data type representing the configuration of @var{mysql-service}.
17635 @item @code{mysql} (default: @var{mariadb})
17636 Package object of the MySQL database server, can be either @var{mariadb}
17639 For MySQL, a temporary root password will be displayed at activation time.
17640 For MariaDB, the root password is empty.
17642 @item @code{port} (default: @code{3306})
17643 TCP port on which the database server listens for incoming connections.
17647 @defvr {Scheme Variable} memcached-service-type
17648 This is the service type for the @uref{https://memcached.org/,
17649 Memcached} service, which provides a distributed in memory cache. The
17650 value for the service type is a @code{memcached-configuration} object.
17654 (service memcached-service-type)
17657 @deftp {Data Type} memcached-configuration
17658 Data type representing the configuration of memcached.
17661 @item @code{memcached} (default: @code{memcached})
17662 The Memcached package to use.
17664 @item @code{interfaces} (default: @code{'("0.0.0.0")})
17665 Network interfaces on which to listen.
17667 @item @code{tcp-port} (default: @code{11211})
17668 Port on which to accept connections on,
17670 @item @code{udp-port} (default: @code{11211})
17671 Port on which to accept UDP connections on, a value of 0 will disable
17672 listening on a UDP socket.
17674 @item @code{additional-options} (default: @code{'()})
17675 Additional command line options to pass to @code{memcached}.
17679 @defvr {Scheme Variable} mongodb-service-type
17680 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
17681 The value for the service type is a @code{mongodb-configuration} object.
17685 (service mongodb-service-type)
17688 @deftp {Data Type} mongodb-configuration
17689 Data type representing the configuration of mongodb.
17692 @item @code{mongodb} (default: @code{mongodb})
17693 The MongoDB package to use.
17695 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
17696 The configuration file for MongoDB.
17698 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
17699 This value is used to create the directory, so that it exists and is
17700 owned by the mongodb user. It should match the data-directory which
17701 MongoDB is configured to use through the configuration file.
17705 @defvr {Scheme Variable} redis-service-type
17706 This is the service type for the @uref{https://redis.io/, Redis}
17707 key/value store, whose value is a @code{redis-configuration} object.
17710 @deftp {Data Type} redis-configuration
17711 Data type representing the configuration of redis.
17714 @item @code{redis} (default: @code{redis})
17715 The Redis package to use.
17717 @item @code{bind} (default: @code{"127.0.0.1"})
17718 Network interface on which to listen.
17720 @item @code{port} (default: @code{6379})
17721 Port on which to accept connections on, a value of 0 will disable
17722 listening on a TCP socket.
17724 @item @code{working-directory} (default: @code{"/var/lib/redis"})
17725 Directory in which to store the database and related files.
17729 @node Mail Services
17730 @subsection Mail Services
17734 The @code{(gnu services mail)} module provides Guix service definitions
17735 for email services: IMAP, POP3, and LMTP servers, as well as mail
17736 transport agents (MTAs). Lots of acronyms! These services are detailed
17737 in the subsections below.
17739 @subsubheading Dovecot Service
17741 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
17742 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
17745 By default, Dovecot does not need much configuration; the default
17746 configuration object created by @code{(dovecot-configuration)} will
17747 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
17748 certificate will be generated for TLS-protected connections, though
17749 Dovecot will also listen on cleartext ports by default. There are a
17750 number of options, though, which mail administrators might need to change,
17751 and as is the case with other services, Guix allows the system
17752 administrator to specify these parameters via a uniform Scheme interface.
17754 For example, to specify that mail is located at @code{maildir~/.mail},
17755 one would instantiate the Dovecot service like this:
17758 (dovecot-service #:config
17759 (dovecot-configuration
17760 (mail-location "maildir:~/.mail")))
17763 The available configuration parameters follow. Each parameter
17764 definition is preceded by its type; for example, @samp{string-list foo}
17765 indicates that the @code{foo} parameter should be specified as a list of
17766 strings. There is also a way to specify the configuration as a string,
17767 if you have an old @code{dovecot.conf} file that you want to port over
17768 from some other system; see the end for more details.
17770 @c The following documentation was initially generated by
17771 @c (generate-documentation) in (gnu services mail). Manually maintained
17772 @c documentation is better, so we shouldn't hesitate to edit below as
17773 @c needed. However if the change you want to make to this documentation
17774 @c can be done in an automated way, it's probably easier to change
17775 @c (generate-documentation) than to make it below and have to deal with
17776 @c the churn as dovecot updates.
17778 Available @code{dovecot-configuration} fields are:
17780 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
17781 The dovecot package.
17784 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
17785 A list of IPs or hosts where to listen for connections. @samp{*}
17786 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
17787 interfaces. If you want to specify non-default ports or anything more
17788 complex, customize the address and port fields of the
17789 @samp{inet-listener} of the specific services you are interested in.
17792 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
17793 List of protocols we want to serve. Available protocols include
17794 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
17796 Available @code{protocol-configuration} fields are:
17798 @deftypevr {@code{protocol-configuration} parameter} string name
17799 The name of the protocol.
17802 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
17803 UNIX socket path to the master authentication server to find users.
17804 This is used by imap (for shared users) and lda.
17805 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
17808 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
17809 Space separated list of plugins to load.
17812 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
17813 Maximum number of IMAP connections allowed for a user from each IP
17814 address. NOTE: The username is compared case-sensitively.
17815 Defaults to @samp{10}.
17820 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
17821 List of services to enable. Available services include @samp{imap},
17822 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
17825 Available @code{service-configuration} fields are:
17827 @deftypevr {@code{service-configuration} parameter} string kind
17828 The service kind. Valid values include @code{director},
17829 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
17830 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
17831 @code{tcpwrap}, @code{quota-warning}, or anything else.
17834 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
17835 Listeners for the service. A listener is either a
17836 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
17837 an @code{inet-listener-configuration}.
17838 Defaults to @samp{()}.
17840 Available @code{unix-listener-configuration} fields are:
17842 @deftypevr {@code{unix-listener-configuration} parameter} string path
17843 Path to the file, relative to @code{base-dir} field. This is also used as
17847 @deftypevr {@code{unix-listener-configuration} parameter} string mode
17848 The access mode for the socket.
17849 Defaults to @samp{"0600"}.
17852 @deftypevr {@code{unix-listener-configuration} parameter} string user
17853 The user to own the socket.
17854 Defaults to @samp{""}.
17857 @deftypevr {@code{unix-listener-configuration} parameter} string group
17858 The group to own the socket.
17859 Defaults to @samp{""}.
17863 Available @code{fifo-listener-configuration} fields are:
17865 @deftypevr {@code{fifo-listener-configuration} parameter} string path
17866 Path to the file, relative to @code{base-dir} field. This is also used as
17870 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
17871 The access mode for the socket.
17872 Defaults to @samp{"0600"}.
17875 @deftypevr {@code{fifo-listener-configuration} parameter} string user
17876 The user to own the socket.
17877 Defaults to @samp{""}.
17880 @deftypevr {@code{fifo-listener-configuration} parameter} string group
17881 The group to own the socket.
17882 Defaults to @samp{""}.
17886 Available @code{inet-listener-configuration} fields are:
17888 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
17889 The protocol to listen for.
17892 @deftypevr {@code{inet-listener-configuration} parameter} string address
17893 The address on which to listen, or empty for all addresses.
17894 Defaults to @samp{""}.
17897 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
17898 The port on which to listen.
17901 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
17902 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
17904 Defaults to @samp{#t}.
17909 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
17910 Maximum number of simultaneous client connections per process. Once
17911 this number of connections is received, the next incoming connection
17912 will prompt Dovecot to spawn another process. If set to 0,
17913 @code{default-client-limit} is used instead.
17915 Defaults to @samp{0}.
17919 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
17920 Number of connections to handle before starting a new process.
17921 Typically the only useful values are 0 (unlimited) or 1. 1 is more
17922 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
17923 Defaults to @samp{1}.
17927 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
17928 Maximum number of processes that can exist for this service. If set to
17929 0, @code{default-process-limit} is used instead.
17931 Defaults to @samp{0}.
17935 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
17936 Number of processes to always keep waiting for more connections.
17937 Defaults to @samp{0}.
17940 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
17941 If you set @samp{service-count 0}, you probably need to grow
17943 Defaults to @samp{256000000}.
17948 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
17949 Dict configuration, as created by the @code{dict-configuration}
17952 Available @code{dict-configuration} fields are:
17954 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
17955 A list of key-value pairs that this dict should hold.
17956 Defaults to @samp{()}.
17961 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
17962 A list of passdb configurations, each one created by the
17963 @code{passdb-configuration} constructor.
17965 Available @code{passdb-configuration} fields are:
17967 @deftypevr {@code{passdb-configuration} parameter} string driver
17968 The driver that the passdb should use. Valid values include
17969 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
17971 Defaults to @samp{"pam"}.
17974 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
17975 Space separated list of arguments to the passdb driver.
17976 Defaults to @samp{""}.
17981 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
17982 List of userdb configurations, each one created by the
17983 @code{userdb-configuration} constructor.
17985 Available @code{userdb-configuration} fields are:
17987 @deftypevr {@code{userdb-configuration} parameter} string driver
17988 The driver that the userdb should use. Valid values include
17989 @samp{passwd} and @samp{static}.
17990 Defaults to @samp{"passwd"}.
17993 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
17994 Space separated list of arguments to the userdb driver.
17995 Defaults to @samp{""}.
17998 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
17999 Override fields from passwd.
18000 Defaults to @samp{()}.
18005 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
18006 Plug-in configuration, created by the @code{plugin-configuration}
18010 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
18011 List of namespaces. Each item in the list is created by the
18012 @code{namespace-configuration} constructor.
18014 Available @code{namespace-configuration} fields are:
18016 @deftypevr {@code{namespace-configuration} parameter} string name
18017 Name for this namespace.
18020 @deftypevr {@code{namespace-configuration} parameter} string type
18021 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
18022 Defaults to @samp{"private"}.
18025 @deftypevr {@code{namespace-configuration} parameter} string separator
18026 Hierarchy separator to use. You should use the same separator for
18027 all namespaces or some clients get confused. @samp{/} is usually a good
18028 one. The default however depends on the underlying mail storage
18030 Defaults to @samp{""}.
18033 @deftypevr {@code{namespace-configuration} parameter} string prefix
18034 Prefix required to access this namespace. This needs to be
18035 different for all namespaces. For example @samp{Public/}.
18036 Defaults to @samp{""}.
18039 @deftypevr {@code{namespace-configuration} parameter} string location
18040 Physical location of the mailbox. This is in the same format as
18041 mail_location, which is also the default for it.
18042 Defaults to @samp{""}.
18045 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
18046 There can be only one INBOX, and this setting defines which
18048 Defaults to @samp{#f}.
18051 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
18052 If namespace is hidden, it's not advertised to clients via NAMESPACE
18053 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
18054 useful when converting from another server with different namespaces
18055 which you want to deprecate but still keep working. For example you can
18056 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
18058 Defaults to @samp{#f}.
18061 @deftypevr {@code{namespace-configuration} parameter} boolean list?
18062 Show the mailboxes under this namespace with the LIST command. This
18063 makes the namespace visible for clients that do not support the NAMESPACE
18064 extension. The special @code{children} value lists child mailboxes, but
18065 hides the namespace prefix.
18066 Defaults to @samp{#t}.
18069 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
18070 Namespace handles its own subscriptions. If set to @code{#f}, the
18071 parent namespace handles them. The empty prefix should always have this
18073 Defaults to @samp{#t}.
18076 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
18077 List of predefined mailboxes in this namespace.
18078 Defaults to @samp{()}.
18080 Available @code{mailbox-configuration} fields are:
18082 @deftypevr {@code{mailbox-configuration} parameter} string name
18083 Name for this mailbox.
18086 @deftypevr {@code{mailbox-configuration} parameter} string auto
18087 @samp{create} will automatically create this mailbox.
18088 @samp{subscribe} will both create and subscribe to the mailbox.
18089 Defaults to @samp{"no"}.
18092 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
18093 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
18094 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
18095 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
18096 Defaults to @samp{()}.
18103 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
18104 Base directory where to store runtime data.
18105 Defaults to @samp{"/var/run/dovecot/"}.
18108 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
18109 Greeting message for clients.
18110 Defaults to @samp{"Dovecot ready."}.
18113 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
18114 List of trusted network ranges. Connections from these IPs are
18115 allowed to override their IP addresses and ports (for logging and for
18116 authentication checks). @samp{disable-plaintext-auth} is also ignored
18117 for these networks. Typically you would specify your IMAP proxy servers
18119 Defaults to @samp{()}.
18122 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
18123 List of login access check sockets (e.g.@: tcpwrap).
18124 Defaults to @samp{()}.
18127 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
18128 Show more verbose process titles (in ps). Currently shows user name
18129 and IP address. Useful for seeing who is actually using the IMAP
18130 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
18132 Defaults to @samp{#f}.
18135 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
18136 Should all processes be killed when Dovecot master process shuts down.
18137 Setting this to @code{#f} means that Dovecot can be upgraded without
18138 forcing existing client connections to close (although that could also
18139 be a problem if the upgrade is e.g.@: due to a security fix).
18140 Defaults to @samp{#t}.
18143 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
18144 If non-zero, run mail commands via this many connections to doveadm
18145 server, instead of running them directly in the same process.
18146 Defaults to @samp{0}.
18149 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
18150 UNIX socket or host:port used for connecting to doveadm server.
18151 Defaults to @samp{"doveadm-server"}.
18154 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
18155 List of environment variables that are preserved on Dovecot startup
18156 and passed down to all of its child processes. You can also give
18157 key=value pairs to always set specific settings.
18160 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
18161 Disable LOGIN command and all other plaintext authentications unless
18162 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
18163 matches the local IP (i.e.@: you're connecting from the same computer),
18164 the connection is considered secure and plaintext authentication is
18165 allowed. See also ssl=required setting.
18166 Defaults to @samp{#t}.
18169 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
18170 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
18171 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
18172 for caching to be used.
18173 Defaults to @samp{0}.
18176 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
18177 Time to live for cached data. After TTL expires the cached record
18178 is no longer used, *except* if the main database lookup returns internal
18179 failure. We also try to handle password changes automatically: If
18180 user's previous authentication was successful, but this one wasn't, the
18181 cache isn't used. For now this works only with plaintext
18183 Defaults to @samp{"1 hour"}.
18186 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
18187 TTL for negative hits (user not found, password mismatch).
18188 0 disables caching them completely.
18189 Defaults to @samp{"1 hour"}.
18192 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
18193 List of realms for SASL authentication mechanisms that need them.
18194 You can leave it empty if you don't want to support multiple realms.
18195 Many clients simply use the first one listed here, so keep the default
18197 Defaults to @samp{()}.
18200 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
18201 Default realm/domain to use if none was specified. This is used for
18202 both SASL realms and appending @@domain to username in plaintext
18204 Defaults to @samp{""}.
18207 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
18208 List of allowed characters in username. If the user-given username
18209 contains a character not listed in here, the login automatically fails.
18210 This is just an extra check to make sure user can't exploit any
18211 potential quote escaping vulnerabilities with SQL/LDAP databases. If
18212 you want to allow all characters, set this value to empty.
18213 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
18216 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
18217 Username character translations before it's looked up from
18218 databases. The value contains series of from -> to characters. For
18219 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
18220 translated to @samp{@@}.
18221 Defaults to @samp{""}.
18224 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
18225 Username formatting before it's looked up from databases. You can
18226 use the standard variables here, e.g.@: %Lu would lowercase the username,
18227 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
18228 change the @samp{@@} into @samp{-AT-}. This translation is done after
18229 @samp{auth-username-translation} changes.
18230 Defaults to @samp{"%Lu"}.
18233 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
18234 If you want to allow master users to log in by specifying the master
18235 username within the normal username string (i.e.@: not using SASL
18236 mechanism's support for it), you can specify the separator character
18237 here. The format is then <username><separator><master username>.
18238 UW-IMAP uses @samp{*} as the separator, so that could be a good
18240 Defaults to @samp{""}.
18243 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
18244 Username to use for users logging in with ANONYMOUS SASL
18246 Defaults to @samp{"anonymous"}.
18249 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
18250 Maximum number of dovecot-auth worker processes. They're used to
18251 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
18252 They're automatically created and destroyed as needed.
18253 Defaults to @samp{30}.
18256 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
18257 Host name to use in GSSAPI principal names. The default is to use
18258 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
18259 allow all keytab entries.
18260 Defaults to @samp{""}.
18263 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
18264 Kerberos keytab to use for the GSSAPI mechanism. Will use the
18265 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
18266 need to change the auth service to run as root to be able to read this
18268 Defaults to @samp{""}.
18271 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
18272 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
18273 and @samp{ntlm-auth} helper.
18274 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
18275 Defaults to @samp{#f}.
18278 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
18279 Path for Samba's @samp{ntlm-auth} helper binary.
18280 Defaults to @samp{"/usr/bin/ntlm_auth"}.
18283 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
18284 Time to delay before replying to failed authentications.
18285 Defaults to @samp{"2 secs"}.
18288 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
18289 Require a valid SSL client certificate or the authentication
18291 Defaults to @samp{#f}.
18294 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
18295 Take the username from client's SSL certificate, using
18296 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
18298 Defaults to @samp{#f}.
18301 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
18302 List of wanted authentication mechanisms. Supported mechanisms are:
18303 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
18304 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
18305 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
18306 @samp{disable-plaintext-auth} setting.
18309 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
18310 List of IPs or hostnames to all director servers, including ourself.
18311 Ports can be specified as ip:port. The default port is the same as what
18312 director service's @samp{inet-listener} is using.
18313 Defaults to @samp{()}.
18316 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
18317 List of IPs or hostnames to all backend mail servers. Ranges are
18318 allowed too, like 10.0.0.10-10.0.0.30.
18319 Defaults to @samp{()}.
18322 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
18323 How long to redirect users to a specific server after it no longer
18324 has any connections.
18325 Defaults to @samp{"15 min"}.
18328 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
18329 How the username is translated before being hashed. Useful values
18330 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
18331 are shared within domain.
18332 Defaults to @samp{"%Lu"}.
18335 @deftypevr {@code{dovecot-configuration} parameter} string log-path
18336 Log file to use for error messages. @samp{syslog} logs to syslog,
18337 @samp{/dev/stderr} logs to stderr.
18338 Defaults to @samp{"syslog"}.
18341 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
18342 Log file to use for informational messages. Defaults to
18344 Defaults to @samp{""}.
18347 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
18348 Log file to use for debug messages. Defaults to
18349 @samp{info-log-path}.
18350 Defaults to @samp{""}.
18353 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
18354 Syslog facility to use if you're logging to syslog. Usually if you
18355 don't want to use @samp{mail}, you'll use local0..local7. Also other
18356 standard facilities are supported.
18357 Defaults to @samp{"mail"}.
18360 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
18361 Log unsuccessful authentication attempts and the reasons why they
18363 Defaults to @samp{#f}.
18366 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
18367 In case of password mismatches, log the attempted password. Valid
18368 values are no, plain and sha1. sha1 can be useful for detecting brute
18369 force password attempts vs. user simply trying the same password over
18370 and over again. You can also truncate the value to n chars by appending
18371 ":n" (e.g.@: sha1:6).
18372 Defaults to @samp{"no"}.
18375 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
18376 Even more verbose logging for debugging purposes. Shows for example
18378 Defaults to @samp{#f}.
18381 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
18382 In case of password mismatches, log the passwords and used scheme so
18383 the problem can be debugged. Enabling this also enables
18385 Defaults to @samp{#f}.
18388 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
18389 Enable mail process debugging. This can help you figure out why
18390 Dovecot isn't finding your mails.
18391 Defaults to @samp{#f}.
18394 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
18395 Show protocol level SSL errors.
18396 Defaults to @samp{#f}.
18399 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
18400 Prefix for each line written to log file. % codes are in
18401 strftime(3) format.
18402 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
18405 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
18406 List of elements we want to log. The elements which have a
18407 non-empty variable value are joined together to form a comma-separated
18411 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
18412 Login log format. %s contains @samp{login-log-format-elements}
18413 string, %$ contains the data we want to log.
18414 Defaults to @samp{"%$: %s"}.
18417 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
18418 Log prefix for mail processes. See doc/wiki/Variables.txt for list
18419 of possible variables you can use.
18420 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
18423 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
18424 Format to use for logging mail deliveries. You can use variables:
18427 Delivery status message (e.g.@: @samp{saved to INBOX})
18439 Defaults to @samp{"msgid=%m: %$"}.
18442 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
18443 Location for users' mailboxes. The default is empty, which means
18444 that Dovecot tries to find the mailboxes automatically. This won't work
18445 if the user doesn't yet have any mail, so you should explicitly tell
18446 Dovecot the full location.
18448 If you're using mbox, giving a path to the INBOX
18449 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
18450 where the other mailboxes are kept. This is called the @emph{root mail
18451 directory}, and it must be the first path given in the
18452 @samp{mail-location} setting.
18454 There are a few special variables you can use, e.g.:
18460 user part in user@@domain, same as %u if there's no domain
18462 domain part in user@@domain, empty if there's no domain
18467 See doc/wiki/Variables.txt for full list. Some examples:
18469 @item maildir:~/Maildir
18470 @item mbox:~/mail:INBOX=/var/mail/%u
18471 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
18473 Defaults to @samp{""}.
18476 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
18477 System user and group used to access mails. If you use multiple,
18478 userdb can override these by returning uid or gid fields. You can use
18479 either numbers or names. <doc/wiki/UserIds.txt>.
18480 Defaults to @samp{""}.
18483 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
18485 Defaults to @samp{""}.
18488 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
18489 Group to enable temporarily for privileged operations. Currently
18490 this is used only with INBOX when either its initial creation or
18491 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
18493 Defaults to @samp{""}.
18496 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
18497 Grant access to these supplementary groups for mail processes.
18498 Typically these are used to set up access to shared mailboxes. Note
18499 that it may be dangerous to set these if users can create symlinks
18500 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
18501 could allow a user to delete others' mailboxes, or @code{ln -s
18502 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
18506 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
18507 Allow full file system access to clients. There's no access checks
18508 other than what the operating system does for the active UID/GID. It
18509 works with both maildir and mboxes, allowing you to prefix mailboxes
18510 names with e.g.@: @file{/path/} or @file{~user/}.
18511 Defaults to @samp{#f}.
18514 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
18515 Don't use @code{mmap()} at all. This is required if you store indexes to
18516 shared file systems (NFS or clustered file system).
18517 Defaults to @samp{#f}.
18520 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
18521 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
18522 supports @samp{O_EXCL} since version 3, so this should be safe to use
18523 nowadays by default.
18524 Defaults to @samp{#t}.
18527 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
18528 When to use fsync() or fdatasync() calls:
18531 Whenever necessary to avoid losing important data
18533 Useful with e.g.@: NFS when @code{write()}s are delayed
18535 Never use it (best performance, but crashes can lose data).
18537 Defaults to @samp{"optimized"}.
18540 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
18541 Mail storage exists in NFS. Set this to yes to make Dovecot flush
18542 NFS caches whenever needed. If you're using only a single mail server
18544 Defaults to @samp{#f}.
18547 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
18548 Mail index files also exist in NFS. Setting this to yes requires
18549 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
18550 Defaults to @samp{#f}.
18553 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
18554 Locking method for index files. Alternatives are fcntl, flock and
18555 dotlock. Dotlocking uses some tricks which may create more disk I/O
18556 than other locking methods. NFS users: flock doesn't work, remember to
18557 change @samp{mmap-disable}.
18558 Defaults to @samp{"fcntl"}.
18561 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
18562 Directory in which LDA/LMTP temporarily stores incoming mails >128
18564 Defaults to @samp{"/tmp"}.
18567 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
18568 Valid UID range for users. This is mostly to make sure that users can't
18569 log in as daemons or other system users. Note that denying root logins is
18570 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
18572 Defaults to @samp{500}.
18575 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
18577 Defaults to @samp{0}.
18580 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
18581 Valid GID range for users. Users having non-valid GID as primary group ID
18582 aren't allowed to log in. If user belongs to supplementary groups with
18583 non-valid GIDs, those groups are not set.
18584 Defaults to @samp{1}.
18587 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
18589 Defaults to @samp{0}.
18592 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
18593 Maximum allowed length for mail keyword name. It's only forced when
18594 trying to create new keywords.
18595 Defaults to @samp{50}.
18598 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
18599 List of directories under which chrooting is allowed for mail
18600 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
18601 too). This setting doesn't affect @samp{login-chroot}
18602 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
18603 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
18604 which local users can modify, that may lead to root exploit. Usually
18605 this should be done only if you don't allow shell access for users.
18606 <doc/wiki/Chrooting.txt>.
18607 Defaults to @samp{()}.
18610 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
18611 Default chroot directory for mail processes. This can be overridden
18612 for specific users in user database by giving @samp{/./} in user's home
18613 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
18614 there is no real need to do chrooting, Dovecot doesn't allow users to
18615 access files outside their mail directory anyway. If your home
18616 directories are prefixed with the chroot directory, append @samp{/.} to
18617 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
18618 Defaults to @samp{""}.
18621 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
18622 UNIX socket path to master authentication server to find users.
18623 This is used by imap (for shared users) and lda.
18624 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
18627 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
18628 Directory where to look up mail plugins.
18629 Defaults to @samp{"/usr/lib/dovecot"}.
18632 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
18633 List of plugins to load for all services. Plugins specific to IMAP,
18634 LDA, etc.@: are added to this list in their own .conf files.
18635 Defaults to @samp{()}.
18638 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
18639 The minimum number of mails in a mailbox before updates are done to
18640 cache file. This allows optimizing Dovecot's behavior to do less disk
18641 writes at the cost of more disk reads.
18642 Defaults to @samp{0}.
18645 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
18646 When IDLE command is running, mailbox is checked once in a while to
18647 see if there are any new mails or other changes. This setting defines
18648 the minimum time to wait between those checks. Dovecot can also use
18649 dnotify, inotify and kqueue to find out immediately when changes
18651 Defaults to @samp{"30 secs"}.
18654 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
18655 Save mails with CR+LF instead of plain LF. This makes sending those
18656 mails take less CPU, especially with sendfile() syscall with Linux and
18657 FreeBSD. But it also creates a bit more disk I/O which may just make it
18658 slower. Also note that if other software reads the mboxes/maildirs,
18659 they may handle the extra CRs wrong and cause problems.
18660 Defaults to @samp{#f}.
18663 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
18664 By default LIST command returns all entries in maildir beginning
18665 with a dot. Enabling this option makes Dovecot return only entries
18666 which are directories. This is done by stat()ing each entry, so it
18667 causes more disk I/O.
18668 (For systems setting struct @samp{dirent->d_type} this check is free
18669 and it's done always regardless of this setting).
18670 Defaults to @samp{#f}.
18673 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
18674 When copying a message, do it with hard links whenever possible.
18675 This makes the performance much better, and it's unlikely to have any
18677 Defaults to @samp{#t}.
18680 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
18681 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
18682 directory only when its mtime changes unexpectedly or when we can't find
18683 the mail otherwise.
18684 Defaults to @samp{#f}.
18687 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
18688 Which locking methods to use for locking mbox. There are four
18693 Create <mailbox>.lock file. This is the oldest and most NFS-safe
18694 solution. If you want to use /var/mail/ like directory, the users will
18695 need write access to that directory.
18697 Same as dotlock, but if it fails because of permissions or because there
18698 isn't enough disk space, just skip it.
18700 Use this if possible. Works with NFS too if lockd is used.
18702 May not exist in all systems. Doesn't work with NFS.
18704 May not exist in all systems. Doesn't work with NFS.
18707 You can use multiple locking methods; if you do the order they're declared
18708 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
18709 locking methods as well. Some operating systems don't allow using some of
18710 them simultaneously.
18713 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
18717 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
18718 Maximum time to wait for lock (all of them) before aborting.
18719 Defaults to @samp{"5 mins"}.
18722 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
18723 If dotlock exists but the mailbox isn't modified in any way,
18724 override the lock file after this much time.
18725 Defaults to @samp{"2 mins"}.
18728 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
18729 When mbox changes unexpectedly we have to fully read it to find out
18730 what changed. If the mbox is large this can take a long time. Since
18731 the change is usually just a newly appended mail, it'd be faster to
18732 simply read the new mails. If this setting is enabled, Dovecot does
18733 this but still safely fallbacks to re-reading the whole mbox file
18734 whenever something in mbox isn't how it's expected to be. The only real
18735 downside to this setting is that if some other MUA changes message
18736 flags, Dovecot doesn't notice it immediately. Note that a full sync is
18737 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
18738 Defaults to @samp{#t}.
18741 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
18742 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
18743 EXAMINE, EXPUNGE or CHECK commands. If this is set,
18744 @samp{mbox-dirty-syncs} is ignored.
18745 Defaults to @samp{#f}.
18748 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
18749 Delay writing mbox headers until doing a full write sync (EXPUNGE
18750 and CHECK commands and when closing the mailbox). This is especially
18751 useful for POP3 where clients often delete all mails. The downside is
18752 that our changes aren't immediately visible to other MUAs.
18753 Defaults to @samp{#t}.
18756 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
18757 If mbox size is smaller than this (e.g.@: 100k), don't write index
18758 files. If an index file already exists it's still read, just not
18760 Defaults to @samp{0}.
18763 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
18764 Maximum dbox file size until it's rotated.
18765 Defaults to @samp{10000000}.
18768 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
18769 Maximum dbox file age until it's rotated. Typically in days. Day
18770 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
18772 Defaults to @samp{"1d"}.
18775 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
18776 When creating new mdbox files, immediately preallocate their size to
18777 @samp{mdbox-rotate-size}. This setting currently works only in Linux
18778 with some file systems (ext4, xfs).
18779 Defaults to @samp{#f}.
18782 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
18783 sdbox and mdbox support saving mail attachments to external files,
18784 which also allows single instance storage for them. Other backends
18785 don't support this for now.
18787 WARNING: This feature hasn't been tested much yet. Use at your own risk.
18789 Directory root where to store mail attachments. Disabled, if empty.
18790 Defaults to @samp{""}.
18793 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
18794 Attachments smaller than this aren't saved externally. It's also
18795 possible to write a plugin to disable saving specific attachments
18797 Defaults to @samp{128000}.
18800 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
18801 File system backend to use for saving attachments:
18804 No SiS done by Dovecot (but this might help FS's own deduplication)
18806 SiS with immediate byte-by-byte comparison during saving
18807 @item sis-queue posix
18808 SiS with delayed comparison and deduplication.
18810 Defaults to @samp{"sis posix"}.
18813 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
18814 Hash format to use in attachment filenames. You can add any text and
18815 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
18816 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
18817 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
18818 Defaults to @samp{"%@{sha1@}"}.
18821 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
18823 Defaults to @samp{100}.
18826 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
18828 Defaults to @samp{1000}.
18831 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
18832 Default VSZ (virtual memory size) limit for service processes.
18833 This is mainly intended to catch and kill processes that leak memory
18834 before they eat up everything.
18835 Defaults to @samp{256000000}.
18838 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
18839 Login user is internally used by login processes. This is the most
18840 untrusted user in Dovecot system. It shouldn't have access to anything
18842 Defaults to @samp{"dovenull"}.
18845 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
18846 Internal user is used by unprivileged processes. It should be
18847 separate from login user, so that login processes can't disturb other
18849 Defaults to @samp{"dovecot"}.
18852 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
18853 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
18854 Defaults to @samp{"required"}.
18857 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
18858 PEM encoded X.509 SSL/TLS certificate (public key).
18859 Defaults to @samp{"</etc/dovecot/default.pem"}.
18862 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
18863 PEM encoded SSL/TLS private key. The key is opened before
18864 dropping root privileges, so keep the key file unreadable by anyone but
18866 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
18869 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
18870 If key file is password protected, give the password here.
18871 Alternatively give it when starting dovecot with -p parameter. Since
18872 this file is often world-readable, you may want to place this setting
18873 instead to a different.
18874 Defaults to @samp{""}.
18877 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
18878 PEM encoded trusted certificate authority. Set this only if you
18879 intend to use @samp{ssl-verify-client-cert? #t}. The file should
18880 contain the CA certificate(s) followed by the matching
18881 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
18882 Defaults to @samp{""}.
18885 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
18886 Require that CRL check succeeds for client certificates.
18887 Defaults to @samp{#t}.
18890 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
18891 Request client to send a certificate. If you also want to require
18892 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
18893 Defaults to @samp{#f}.
18896 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
18897 Which field from certificate to use for username. commonName and
18898 x500UniqueIdentifier are the usual choices. You'll also need to set
18899 @samp{auth-ssl-username-from-cert? #t}.
18900 Defaults to @samp{"commonName"}.
18903 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
18904 Minimum SSL protocol version to accept.
18905 Defaults to @samp{"TLSv1"}.
18908 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
18909 SSL ciphers to use.
18910 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
18913 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
18914 SSL crypto device to use, for valid values run "openssl engine".
18915 Defaults to @samp{""}.
18918 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
18919 Address to use when sending rejection mails.
18920 %d expands to recipient domain.
18921 Defaults to @samp{"postmaster@@%d"}.
18924 @deftypevr {@code{dovecot-configuration} parameter} string hostname
18925 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
18926 and in LMTP replies. Default is the system's real hostname@@domain.
18927 Defaults to @samp{""}.
18930 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
18931 If user is over quota, return with temporary failure instead of
18933 Defaults to @samp{#f}.
18936 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
18937 Binary to use for sending mails.
18938 Defaults to @samp{"/usr/sbin/sendmail"}.
18941 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
18942 If non-empty, send mails via this SMTP host[:port] instead of
18944 Defaults to @samp{""}.
18947 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
18948 Subject: header to use for rejection mails. You can use the same
18949 variables as for @samp{rejection-reason} below.
18950 Defaults to @samp{"Rejected: %s"}.
18953 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
18954 Human readable error message for rejection mails. You can use
18967 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
18970 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
18971 Delimiter character between local-part and detail in email
18973 Defaults to @samp{"+"}.
18976 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
18977 Header where the original recipient address (SMTP's RCPT TO:
18978 address) is taken from if not available elsewhere. With dovecot-lda -a
18979 parameter overrides this. A commonly used header for this is
18981 Defaults to @samp{""}.
18984 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
18985 Should saving a mail to a nonexistent mailbox automatically create
18987 Defaults to @samp{#f}.
18990 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
18991 Should automatically created mailboxes be also automatically
18993 Defaults to @samp{#f}.
18996 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
18997 Maximum IMAP command line length. Some clients generate very long
18998 command lines with huge mailboxes, so you may need to raise this if you
18999 get "Too long argument" or "IMAP command line too large" errors
19001 Defaults to @samp{64000}.
19004 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
19005 IMAP logout format string:
19008 total number of bytes read from client
19010 total number of bytes sent to client.
19012 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
19013 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@}"}.
19016 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
19017 Override the IMAP CAPABILITY response. If the value begins with '+',
19018 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
19019 Defaults to @samp{""}.
19022 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
19023 How long to wait between "OK Still here" notifications when client
19025 Defaults to @samp{"2 mins"}.
19028 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
19029 ID field names and values to send to clients. Using * as the value
19030 makes Dovecot use the default value. The following fields have default
19031 values currently: name, version, os, os-version, support-url,
19033 Defaults to @samp{""}.
19036 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
19037 ID fields sent by client to log. * means everything.
19038 Defaults to @samp{""}.
19041 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
19042 Workarounds for various client bugs:
19045 @item delay-newmail
19046 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
19047 CHECK commands. Some clients ignore them otherwise, for example OSX
19048 Mail (<v2.1). Outlook Express breaks more badly though, without this it
19049 may show user "Message no longer in server" errors. Note that OE6
19050 still breaks even with this workaround if synchronization is set to
19053 @item tb-extra-mailbox-sep
19054 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
19055 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
19056 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
19058 @item tb-lsub-flags
19059 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
19060 This makes Thunderbird realize they aren't selectable and show them
19061 greyed out, instead of only later giving "not selectable" popup error.
19063 Defaults to @samp{()}.
19066 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
19067 Host allowed in URLAUTH URLs sent by client. "*" allows all.
19068 Defaults to @samp{""}.
19072 Whew! Lots of configuration options. The nice thing about it though is
19073 that Guix has a complete interface to Dovecot's configuration
19074 language. This allows not only a nice way to declare configurations,
19075 but also offers reflective capabilities as well: users can write code to
19076 inspect and transform configurations from within Scheme.
19078 However, it could be that you just want to get a @code{dovecot.conf} up
19079 and running. In that case, you can pass an
19080 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
19081 @code{dovecot-service}. As its name indicates, an opaque configuration
19082 does not have easy reflective capabilities.
19084 Available @code{opaque-dovecot-configuration} fields are:
19086 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
19087 The dovecot package.
19090 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
19091 The contents of the @code{dovecot.conf}, as a string.
19094 For example, if your @code{dovecot.conf} is just the empty string, you
19095 could instantiate a dovecot service like this:
19098 (dovecot-service #:config
19099 (opaque-dovecot-configuration
19103 @subsubheading OpenSMTPD Service
19105 @deffn {Scheme Variable} opensmtpd-service-type
19106 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
19107 service, whose value should be an @code{opensmtpd-configuration} object
19108 as in this example:
19111 (service opensmtpd-service-type
19112 (opensmtpd-configuration
19113 (config-file (local-file "./my-smtpd.conf"))))
19117 @deftp {Data Type} opensmtpd-configuration
19118 Data type representing the configuration of opensmtpd.
19121 @item @code{package} (default: @var{opensmtpd})
19122 Package object of the OpenSMTPD SMTP server.
19124 @item @code{config-file} (default: @code{%default-opensmtpd-file})
19125 File-like object of the OpenSMTPD configuration file to use. By default
19126 it listens on the loopback network interface, and allows for mail from
19127 users and daemons on the local machine, as well as permitting email to
19128 remote servers. Run @command{man smtpd.conf} for more information.
19133 @subsubheading Exim Service
19135 @cindex mail transfer agent (MTA)
19136 @cindex MTA (mail transfer agent)
19139 @deffn {Scheme Variable} exim-service-type
19140 This is the type of the @uref{https://exim.org, Exim} mail transfer
19141 agent (MTA), whose value should be an @code{exim-configuration} object
19142 as in this example:
19145 (service exim-service-type
19146 (exim-configuration
19147 (config-file (local-file "./my-exim.conf"))))
19151 In order to use an @code{exim-service-type} service you must also have a
19152 @code{mail-aliases-service-type} service present in your
19153 @code{operating-system} (even if it has no aliases).
19155 @deftp {Data Type} exim-configuration
19156 Data type representing the configuration of exim.
19159 @item @code{package} (default: @var{exim})
19160 Package object of the Exim server.
19162 @item @code{config-file} (default: @code{#f})
19163 File-like object of the Exim configuration file to use. If its value is
19164 @code{#f} then use the default configuration file from the package
19165 provided in @code{package}. The resulting configuration file is loaded
19166 after setting the @code{exim_user} and @code{exim_group} configuration
19172 @subsubheading Getmail service
19177 @deffn {Scheme Variable} getmail-service-type
19178 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
19179 mail retriever, whose value should be an @code{getmail-configuration}.
19182 Available @code{getmail-configuration} fields are:
19184 @deftypevr {@code{getmail-configuration} parameter} symbol name
19185 A symbol to identify the getmail service.
19187 Defaults to @samp{"unset"}.
19191 @deftypevr {@code{getmail-configuration} parameter} package package
19192 The getmail package to use.
19196 @deftypevr {@code{getmail-configuration} parameter} string user
19197 The user to run getmail as.
19199 Defaults to @samp{"getmail"}.
19203 @deftypevr {@code{getmail-configuration} parameter} string group
19204 The group to run getmail as.
19206 Defaults to @samp{"getmail"}.
19210 @deftypevr {@code{getmail-configuration} parameter} string directory
19211 The getmail directory to use.
19213 Defaults to @samp{"/var/lib/getmail/default"}.
19217 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
19218 The getmail configuration file to use.
19220 Available @code{getmail-configuration-file} fields are:
19222 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
19223 What mail account to retrieve mail from, and how to access that account.
19225 Available @code{getmail-retriever-configuration} fields are:
19227 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
19228 The type of mail retriever to use. Valid values include @samp{passwd}
19231 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
19235 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
19236 Username to login to the mail server with.
19238 Defaults to @samp{unset}.
19242 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
19243 Username to login to the mail server with.
19245 Defaults to @samp{unset}.
19249 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
19250 Port number to connect to.
19252 Defaults to @samp{#f}.
19256 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
19257 Override fields from passwd.
19259 Defaults to @samp{""}.
19263 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
19264 Override fields from passwd.
19266 Defaults to @samp{()}.
19270 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
19271 PEM-formatted key file to use for the TLS negotiation.
19273 Defaults to @samp{""}.
19277 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
19278 PEM-formatted certificate file to use for the TLS negotiation.
19280 Defaults to @samp{""}.
19284 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
19285 CA certificates to use.
19287 Defaults to @samp{""}.
19291 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
19292 Extra retriever parameters.
19294 Defaults to @samp{()}.
19300 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
19301 What to do with retrieved messages.
19303 Available @code{getmail-destination-configuration} fields are:
19305 @deftypevr {@code{getmail-destination-configuration} parameter} string type
19306 The type of mail destination. Valid values include @samp{Maildir},
19307 @samp{Mboxrd} and @samp{MDA_external}.
19309 Defaults to @samp{unset}.
19313 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
19314 The path option for the mail destination. The behaviour depends on the
19317 Defaults to @samp{""}.
19321 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
19322 Extra destination parameters
19324 Defaults to @samp{()}.
19330 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
19333 Available @code{getmail-options-configuration} fields are:
19335 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
19336 If set to @samp{0}, getmail will only print warnings and errors. A
19337 value of @samp{1} means that messages will be printed about retrieving
19338 and deleting messages. If set to @samp{2}, getmail will print messages
19339 about each of it's actions.
19341 Defaults to @samp{1}.
19345 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
19346 If true, getmail will retrieve all available messages. Otherwise it
19347 will only retrieve messages it hasn't seen previously.
19349 Defaults to @samp{#t}.
19353 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
19354 If set to true, messages will be deleted from the server after
19355 retrieving and successfully delivering them. Otherwise, messages will
19356 be left on the server.
19358 Defaults to @samp{#f}.
19362 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
19363 Getmail will delete messages this number of days after seeing them, if
19364 they have been delivered. This means messages will be left on the
19365 server this number of days after delivering them. A value of @samp{0}
19366 disabled this feature.
19368 Defaults to @samp{0}.
19372 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
19373 Delete messages larger than this of bytes after retrieving them, even if
19374 the delete and delete-after options are disabled. A value of @samp{0}
19375 disables this feature.
19377 Defaults to @samp{0}.
19381 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
19382 Retrieve messages totalling up to this number of bytes before closing
19383 the session with the server. A value of @samp{0} disables this feature.
19385 Defaults to @samp{0}.
19389 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
19390 Don't retrieve messages larger than this number of bytes. A value of
19391 @samp{0} disables this feature.
19393 Defaults to @samp{0}.
19397 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
19398 If true, getmail will add a Delivered-To header to messages.
19400 Defaults to @samp{#t}.
19404 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
19405 If set, getmail adds a Received header to the messages.
19407 Defaults to @samp{#t}.
19411 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
19412 Getmail will record a log of its actions to the named file. A value of
19413 @samp{""} disables this feature.
19415 Defaults to @samp{""}.
19419 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
19420 If true, getmail will record a log of its actions using the system
19423 Defaults to @samp{#f}.
19427 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
19428 If true, getmail will log information about messages not retrieved and
19429 the reason for not retrieving them, as well as starting and ending
19432 Defaults to @samp{#f}.
19436 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
19437 Extra options to include.
19439 Defaults to @samp{()}.
19447 @deftypevr {@code{getmail-configuration} parameter} list idle
19448 A list of mailboxes that getmail should wait on the server for new mail
19449 notifications. This depends on the server supporting the IDLE
19452 Defaults to @samp{()}.
19456 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
19457 Environment variables to set for getmail.
19459 Defaults to @samp{()}.
19463 @subsubheading Mail Aliases Service
19465 @cindex email aliases
19466 @cindex aliases, for email addresses
19468 @deffn {Scheme Variable} mail-aliases-service-type
19469 This is the type of the service which provides @code{/etc/aliases},
19470 specifying how to deliver mail to users on this system.
19473 (service mail-aliases-service-type
19474 '(("postmaster" "bob")
19475 ("bob" "bob@@example.com" "bob@@example2.com")))
19479 The configuration for a @code{mail-aliases-service-type} service is an
19480 association list denoting how to deliver mail that comes to this
19481 system. Each entry is of the form @code{(alias addresses ...)}, with
19482 @code{alias} specifying the local alias and @code{addresses} specifying
19483 where to deliver this user's mail.
19485 The aliases aren't required to exist as users on the local system. In
19486 the above example, there doesn't need to be a @code{postmaster} entry in
19487 the @code{operating-system}'s @code{user-accounts} in order to deliver
19488 the @code{postmaster} mail to @code{bob} (which subsequently would
19489 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
19491 @subsubheading GNU Mailutils IMAP4 Daemon
19492 @cindex GNU Mailutils IMAP4 Daemon
19494 @deffn {Scheme Variable} imap4d-service-type
19495 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
19496 mailutils, GNU Mailutils Manual}), whose value should be an
19497 @code{imap4d-configuration} object as in this example:
19500 (service imap4d-service-type
19501 (imap4d-configuration
19502 (config-file (local-file "imap4d.conf"))))
19506 @deftp {Data Type} imap4d-configuration
19507 Data type representing the configuration of @command{imap4d}.
19510 @item @code{package} (default: @code{mailutils})
19511 The package that provides @command{imap4d}.
19513 @item @code{config-file} (default: @code{%default-imap4d-config-file})
19514 File-like object of the configuration file to use, by default it will listen
19515 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
19516 Mailutils Manual}, for details.
19521 @node Messaging Services
19522 @subsection Messaging Services
19527 The @code{(gnu services messaging)} module provides Guix service
19528 definitions for messaging services: currently only Prosody is supported.
19530 @subsubheading Prosody Service
19532 @deffn {Scheme Variable} prosody-service-type
19533 This is the type for the @uref{https://prosody.im, Prosody XMPP
19534 communication server}. Its value must be a @code{prosody-configuration}
19535 record as in this example:
19538 (service prosody-service-type
19539 (prosody-configuration
19540 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
19543 (int-component-configuration
19544 (hostname "conference.example.net")
19546 (mod-muc (mod-muc-configuration)))))
19549 (virtualhost-configuration
19550 (domain "example.net"))))))
19553 See below for details about @code{prosody-configuration}.
19557 By default, Prosody does not need much configuration. Only one
19558 @code{virtualhosts} field is needed: it specifies the domain you wish
19561 You can perform various sanity checks on the generated configuration
19562 with the @code{prosodyctl check} command.
19564 Prosodyctl will also help you to import certificates from the
19565 @code{letsencrypt} directory so that the @code{prosody} user can access
19566 them. See @url{https://prosody.im/doc/letsencrypt}.
19569 prosodyctl --root cert import /etc/letsencrypt/live
19572 The available configuration parameters follow. Each parameter
19573 definition is preceded by its type; for example, @samp{string-list foo}
19574 indicates that the @code{foo} parameter should be specified as a list of
19575 strings. Types starting with @code{maybe-} denote parameters that won't
19576 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
19578 There is also a way to specify the configuration as a string, if you
19579 have an old @code{prosody.cfg.lua} file that you want to port over from
19580 some other system; see the end for more details.
19582 The @code{file-object} type designates either a file-like object
19583 (@pxref{G-Expressions, file-like objects}) or a file name.
19585 @c The following documentation was initially generated by
19586 @c (generate-documentation) in (gnu services messaging). Manually maintained
19587 @c documentation is better, so we shouldn't hesitate to edit below as
19588 @c needed. However if the change you want to make to this documentation
19589 @c can be done in an automated way, it's probably easier to change
19590 @c (generate-documentation) than to make it below and have to deal with
19591 @c the churn as Prosody updates.
19593 Available @code{prosody-configuration} fields are:
19595 @deftypevr {@code{prosody-configuration} parameter} package prosody
19596 The Prosody package.
19599 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
19600 Location of the Prosody data storage directory. See
19601 @url{https://prosody.im/doc/configure}.
19602 Defaults to @samp{"/var/lib/prosody"}.
19605 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
19606 Additional plugin directories. They are searched in all the specified
19607 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
19608 Defaults to @samp{()}.
19611 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
19612 Every virtual host and component needs a certificate so that clients and
19613 servers can securely verify its identity. Prosody will automatically load
19614 certificates/keys from the directory specified here.
19615 Defaults to @samp{"/etc/prosody/certs"}.
19618 @deftypevr {@code{prosody-configuration} parameter} string-list admins
19619 This is a list of accounts that are admins for the server. Note that you
19620 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
19621 @url{https://prosody.im/doc/creating_accounts}.
19622 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
19623 Defaults to @samp{()}.
19626 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
19627 Enable use of libevent for better performance under high load. See
19628 @url{https://prosody.im/doc/libevent}.
19629 Defaults to @samp{#f}.
19632 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
19633 This is the list of modules Prosody will load on startup. It looks for
19634 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
19635 Documentation on modules can be found at:
19636 @url{https://prosody.im/doc/modules}.
19637 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
19640 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
19641 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
19642 should you want to disable them then add them to this list.
19643 Defaults to @samp{()}.
19646 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
19647 Path to a text file where the shared groups are defined. If this path is
19648 empty then @samp{mod_groups} does nothing. See
19649 @url{https://prosody.im/doc/modules/mod_groups}.
19650 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
19653 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
19654 Disable account creation by default, for security. See
19655 @url{https://prosody.im/doc/creating_accounts}.
19656 Defaults to @samp{#f}.
19659 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
19660 These are the SSL/TLS-related settings. Most of them are disabled so to
19661 use Prosody's defaults. If you do not completely understand these options, do
19662 not add them to your config, it is easy to lower the security of your server
19663 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
19665 Available @code{ssl-configuration} fields are:
19667 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
19668 This determines what handshake to use.
19671 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
19672 Path to your private key file.
19675 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
19676 Path to your certificate file.
19679 @deftypevr {@code{ssl-configuration} parameter} file-object capath
19680 Path to directory containing root certificates that you wish Prosody to
19681 trust when verifying the certificates of remote servers.
19682 Defaults to @samp{"/etc/ssl/certs"}.
19685 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
19686 Path to a file containing root certificates that you wish Prosody to trust.
19687 Similar to @code{capath} but with all certificates concatenated together.
19690 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
19691 A list of verification options (these mostly map to OpenSSL's
19692 @code{set_verify()} flags).
19695 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
19696 A list of general options relating to SSL/TLS. These map to OpenSSL's
19697 @code{set_options()}. For a full list of options available in LuaSec, see the
19701 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
19702 How long a chain of certificate authorities to check when looking for a
19703 trusted root certificate.
19706 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
19707 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
19708 clients, and in what order.
19711 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
19712 A path to a file containing parameters for Diffie-Hellman key exchange. You
19713 can create such a file with:
19714 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
19717 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
19718 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
19719 @samp{"secp384r1"}.
19722 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
19723 A list of ``extra'' verification options.
19726 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
19727 Password for encrypted private keys.
19732 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
19733 Whether to force all client-to-server connections to be encrypted or not.
19734 See @url{https://prosody.im/doc/modules/mod_tls}.
19735 Defaults to @samp{#f}.
19738 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
19739 Set of mechanisms that will never be offered. See
19740 @url{https://prosody.im/doc/modules/mod_saslauth}.
19741 Defaults to @samp{("DIGEST-MD5")}.
19744 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
19745 Whether to force all server-to-server connections to be encrypted or not.
19746 See @url{https://prosody.im/doc/modules/mod_tls}.
19747 Defaults to @samp{#f}.
19750 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
19751 Whether to require encryption and certificate authentication. This
19752 provides ideal security, but requires servers you communicate with to support
19753 encryption AND present valid, trusted certificates. See
19754 @url{https://prosody.im/doc/s2s#security}.
19755 Defaults to @samp{#f}.
19758 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
19759 Many servers don't support encryption or have invalid or self-signed
19760 certificates. You can list domains here that will not be required to
19761 authenticate using certificates. They will be authenticated using DNS. See
19762 @url{https://prosody.im/doc/s2s#security}.
19763 Defaults to @samp{()}.
19766 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
19767 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
19768 valid certificates for some domains by specifying a list here. See
19769 @url{https://prosody.im/doc/s2s#security}.
19770 Defaults to @samp{()}.
19773 @deftypevr {@code{prosody-configuration} parameter} string authentication
19774 Select the authentication backend to use. The default provider stores
19775 passwords in plaintext and uses Prosody's configured data storage to store the
19776 authentication data. If you do not trust your server please see
19777 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
19778 about using the hashed backend. See also
19779 @url{https://prosody.im/doc/authentication}
19780 Defaults to @samp{"internal_plain"}.
19783 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
19784 Set logging options. Advanced logging configuration is not yet supported
19785 by the Prosody service. See @url{https://prosody.im/doc/logging}.
19786 Defaults to @samp{"*syslog"}.
19789 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
19790 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
19791 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
19794 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
19795 Maximum allowed size of the HTTP body (in bytes).
19798 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
19799 Some modules expose their own URL in various ways. This URL is built
19800 from the protocol, host and port used. If Prosody sits behind a proxy, the
19801 public URL will be @code{http-external-url} instead. See
19802 @url{https://prosody.im/doc/http#external_url}.
19805 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
19806 A host in Prosody is a domain on which user accounts can be created. For
19807 example if you want your users to have addresses like
19808 @samp{"john.smith@@example.com"} then you need to add a host
19809 @samp{"example.com"}. All options in this list will apply only to this host.
19811 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
19812 the actual physical host that Prosody is installed on. A single Prosody
19813 instance can serve many domains, each one defined as a VirtualHost entry in
19814 Prosody's configuration. Conversely a server that hosts a single domain would
19815 have just one VirtualHost entry.
19817 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
19819 Available @code{virtualhost-configuration} fields are:
19821 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:
19822 @deftypevr {@code{virtualhost-configuration} parameter} string domain
19823 Domain you wish Prosody to serve.
19828 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
19829 Components are extra services on a server which are available to clients,
19830 usually on a subdomain of the main server (such as
19831 @samp{"mycomponent.example.com"}). Example components might be chatroom
19832 servers, user directories, or gateways to other protocols.
19834 Internal components are implemented with Prosody-specific plugins. To add an
19835 internal component, you simply fill the hostname field, and the plugin you wish
19836 to use for the component.
19838 See @url{https://prosody.im/doc/components}.
19839 Defaults to @samp{()}.
19841 Available @code{int-component-configuration} fields are:
19843 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:
19844 @deftypevr {@code{int-component-configuration} parameter} string hostname
19845 Hostname of the component.
19848 @deftypevr {@code{int-component-configuration} parameter} string plugin
19849 Plugin you wish to use for the component.
19852 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
19853 Multi-user chat (MUC) is Prosody's module for allowing you to create
19854 hosted chatrooms/conferences for XMPP users.
19856 General information on setting up and using multi-user chatrooms can be found
19857 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
19858 which you should read if you are new to XMPP chatrooms.
19860 See also @url{https://prosody.im/doc/modules/mod_muc}.
19862 Available @code{mod-muc-configuration} fields are:
19864 @deftypevr {@code{mod-muc-configuration} parameter} string name
19865 The name to return in service discovery responses.
19866 Defaults to @samp{"Prosody Chatrooms"}.
19869 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
19870 If @samp{#t}, this will only allow admins to create new chatrooms.
19871 Otherwise anyone can create a room. The value @samp{"local"} restricts room
19872 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
19873 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
19874 restricts to service administrators only.
19875 Defaults to @samp{#f}.
19878 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
19879 Maximum number of history messages that will be sent to the member that has
19880 just joined the room.
19881 Defaults to @samp{20}.
19888 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
19889 External components use XEP-0114, which most standalone components
19890 support. To add an external component, you simply fill the hostname field. See
19891 @url{https://prosody.im/doc/components}.
19892 Defaults to @samp{()}.
19894 Available @code{ext-component-configuration} fields are:
19896 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:
19897 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
19898 Password which the component will use to log in.
19901 @deftypevr {@code{ext-component-configuration} parameter} string hostname
19902 Hostname of the component.
19907 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
19908 Port(s) Prosody listens on for component connections.
19909 Defaults to @samp{(5347)}.
19912 @deftypevr {@code{prosody-configuration} parameter} string component-interface
19913 Interface Prosody listens on for component connections.
19914 Defaults to @samp{"127.0.0.1"}.
19917 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
19918 Raw content that will be added to the configuration file.
19921 It could be that you just want to get a @code{prosody.cfg.lua}
19922 up and running. In that case, you can pass an
19923 @code{opaque-prosody-configuration} record as the value of
19924 @code{prosody-service-type}. As its name indicates, an opaque configuration
19925 does not have easy reflective capabilities.
19926 Available @code{opaque-prosody-configuration} fields are:
19928 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
19929 The prosody package.
19932 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
19933 The contents of the @code{prosody.cfg.lua} to use.
19936 For example, if your @code{prosody.cfg.lua} is just the empty
19937 string, you could instantiate a prosody service like this:
19940 (service prosody-service-type
19941 (opaque-prosody-configuration
19942 (prosody.cfg.lua "")))
19945 @c end of Prosody auto-generated documentation
19947 @subsubheading BitlBee Service
19949 @cindex IRC (Internet Relay Chat)
19950 @cindex IRC gateway
19951 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
19952 interface to a variety of messaging protocols such as XMPP.
19954 @defvr {Scheme Variable} bitlbee-service-type
19955 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
19956 gateway daemon. Its value is a @code{bitlbee-configuration} (see
19959 To have BitlBee listen on port 6667 on localhost, add this line to your
19963 (service bitlbee-service-type)
19967 @deftp {Data Type} bitlbee-configuration
19968 This is the configuration for BitlBee, with the following fields:
19971 @item @code{interface} (default: @code{"127.0.0.1"})
19972 @itemx @code{port} (default: @code{6667})
19973 Listen on the network interface corresponding to the IP address
19974 specified in @var{interface}, on @var{port}.
19976 When @var{interface} is @code{127.0.0.1}, only local clients can
19977 connect; when it is @code{0.0.0.0}, connections can come from any
19978 networking interface.
19980 @item @code{bitlbee} (default: @code{bitlbee})
19981 The BitlBee package to use.
19983 @item @code{plugins} (default: @code{'()})
19984 List of plugin packages to use---e.g., @code{bitlbee-discord}.
19986 @item @code{extra-settings} (default: @code{""})
19987 Configuration snippet added as-is to the BitlBee configuration file.
19991 @subsubheading Quassel Service
19993 @cindex IRC (Internet Relay Chat)
19994 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
19995 meaning that one or more clients can attach to and detach from the
19998 @defvr {Scheme Variable} quassel-service-type
19999 This is the service type for the @url{https://quassel-irc.org/,Quassel}
20000 IRC backend daemon. Its value is a @code{quassel-configuration}
20004 @deftp {Data Type} quassel-configuration
20005 This is the configuration for Quassel, with the following fields:
20008 @item @code{quassel} (default: @code{quassel})
20009 The Quassel package to use.
20011 @item @code{interface} (default: @code{"::,0.0.0.0"})
20012 @item @code{port} (default: @code{4242})
20013 Listen on the network interface(s) corresponding to the IPv4 or IPv6
20014 interfaces specified in the comma delimited @var{interface}, on
20017 @item @code{loglevel} (default: @code{"Info"})
20018 The level of logging desired. Accepted values are Debug, Info, Warning
20023 @node Telephony Services
20024 @subsection Telephony Services
20026 @cindex Murmur (VoIP server)
20027 @cindex VoIP server
20028 This section describes how to set up and run a Murmur server. Murmur is
20029 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
20032 @deftp {Data Type} murmur-configuration
20033 The service type for the Murmur server. An example configuration can
20037 (service murmur-service-type
20038 (murmur-configuration
20040 "Welcome to this Mumble server running on Guix!")
20041 (cert-required? #t) ;disallow text password logins
20042 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
20043 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
20046 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
20047 password with the command that is printed during the activation phase.
20049 It is recommended to register a normal Mumble user account
20050 and grant it admin or moderator rights.
20051 You can use the @code{mumble} client to
20052 login as new normal user, register yourself, and log out.
20053 For the next step login with the name @code{SuperUser} use
20054 the @code{SuperUser} password that you set previously,
20055 and grant your newly registered mumble user administrator or moderator
20056 rights and create some channels.
20058 Available @code{murmur-configuration} fields are:
20061 @item @code{package} (default: @code{mumble})
20062 Package that contains @code{bin/murmurd}.
20064 @item @code{user} (default: @code{"murmur"})
20065 User who will run the Murmur server.
20067 @item @code{group} (default: @code{"murmur"})
20068 Group of the user who will run the murmur server.
20070 @item @code{port} (default: @code{64738})
20071 Port on which the server will listen.
20073 @item @code{welcome-text} (default: @code{""})
20074 Welcome text sent to clients when they connect.
20076 @item @code{server-password} (default: @code{""})
20077 Password the clients have to enter in order to connect.
20079 @item @code{max-users} (default: @code{100})
20080 Maximum of users that can be connected to the server at once.
20082 @item @code{max-user-bandwidth} (default: @code{#f})
20083 Maximum voice traffic a user can send per second.
20085 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
20086 File name of the sqlite database.
20087 The service's user will become the owner of the directory.
20089 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
20090 File name of the log file.
20091 The service's user will become the owner of the directory.
20093 @item @code{autoban-attempts} (default: @code{10})
20094 Maximum number of logins a user can make in @code{autoban-timeframe}
20095 without getting auto banned for @code{autoban-time}.
20097 @item @code{autoban-timeframe} (default: @code{120})
20098 Timeframe for autoban in seconds.
20100 @item @code{autoban-time} (default: @code{300})
20101 Amount of time in seconds for which a client gets banned
20102 when violating the autoban limits.
20104 @item @code{opus-threshold} (default: @code{100})
20105 Percentage of clients that need to support opus
20106 before switching over to opus audio codec.
20108 @item @code{channel-nesting-limit} (default: @code{10})
20109 How deep channels can be nested at maximum.
20111 @item @code{channelname-regex} (default: @code{#f})
20112 A string in form of a Qt regular expression that channel names must conform to.
20114 @item @code{username-regex} (default: @code{#f})
20115 A string in form of a Qt regular expression that user names must conform to.
20117 @item @code{text-message-length} (default: @code{5000})
20118 Maximum size in bytes that a user can send in one text chat message.
20120 @item @code{image-message-length} (default: @code{(* 128 1024)})
20121 Maximum size in bytes that a user can send in one image message.
20123 @item @code{cert-required?} (default: @code{#f})
20124 If it is set to @code{#t} clients that use weak password authentication
20125 will not be accepted. Users must have completed the certificate wizard to join.
20127 @item @code{remember-channel?} (default: @code{#f})
20128 Should murmur remember the last channel each user was in when they disconnected
20129 and put them into the remembered channel when they rejoin.
20131 @item @code{allow-html?} (default: @code{#f})
20132 Should html be allowed in text messages, user comments, and channel descriptions.
20134 @item @code{allow-ping?} (default: @code{#f})
20135 Setting to true exposes the current user count, the maximum user count, and
20136 the server's maximum bandwidth per client to unauthenticated users. In the
20137 Mumble client, this information is shown in the Connect dialog.
20139 Disabling this setting will prevent public listing of the server.
20141 @item @code{bonjour?} (default: @code{#f})
20142 Should the server advertise itself in the local network through the bonjour protocol.
20144 @item @code{send-version?} (default: @code{#f})
20145 Should the murmur server version be exposed in ping requests.
20147 @item @code{log-days} (default: @code{31})
20148 Murmur also stores logs in the database, which are accessible via RPC.
20149 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
20150 or -1 to disable logging to the database.
20152 @item @code{obfuscate-ips?} (default: @code{#t})
20153 Should logged ips be obfuscated to protect the privacy of users.
20155 @item @code{ssl-cert} (default: @code{#f})
20156 File name of the SSL/TLS certificate used for encrypted connections.
20159 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
20161 @item @code{ssl-key} (default: @code{#f})
20162 Filepath to the ssl private key used for encrypted connections.
20164 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
20167 @item @code{ssl-dh-params} (default: @code{#f})
20168 File name of a PEM-encoded file with Diffie-Hellman parameters
20169 for the SSL/TLS encryption. Alternatively you set it to
20170 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
20171 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
20173 @item @code{ssl-ciphers} (default: @code{#f})
20174 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
20177 This option is specified using
20178 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
20179 OpenSSL cipher list notation}.
20181 It is recommended that you try your cipher string using 'openssl ciphers <string>'
20182 before setting it here, to get a feel for which cipher suites you will get.
20183 After setting this option, it is recommend that you inspect your Murmur log
20184 to ensure that Murmur is using the cipher suites that you expected it to.
20186 Note: Changing this option may impact the backwards compatibility of your
20187 Murmur server, and can remove the ability for older Mumble clients to be able
20190 @item @code{public-registration} (default: @code{#f})
20191 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
20193 You can optionally register your server in the public server list that the
20194 @code{mumble} client shows on startup.
20195 You cannot register your server if you have set a @code{server-password},
20196 or set @code{allow-ping} to @code{#f}.
20198 It might take a few hours until it shows up in the public list.
20200 @item @code{file} (default: @code{#f})
20201 Optional alternative override for this configuration.
20205 @deftp {Data Type} murmur-public-registration-configuration
20206 Configuration for public registration of a murmur service.
20210 This is a display name for your server. Not to be confused with the hostname.
20212 @item @code{password}
20213 A password to identify your registration.
20214 Subsequent updates will need the same password. Don't lose your password.
20217 This should be a @code{http://} or @code{https://} link to your web
20220 @item @code{hostname} (default: @code{#f})
20221 By default your server will be listed by its IP address.
20222 If it is set your server will be linked by this host name instead.
20228 @node Monitoring Services
20229 @subsection Monitoring Services
20231 @subsubheading Tailon Service
20233 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
20234 viewing and searching log files.
20236 The following example will configure the service with default values.
20237 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
20240 (service tailon-service-type)
20243 The following example customises more of the Tailon configuration,
20244 adding @command{sed} to the list of allowed commands.
20247 (service tailon-service-type
20248 (tailon-configuration
20250 (tailon-configuration-file
20251 (allowed-commands '("tail" "grep" "awk" "sed"))))))
20255 @deftp {Data Type} tailon-configuration
20256 Data type representing the configuration of Tailon.
20257 This type has the following parameters:
20260 @item @code{config-file} (default: @code{(tailon-configuration-file)})
20261 The configuration file to use for Tailon. This can be set to a
20262 @dfn{tailon-configuration-file} record value, or any gexp
20263 (@pxref{G-Expressions}).
20265 For example, to instead use a local file, the @code{local-file} function
20269 (service tailon-service-type
20270 (tailon-configuration
20271 (config-file (local-file "./my-tailon.conf"))))
20274 @item @code{package} (default: @code{tailon})
20275 The tailon package to use.
20280 @deftp {Data Type} tailon-configuration-file
20281 Data type representing the configuration options for Tailon.
20282 This type has the following parameters:
20285 @item @code{files} (default: @code{(list "/var/log")})
20286 List of files to display. The list can include strings for a single file
20287 or directory, or a list, where the first item is the name of a
20288 subsection, and the remaining items are the files or directories in that
20291 @item @code{bind} (default: @code{"localhost:8080"})
20292 Address and port to which Tailon should bind on.
20294 @item @code{relative-root} (default: @code{#f})
20295 URL path to use for Tailon, set to @code{#f} to not use a path.
20297 @item @code{allow-transfers?} (default: @code{#t})
20298 Allow downloading the log files in the web interface.
20300 @item @code{follow-names?} (default: @code{#t})
20301 Allow tailing of not-yet existent files.
20303 @item @code{tail-lines} (default: @code{200})
20304 Number of lines to read initially from each file.
20306 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
20307 Commands to allow running. By default, @code{sed} is disabled.
20309 @item @code{debug?} (default: @code{#f})
20310 Set @code{debug?} to @code{#t} to show debug messages.
20312 @item @code{wrap-lines} (default: @code{#t})
20313 Initial line wrapping state in the web interface. Set to @code{#t} to
20314 initially wrap lines (the default), or to @code{#f} to initially not
20317 @item @code{http-auth} (default: @code{#f})
20318 HTTP authentication type to use. Set to @code{#f} to disable
20319 authentication (the default). Supported values are @code{"digest"} or
20322 @item @code{users} (default: @code{#f})
20323 If HTTP authentication is enabled (see @code{http-auth}), access will be
20324 restricted to the credentials provided here. To configure users, use a
20325 list of pairs, where the first element of the pair is the username, and
20326 the 2nd element of the pair is the password.
20329 (tailon-configuration-file
20330 (http-auth "basic")
20331 (users '(("user1" . "password1")
20332 ("user2" . "password2"))))
20339 @subsubheading Darkstat Service
20341 Darkstat is a packet sniffer that captures network traffic, calculates
20342 statistics about usage, and serves reports over HTTP.
20344 @defvar {Scheme Variable} darkstat-service-type
20345 This is the service type for the
20346 @uref{https://unix4lyfe.org/darkstat/, darkstat}
20347 service, its value must be a @code{darkstat-configuration} record as in
20351 (service darkstat-service-type
20352 (darkstat-configuration
20353 (interface "eno1")))
20357 @deftp {Data Type} darkstat-configuration
20358 Data type representing the configuration of @command{darkstat}.
20361 @item @code{package} (default: @code{darkstat})
20362 The darkstat package to use.
20364 @item @code{interface}
20365 Capture traffic on the specified network interface.
20367 @item @code{port} (default: @code{"667"})
20368 Bind the web interface to the specified port.
20370 @item @code{bind-address} (default: @code{"127.0.0.1"})
20371 Bind the web interface to the specified address.
20373 @item @code{base} (default: @code{"/"})
20374 Specify the path of the base URL. This can be useful if
20375 @command{darkstat} is accessed via a reverse proxy.
20380 @subsubheading Prometheus Node Exporter Service
20382 @cindex prometheus-node-exporter
20383 The Prometheus ``node exporter'' makes hardware and operating system statistics
20384 provided by the Linux kernel available for the Prometheus monitoring system.
20385 This service should be deployed on all physical nodes and virtual machines,
20386 where monitoring these statistics is desirable.
20388 @defvar {Scheme variable} prometheus-node-exporter-service-type
20389 This is the service type for the
20390 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
20391 service, its value must be a @code{prometheus-node-exporter-configuration}
20392 record as in this example:
20395 (service prometheus-node-exporter-service-type
20396 (prometheus-node-exporter-configuration
20397 (web-listen-address ":9100")))
20401 @deftp {Data Type} prometheus-node-exporter-configuration
20402 Data type representing the configuration of @command{node_exporter}.
20405 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
20406 The prometheus-node-exporter package to use.
20408 @item @code{web-listen-address} (default: @code{":9100"})
20409 Bind the web interface to the specified address.
20414 @subsubheading Zabbix server
20415 @cindex zabbix zabbix-server
20416 Zabbix provides monitoring metrics, among others network utilization, CPU load
20417 and disk space consumption:
20420 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
20421 @item Auto-discovery of servers and network devices and interfaces.
20422 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
20423 @item Distributed monitoring with centralized web administration.
20424 @item Native high performance agents.
20425 @item SLA, and ITIL KPI metrics on reporting.
20426 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
20427 @item Remote command execution through Zabbix proxies.
20430 @c %start of fragment
20432 Available @code{zabbix-server-configuration} fields are:
20434 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
20435 The zabbix-server package.
20439 @deftypevr {@code{zabbix-server-configuration} parameter} string user
20440 User who will run the Zabbix server.
20442 Defaults to @samp{"zabbix"}.
20446 @deftypevr {@code{zabbix-server-configuration} parameter} group group
20447 Group who will run the Zabbix server.
20449 Defaults to @samp{"zabbix"}.
20453 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
20454 Database host name.
20456 Defaults to @samp{"127.0.0.1"}.
20460 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
20463 Defaults to @samp{"zabbix"}.
20467 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
20470 Defaults to @samp{"zabbix"}.
20474 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
20475 Database password. Please, use @code{include-files} with
20476 @code{DBPassword=SECRET} inside a specified file instead.
20478 Defaults to @samp{""}.
20482 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
20485 Defaults to @samp{5432}.
20489 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
20490 Specifies where log messages are written to:
20494 @code{system} - syslog.
20497 @code{file} - file specified with @code{log-file} parameter.
20500 @code{console} - standard output.
20504 Defaults to @samp{""}.
20508 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
20509 Log file name for @code{log-type} @code{file} parameter.
20511 Defaults to @samp{"/var/log/zabbix/server.log"}.
20515 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
20518 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
20522 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
20523 The location of certificate authority (CA) files for SSL server
20524 certificate verification.
20526 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
20530 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
20531 Location of SSL client certificates.
20533 Defaults to @samp{"/etc/ssl/certs"}.
20537 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
20538 Extra options will be appended to Zabbix server configuration file.
20540 Defaults to @samp{""}.
20544 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
20545 You may include individual files or all files in a directory in the
20546 configuration file.
20548 Defaults to @samp{()}.
20552 @c %end of fragment
20554 @subsubheading Zabbix agent
20555 @cindex zabbix zabbix-agent
20557 Zabbix agent gathers information for Zabbix server.
20559 @c %start of fragment
20561 Available @code{zabbix-agent-configuration} fields are:
20563 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
20564 The zabbix-agent package.
20568 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
20569 User who will run the Zabbix agent.
20571 Defaults to @samp{"zabbix"}.
20575 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
20576 Group who will run the Zabbix agent.
20578 Defaults to @samp{"zabbix"}.
20582 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
20583 Unique, case sensitive hostname which is required for active checks and
20584 must match hostname as configured on the server.
20586 Defaults to @samp{"Zabbix server"}.
20590 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
20591 Specifies where log messages are written to:
20595 @code{system} - syslog.
20598 @code{file} - file specified with @code{log-file} parameter.
20601 @code{console} - standard output.
20605 Defaults to @samp{""}.
20609 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
20610 Log file name for @code{log-type} @code{file} parameter.
20612 Defaults to @samp{"/var/log/zabbix/agent.log"}.
20616 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
20619 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
20623 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
20624 List of IP addresses, optionally in CIDR notation, or hostnames of
20625 Zabbix servers and Zabbix proxies. Incoming connections will be
20626 accepted only from the hosts listed here.
20628 Defaults to @samp{("127.0.0.1")}.
20632 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
20633 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
20634 proxies for active checks. If port is not specified, default port is
20635 used. If this parameter is not specified, active checks are disabled.
20637 Defaults to @samp{("127.0.0.1")}.
20641 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
20642 Extra options will be appended to Zabbix server configuration file.
20644 Defaults to @samp{""}.
20648 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
20649 You may include individual files or all files in a directory in the
20650 configuration file.
20652 Defaults to @samp{()}.
20656 @c %end of fragment
20658 @subsubheading Zabbix front-end
20659 @cindex zabbix zabbix-front-end
20661 This service provides a WEB interface to Zabbix server.
20663 @c %start of fragment
20665 Available @code{zabbix-front-end-configuration} fields are:
20667 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
20668 NGINX configuration.
20672 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
20673 Database host name.
20675 Defaults to @samp{"localhost"}.
20679 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
20682 Defaults to @samp{5432}.
20686 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
20689 Defaults to @samp{"zabbix"}.
20693 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
20696 Defaults to @samp{"zabbix"}.
20700 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
20701 Database password. Please, use @code{db-secret-file} instead.
20703 Defaults to @samp{""}.
20707 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
20708 Secret file which will be appended to @file{zabbix.conf.php} file. This
20709 file contains credentials for use by Zabbix front-end. You are expected
20710 to create it manually.
20712 Defaults to @samp{""}.
20716 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
20717 Zabbix server hostname.
20719 Defaults to @samp{"localhost"}.
20723 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
20724 Zabbix server port.
20726 Defaults to @samp{10051}.
20731 @c %end of fragment
20733 @node Kerberos Services
20734 @subsection Kerberos Services
20737 The @code{(gnu services kerberos)} module provides services relating to
20738 the authentication protocol @dfn{Kerberos}.
20740 @subsubheading Krb5 Service
20742 Programs using a Kerberos client library normally
20743 expect a configuration file in @file{/etc/krb5.conf}.
20744 This service generates such a file from a definition provided in the
20745 operating system declaration.
20746 It does not cause any daemon to be started.
20748 No ``keytab'' files are provided by this service---you must explicitly create them.
20749 This service is known to work with the MIT client library, @code{mit-krb5}.
20750 Other implementations have not been tested.
20752 @defvr {Scheme Variable} krb5-service-type
20753 A service type for Kerberos 5 clients.
20757 Here is an example of its use:
20759 (service krb5-service-type
20760 (krb5-configuration
20761 (default-realm "EXAMPLE.COM")
20762 (allow-weak-crypto? #t)
20765 (name "EXAMPLE.COM")
20766 (admin-server "groucho.example.com")
20767 (kdc "karl.example.com"))
20770 (admin-server "kerb-admin.argrx.edu")
20771 (kdc "keys.argrx.edu"))))))
20775 This example provides a Kerberos@tie{}5 client configuration which:
20777 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
20778 of which have distinct administration servers and key distribution centers;
20779 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
20780 specified by clients;
20781 @item Accepts services which only support encryption types known to be weak.
20784 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
20785 Only the most commonly used ones are described here.
20786 For a full list, and more detailed explanation of each, see the MIT
20787 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
20791 @deftp {Data Type} krb5-realm
20792 @cindex realm, kerberos
20795 This field is a string identifying the name of the realm.
20796 A common convention is to use the fully qualified DNS name of your organization,
20797 converted to upper case.
20799 @item @code{admin-server}
20800 This field is a string identifying the host where the administration server is
20804 This field is a string identifying the key distribution center
20809 @deftp {Data Type} krb5-configuration
20812 @item @code{allow-weak-crypto?} (default: @code{#f})
20813 If this flag is @code{#t} then services which only offer encryption algorithms
20814 known to be weak will be accepted.
20816 @item @code{default-realm} (default: @code{#f})
20817 This field should be a string identifying the default Kerberos
20818 realm for the client.
20819 You should set this field to the name of your Kerberos realm.
20820 If this value is @code{#f}
20821 then a realm must be specified with every Kerberos principal when invoking programs
20822 such as @command{kinit}.
20824 @item @code{realms}
20825 This should be a non-empty list of @code{krb5-realm} objects, which clients may
20827 Normally, one of them will have a @code{name} field matching the @code{default-realm}
20833 @subsubheading PAM krb5 Service
20836 The @code{pam-krb5} service allows for login authentication and password
20837 management via Kerberos.
20838 You will need this service if you want PAM enabled applications to authenticate
20839 users using Kerberos.
20841 @defvr {Scheme Variable} pam-krb5-service-type
20842 A service type for the Kerberos 5 PAM module.
20845 @deftp {Data Type} pam-krb5-configuration
20846 Data type representing the configuration of the Kerberos 5 PAM module.
20847 This type has the following parameters:
20849 @item @code{pam-krb5} (default: @code{pam-krb5})
20850 The pam-krb5 package to use.
20852 @item @code{minimum-uid} (default: @code{1000})
20853 The smallest user ID for which Kerberos authentications should be attempted.
20854 Local accounts with lower values will silently fail to authenticate.
20859 @node LDAP Services
20860 @subsection LDAP Services
20862 @cindex nslcd, LDAP service
20864 The @code{(gnu services authentication)} module provides the
20865 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
20866 server. In addition to configuring the service itself, you may want to add
20867 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
20868 Switch} for detailed information.
20870 Here is a simple operating system declaration with a default configuration of
20871 the @code{nslcd-service-type} and a Name Service Switch configuration that
20872 consults the @code{ldap} name service last:
20875 (use-service-modules authentication)
20876 (use-modules (gnu system nss))
20882 (service nslcd-service-type)
20883 (service dhcp-client-service-type)
20885 (name-service-switch
20886 (let ((services (list (name-service (name "db"))
20887 (name-service (name "files"))
20888 (name-service (name "ldap")))))
20889 (name-service-switch
20890 (inherit %mdns-host-lookup-nss)
20891 (password services)
20894 (netgroup services)
20895 (gshadow services)))))
20898 @c %start of generated documentation for nslcd-configuration
20900 Available @code{nslcd-configuration} fields are:
20902 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
20903 The @code{nss-pam-ldapd} package to use.
20907 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
20908 The number of threads to start that can handle requests and perform LDAP
20909 queries. Each thread opens a separate connection to the LDAP server.
20910 The default is to start 5 threads.
20912 Defaults to @samp{disabled}.
20916 @deftypevr {@code{nslcd-configuration} parameter} string uid
20917 This specifies the user id with which the daemon should be run.
20919 Defaults to @samp{"nslcd"}.
20923 @deftypevr {@code{nslcd-configuration} parameter} string gid
20924 This specifies the group id with which the daemon should be run.
20926 Defaults to @samp{"nslcd"}.
20930 @deftypevr {@code{nslcd-configuration} parameter} log-option log
20931 This option controls the way logging is done via a list containing
20932 SCHEME and LEVEL. The SCHEME argument may either be the symbols
20933 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
20934 argument is optional and specifies the log level. The log level may be
20935 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
20936 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
20937 specified log level or higher are logged.
20939 Defaults to @samp{("/var/log/nslcd" info)}.
20943 @deftypevr {@code{nslcd-configuration} parameter} list uri
20944 The list of LDAP server URIs. Normally, only the first server will be
20945 used with the following servers as fall-back.
20947 Defaults to @samp{("ldap://localhost:389/")}.
20951 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
20952 The version of the LDAP protocol to use. The default is to use the
20953 maximum version supported by the LDAP library.
20955 Defaults to @samp{disabled}.
20959 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
20960 Specifies the distinguished name with which to bind to the directory
20961 server for lookups. The default is to bind anonymously.
20963 Defaults to @samp{disabled}.
20967 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
20968 Specifies the credentials with which to bind. This option is only
20969 applicable when used with binddn.
20971 Defaults to @samp{disabled}.
20975 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
20976 Specifies the distinguished name to use when the root user tries to
20977 modify a user's password using the PAM module.
20979 Defaults to @samp{disabled}.
20983 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
20984 Specifies the credentials with which to bind if the root user tries to
20985 change a user's password. This option is only applicable when used with
20988 Defaults to @samp{disabled}.
20992 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
20993 Specifies the SASL mechanism to be used when performing SASL
20996 Defaults to @samp{disabled}.
21000 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
21001 Specifies the SASL realm to be used when performing SASL authentication.
21003 Defaults to @samp{disabled}.
21007 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
21008 Specifies the authentication identity to be used when performing SASL
21011 Defaults to @samp{disabled}.
21015 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
21016 Specifies the authorization identity to be used when performing SASL
21019 Defaults to @samp{disabled}.
21023 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
21024 Determines whether the LDAP server host name should be canonicalised. If
21025 this is enabled the LDAP library will do a reverse host name lookup. By
21026 default, it is left up to the LDAP library whether this check is
21029 Defaults to @samp{disabled}.
21033 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
21034 Set the name for the GSS-API Kerberos credentials cache.
21036 Defaults to @samp{disabled}.
21040 @deftypevr {@code{nslcd-configuration} parameter} string base
21041 The directory search base.
21043 Defaults to @samp{"dc=example,dc=com"}.
21047 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
21048 Specifies the search scope (subtree, onelevel, base or children). The
21049 default scope is subtree; base scope is almost never useful for name
21050 service lookups; children scope is not supported on all servers.
21052 Defaults to @samp{(subtree)}.
21056 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
21057 Specifies the policy for dereferencing aliases. The default policy is
21058 to never dereference aliases.
21060 Defaults to @samp{disabled}.
21064 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
21065 Specifies whether automatic referral chasing should be enabled. The
21066 default behaviour is to chase referrals.
21068 Defaults to @samp{disabled}.
21072 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
21073 This option allows for custom attributes to be looked up instead of the
21074 default RFC 2307 attributes. It is a list of maps, each consisting of
21075 the name of a map, the RFC 2307 attribute to match and the query
21076 expression for the attribute as it is available in the directory.
21078 Defaults to @samp{()}.
21082 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
21083 A list of filters consisting of the name of a map to which the filter
21084 applies and an LDAP search filter expression.
21086 Defaults to @samp{()}.
21090 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
21091 Specifies the time limit in seconds to use when connecting to the
21092 directory server. The default value is 10 seconds.
21094 Defaults to @samp{disabled}.
21098 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
21099 Specifies the time limit (in seconds) to wait for a response from the
21100 LDAP server. A value of zero, which is the default, is to wait
21101 indefinitely for searches to be completed.
21103 Defaults to @samp{disabled}.
21107 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
21108 Specifies the period if inactivity (in seconds) after which the con‐
21109 nection to the LDAP server will be closed. The default is not to time
21112 Defaults to @samp{disabled}.
21116 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
21117 Specifies the number of seconds to sleep when connecting to all LDAP
21118 servers fails. By default one second is waited between the first
21119 failure and the first retry.
21121 Defaults to @samp{disabled}.
21125 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
21126 Specifies the time after which the LDAP server is considered to be
21127 permanently unavailable. Once this time is reached retries will be done
21128 only once per this time period. The default value is 10 seconds.
21130 Defaults to @samp{disabled}.
21134 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
21135 Specifies whether to use SSL/TLS or not (the default is not to). If
21136 'start-tls is specified then StartTLS is used rather than raw LDAP over
21139 Defaults to @samp{disabled}.
21143 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
21144 Specifies what checks to perform on a server-supplied certificate. The
21145 meaning of the values is described in the ldap.conf(5) manual page.
21147 Defaults to @samp{disabled}.
21151 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
21152 Specifies the directory containing X.509 certificates for peer authen‐
21153 tication. This parameter is ignored when using GnuTLS.
21155 Defaults to @samp{disabled}.
21159 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
21160 Specifies the path to the X.509 certificate for peer authentication.
21162 Defaults to @samp{disabled}.
21166 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
21167 Specifies the path to an entropy source. This parameter is ignored when
21170 Defaults to @samp{disabled}.
21174 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
21175 Specifies the ciphers to use for TLS as a string.
21177 Defaults to @samp{disabled}.
21181 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
21182 Specifies the path to the file containing the local certificate for
21183 client TLS authentication.
21185 Defaults to @samp{disabled}.
21189 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
21190 Specifies the path to the file containing the private key for client TLS
21193 Defaults to @samp{disabled}.
21197 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
21198 Set this to a number greater than 0 to request paged results from the
21199 LDAP server in accordance with RFC2696. The default (0) is to not
21200 request paged results.
21202 Defaults to @samp{disabled}.
21206 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
21207 This option prevents group membership lookups through LDAP for the
21208 specified users. Alternatively, the value 'all-local may be used. With
21209 that value nslcd builds a full list of non-LDAP users on startup.
21211 Defaults to @samp{disabled}.
21215 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
21216 This option ensures that LDAP users with a numeric user id lower than
21217 the specified value are ignored.
21219 Defaults to @samp{disabled}.
21223 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
21224 This option specifies an offset that is added to all LDAP numeric user
21225 ids. This can be used to avoid user id collisions with local users.
21227 Defaults to @samp{disabled}.
21231 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
21232 This option specifies an offset that is added to all LDAP numeric group
21233 ids. This can be used to avoid user id collisions with local groups.
21235 Defaults to @samp{disabled}.
21239 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
21240 If this option is set, the member attribute of a group may point to
21241 another group. Members of nested groups are also returned in the higher
21242 level group and parent groups are returned when finding groups for a
21243 specific user. The default is not to perform extra searches for nested
21246 Defaults to @samp{disabled}.
21250 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
21251 If this option is set, the group member list is not retrieved when
21252 looking up groups. Lookups for finding which groups a user belongs to
21253 will remain functional so the user will likely still get the correct
21254 groups assigned on login.
21256 Defaults to @samp{disabled}.
21260 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
21261 If this option is set, functions which cause all user/group entries to
21262 be loaded from the directory will not succeed in doing so. This can
21263 dramatically reduce LDAP server load in situations where there are a
21264 great number of users and/or groups. This option is not recommended for
21265 most configurations.
21267 Defaults to @samp{disabled}.
21271 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
21272 This option can be used to specify how user and group names are verified
21273 within the system. This pattern is used to check all user and group
21274 names that are requested and returned from LDAP.
21276 Defaults to @samp{disabled}.
21280 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
21281 This specifies whether or not to perform searches using case-insensitive
21282 matching. Enabling this could open up the system to authorization
21283 bypass vulnerabilities and introduce nscd cache poisoning
21284 vulnerabilities which allow denial of service.
21286 Defaults to @samp{disabled}.
21290 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
21291 This option specifies whether password policy controls are requested and
21292 handled from the LDAP server when performing user authentication.
21294 Defaults to @samp{disabled}.
21298 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
21299 By default nslcd performs an LDAP search with the user's credentials
21300 after BIND (authentication) to ensure that the BIND operation was
21301 successful. The default search is a simple check to see if the user's
21302 DN exists. A search filter can be specified that will be used instead.
21303 It should return at least one entry.
21305 Defaults to @samp{disabled}.
21309 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
21310 This option allows flexible fine tuning of the authorisation check that
21311 should be performed. The search filter specified is executed and if any
21312 entries match, access is granted, otherwise access is denied.
21314 Defaults to @samp{disabled}.
21318 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
21319 If this option is set password modification using pam_ldap will be
21320 denied and the specified message will be presented to the user instead.
21321 The message can be used to direct the user to an alternative means of
21322 changing their password.
21324 Defaults to @samp{disabled}.
21328 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
21329 List of pam service names for which LDAP authentication should suffice.
21331 Defaults to @samp{()}.
21335 @c %end of generated documentation for nslcd-configuration
21339 @subsection Web Services
21344 The @code{(gnu services web)} module provides the Apache HTTP Server,
21345 the nginx web server, and also a fastcgi wrapper daemon.
21347 @subsubheading Apache HTTP Server
21349 @deffn {Scheme Variable} httpd-service-type
21350 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
21351 (@dfn{httpd}). The value for this service type is a
21352 @code{httpd-configuration} record.
21354 A simple example configuration is given below.
21357 (service httpd-service-type
21358 (httpd-configuration
21361 (server-name "www.example.com")
21362 (document-root "/srv/http/www.example.com")))))
21365 Other services can also extend the @code{httpd-service-type} to add to
21369 (simple-service 'www.example.com-server httpd-service-type
21373 (list (string-join '("ServerName www.example.com"
21374 "DocumentRoot /srv/http/www.example.com")
21379 The details for the @code{httpd-configuration}, @code{httpd-module},
21380 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
21383 @deffn {Data Type} httpd-configuration
21384 This data type represents the configuration for the httpd service.
21387 @item @code{package} (default: @code{httpd})
21388 The httpd package to use.
21390 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21391 The pid file used by the shepherd-service.
21393 @item @code{config} (default: @code{(httpd-config-file)})
21394 The configuration file to use with the httpd service. The default value
21395 is a @code{httpd-config-file} record, but this can also be a different
21396 G-expression that generates a file, for example a @code{plain-file}. A
21397 file outside of the store can also be specified through a string.
21402 @deffn {Data Type} httpd-module
21403 This data type represents a module for the httpd service.
21407 The name of the module.
21410 The file for the module. This can be relative to the httpd package being
21411 used, the absolute location of a file, or a G-expression for a file
21412 within the store, for example @code{(file-append mod-wsgi
21413 "/modules/mod_wsgi.so")}.
21418 @defvr {Scheme Variable} %default-httpd-modules
21419 A default list of @code{httpd-module} objects.
21422 @deffn {Data Type} httpd-config-file
21423 This data type represents a configuration file for the httpd service.
21426 @item @code{modules} (default: @code{%default-httpd-modules})
21427 The modules to load. Additional modules can be added here, or loaded by
21428 additional configuration.
21430 For example, in order to handle requests for PHP files, you can use Apache’s
21431 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
21434 (service httpd-service-type
21435 (httpd-configuration
21440 (name "proxy_module")
21441 (file "modules/mod_proxy.so"))
21443 (name "proxy_fcgi_module")
21444 (file "modules/mod_proxy_fcgi.so"))
21445 %default-httpd-modules))
21446 (extra-config (list "\
21447 <FilesMatch \\.php$>
21448 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
21449 </FilesMatch>"))))))
21450 (service php-fpm-service-type
21451 (php-fpm-configuration
21452 (socket "/var/run/php-fpm.sock")
21453 (socket-group "httpd")))
21456 @item @code{server-root} (default: @code{httpd})
21457 The @code{ServerRoot} in the configuration file, defaults to the httpd
21458 package. Directives including @code{Include} and @code{LoadModule} are
21459 taken as relative to the server root.
21461 @item @code{server-name} (default: @code{#f})
21462 The @code{ServerName} in the configuration file, used to specify the
21463 request scheme, hostname and port that the server uses to identify
21466 This doesn't need to be set in the server config, and can be specified
21467 in virtual hosts. The default is @code{#f} to not specify a
21470 @item @code{document-root} (default: @code{"/srv/http"})
21471 The @code{DocumentRoot} from which files will be served.
21473 @item @code{listen} (default: @code{'("80")})
21474 The list of values for the @code{Listen} directives in the config
21475 file. The value should be a list of strings, when each string can
21476 specify the port number to listen on, and optionally the IP address and
21479 @item @code{pid-file} (default: @code{"/var/run/httpd"})
21480 The @code{PidFile} to use. This should match the @code{pid-file} set in
21481 the @code{httpd-configuration} so that the Shepherd service is
21482 configured correctly.
21484 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
21485 The @code{ErrorLog} to which the server will log errors.
21487 @item @code{user} (default: @code{"httpd"})
21488 The @code{User} which the server will answer requests as.
21490 @item @code{group} (default: @code{"httpd"})
21491 The @code{Group} which the server will answer requests as.
21493 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
21494 A flat list of strings and G-expressions which will be added to the end
21495 of the configuration file.
21497 Any values which the service is extended with will be appended to this
21503 @deffn {Data Type} httpd-virtualhost
21504 This data type represents a virtualhost configuration block for the httpd service.
21506 These should be added to the extra-config for the httpd-service.
21509 (simple-service 'www.example.com-server httpd-service-type
21513 (list (string-join '("ServerName www.example.com"
21514 "DocumentRoot /srv/http/www.example.com")
21519 @item @code{addresses-and-ports}
21520 The addresses and ports for the @code{VirtualHost} directive.
21522 @item @code{contents}
21523 The contents of the @code{VirtualHost} directive, this should be a list
21524 of strings and G-expressions.
21529 @subsubheading NGINX
21531 @deffn {Scheme Variable} nginx-service-type
21532 Service type for the @uref{https://nginx.org/,NGinx} web server. The
21533 value for this service type is a @code{<nginx-configuration>} record.
21535 A simple example configuration is given below.
21538 (service nginx-service-type
21539 (nginx-configuration
21541 (list (nginx-server-configuration
21542 (server-name '("www.example.com"))
21543 (root "/srv/http/www.example.com"))))))
21546 In addition to adding server blocks to the service configuration
21547 directly, this service can be extended by other services to add server
21548 blocks, as in this example:
21551 (simple-service 'my-extra-server nginx-service-type
21552 (list (nginx-server-configuration
21553 (root "/srv/http/extra-website")
21554 (try-files (list "$uri" "$uri/index.html")))))
21558 At startup, @command{nginx} has not yet read its configuration file, so
21559 it uses a default file to log error messages. If it fails to load its
21560 configuration file, that is where error messages are logged. After the
21561 configuration file is loaded, the default error log file changes as per
21562 configuration. In our case, startup error messages can be found in
21563 @file{/var/run/nginx/logs/error.log}, and after configuration in
21564 @file{/var/log/nginx/error.log}. The second location can be changed
21565 with the @var{log-directory} configuration option.
21567 @deffn {Data Type} nginx-configuration
21568 This data type represents the configuration for NGinx. Some
21569 configuration can be done through this and the other provided record
21570 types, or alternatively, a config file can be provided.
21573 @item @code{nginx} (default: @code{nginx})
21574 The nginx package to use.
21576 @item @code{log-directory} (default: @code{"/var/log/nginx"})
21577 The directory to which NGinx will write log files.
21579 @item @code{run-directory} (default: @code{"/var/run/nginx"})
21580 The directory in which NGinx will create a pid file, and write temporary
21583 @item @code{server-blocks} (default: @code{'()})
21584 A list of @dfn{server blocks} to create in the generated configuration
21585 file, the elements should be of type
21586 @code{<nginx-server-configuration>}.
21588 The following example would setup NGinx to serve @code{www.example.com}
21589 from the @code{/srv/http/www.example.com} directory, without using
21592 (service nginx-service-type
21593 (nginx-configuration
21595 (list (nginx-server-configuration
21596 (server-name '("www.example.com"))
21597 (root "/srv/http/www.example.com"))))))
21600 @item @code{upstream-blocks} (default: @code{'()})
21601 A list of @dfn{upstream blocks} to create in the generated configuration
21602 file, the elements should be of type
21603 @code{<nginx-upstream-configuration>}.
21605 Configuring upstreams through the @code{upstream-blocks} can be useful
21606 when combined with @code{locations} in the
21607 @code{<nginx-server-configuration>} records. The following example
21608 creates a server configuration with one location configuration, that
21609 will proxy requests to a upstream configuration, which will handle
21610 requests with two servers.
21615 (nginx-configuration
21617 (list (nginx-server-configuration
21618 (server-name '("www.example.com"))
21619 (root "/srv/http/www.example.com")
21622 (nginx-location-configuration
21624 (body '("proxy_pass http://server-proxy;"))))))))
21626 (list (nginx-upstream-configuration
21627 (name "server-proxy")
21628 (servers (list "server1.example.com"
21629 "server2.example.com")))))))
21632 @item @code{file} (default: @code{#f})
21633 If a configuration @var{file} is provided, this will be used, rather than
21634 generating a configuration file from the provided @code{log-directory},
21635 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
21636 proper operation, these arguments should match what is in @var{file} to ensure
21637 that the directories are created when the service is activated.
21639 This can be useful if you have an existing configuration file, or it's
21640 not possible to do what is required through the other parts of the
21641 nginx-configuration record.
21643 @item @code{server-names-hash-bucket-size} (default: @code{#f})
21644 Bucket size for the server names hash tables, defaults to @code{#f} to
21645 use the size of the processors cache line.
21647 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
21648 Maximum bucket size for the server names hash tables.
21650 @item @code{modules} (default: @code{'()})
21651 List of nginx dynamic modules to load. This should be a list of file
21652 names of loadable modules, as in this example:
21657 (file-append nginx-accept-language-module "\
21658 /etc/nginx/modules/ngx_http_accept_language_module.so")))
21661 @item @code{global-directives} (default: @code{'((events . ()))})
21662 Association list of global directives for the top level of the nginx
21663 configuration. Values may themselves be association lists.
21667 `((worker_processes . 16)
21669 (events . ((worker_connections . 1024)))))
21672 @item @code{extra-content} (default: @code{""})
21673 Extra content for the @code{http} block. Should be string or a string
21674 valued G-expression.
21679 @deftp {Data Type} nginx-server-configuration
21680 Data type representing the configuration of an nginx server block.
21681 This type has the following parameters:
21684 @item @code{listen} (default: @code{'("80" "443 ssl")})
21685 Each @code{listen} directive sets the address and port for IP, or the
21686 path for a UNIX-domain socket on which the server will accept requests.
21687 Both address and port, or only address or only port can be specified.
21688 An address may also be a hostname, for example:
21691 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
21694 @item @code{server-name} (default: @code{(list 'default)})
21695 A list of server names this server represents. @code{'default} represents the
21696 default server for connections matching no other server.
21698 @item @code{root} (default: @code{"/srv/http"})
21699 Root of the website nginx will serve.
21701 @item @code{locations} (default: @code{'()})
21702 A list of @dfn{nginx-location-configuration} or
21703 @dfn{nginx-named-location-configuration} records to use within this
21706 @item @code{index} (default: @code{(list "index.html")})
21707 Index files to look for when clients ask for a directory. If it cannot be found,
21708 Nginx will send the list of files in the directory.
21710 @item @code{try-files} (default: @code{'()})
21711 A list of files whose existence is checked in the specified order.
21712 @code{nginx} will use the first file it finds to process the request.
21714 @item @code{ssl-certificate} (default: @code{#f})
21715 Where to find the certificate for secure connections. Set it to @code{#f} if
21716 you don't have a certificate or you don't want to use HTTPS.
21718 @item @code{ssl-certificate-key} (default: @code{#f})
21719 Where to find the private key for secure connections. Set it to @code{#f} if
21720 you don't have a key or you don't want to use HTTPS.
21722 @item @code{server-tokens?} (default: @code{#f})
21723 Whether the server should add its configuration to response.
21725 @item @code{raw-content} (default: @code{'()})
21726 A list of raw lines added to the server block.
21731 @deftp {Data Type} nginx-upstream-configuration
21732 Data type representing the configuration of an nginx @code{upstream}
21733 block. This type has the following parameters:
21737 Name for this group of servers.
21739 @item @code{servers}
21740 Specify the addresses of the servers in the group. The address can be
21741 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
21742 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
21743 prefix @samp{unix:}. For addresses using an IP address or domain name,
21744 the default port is 80, and a different port can be specified
21750 @deftp {Data Type} nginx-location-configuration
21751 Data type representing the configuration of an nginx @code{location}
21752 block. This type has the following parameters:
21756 URI which this location block matches.
21758 @anchor{nginx-location-configuration body}
21760 Body of the location block, specified as a list of strings. This can contain
21762 configuration directives. For example, to pass requests to a upstream
21763 server group defined using an @code{nginx-upstream-configuration} block,
21764 the following directive would be specified in the body @samp{(list "proxy_pass
21765 http://upstream-name;")}.
21770 @deftp {Data Type} nginx-named-location-configuration
21771 Data type representing the configuration of an nginx named location
21772 block. Named location blocks are used for request redirection, and not
21773 used for regular request processing. This type has the following
21778 Name to identify this location block.
21781 @xref{nginx-location-configuration body}, as the body for named location
21782 blocks can be used in a similar way to the
21783 @code{nginx-location-configuration body}. One restriction is that the
21784 body of a named location block cannot contain location blocks.
21789 @subsubheading Varnish Cache
21791 Varnish is a fast cache server that sits in between web applications
21792 and end users. It proxies requests from clients and caches the
21793 accessed URLs such that multiple requests for the same resource only
21794 creates one request to the back-end.
21796 @defvr {Scheme Variable} varnish-service-type
21797 Service type for the Varnish daemon.
21800 @deftp {Data Type} varnish-configuration
21801 Data type representing the @code{varnish} service configuration.
21802 This type has the following parameters:
21805 @item @code{package} (default: @code{varnish})
21806 The Varnish package to use.
21808 @item @code{name} (default: @code{"default"})
21809 A name for this Varnish instance. Varnish will create a directory in
21810 @file{/var/varnish/} with this name and keep temporary files there. If
21811 the name starts with a forward slash, it is interpreted as an absolute
21814 Pass the @code{-n} argument to other Varnish programs to connect to the
21815 named instance, e.g.@: @command{varnishncsa -n default}.
21817 @item @code{backend} (default: @code{"localhost:8080"})
21818 The backend to use. This option has no effect if @code{vcl} is set.
21820 @item @code{vcl} (default: #f)
21821 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
21822 is @code{#f}, Varnish will proxy @code{backend} using the default
21823 configuration. Otherwise this must be a file-like object with valid
21826 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
21827 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
21828 can do something along these lines:
21831 (define %gnu-mirror
21832 (plain-file "gnu.vcl"
21834 backend gnu @{ .host = \"www.gnu.org\"; @}"))
21838 (services (cons (service varnish-service-type
21839 (varnish-configuration
21841 (vcl %gnu-mirror)))
21845 The configuration of an already running Varnish instance can be inspected
21846 and changed using the @command{varnishadm} program.
21848 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
21849 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
21850 comprehensive documentation on Varnish and its configuration language.
21852 @item @code{listen} (default: @code{'("localhost:80")})
21853 List of addresses Varnish will listen on.
21855 @item @code{storage} (default: @code{'("malloc,128m")})
21856 List of storage backends that will be available in VCL.
21858 @item @code{parameters} (default: @code{'()})
21859 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
21861 @item @code{extra-options} (default: @code{'()})
21862 Additional arguments to pass to the @command{varnishd} process.
21867 @subsubheading Patchwork
21869 Patchwork is a patch tracking system. It can collect patches sent to a
21870 mailing list, and display them in a web interface.
21872 @defvr {Scheme Variable} patchwork-service-type
21873 Service type for Patchwork.
21876 The following example is an example of a minimal service for Patchwork, for
21877 the @code{patchwork.example.com} domain.
21880 (service patchwork-service-type
21881 (patchwork-configuration
21882 (domain "patchwork.example.com")
21884 (patchwork-settings-module
21885 (allowed-hosts (list domain))
21886 (default-from-email "patchwork@@patchwork.example.com")))
21887 (getmail-retriever-config
21888 (getmail-retriever-configuration
21889 (type "SimpleIMAPSSLRetriever")
21890 (server "imap.example.com")
21892 (username "patchwork")
21894 (list (file-append coreutils "/bin/cat")
21895 "/etc/getmail-patchwork-imap-password"))
21897 '((mailboxes . ("Patches"))))))))
21901 There are three records for configuring the Patchwork service. The
21902 @code{<patchwork-configuration>} relates to the configuration for Patchwork
21903 within the HTTPD service.
21905 The @code{settings-module} field within the @code{<patchwork-configuration>}
21906 record can be populated with the @code{<patchwork-settings-module>} record,
21907 which describes a settings module that is generated within the Guix store.
21909 For the @code{database-configuration} field within the
21910 @code{<patchwork-settings-module>}, the
21911 @code{<patchwork-database-configuration>} must be used.
21913 @deftp {Data Type} patchwork-configuration
21914 Data type representing the Patchwork service configuration. This type has the
21915 following parameters:
21918 @item @code{patchwork} (default: @code{patchwork})
21919 The Patchwork package to use.
21921 @item @code{domain}
21922 The domain to use for Patchwork, this is used in the HTTPD service virtual
21925 @item @code{settings-module}
21926 The settings module to use for Patchwork. As a Django application, Patchwork
21927 is configured with a Python module containing the settings. This can either be
21928 an instance of the @code{<patchwork-settings-module>} record, any other record
21929 that represents the settings in the store, or a directory outside of the
21932 @item @code{static-path} (default: @code{"/static/"})
21933 The path under which the HTTPD service should serve the static files.
21935 @item @code{getmail-retriever-config}
21936 The getmail-retriever-configuration record value to use with
21937 Patchwork. Getmail will be configured with this value, the messages will be
21938 delivered to Patchwork.
21943 @deftp {Data Type} patchwork-settings-module
21944 Data type representing a settings module for Patchwork. Some of these
21945 settings relate directly to Patchwork, but others relate to Django, the web
21946 framework used by Patchwork, or the Django Rest Framework library. This type
21947 has the following parameters:
21950 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
21951 The database connection settings used for Patchwork. See the
21952 @code{<patchwork-database-configuration>} record type for more information.
21954 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
21955 Patchwork, as a Django web application uses a secret key for cryptographically
21956 signing values. This file should contain a unique unpredictable value.
21958 If this file does not exist, it will be created and populated with a random
21959 value by the patchwork-setup shepherd service.
21961 This setting relates to Django.
21963 @item @code{allowed-hosts}
21964 A list of valid hosts for this Patchwork service. This should at least include
21965 the domain specified in the @code{<patchwork-configuration>} record.
21967 This is a Django setting.
21969 @item @code{default-from-email}
21970 The email address from which Patchwork should send email by default.
21972 This is a Patchwork setting.
21974 @item @code{static-url} (default: @code{#f})
21975 The URL to use when serving static assets. It can be part of a URL, or a full
21976 URL, but must end in a @code{/}.
21978 If the default value is used, the @code{static-path} value from the
21979 @code{<patchwork-configuration>} record will be used.
21981 This is a Django setting.
21983 @item @code{admins} (default: @code{'()})
21984 Email addresses to send the details of errors that occur. Each value should
21985 be a list containing two elements, the name and then the email address.
21987 This is a Django setting.
21989 @item @code{debug?} (default: @code{#f})
21990 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
21991 messages will be shown.
21993 This is a Django setting.
21995 @item @code{enable-rest-api?} (default: @code{#t})
21996 Whether to enable the Patchwork REST API.
21998 This is a Patchwork setting.
22000 @item @code{enable-xmlrpc?} (default: @code{#t})
22001 Whether to enable the XML RPC API.
22003 This is a Patchwork setting.
22005 @item @code{force-https-links?} (default: @code{#t})
22006 Whether to use HTTPS links on Patchwork pages.
22008 This is a Patchwork setting.
22010 @item @code{extra-settings} (default: @code{""})
22011 Extra code to place at the end of the Patchwork settings module.
22016 @deftp {Data Type} patchwork-database-configuration
22017 Data type representing the database configuration for Patchwork.
22020 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
22021 The database engine to use.
22023 @item @code{name} (default: @code{"patchwork"})
22024 The name of the database to use.
22026 @item @code{user} (default: @code{"httpd"})
22027 The user to connect to the database as.
22029 @item @code{password} (default: @code{""})
22030 The password to use when connecting to the database.
22032 @item @code{host} (default: @code{""})
22033 The host to make the database connection to.
22035 @item @code{port} (default: @code{""})
22036 The port on which to connect to the database.
22041 @subsubheading Mumi
22043 @cindex Mumi, Debbugs Web interface
22044 @cindex Debbugs, Mumi Web interface
22045 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
22046 Web interface to the Debbugs bug tracker, by default for
22047 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
22048 but it also fetches and indexes mail retrieved from Debbugs.
22050 @defvr {Scheme Variable} mumi-service-type
22051 This is the service type for Mumi.
22054 @deftp {Data Type} mumi-configuration
22055 Data type representing the Mumi service configuration. This type has the
22059 @item @code{mumi} (default: @code{mumi})
22060 The Mumi package to use.
22062 @item @code{mailer?} (default: @code{#true})
22063 Whether to enable or disable the mailer component.
22065 @item @code{mumi-configuration-sender}
22066 The email address used as the sender for comments.
22068 @item @code{mumi-configuration-smtp}
22069 A URI to configure the SMTP settings for Mailutils. This could be
22070 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
22071 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
22072 mailutils, GNU@tie{}Mailutils}.
22078 @subsubheading FastCGI
22081 FastCGI is an interface between the front-end and the back-end of a web
22082 service. It is a somewhat legacy facility; new web services should
22083 generally just talk HTTP between the front-end and the back-end.
22084 However there are a number of back-end services such as PHP or the
22085 optimized HTTP Git repository access that use FastCGI, so we have
22086 support for it in Guix.
22088 To use FastCGI, you configure the front-end web server (e.g., nginx) to
22089 dispatch some subset of its requests to the fastcgi backend, which
22090 listens on a local TCP or UNIX socket. There is an intermediary
22091 @code{fcgiwrap} program that sits between the actual backend process and
22092 the web server. The front-end indicates which backend program to run,
22093 passing that information to the @code{fcgiwrap} process.
22095 @defvr {Scheme Variable} fcgiwrap-service-type
22096 A service type for the @code{fcgiwrap} FastCGI proxy.
22099 @deftp {Data Type} fcgiwrap-configuration
22100 Data type representing the configuration of the @code{fcgiwrap} service.
22101 This type has the following parameters:
22103 @item @code{package} (default: @code{fcgiwrap})
22104 The fcgiwrap package to use.
22106 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
22107 The socket on which the @code{fcgiwrap} process should listen, as a
22108 string. Valid @var{socket} values include
22109 @code{unix:@var{/path/to/unix/socket}},
22110 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
22111 @code{tcp6:[@var{ipv6_addr}]:port}.
22113 @item @code{user} (default: @code{fcgiwrap})
22114 @itemx @code{group} (default: @code{fcgiwrap})
22115 The user and group names, as strings, under which to run the
22116 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
22117 the user asks for the specific user or group names @code{fcgiwrap} that
22118 the corresponding user and/or group is present on the system.
22120 It is possible to configure a FastCGI-backed web service to pass HTTP
22121 authentication information from the front-end to the back-end, and to
22122 allow @code{fcgiwrap} to run the back-end process as a corresponding
22123 local user. To enable this capability on the back-end, run
22124 @code{fcgiwrap} as the @code{root} user and group. Note that this
22125 capability also has to be configured on the front-end as well.
22130 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
22131 with some additional features useful for sites of any size.
22133 These features include:
22135 @item Adaptive process spawning
22136 @item Basic statistics (similar to Apache's mod_status)
22137 @item Advanced process management with graceful stop/start
22138 @item Ability to start workers with different uid/gid/chroot/environment
22139 and different php.ini (replaces safe_mode)
22140 @item Stdout & stderr logging
22141 @item Emergency restart in case of accidental opcode cache destruction
22142 @item Accelerated upload support
22143 @item Support for a "slowlog"
22144 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
22145 a special function to finish request & flush all data while continuing to do
22146 something time-consuming (video converting, stats processing, etc.)
22148 ...@: and much more.
22150 @defvr {Scheme Variable} php-fpm-service-type
22151 A Service type for @code{php-fpm}.
22154 @deftp {Data Type} php-fpm-configuration
22155 Data Type for php-fpm service configuration.
22157 @item @code{php} (default: @code{php})
22158 The php package to use.
22159 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
22160 The address on which to accept FastCGI requests. Valid syntaxes are:
22162 @item @code{"ip.add.re.ss:port"}
22163 Listen on a TCP socket to a specific address on a specific port.
22164 @item @code{"port"}
22165 Listen on a TCP socket to all addresses on a specific port.
22166 @item @code{"/path/to/unix/socket"}
22167 Listen on a unix socket.
22170 @item @code{user} (default: @code{php-fpm})
22171 User who will own the php worker processes.
22172 @item @code{group} (default: @code{php-fpm})
22173 Group of the worker processes.
22174 @item @code{socket-user} (default: @code{php-fpm})
22175 User who can speak to the php-fpm socket.
22176 @item @code{socket-group} (default: @code{nginx})
22177 Group that can speak to the php-fpm socket.
22178 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
22179 The process id of the php-fpm process is written to this file
22180 once the service has started.
22181 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
22182 Log for the php-fpm master process.
22183 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
22184 Detailed settings for the php-fpm process manager.
22187 @item @code{<php-fpm-dynamic-process-manager-configuration>}
22188 @item @code{<php-fpm-static-process-manager-configuration>}
22189 @item @code{<php-fpm-on-demand-process-manager-configuration>}
22191 @item @code{display-errors} (default @code{#f})
22192 Determines whether php errors and warning should be sent to clients
22193 and displayed in their browsers.
22194 This is useful for local php development, but a security risk for public sites,
22195 as error messages can reveal passwords and personal data.
22196 @item @code{timezone} (default @code{#f})
22197 Specifies @code{php_admin_value[date.timezone]} parameter.
22198 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
22199 This file will log the @code{stderr} outputs of php worker processes.
22200 Can be set to @code{#f} to disable logging.
22201 @item @code{file} (default @code{#f})
22202 An optional override of the whole configuration.
22203 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22204 @item @code{php-ini-file} (default @code{#f})
22205 An optional override of the default php settings.
22206 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
22207 You can use the @code{mixed-text-file} function or an absolute filepath for it.
22209 For local development it is useful to set a higher timeout and memory
22210 limit for spawned php processes. This be accomplished with the
22211 following operating system configuration snippet:
22213 (define %local-php-ini
22214 (plain-file "php.ini"
22216 max_execution_time = 1800"))
22220 (services (cons (service php-fpm-service-type
22221 (php-fpm-configuration
22222 (php-ini-file %local-php-ini)))
22226 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
22227 directives} for comprehensive documentation on the acceptable
22228 @file{php.ini} directives.
22232 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
22233 Data Type for the @code{dynamic} php-fpm process manager. With the
22234 @code{dynamic} process manager, spare worker processes are kept around
22235 based on it's configured limits.
22237 @item @code{max-children} (default: @code{5})
22238 Maximum of worker processes.
22239 @item @code{start-servers} (default: @code{2})
22240 How many worker processes should be started on start-up.
22241 @item @code{min-spare-servers} (default: @code{1})
22242 How many spare worker processes should be kept around at minimum.
22243 @item @code{max-spare-servers} (default: @code{3})
22244 How many spare worker processes should be kept around at maximum.
22248 @deftp {Data type} php-fpm-static-process-manager-configuration
22249 Data Type for the @code{static} php-fpm process manager. With the
22250 @code{static} process manager, an unchanging number of worker processes
22253 @item @code{max-children} (default: @code{5})
22254 Maximum of worker processes.
22258 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
22259 Data Type for the @code{on-demand} php-fpm process manager. With the
22260 @code{on-demand} process manager, worker processes are only created as
22263 @item @code{max-children} (default: @code{5})
22264 Maximum of worker processes.
22265 @item @code{process-idle-timeout} (default: @code{10})
22266 The time in seconds after which a process with no requests is killed.
22271 @deffn {Scheme Procedure} nginx-php-location @
22272 [#:nginx-package nginx] @
22273 [socket (string-append "/var/run/php" @
22274 (version-major (package-version php)) @
22276 A helper function to quickly add php to an @code{nginx-server-configuration}.
22279 A simple services setup for nginx with php can look like this:
22281 (services (cons* (service dhcp-client-service-type)
22282 (service php-fpm-service-type)
22283 (service nginx-service-type
22284 (nginx-server-configuration
22285 (server-name '("example.com"))
22286 (root "/srv/http/")
22288 (list (nginx-php-location)))
22290 (ssl-certificate #f)
22291 (ssl-certificate-key #f)))
22295 @cindex cat-avatar-generator
22296 The cat avatar generator is a simple service to demonstrate the use of php-fpm
22297 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
22298 the hash of a user's email address.
22300 @deffn {Scheme Procedure} cat-avatar-generator-service @
22301 [#:cache-dir "/var/cache/cat-avatar-generator"] @
22302 [#:package cat-avatar-generator] @
22303 [#:configuration (nginx-server-configuration)]
22304 Returns an nginx-server-configuration that inherits @code{configuration}. It
22305 extends the nginx configuration to add a server block that serves @code{package},
22306 a version of cat-avatar-generator. During execution, cat-avatar-generator will
22307 be able to use @code{cache-dir} as its cache directory.
22310 A simple setup for cat-avatar-generator can look like this:
22312 (services (cons* (cat-avatar-generator-service
22314 (nginx-server-configuration
22315 (server-name '("example.com"))))
22320 @subsubheading Hpcguix-web
22322 @cindex hpcguix-web
22323 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
22324 program is a customizable web interface to browse Guix packages,
22325 initially designed for users of high-performance computing (HPC)
22328 @defvr {Scheme Variable} hpcguix-web-service-type
22329 The service type for @code{hpcguix-web}.
22332 @deftp {Data Type} hpcguix-web-configuration
22333 Data type for the hpcguix-web service configuration.
22337 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
22338 configuration. The main items available in this spec are:
22341 @item @code{title-prefix} (default: @code{"hpcguix | "})
22342 The page title prefix.
22344 @item @code{guix-command} (default: @code{"guix"})
22345 The @command{guix} command.
22347 @item @code{package-filter-proc} (default: @code{(const #t)})
22348 A procedure specifying how to filter packages that are displayed.
22350 @item @code{package-page-extension-proc} (default: @code{(const '())})
22351 Extension package for @code{hpcguix-web}.
22353 @item @code{menu} (default: @code{'()})
22354 Additional entry in page @code{menu}.
22356 @item @code{channels} (default: @code{%default-channels})
22357 List of channels from which the package list is built (@pxref{Channels}).
22359 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
22360 The expiration time, in seconds, after which the package list is rebuilt from
22361 the latest instances of the given channels.
22364 See the hpcguix-web repository for a
22365 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
22368 @item @code{package} (default: @code{hpcguix-web})
22369 The hpcguix-web package to use.
22373 A typical hpcguix-web service declaration looks like this:
22376 (service hpcguix-web-service-type
22377 (hpcguix-web-configuration
22379 #~(define site-config
22380 (hpcweb-configuration
22381 (title-prefix "Guix-HPC - ")
22382 (menu '(("/about" "ABOUT"))))))))
22386 The hpcguix-web service periodically updates the package list it publishes by
22387 pulling channels from Git. To that end, it needs to access X.509 certificates
22388 so that it can authenticate Git servers when communicating over HTTPS, and it
22389 assumes that @file{/etc/ssl/certs} contains those certificates.
22391 Thus, make sure to add @code{nss-certs} or another certificate package to the
22392 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
22393 more information on X.509 certificates.
22396 @node Certificate Services
22397 @subsection Certificate Services
22400 @cindex HTTP, HTTPS
22401 @cindex Let's Encrypt
22402 @cindex TLS certificates
22403 The @code{(gnu services certbot)} module provides a service to
22404 automatically obtain a valid TLS certificate from the Let's Encrypt
22405 certificate authority. These certificates can then be used to serve
22406 content securely over HTTPS or other TLS-based protocols, with the
22407 knowledge that the client will be able to verify the server's
22410 @url{https://letsencrypt.org/, Let's Encrypt} provides the
22411 @code{certbot} tool to automate the certification process. This tool
22412 first securely generates a key on the server. It then makes a request
22413 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
22414 checks that the request originates from the host in question by using a
22415 challenge-response protocol, requiring the server to provide its
22416 response over HTTP. If that protocol completes successfully, the CA
22417 signs the key, resulting in a certificate. That certificate is valid
22418 for a limited period of time, and therefore to continue to provide TLS
22419 services, the server needs to periodically ask the CA to renew its
22422 The certbot service automates this process: the initial key
22423 generation, the initial certification request to the Let's Encrypt
22424 service, the web server challenge/response integration, writing the
22425 certificate to disk, the automated periodic renewals, and the deployment
22426 tasks associated with the renewal (e.g.@: reloading services, copying keys
22427 with different permissions).
22429 Certbot is run twice a day, at a random minute within the hour. It
22430 won't do anything until your certificates are due for renewal or
22431 revoked, but running it regularly would give your service a chance of
22432 staying online in case a Let's Encrypt-initiated revocation happened for
22435 By using this service, you agree to the ACME Subscriber Agreement, which
22436 can be found there:
22437 @url{https://acme-v01.api.letsencrypt.org/directory}.
22439 @defvr {Scheme Variable} certbot-service-type
22440 A service type for the @code{certbot} Let's Encrypt client. Its value
22441 must be a @code{certbot-configuration} record as in this example:
22444 (define %nginx-deploy-hook
22446 "nginx-deploy-hook"
22447 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
22448 (kill pid SIGHUP))))
22450 (service certbot-service-type
22451 (certbot-configuration
22452 (email "foo@@example.net")
22455 (certificate-configuration
22456 (domains '("example.net" "www.example.net"))
22457 (deploy-hook %nginx-deploy-hook))
22458 (certificate-configuration
22459 (domains '("bar.example.net")))))))
22462 See below for details about @code{certbot-configuration}.
22465 @deftp {Data Type} certbot-configuration
22466 Data type representing the configuration of the @code{certbot} service.
22467 This type has the following parameters:
22470 @item @code{package} (default: @code{certbot})
22471 The certbot package to use.
22473 @item @code{webroot} (default: @code{/var/www})
22474 The directory from which to serve the Let's Encrypt challenge/response
22477 @item @code{certificates} (default: @code{()})
22478 A list of @code{certificates-configuration}s for which to generate
22479 certificates and request signatures. Each certificate has a @code{name}
22480 and several @code{domains}.
22482 @item @code{email} (default: @code{#f})
22483 Optional email address used for registration and recovery contact.
22484 Setting this is encouraged as it allows you to receive important
22485 notifications about the account and issued certificates.
22487 @item @code{server} (default: @code{#f})
22488 Optional URL of ACME server. Setting this overrides certbot's default,
22489 which is the Let's Encrypt server.
22491 @item @code{rsa-key-size} (default: @code{2048})
22492 Size of the RSA key.
22494 @item @code{default-location} (default: @i{see below})
22495 The default @code{nginx-location-configuration}. Because @code{certbot}
22496 needs to be able to serve challenges and responses, it needs to be able
22497 to run a web server. It does so by extending the @code{nginx} web
22498 service with an @code{nginx-server-configuration} listening on the
22499 @var{domains} on port 80, and which has a
22500 @code{nginx-location-configuration} for the @code{/.well-known/} URI
22501 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
22502 these nginx configuration data types.
22504 Requests to other URL paths will be matched by the
22505 @code{default-location}, which if present is added to all
22506 @code{nginx-server-configuration}s.
22508 By default, the @code{default-location} will issue a redirect from
22509 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
22510 you to define what to serve on your site via @code{https}.
22512 Pass @code{#f} to not issue a default location.
22516 @deftp {Data Type} certificate-configuration
22517 Data type representing the configuration of a certificate.
22518 This type has the following parameters:
22521 @item @code{name} (default: @i{see below})
22522 This name is used by Certbot for housekeeping and in file paths; it
22523 doesn't affect the content of the certificate itself. To see
22524 certificate names, run @code{certbot certificates}.
22526 Its default is the first provided domain.
22528 @item @code{domains} (default: @code{()})
22529 The first domain provided will be the subject CN of the certificate, and
22530 all domains will be Subject Alternative Names on the certificate.
22532 @item @code{challenge} (default: @code{#f})
22533 The challenge type that has to be run by certbot. If @code{#f} is specified,
22534 default to the HTTP challenge. If a value is specified, defaults to the
22535 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
22536 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
22537 and gives Let's Encrypt permission to log the public IP address of the
22538 requesting machine.
22540 @item @code{authentication-hook} (default: @code{#f})
22541 Command to be run in a shell once for each certificate challenge to be
22542 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
22543 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
22544 contains the validation string and @code{$CERTBOT_TOKEN} contains the
22545 file name of the resource requested when performing an HTTP-01 challenge.
22547 @item @code{cleanup-hook} (default: @code{#f})
22548 Command to be run in a shell once for each certificate challenge that
22549 have been answered by the @code{auth-hook}. For this command, the shell
22550 variables available in the @code{auth-hook} script are still available, and
22551 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
22552 of the @code{auth-hook} script.
22554 @item @code{deploy-hook} (default: @code{#f})
22555 Command to be run in a shell once for each successfully issued
22556 certificate. For this command, the shell variable
22557 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
22558 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
22559 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
22560 contain a space-delimited list of renewed certificate domains (for
22561 example, @samp{"example.com www.example.com"}.
22566 For each @code{certificate-configuration}, the certificate is saved to
22567 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
22568 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
22570 @subsection DNS Services
22571 @cindex DNS (domain name system)
22572 @cindex domain name system (DNS)
22574 The @code{(gnu services dns)} module provides services related to the
22575 @dfn{domain name system} (DNS). It provides a server service for hosting
22576 an @emph{authoritative} DNS server for multiple zones, slave or master.
22577 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
22578 caching and forwarding DNS server for the LAN, which uses
22579 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
22581 @subsubheading Knot Service
22583 An example configuration of an authoritative server for two zones, one master
22587 (define-zone-entries example.org.zone
22588 ;; Name TTL Class Type Data
22589 ("@@" "" "IN" "A" "127.0.0.1")
22590 ("@@" "" "IN" "NS" "ns")
22591 ("ns" "" "IN" "A" "127.0.0.1"))
22593 (define master-zone
22594 (knot-zone-configuration
22595 (domain "example.org")
22597 (origin "example.org")
22598 (entries example.org.zone)))))
22601 (knot-zone-configuration
22602 (domain "plop.org")
22603 (dnssec-policy "default")
22604 (master (list "plop-master"))))
22606 (define plop-master
22607 (knot-remote-configuration
22609 (address (list "208.76.58.171"))))
22613 (services (cons* (service knot-service-type
22614 (knot-configuration
22615 (remotes (list plop-master))
22616 (zones (list master-zone slave-zone))))
22621 @deffn {Scheme Variable} knot-service-type
22622 This is the type for the Knot DNS server.
22624 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
22625 zones, that is to say domain names you would buy from a registrar. This server
22626 is not a resolver, meaning that it can only resolve names for which it is
22627 authoritative. This server can be configured to serve zones as a master server
22628 or a slave server as a per-zone basis. Slave zones will get their data from
22629 masters, and will serve it as an authoritative server. From the point of view
22630 of a resolver, there is no difference between master and slave.
22632 The following data types are used to configure the Knot DNS server:
22635 @deftp {Data Type} knot-key-configuration
22636 Data type representing a key.
22637 This type has the following parameters:
22640 @item @code{id} (default: @code{""})
22641 An identifier for other configuration fields to refer to this key. IDs must
22642 be unique and must not be empty.
22644 @item @code{algorithm} (default: @code{#f})
22645 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
22646 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
22647 and @code{'hmac-sha512}.
22649 @item @code{secret} (default: @code{""})
22650 The secret key itself.
22655 @deftp {Data Type} knot-acl-configuration
22656 Data type representing an Access Control List (ACL) configuration.
22657 This type has the following parameters:
22660 @item @code{id} (default: @code{""})
22661 An identifier for ether configuration fields to refer to this key. IDs must be
22662 unique and must not be empty.
22664 @item @code{address} (default: @code{'()})
22665 An ordered list of IP addresses, network subnets, or network ranges represented
22666 with strings. The query must match one of them. Empty value means that
22667 address match is not required.
22669 @item @code{key} (default: @code{'()})
22670 An ordered list of references to keys represented with strings. The string
22671 must match a key ID defined in a @code{knot-key-configuration}. No key means
22672 that a key is not require to match that ACL.
22674 @item @code{action} (default: @code{'()})
22675 An ordered list of actions that are permitted or forbidden by this ACL. Possible
22676 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
22677 and @code{'update}.
22679 @item @code{deny?} (default: @code{#f})
22680 When true, the ACL defines restrictions. Listed actions are forbidden. When
22681 false, listed actions are allowed.
22686 @deftp {Data Type} zone-entry
22687 Data type representing a record entry in a zone file.
22688 This type has the following parameters:
22691 @item @code{name} (default: @code{"@@"})
22692 The name of the record. @code{"@@"} refers to the origin of the zone. Names
22693 are relative to the origin of the zone. For example, in the @code{example.org}
22694 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
22695 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
22696 refers to @code{ns.example.org}.
22698 @item @code{ttl} (default: @code{""})
22699 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
22701 @item @code{class} (default: @code{"IN"})
22702 The class of the record. Knot currently supports only @code{"IN"} and
22703 partially @code{"CH"}.
22705 @item @code{type} (default: @code{"A"})
22706 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
22707 address), NS (Name Server) and MX (Mail eXchange). Many other types are
22710 @item @code{data} (default: @code{""})
22711 The data contained in the record. For instance an IP address associated with
22712 an A record, or a domain name associated with an NS record. Remember that
22713 domain names are relative to the origin unless they end with a dot.
22718 @deftp {Data Type} zone-file
22719 Data type representing the content of a zone file.
22720 This type has the following parameters:
22723 @item @code{entries} (default: @code{'()})
22724 The list of entries. The SOA record is taken care of, so you don't need to
22725 put it in the list of entries. This list should probably contain an entry
22726 for your primary authoritative DNS server. Other than using a list of entries
22727 directly, you can use @code{define-zone-entries} to define a object containing
22728 the list of entries more easily, that you can later pass to the @code{entries}
22729 field of the @code{zone-file}.
22731 @item @code{origin} (default: @code{""})
22732 The name of your zone. This parameter cannot be empty.
22734 @item @code{ns} (default: @code{"ns"})
22735 The domain of your primary authoritative DNS server. The name is relative to
22736 the origin, unless it ends with a dot. It is mandatory that this primary
22737 DNS server corresponds to an NS record in the zone and that it is associated
22738 to an IP address in the list of entries.
22740 @item @code{mail} (default: @code{"hostmaster"})
22741 An email address people can contact you at, as the owner of the zone. This
22742 is translated as @code{<mail>@@<origin>}.
22744 @item @code{serial} (default: @code{1})
22745 The serial number of the zone. As this is used to keep track of changes by
22746 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
22747 Always increment it when you make a change in your zone.
22749 @item @code{refresh} (default: @code{(* 2 24 3600)})
22750 The frequency at which slaves will do a zone transfer. This value is a number
22751 of seconds. It can be computed by multiplications or with
22752 @code{(string->duration)}.
22754 @item @code{retry} (default: @code{(* 15 60)})
22755 The period after which a slave will retry to contact its master when it fails
22756 to do so a first time.
22758 @item @code{expiry} (default: @code{(* 14 24 3600)})
22759 Default TTL of records. Existing records are considered correct for at most
22760 this amount of time. After this period, resolvers will invalidate their cache
22761 and check again that it still exists.
22763 @item @code{nx} (default: @code{3600})
22764 Default TTL of inexistant records. This delay is usually short because you want
22765 your new domains to reach everyone quickly.
22770 @deftp {Data Type} knot-remote-configuration
22771 Data type representing a remote configuration.
22772 This type has the following parameters:
22775 @item @code{id} (default: @code{""})
22776 An identifier for other configuration fields to refer to this remote. IDs must
22777 be unique and must not be empty.
22779 @item @code{address} (default: @code{'()})
22780 An ordered list of destination IP addresses. Addresses are tried in sequence.
22781 An optional port can be given with the @@ separator. For instance:
22782 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
22784 @item @code{via} (default: @code{'()})
22785 An ordered list of source IP addresses. An empty list will have Knot choose
22786 an appropriate source IP. An optional port can be given with the @@ separator.
22787 The default is to choose at random.
22789 @item @code{key} (default: @code{#f})
22790 A reference to a key, that is a string containing the identifier of a key
22791 defined in a @code{knot-key-configuration} field.
22796 @deftp {Data Type} knot-keystore-configuration
22797 Data type representing a keystore to hold dnssec keys.
22798 This type has the following parameters:
22801 @item @code{id} (default: @code{""})
22802 The id of the keystore. It must not be empty.
22804 @item @code{backend} (default: @code{'pem})
22805 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
22807 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
22808 The configuration string of the backend. An example for the PKCS#11 is:
22809 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
22810 For the pem backend, the string represents a path in the file system.
22815 @deftp {Data Type} knot-policy-configuration
22816 Data type representing a dnssec policy. Knot DNS is able to automatically
22817 sign your zones. It can either generate and manage your keys automatically or
22818 use keys that you generate.
22820 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
22821 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
22822 zone. In order to be trusted, the KSK needs to be present in the parent zone
22823 (usually a top-level domain). If your registrar supports dnssec, you will
22824 have to send them your KSK's hash so they can add a DS record in their zone.
22825 This is not automated and need to be done each time you change your KSK.
22827 The policy also defines the lifetime of keys. Usually, ZSK can be changed
22828 easily and use weaker cryptographic functions (they use lower parameters) in
22829 order to sign records quickly, so they are changed often. The KSK however
22830 requires manual interaction with the registrar, so they are changed less often
22831 and use stronger parameters because they sign only one record.
22833 This type has the following parameters:
22836 @item @code{id} (default: @code{""})
22837 The id of the policy. It must not be empty.
22839 @item @code{keystore} (default: @code{"default"})
22840 A reference to a keystore, that is a string containing the identifier of a
22841 keystore defined in a @code{knot-keystore-configuration} field. The
22842 @code{"default"} identifier means the default keystore (a kasp database that
22843 was setup by this service).
22845 @item @code{manual?} (default: @code{#f})
22846 Whether the key management is manual or automatic.
22848 @item @code{single-type-signing?} (default: @code{#f})
22849 When @code{#t}, use the Single-Type Signing Scheme.
22851 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
22852 An algorithm of signing keys and issued signatures.
22854 @item @code{ksk-size} (default: @code{256})
22855 The length of the KSK. Note that this value is correct for the default
22856 algorithm, but would be unsecure for other algorithms.
22858 @item @code{zsk-size} (default: @code{256})
22859 The length of the ZSK. Note that this value is correct for the default
22860 algorithm, but would be unsecure for other algorithms.
22862 @item @code{dnskey-ttl} (default: @code{'default})
22863 The TTL value for DNSKEY records added into zone apex. The special
22864 @code{'default} value means same as the zone SOA TTL.
22866 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
22867 The period between ZSK publication and the next rollover initiation.
22869 @item @code{propagation-delay} (default: @code{(* 24 3600)})
22870 An extra delay added for each key rollover step. This value should be high
22871 enough to cover propagation of data from the master server to all slaves.
22873 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
22874 A validity period of newly issued signatures.
22876 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
22877 A period how long before a signature expiration the signature will be refreshed.
22879 @item @code{nsec3?} (default: @code{#f})
22880 When @code{#t}, NSEC3 will be used instead of NSEC.
22882 @item @code{nsec3-iterations} (default: @code{5})
22883 The number of additional times the hashing is performed.
22885 @item @code{nsec3-salt-length} (default: @code{8})
22886 The length of a salt field in octets, which is appended to the original owner
22887 name before hashing.
22889 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
22890 The validity period of newly issued salt field.
22895 @deftp {Data Type} knot-zone-configuration
22896 Data type representing a zone served by Knot.
22897 This type has the following parameters:
22900 @item @code{domain} (default: @code{""})
22901 The domain served by this configuration. It must not be empty.
22903 @item @code{file} (default: @code{""})
22904 The file where this zone is saved. This parameter is ignored by master zones.
22905 Empty means default location that depends on the domain name.
22907 @item @code{zone} (default: @code{(zone-file)})
22908 The content of the zone file. This parameter is ignored by slave zones. It
22909 must contain a zone-file record.
22911 @item @code{master} (default: @code{'()})
22912 A list of master remotes. When empty, this zone is a master. When set, this
22913 zone is a slave. This is a list of remotes identifiers.
22915 @item @code{ddns-master} (default: @code{#f})
22916 The main master. When empty, it defaults to the first master in the list of
22919 @item @code{notify} (default: @code{'()})
22920 A list of slave remote identifiers.
22922 @item @code{acl} (default: @code{'()})
22923 A list of acl identifiers.
22925 @item @code{semantic-checks?} (default: @code{#f})
22926 When set, this adds more semantic checks to the zone.
22928 @item @code{disable-any?} (default: @code{#f})
22929 When set, this forbids queries of the ANY type.
22931 @item @code{zonefile-sync} (default: @code{0})
22932 The delay between a modification in memory and on disk. 0 means immediate
22935 @item @code{zonefile-load} (default: @code{#f})
22936 The way the zone file contents are applied during zone load. Possible values
22940 @item @code{#f} for using the default value from Knot,
22941 @item @code{'none} for not using the zone file at all,
22942 @item @code{'difference} for computing the difference between already available
22943 contents and zone contents and applying it to the current zone contents,
22944 @item @code{'difference-no-serial} for the same as @code{'difference}, but
22945 ignoring the SOA serial in the zone file, while the server takes care of it
22947 @item @code{'whole} for loading zone contents from the zone file.
22950 @item @code{journal-content} (default: @code{#f})
22951 The way the journal is used to store zone and its changes. Possible values
22952 are @code{'none} to not use it at all, @code{'changes} to store changes and
22953 @code{'all} to store contents. @code{#f} does not set this option, so the
22954 default value from Knot is used.
22956 @item @code{max-journal-usage} (default: @code{#f})
22957 The maximum size for the journal on disk. @code{#f} does not set this option,
22958 so the default value from Knot is used.
22960 @item @code{max-journal-depth} (default: @code{#f})
22961 The maximum size of the history. @code{#f} does not set this option, so the
22962 default value from Knot is used.
22964 @item @code{max-zone-size} (default: @code{#f})
22965 The maximum size of the zone file. This limit is enforced for incoming
22966 transfer and updates. @code{#f} does not set this option, so the default
22967 value from Knot is used.
22969 @item @code{dnssec-policy} (default: @code{#f})
22970 A reference to a @code{knot-policy-configuration} record, or the special
22971 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
22974 @item @code{serial-policy} (default: @code{'increment})
22975 A policy between @code{'increment} and @code{'unixtime}.
22980 @deftp {Data Type} knot-configuration
22981 Data type representing the Knot configuration.
22982 This type has the following parameters:
22985 @item @code{knot} (default: @code{knot})
22988 @item @code{run-directory} (default: @code{"/var/run/knot"})
22989 The run directory. This directory will be used for pid file and sockets.
22991 @item @code{includes} (default: @code{'()})
22992 A list of strings or file-like objects denoting other files that must be
22993 included at the top of the configuration file.
22995 @cindex secrets, Knot service
22996 This can be used to manage secrets out-of-band. For example, secret
22997 keys may be stored in an out-of-band file not managed by Guix, and
22998 thus not visible in @file{/gnu/store}---e.g., you could store secret
22999 key configuration in @file{/etc/knot/secrets.conf} and add this file
23000 to the @code{includes} list.
23002 One can generate a secret tsig key (for nsupdate and zone transfers with the
23003 keymgr command from the knot package. Note that the package is not automatically
23004 installed by the service. The following example shows how to generate a new
23008 keymgr -t mysecret > /etc/knot/secrets.conf
23009 chmod 600 /etc/knot/secrets.conf
23012 Also note that the generated key will be named @var{mysecret}, so it is the
23013 name that needs to be used in the @var{key} field of the
23014 @code{knot-acl-configuration} record and in other places that need to refer
23017 It can also be used to add configuration not supported by this interface.
23019 @item @code{listen-v4} (default: @code{"0.0.0.0"})
23020 An ip address on which to listen.
23022 @item @code{listen-v6} (default: @code{"::"})
23023 An ip address on which to listen.
23025 @item @code{listen-port} (default: @code{53})
23026 A port on which to listen.
23028 @item @code{keys} (default: @code{'()})
23029 The list of knot-key-configuration used by this configuration.
23031 @item @code{acls} (default: @code{'()})
23032 The list of knot-acl-configuration used by this configuration.
23034 @item @code{remotes} (default: @code{'()})
23035 The list of knot-remote-configuration used by this configuration.
23037 @item @code{zones} (default: @code{'()})
23038 The list of knot-zone-configuration used by this configuration.
23043 @subsubheading Knot Resolver Service
23045 @deffn {Scheme Variable} knot-resolver-service-type
23046 This this the type of the knot resolver service, whose value should be
23047 an @code{knot-resolver-configuration} object as in this example:
23050 (service knot-resolver-service-type
23051 (knot-resolver-configuration
23052 (kresd-config-file (plain-file "kresd.conf" "
23053 net.listen('192.168.0.1', 5353)
23054 user('knot-resolver', 'knot-resolver')
23055 modules = @{ 'hints > iterate', 'stats', 'predict' @}
23056 cache.size = 100 * MB
23060 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
23063 @deftp {Data Type} knot-resolver-configuration
23064 Data type representing the configuration of knot-resolver.
23067 @item @code{package} (default: @var{knot-resolver})
23068 Package object of the knot DNS resolver.
23070 @item @code{kresd-config-file} (default: %kresd.conf)
23071 File-like object of the kresd configuration file to use, by default it
23072 will listen on @code{127.0.0.1} and @code{::1}.
23074 @item @code{garbage-collection-interval} (default: 1000)
23075 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
23081 @subsubheading Dnsmasq Service
23083 @deffn {Scheme Variable} dnsmasq-service-type
23084 This is the type of the dnsmasq service, whose value should be an
23085 @code{dnsmasq-configuration} object as in this example:
23088 (service dnsmasq-service-type
23089 (dnsmasq-configuration
23091 (servers '("192.168.1.1"))))
23095 @deftp {Data Type} dnsmasq-configuration
23096 Data type representing the configuration of dnsmasq.
23099 @item @code{package} (default: @var{dnsmasq})
23100 Package object of the dnsmasq server.
23102 @item @code{no-hosts?} (default: @code{#f})
23103 When true, don't read the hostnames in /etc/hosts.
23105 @item @code{port} (default: @code{53})
23106 The port to listen on. Setting this to zero completely disables DNS
23107 responses, leaving only DHCP and/or TFTP functions.
23109 @item @code{local-service?} (default: @code{#t})
23110 Accept DNS queries only from hosts whose address is on a local subnet,
23111 ie a subnet for which an interface exists on the server.
23113 @item @code{listen-addresses} (default: @code{'()})
23114 Listen on the given IP addresses.
23116 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
23117 The file to read the IP address of the upstream nameservers from.
23119 @item @code{no-resolv?} (default: @code{#f})
23120 When true, don't read @var{resolv-file}.
23122 @item @code{servers} (default: @code{'()})
23123 Specify IP address of upstream servers directly.
23125 @item @code{addresses} (default: @code{'()})
23126 For each entry, specify an IP address to return for any host in the
23127 given domains. Queries in the domains are never forwarded and always
23128 replied to with the specified IP address.
23130 This is useful for redirecting hosts locally, for example:
23133 (service dnsmasq-service-type
23134 (dnsmasq-configuration
23136 '(; Redirect to a local web-server.
23137 "/example.org/127.0.0.1"
23138 ; Redirect subdomain to a specific IP.
23139 "/subdomain.example.org/192.168.1.42"))))
23142 Note that rules in @file{/etc/hosts} take precedence over this.
23144 @item @code{cache-size} (default: @code{150})
23145 Set the size of dnsmasq's cache. Setting the cache size to zero
23148 @item @code{negative-cache?} (default: @code{#t})
23149 When false, disable negative caching.
23154 @subsubheading ddclient Service
23157 The ddclient service described below runs the ddclient daemon, which takes
23158 care of automatically updating DNS entries for service providers such as
23159 @uref{https://dyn.com/dns/, Dyn}.
23161 The following example show instantiates the service with its default
23165 (service ddclient-service-type)
23168 Note that ddclient needs to access credentials that are stored in a
23169 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
23170 @code{secret-file} below). You are expected to create this file manually, in
23171 an ``out-of-band'' fashion (you @emph{could} make this file part of the
23172 service configuration, for instance by using @code{plain-file}, but it will be
23173 world-readable @i{via} @file{/gnu/store}). See the examples in the
23174 @file{share/ddclient} directory of the @code{ddclient} package.
23176 @c %start of fragment
23178 Available @code{ddclient-configuration} fields are:
23180 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
23181 The ddclient package.
23185 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
23186 The period after which ddclient will retry to check IP and domain name.
23188 Defaults to @samp{300}.
23192 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
23193 Use syslog for the output.
23195 Defaults to @samp{#t}.
23199 @deftypevr {@code{ddclient-configuration} parameter} string mail
23202 Defaults to @samp{"root"}.
23206 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
23207 Mail failed update to user.
23209 Defaults to @samp{"root"}.
23213 @deftypevr {@code{ddclient-configuration} parameter} string pid
23214 The ddclient PID file.
23216 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
23220 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
23221 Enable SSL support.
23223 Defaults to @samp{#t}.
23227 @deftypevr {@code{ddclient-configuration} parameter} string user
23228 Specifies the user name or ID that is used when running ddclient
23231 Defaults to @samp{"ddclient"}.
23235 @deftypevr {@code{ddclient-configuration} parameter} string group
23236 Group of the user who will run the ddclient program.
23238 Defaults to @samp{"ddclient"}.
23242 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
23243 Secret file which will be appended to @file{ddclient.conf} file. This
23244 file contains credentials for use by ddclient. You are expected to
23245 create it manually.
23247 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
23251 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
23252 Extra options will be appended to @file{ddclient.conf} file.
23254 Defaults to @samp{()}.
23259 @c %end of fragment
23263 @subsection VPN Services
23264 @cindex VPN (virtual private network)
23265 @cindex virtual private network (VPN)
23267 The @code{(gnu services vpn)} module provides services related to
23268 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
23269 your machine to connect to a VPN, and a @emph{server} service for your machine
23270 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
23272 @deffn {Scheme Procedure} openvpn-client-service @
23273 [#:config (openvpn-client-configuration)]
23275 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
23278 @deffn {Scheme Procedure} openvpn-server-service @
23279 [#:config (openvpn-server-configuration)]
23281 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
23283 Both can be run simultaneously.
23286 @c %automatically generated documentation
23288 Available @code{openvpn-client-configuration} fields are:
23290 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
23291 The OpenVPN package.
23295 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
23296 The OpenVPN pid file.
23298 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23302 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
23303 The protocol (UDP or TCP) used to open a channel between clients and
23306 Defaults to @samp{udp}.
23310 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
23311 The device type used to represent the VPN connection.
23313 Defaults to @samp{tun}.
23317 @deftypevr {@code{openvpn-client-configuration} parameter} string ca
23318 The certificate authority to check connections against.
23320 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23324 @deftypevr {@code{openvpn-client-configuration} parameter} string cert
23325 The certificate of the machine the daemon is running on. It should be
23326 signed by the authority given in @code{ca}.
23328 Defaults to @samp{"/etc/openvpn/client.crt"}.
23332 @deftypevr {@code{openvpn-client-configuration} parameter} string key
23333 The key of the machine the daemon is running on. It must be the key whose
23334 certificate is @code{cert}.
23336 Defaults to @samp{"/etc/openvpn/client.key"}.
23340 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
23341 Whether to use the lzo compression algorithm.
23343 Defaults to @samp{#t}.
23347 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
23348 Don't re-read key files across SIGUSR1 or --ping-restart.
23350 Defaults to @samp{#t}.
23354 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
23355 Don't close and reopen TUN/TAP device or run up/down scripts across
23356 SIGUSR1 or --ping-restart restarts.
23358 Defaults to @samp{#t}.
23362 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
23363 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23364 poll/epoll/select prior to the write operation.
23366 Defaults to @samp{#f}.
23369 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
23372 Defaults to @samp{3}.
23376 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
23377 Add an additional layer of HMAC authentication on top of the TLS control
23378 channel to protect against DoS attacks.
23380 Defaults to @samp{#f}.
23384 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
23385 Authenticate with server using username/password. The option is a file
23386 containing username/password on 2 lines. Do not use a file-like object as it
23387 would be added to the store and readable by any user.
23389 Defaults to @samp{'disabled}.
23392 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
23393 Whether to check the server certificate has server usage extension.
23395 Defaults to @samp{#t}.
23399 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
23400 Bind to a specific local port number.
23402 Defaults to @samp{#f}.
23406 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
23407 Retry resolving server address.
23409 Defaults to @samp{#t}.
23413 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
23414 A list of remote servers to connect to.
23416 Defaults to @samp{()}.
23418 Available @code{openvpn-remote-configuration} fields are:
23420 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
23423 Defaults to @samp{"my-server"}.
23427 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
23428 Port number the server listens to.
23430 Defaults to @samp{1194}.
23435 @c %end of automatic openvpn-client documentation
23437 @c %automatically generated documentation
23439 Available @code{openvpn-server-configuration} fields are:
23441 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
23442 The OpenVPN package.
23446 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
23447 The OpenVPN pid file.
23449 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
23453 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
23454 The protocol (UDP or TCP) used to open a channel between clients and
23457 Defaults to @samp{udp}.
23461 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
23462 The device type used to represent the VPN connection.
23464 Defaults to @samp{tun}.
23468 @deftypevr {@code{openvpn-server-configuration} parameter} string ca
23469 The certificate authority to check connections against.
23471 Defaults to @samp{"/etc/openvpn/ca.crt"}.
23475 @deftypevr {@code{openvpn-server-configuration} parameter} string cert
23476 The certificate of the machine the daemon is running on. It should be
23477 signed by the authority given in @code{ca}.
23479 Defaults to @samp{"/etc/openvpn/client.crt"}.
23483 @deftypevr {@code{openvpn-server-configuration} parameter} string key
23484 The key of the machine the daemon is running on. It must be the key whose
23485 certificate is @code{cert}.
23487 Defaults to @samp{"/etc/openvpn/client.key"}.
23491 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
23492 Whether to use the lzo compression algorithm.
23494 Defaults to @samp{#t}.
23498 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
23499 Don't re-read key files across SIGUSR1 or --ping-restart.
23501 Defaults to @samp{#t}.
23505 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
23506 Don't close and reopen TUN/TAP device or run up/down scripts across
23507 SIGUSR1 or --ping-restart restarts.
23509 Defaults to @samp{#t}.
23513 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
23514 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
23515 poll/epoll/select prior to the write operation.
23517 Defaults to @samp{#f}.
23520 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
23523 Defaults to @samp{3}.
23527 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
23528 Add an additional layer of HMAC authentication on top of the TLS control
23529 channel to protect against DoS attacks.
23531 Defaults to @samp{#f}.
23535 @deftypevr {@code{openvpn-server-configuration} parameter} number port
23536 Specifies the port number on which the server listens.
23538 Defaults to @samp{1194}.
23542 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
23543 An ip and mask specifying the subnet inside the virtual network.
23545 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
23549 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
23550 A CIDR notation specifying the IPv6 subnet inside the virtual network.
23552 Defaults to @samp{#f}.
23556 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
23557 The Diffie-Hellman parameters file.
23559 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
23563 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
23564 The file that records client IPs.
23566 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
23570 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
23571 When true, the server will act as a gateway for its clients.
23573 Defaults to @samp{#f}.
23577 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
23578 When true, clients are allowed to talk to each other inside the VPN.
23580 Defaults to @samp{#f}.
23584 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
23585 Causes ping-like messages to be sent back and forth over the link so
23586 that each side knows when the other side has gone down. @code{keepalive}
23587 requires a pair. The first element is the period of the ping sending,
23588 and the second element is the timeout before considering the other side
23593 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
23594 The maximum number of clients.
23596 Defaults to @samp{100}.
23600 @deftypevr {@code{openvpn-server-configuration} parameter} string status
23601 The status file. This file shows a small report on current connection.
23602 It is truncated and rewritten every minute.
23604 Defaults to @samp{"/var/run/openvpn/status"}.
23608 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
23609 The list of configuration for some clients.
23611 Defaults to @samp{()}.
23613 Available @code{openvpn-ccd-configuration} fields are:
23615 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
23618 Defaults to @samp{"client"}.
23622 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
23625 Defaults to @samp{#f}.
23629 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
23632 Defaults to @samp{#f}.
23639 @c %end of automatic openvpn-server documentation
23642 @node Network File System
23643 @subsection Network File System
23646 The @code{(gnu services nfs)} module provides the following services,
23647 which are most commonly used in relation to mounting or exporting
23648 directory trees as @dfn{network file systems} (NFS).
23650 While it is possible to use the individual components that together make
23651 up a Network File System service, we recommended to configure an NFS
23652 server with the @code{nfs-service-type}.
23654 @subsubheading NFS Service
23655 @cindex NFS, server
23657 The NFS service takes care of setting up all NFS component services,
23658 kernel configuration file systems, and installs configuration files in
23659 the locations that NFS expects.
23661 @defvr {Scheme Variable} nfs-service-type
23662 A service type for a complete NFS server.
23665 @deftp {Data Type} nfs-configuration
23666 This data type represents the configuration of the NFS service and all
23669 It has the following parameters:
23671 @item @code{nfs-utils} (default: @code{nfs-utils})
23672 The nfs-utils package to use.
23674 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
23675 If a list of string values is provided, the @command{rpc.nfsd} daemon
23676 will be limited to supporting the given versions of the NFS protocol.
23678 @item @code{exports} (default: @code{'()})
23679 This is a list of directories the NFS server should export. Each entry
23680 is a list consisting of two elements: a directory name and a string
23681 containing all options. This is an example in which the directory
23682 @file{/export} is served to all NFS clients as a read-only share:
23688 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
23691 @item @code{rpcmountd-port} (default: @code{#f})
23692 The network port that the @command{rpc.mountd} daemon should use.
23694 @item @code{rpcstatd-port} (default: @code{#f})
23695 The network port that the @command{rpc.statd} daemon should use.
23697 @item @code{rpcbind} (default: @code{rpcbind})
23698 The rpcbind package to use.
23700 @item @code{idmap-domain} (default: @code{"localdomain"})
23701 The local NFSv4 domain name.
23703 @item @code{nfsd-port} (default: @code{2049})
23704 The network port that the @command{nfsd} daemon should use.
23706 @item @code{nfsd-threads} (default: @code{8})
23707 The number of threads used by the @command{nfsd} daemon.
23709 @item @code{nfsd-tcp?} (default: @code{#t})
23710 Whether the @command{nfsd} daemon should listen on a TCP socket.
23712 @item @code{nfsd-udp?} (default: @code{#f})
23713 Whether the @command{nfsd} daemon should listen on a UDP socket.
23715 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23716 The directory where the pipefs file system is mounted.
23718 @item @code{debug} (default: @code{'()"})
23719 A list of subsystems for which debugging output should be enabled. This
23720 is a list of symbols. Any of these symbols are valid: @code{nfsd},
23721 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
23725 If you don't need a complete NFS service or prefer to build it yourself
23726 you can use the individual component services that are documented below.
23728 @subsubheading RPC Bind Service
23731 The RPC Bind service provides a facility to map program numbers into
23732 universal addresses.
23733 Many NFS related services use this facility. Hence it is automatically
23734 started when a dependent service starts.
23736 @defvr {Scheme Variable} rpcbind-service-type
23737 A service type for the RPC portmapper daemon.
23741 @deftp {Data Type} rpcbind-configuration
23742 Data type representing the configuration of the RPC Bind Service.
23743 This type has the following parameters:
23745 @item @code{rpcbind} (default: @code{rpcbind})
23746 The rpcbind package to use.
23748 @item @code{warm-start?} (default: @code{#t})
23749 If this parameter is @code{#t}, then the daemon will read a
23750 state file on startup thus reloading state information saved by a previous
23756 @subsubheading Pipefs Pseudo File System
23760 The pipefs file system is used to transfer NFS related data
23761 between the kernel and user space programs.
23763 @defvr {Scheme Variable} pipefs-service-type
23764 A service type for the pipefs pseudo file system.
23767 @deftp {Data Type} pipefs-configuration
23768 Data type representing the configuration of the pipefs pseudo file system service.
23769 This type has the following parameters:
23771 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23772 The directory to which the file system is to be attached.
23777 @subsubheading GSS Daemon Service
23780 @cindex global security system
23782 The @dfn{global security system} (GSS) daemon provides strong security for RPC
23784 Before exchanging RPC requests an RPC client must establish a security
23785 context. Typically this is done using the Kerberos command @command{kinit}
23786 or automatically at login time using PAM services (@pxref{Kerberos Services}).
23788 @defvr {Scheme Variable} gss-service-type
23789 A service type for the Global Security System (GSS) daemon.
23792 @deftp {Data Type} gss-configuration
23793 Data type representing the configuration of the GSS daemon service.
23794 This type has the following parameters:
23796 @item @code{nfs-utils} (default: @code{nfs-utils})
23797 The package in which the @command{rpc.gssd} command is to be found.
23799 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23800 The directory where the pipefs file system is mounted.
23806 @subsubheading IDMAP Daemon Service
23808 @cindex name mapper
23810 The idmap daemon service provides mapping between user IDs and user names.
23811 Typically it is required in order to access file systems mounted via NFSv4.
23813 @defvr {Scheme Variable} idmap-service-type
23814 A service type for the Identity Mapper (IDMAP) daemon.
23817 @deftp {Data Type} idmap-configuration
23818 Data type representing the configuration of the IDMAP daemon service.
23819 This type has the following parameters:
23821 @item @code{nfs-utils} (default: @code{nfs-utils})
23822 The package in which the @command{rpc.idmapd} command is to be found.
23824 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
23825 The directory where the pipefs file system is mounted.
23827 @item @code{domain} (default: @code{#f})
23828 The local NFSv4 domain name.
23829 This must be a string or @code{#f}.
23830 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
23832 @item @code{verbosity} (default: @code{0})
23833 The verbosity level of the daemon.
23838 @node Continuous Integration
23839 @subsection Continuous Integration
23841 @cindex continuous integration
23842 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
23843 continuous integration tool for Guix. It can be used both for development and
23844 for providing substitutes to others (@pxref{Substitutes}).
23846 The @code{(gnu services cuirass)} module provides the following service.
23848 @defvr {Scheme Procedure} cuirass-service-type
23849 The type of the Cuirass service. Its value must be a
23850 @code{cuirass-configuration} object, as described below.
23853 To add build jobs, you have to set the @code{specifications} field of the
23854 configuration. Here is an example of a service that polls the Guix repository
23855 and builds the packages from a manifest. Some of the packages are defined in
23856 the @code{"custom-packages"} input, which is the equivalent of
23857 @env{GUIX_PACKAGE_PATH}.
23860 (define %cuirass-specs
23862 '((#:name . "my-manifest")
23863 (#:load-path-inputs . ("guix"))
23864 (#:package-path-inputs . ("custom-packages"))
23865 (#:proc-input . "guix")
23866 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
23867 (#:proc . cuirass-jobs)
23868 (#:proc-args . ((subset . "manifests")
23869 (systems . ("x86_64-linux"))
23870 (manifests . (("config" . "guix/manifest.scm")))))
23871 (#:inputs . (((#:name . "guix")
23872 (#:url . "git://git.savannah.gnu.org/guix.git")
23873 (#:load-path . ".")
23874 (#:branch . "master")
23875 (#:no-compile? . #t))
23876 ((#:name . "config")
23877 (#:url . "https://git.example.org/config.git")
23878 (#:load-path . ".")
23879 (#:branch . "master")
23880 (#:no-compile? . #t))
23881 ((#:name . "custom-packages")
23882 (#:url . "https://git.example.org/custom-packages.git")
23883 (#:load-path . ".")
23884 (#:branch . "master")
23885 (#:no-compile? . #t)))))))
23887 (service cuirass-service-type
23888 (cuirass-configuration
23889 (specifications %cuirass-specs)))
23892 While information related to build jobs is located directly in the
23893 specifications, global settings for the @command{cuirass} process are
23894 accessible in other @code{cuirass-configuration} fields.
23896 @deftp {Data Type} cuirass-configuration
23897 Data type representing the configuration of Cuirass.
23900 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
23901 Location of the log file.
23903 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
23904 Location of the log file used by the web interface.
23906 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
23907 Location of the repository cache.
23909 @item @code{user} (default: @code{"cuirass"})
23910 Owner of the @code{cuirass} process.
23912 @item @code{group} (default: @code{"cuirass"})
23913 Owner's group of the @code{cuirass} process.
23915 @item @code{interval} (default: @code{60})
23916 Number of seconds between the poll of the repositories followed by the
23919 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
23920 Location of sqlite database which contains the build results and previously
23921 added specifications.
23923 @item @code{ttl} (default: @code{(* 30 24 3600)})
23924 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
23925 are registered for build results. This means that build results are protected
23926 from garbage collection for at least @var{ttl} seconds.
23928 @item @code{port} (default: @code{8081})
23929 Port number used by the HTTP server.
23931 @item @code{host} (default: @code{"localhost"})
23932 Listen on the network interface for @var{host}. The default is to
23933 accept connections from localhost.
23935 @item @code{specifications} (default: @code{#~'()})
23936 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
23937 where a specification is an association list
23938 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
23939 keys are keywords (@code{#:keyword-example}) as shown in the example
23942 @item @code{use-substitutes?} (default: @code{#f})
23943 This allows using substitutes to avoid building every dependencies of a job
23946 @item @code{one-shot?} (default: @code{#f})
23947 Only evaluate specifications and build derivations once.
23949 @item @code{fallback?} (default: @code{#f})
23950 When substituting a pre-built binary fails, fall back to building
23953 @item @code{extra-options} (default: @code{'()})
23954 Extra options to pass when running the Cuirass processes.
23956 @item @code{cuirass} (default: @code{cuirass})
23957 The Cuirass package to use.
23961 @node Power Management Services
23962 @subsection Power Management Services
23965 @cindex power management with TLP
23966 @subsubheading TLP daemon
23968 The @code{(gnu services pm)} module provides a Guix service definition
23969 for the Linux power management tool TLP.
23971 TLP enables various powersaving modes in userspace and kernel.
23972 Contrary to @code{upower-service}, it is not a passive,
23973 monitoring tool, as it will apply custom settings each time a new power
23974 source is detected. More information can be found at
23975 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
23977 @deffn {Scheme Variable} tlp-service-type
23978 The service type for the TLP tool. The default settings are optimised
23979 for battery life on most systems, but you can tweak them to your heart's
23980 content by adding a valid @code{tlp-configuration}:
23982 (service tlp-service-type
23984 (cpu-scaling-governor-on-ac (list "performance"))
23985 (sched-powersave-on-bat? #t)))
23989 Each parameter definition is preceded by its type; for example,
23990 @samp{boolean foo} indicates that the @code{foo} parameter
23991 should be specified as a boolean. Types starting with
23992 @code{maybe-} denote parameters that won't show up in TLP config file
23993 when their value is @code{'disabled}.
23995 @c The following documentation was initially generated by
23996 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
23997 @c documentation is better, so we shouldn't hesitate to edit below as
23998 @c needed. However if the change you want to make to this documentation
23999 @c can be done in an automated way, it's probably easier to change
24000 @c (generate-documentation) than to make it below and have to deal with
24001 @c the churn as TLP updates.
24003 Available @code{tlp-configuration} fields are:
24005 @deftypevr {@code{tlp-configuration} parameter} package tlp
24010 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
24011 Set to true if you wish to enable TLP.
24013 Defaults to @samp{#t}.
24017 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
24018 Default mode when no power supply can be detected. Alternatives are AC
24021 Defaults to @samp{"AC"}.
24025 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
24026 Number of seconds Linux kernel has to wait after the disk goes idle,
24027 before syncing on AC.
24029 Defaults to @samp{0}.
24033 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
24034 Same as @code{disk-idle-ac} but on BAT mode.
24036 Defaults to @samp{2}.
24040 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
24041 Dirty pages flushing periodicity, expressed in seconds.
24043 Defaults to @samp{15}.
24047 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
24048 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
24050 Defaults to @samp{60}.
24054 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
24055 CPU frequency scaling governor on AC mode. With intel_pstate driver,
24056 alternatives are powersave and performance. With acpi-cpufreq driver,
24057 alternatives are ondemand, powersave, performance and conservative.
24059 Defaults to @samp{disabled}.
24063 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
24064 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
24066 Defaults to @samp{disabled}.
24070 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
24071 Set the min available frequency for the scaling governor on AC.
24073 Defaults to @samp{disabled}.
24077 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
24078 Set the max available frequency for the scaling governor on AC.
24080 Defaults to @samp{disabled}.
24084 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
24085 Set the min available frequency for the scaling governor on BAT.
24087 Defaults to @samp{disabled}.
24091 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
24092 Set the max available frequency for the scaling governor on BAT.
24094 Defaults to @samp{disabled}.
24098 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
24099 Limit the min P-state to control the power dissipation of the CPU, in AC
24100 mode. Values are stated as a percentage of the available performance.
24102 Defaults to @samp{disabled}.
24106 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
24107 Limit the max P-state to control the power dissipation of the CPU, in AC
24108 mode. Values are stated as a percentage of the available performance.
24110 Defaults to @samp{disabled}.
24114 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
24115 Same as @code{cpu-min-perf-on-ac} on BAT mode.
24117 Defaults to @samp{disabled}.
24121 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
24122 Same as @code{cpu-max-perf-on-ac} on BAT mode.
24124 Defaults to @samp{disabled}.
24128 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
24129 Enable CPU turbo boost feature on AC mode.
24131 Defaults to @samp{disabled}.
24135 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
24136 Same as @code{cpu-boost-on-ac?} on BAT mode.
24138 Defaults to @samp{disabled}.
24142 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
24143 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
24144 used under light load conditions.
24146 Defaults to @samp{#f}.
24150 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
24151 Same as @code{sched-powersave-on-ac?} but on BAT mode.
24153 Defaults to @samp{#t}.
24157 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
24158 Enable Linux kernel NMI watchdog.
24160 Defaults to @samp{#f}.
24164 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
24165 For Linux kernels with PHC patch applied, change CPU voltages. An
24166 example value would be @samp{"F:V F:V F:V F:V"}.
24168 Defaults to @samp{disabled}.
24172 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
24173 Set CPU performance versus energy saving policy on AC. Alternatives are
24174 performance, normal, powersave.
24176 Defaults to @samp{"performance"}.
24180 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
24181 Same as @code{energy-perf-policy-ac} but on BAT mode.
24183 Defaults to @samp{"powersave"}.
24187 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
24192 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
24193 Hard disk advanced power management level.
24197 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
24198 Same as @code{disk-apm-bat} but on BAT mode.
24202 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
24203 Hard disk spin down timeout. One value has to be specified for each
24204 declared hard disk.
24206 Defaults to @samp{disabled}.
24210 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
24211 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
24213 Defaults to @samp{disabled}.
24217 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
24218 Select IO scheduler for disk devices. One value has to be specified for
24219 each declared hard disk. Example alternatives are cfq, deadline and
24222 Defaults to @samp{disabled}.
24226 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
24227 SATA aggressive link power management (ALPM) level. Alternatives are
24228 min_power, medium_power, max_performance.
24230 Defaults to @samp{"max_performance"}.
24234 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
24235 Same as @code{sata-linkpwr-ac} but on BAT mode.
24237 Defaults to @samp{"min_power"}.
24241 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
24242 Exclude specified SATA host devices for link power management.
24244 Defaults to @samp{disabled}.
24248 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
24249 Enable Runtime Power Management for AHCI controller and disks on AC
24252 Defaults to @samp{disabled}.
24256 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
24257 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
24259 Defaults to @samp{disabled}.
24263 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
24264 Seconds of inactivity before disk is suspended.
24266 Defaults to @samp{15}.
24270 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
24271 PCI Express Active State Power Management level. Alternatives are
24272 default, performance, powersave.
24274 Defaults to @samp{"performance"}.
24278 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
24279 Same as @code{pcie-aspm-ac} but on BAT mode.
24281 Defaults to @samp{"powersave"}.
24285 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
24286 Radeon graphics clock speed level. Alternatives are low, mid, high,
24289 Defaults to @samp{"high"}.
24293 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
24294 Same as @code{radeon-power-ac} but on BAT mode.
24296 Defaults to @samp{"low"}.
24300 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
24301 Radeon dynamic power management method (DPM). Alternatives are battery,
24304 Defaults to @samp{"performance"}.
24308 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
24309 Same as @code{radeon-dpm-state-ac} but on BAT mode.
24311 Defaults to @samp{"battery"}.
24315 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
24316 Radeon DPM performance level. Alternatives are auto, low, high.
24318 Defaults to @samp{"auto"}.
24322 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
24323 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
24325 Defaults to @samp{"auto"}.
24329 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
24330 Wifi power saving mode.
24332 Defaults to @samp{#f}.
24336 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
24337 Same as @code{wifi-power-ac?} but on BAT mode.
24339 Defaults to @samp{#t}.
24343 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
24344 Disable wake on LAN.
24346 Defaults to @samp{#t}.
24350 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
24351 Timeout duration in seconds before activating audio power saving on
24352 Intel HDA and AC97 devices. A value of 0 disables power saving.
24354 Defaults to @samp{0}.
24358 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
24359 Same as @code{sound-powersave-ac} but on BAT mode.
24361 Defaults to @samp{1}.
24365 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
24366 Disable controller in powersaving mode on Intel HDA devices.
24368 Defaults to @samp{#t}.
24372 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
24373 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
24374 powered on again by releasing (and reinserting) the eject lever or by
24375 pressing the disc eject button on newer models.
24377 Defaults to @samp{#f}.
24381 @deftypevr {@code{tlp-configuration} parameter} string bay-device
24382 Name of the optical drive device to power off.
24384 Defaults to @samp{"sr0"}.
24388 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
24389 Runtime Power Management for PCI(e) bus devices. Alternatives are on
24392 Defaults to @samp{"on"}.
24396 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
24397 Same as @code{runtime-pm-ac} but on BAT mode.
24399 Defaults to @samp{"auto"}.
24403 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
24404 Runtime Power Management for all PCI(e) bus devices, except blacklisted
24407 Defaults to @samp{#t}.
24411 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
24412 Exclude specified PCI(e) device addresses from Runtime Power Management.
24414 Defaults to @samp{disabled}.
24418 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
24419 Exclude PCI(e) devices assigned to the specified drivers from Runtime
24424 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
24425 Enable USB autosuspend feature.
24427 Defaults to @samp{#t}.
24431 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
24432 Exclude specified devices from USB autosuspend.
24434 Defaults to @samp{disabled}.
24438 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
24439 Exclude WWAN devices from USB autosuspend.
24441 Defaults to @samp{#t}.
24445 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
24446 Include specified devices into USB autosuspend, even if they are already
24447 excluded by the driver or via @code{usb-blacklist-wwan?}.
24449 Defaults to @samp{disabled}.
24453 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
24454 Enable USB autosuspend before shutdown.
24456 Defaults to @samp{disabled}.
24460 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
24461 Restore radio device state (bluetooth, wifi, wwan) from previous
24462 shutdown on system startup.
24464 Defaults to @samp{#f}.
24469 @cindex CPU frequency scaling with thermald
24470 @subsubheading Thermald daemon
24472 The @code{(gnu services pm)} module provides an interface to
24473 thermald, a CPU frequency scaling service which helps prevent overheating.
24475 @defvr {Scheme Variable} thermald-service-type
24476 This is the service type for
24477 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
24478 Thermal Daemon, which is responsible for controlling the thermal state
24479 of processors and preventing overheating.
24482 @deftp {Data Type} thermald-configuration
24483 Data type representing the configuration of @code{thermald-service-type}.
24486 @item @code{ignore-cpuid-check?} (default: @code{#f})
24487 Ignore cpuid check for supported CPU models.
24489 @item @code{thermald} (default: @var{thermald})
24490 Package object of thermald.
24495 @node Audio Services
24496 @subsection Audio Services
24498 The @code{(gnu services audio)} module provides a service to start MPD
24499 (the Music Player Daemon).
24502 @subsubheading Music Player Daemon
24504 The Music Player Daemon (MPD) is a service that can play music while
24505 being controlled from the local machine or over the network by a variety
24508 The following example shows how one might run @code{mpd} as user
24509 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
24512 (service mpd-service-type
24518 @defvr {Scheme Variable} mpd-service-type
24519 The service type for @command{mpd}
24522 @deftp {Data Type} mpd-configuration
24523 Data type representing the configuration of @command{mpd}.
24526 @item @code{user} (default: @code{"mpd"})
24527 The user to run mpd as.
24529 @item @code{music-dir} (default: @code{"~/Music"})
24530 The directory to scan for music files.
24532 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
24533 The directory to store playlists.
24535 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
24536 The location of the music database.
24538 @item @code{state-file} (default: @code{"~/.mpd/state"})
24539 The location of the file that stores current MPD's state.
24541 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
24542 The location of the sticker database.
24544 @item @code{port} (default: @code{"6600"})
24545 The port to run mpd on.
24547 @item @code{address} (default: @code{"any"})
24548 The address that mpd will bind to. To use a Unix domain socket,
24549 an absolute path can be specified here.
24551 @item @code{outputs} (default: @code{"(list (mpd-output))"})
24552 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
24557 @deftp {Data Type} mpd-output
24558 Data type representing an @command{mpd} audio output.
24561 @item @code{name} (default: @code{"MPD"})
24562 The name of the audio output.
24564 @item @code{type} (default: @code{"pulse"})
24565 The type of audio output.
24567 @item @code{enabled?} (default: @code{#t})
24568 Specifies whether this audio output is enabled when MPD is started. By
24569 default, all audio outputs are enabled. This is just the default
24570 setting when there is no state file; with a state file, the previous
24573 @item @code{tags?} (default: @code{#t})
24574 If set to @code{#f}, then MPD will not send tags to this output. This
24575 is only useful for output plugins that can receive tags, for example the
24576 @code{httpd} output plugin.
24578 @item @code{always-on?} (default: @code{#f})
24579 If set to @code{#t}, then MPD attempts to keep this audio output always
24580 open. This may be useful for streaming servers, when you don’t want to
24581 disconnect all listeners even when playback is accidentally stopped.
24583 @item @code{mixer-type}
24584 This field accepts a symbol that specifies which mixer should be used
24585 for this audio output: the @code{hardware} mixer, the @code{software}
24586 mixer, the @code{null} mixer (allows setting the volume, but with no
24587 effect; this can be used as a trick to implement an external mixer
24588 External Mixer) or no mixer (@code{none}).
24590 @item @code{extra-options} (default: @code{'()"})
24591 An association list of option symbols to string values to be appended to
24592 the audio output configuration.
24597 The following example shows a configuration of @code{mpd} that provides
24598 an HTTP audio streaming output.
24601 (service mpd-service-type
24609 `((encoder . "vorbis")
24610 (port . "8080"))))))))
24614 @node Virtualization Services
24615 @subsection Virtualization services
24617 The @code{(gnu services virtualization)} module provides services for
24618 the libvirt and virtlog daemons, as well as other virtualization-related
24621 @subsubheading Libvirt daemon
24622 @code{libvirtd} is the server side daemon component of the libvirt
24623 virtualization management system. This daemon runs on host servers
24624 and performs required management tasks for virtualized guests.
24626 @deffn {Scheme Variable} libvirt-service-type
24627 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
24628 Its value must be a @code{libvirt-configuration}.
24631 (service libvirt-service-type
24632 (libvirt-configuration
24633 (unix-sock-group "libvirt")
24634 (tls-port "16555")))
24638 @c Auto-generated with (generate-libvirt-documentation)
24639 Available @code{libvirt-configuration} fields are:
24641 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
24646 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
24647 Flag listening for secure TLS connections on the public TCP/IP port.
24648 must set @code{listen} for this to have any effect.
24650 It is necessary to setup a CA and issue server certificates before using
24653 Defaults to @samp{#t}.
24657 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
24658 Listen for unencrypted TCP connections on the public TCP/IP port. must
24659 set @code{listen} for this to have any effect.
24661 Using the TCP socket requires SASL authentication by default. Only SASL
24662 mechanisms which support data encryption are allowed. This is
24663 DIGEST_MD5 and GSSAPI (Kerberos5)
24665 Defaults to @samp{#f}.
24669 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
24670 Port for accepting secure TLS connections This can be a port number, or
24673 Defaults to @samp{"16514"}.
24677 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
24678 Port for accepting insecure TCP connections This can be a port number,
24681 Defaults to @samp{"16509"}.
24685 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
24686 IP address or hostname used for client connections.
24688 Defaults to @samp{"0.0.0.0"}.
24692 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
24693 Flag toggling mDNS advertisement of the libvirt service.
24695 Alternatively can disable for all services on a host by stopping the
24698 Defaults to @samp{#f}.
24702 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
24703 Default mDNS advertisement name. This must be unique on the immediate
24706 Defaults to @samp{"Virtualization Host <hostname>"}.
24710 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
24711 UNIX domain socket group ownership. This can be used to allow a
24712 'trusted' set of users access to management capabilities without
24715 Defaults to @samp{"root"}.
24719 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
24720 UNIX socket permissions for the R/O socket. This is used for monitoring
24723 Defaults to @samp{"0777"}.
24727 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
24728 UNIX socket permissions for the R/W socket. Default allows only root.
24729 If PolicyKit is enabled on the socket, the default will change to allow
24730 everyone (eg, 0777)
24732 Defaults to @samp{"0770"}.
24736 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
24737 UNIX socket permissions for the admin socket. Default allows only owner
24738 (root), do not change it unless you are sure to whom you are exposing
24741 Defaults to @samp{"0777"}.
24745 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
24746 The directory in which sockets will be found/created.
24748 Defaults to @samp{"/var/run/libvirt"}.
24752 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
24753 Authentication scheme for UNIX read-only sockets. By default socket
24754 permissions allow anyone to connect
24756 Defaults to @samp{"polkit"}.
24760 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
24761 Authentication scheme for UNIX read-write sockets. By default socket
24762 permissions only allow root. If PolicyKit support was compiled into
24763 libvirt, the default will be to use 'polkit' auth.
24765 Defaults to @samp{"polkit"}.
24769 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
24770 Authentication scheme for TCP sockets. If you don't enable SASL, then
24771 all TCP traffic is cleartext. Don't do this outside of a dev/test
24774 Defaults to @samp{"sasl"}.
24778 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
24779 Authentication scheme for TLS sockets. TLS sockets already have
24780 encryption provided by the TLS layer, and limited authentication is done
24783 It is possible to make use of any SASL authentication mechanism as well,
24784 by using 'sasl' for this option
24786 Defaults to @samp{"none"}.
24790 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
24791 API access control scheme.
24793 By default an authenticated user is allowed access to all APIs. Access
24794 drivers can place restrictions on this.
24796 Defaults to @samp{()}.
24800 @deftypevr {@code{libvirt-configuration} parameter} string key-file
24801 Server key file path. If set to an empty string, then no private key is
24804 Defaults to @samp{""}.
24808 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
24809 Server key file path. If set to an empty string, then no certificate is
24812 Defaults to @samp{""}.
24816 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
24817 Server key file path. If set to an empty string, then no CA certificate
24820 Defaults to @samp{""}.
24824 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
24825 Certificate revocation list path. If set to an empty string, then no
24828 Defaults to @samp{""}.
24832 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
24833 Disable verification of our own server certificates.
24835 When libvirtd starts it performs some sanity checks against its own
24838 Defaults to @samp{#f}.
24842 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
24843 Disable verification of client certificates.
24845 Client certificate verification is the primary authentication mechanism.
24846 Any client which does not present a certificate signed by the CA will be
24849 Defaults to @samp{#f}.
24853 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
24854 Whitelist of allowed x509 Distinguished Name.
24856 Defaults to @samp{()}.
24860 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
24861 Whitelist of allowed SASL usernames. The format for username depends on
24862 the SASL authentication mechanism.
24864 Defaults to @samp{()}.
24868 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
24869 Override the compile time default TLS priority string. The default is
24870 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
24871 is desired for libvirt to deviate from the global default settings.
24873 Defaults to @samp{"NORMAL"}.
24877 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
24878 Maximum number of concurrent client connections to allow over all
24881 Defaults to @samp{5000}.
24885 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
24886 Maximum length of queue of connections waiting to be accepted by the
24887 daemon. Note, that some protocols supporting retransmission may obey
24888 this so that a later reattempt at connection succeeds.
24890 Defaults to @samp{1000}.
24894 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
24895 Maximum length of queue of accepted but not yet authenticated clients.
24896 Set this to zero to turn this feature off
24898 Defaults to @samp{20}.
24902 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
24903 Number of workers to start up initially.
24905 Defaults to @samp{5}.
24909 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
24910 Maximum number of worker threads.
24912 If the number of active clients exceeds @code{min-workers}, then more
24913 threads are spawned, up to max_workers limit. Typically you'd want
24914 max_workers to equal maximum number of clients allowed.
24916 Defaults to @samp{20}.
24920 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
24921 Number of priority workers. If all workers from above pool are stuck,
24922 some calls marked as high priority (notably domainDestroy) can be
24923 executed in this pool.
24925 Defaults to @samp{5}.
24929 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
24930 Total global limit on concurrent RPC calls.
24932 Defaults to @samp{20}.
24936 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
24937 Limit on concurrent requests from a single client connection. To avoid
24938 one client monopolizing the server this should be a small fraction of
24939 the global max_requests and max_workers parameter.
24941 Defaults to @samp{5}.
24945 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
24946 Same as @code{min-workers} but for the admin interface.
24948 Defaults to @samp{1}.
24952 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
24953 Same as @code{max-workers} but for the admin interface.
24955 Defaults to @samp{5}.
24959 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
24960 Same as @code{max-clients} but for the admin interface.
24962 Defaults to @samp{5}.
24966 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
24967 Same as @code{max-queued-clients} but for the admin interface.
24969 Defaults to @samp{5}.
24973 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
24974 Same as @code{max-client-requests} but for the admin interface.
24976 Defaults to @samp{5}.
24980 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
24981 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
24983 Defaults to @samp{3}.
24987 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
24990 A filter allows to select a different logging level for a given category
24991 of logs The format for a filter is one of:
25002 where @code{name} is a string which is matched against the category
25003 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25004 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
25005 name in the filter can be a substring of the full category name, in
25006 order to match multiple similar categories), the optional @samp{"+"}
25007 prefix tells libvirt to log stack trace for each message matching name,
25008 and @code{x} is the minimal level where matching messages should be
25026 Multiple filters can be defined in a single filters statement, they just
25027 need to be separated by spaces.
25029 Defaults to @samp{"3:remote 4:event"}.
25033 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
25036 An output is one of the places to save logging information. The format
25037 for an output can be:
25041 output goes to stderr
25043 @item x:syslog:name
25044 use syslog for the output and use the given name as the ident
25046 @item x:file:file_path
25047 output to a file, with the given filepath
25050 output to journald logging system
25054 In all case the x prefix is the minimal level, acting as a filter
25071 Multiple outputs can be defined, they just need to be separated by
25074 Defaults to @samp{"3:stderr"}.
25078 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
25079 Allows usage of the auditing subsystem to be altered
25083 0: disable all auditing
25086 1: enable auditing, only if enabled on host
25089 2: enable auditing, and exit if disabled on host.
25093 Defaults to @samp{1}.
25097 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
25098 Send audit messages via libvirt logging infrastructure.
25100 Defaults to @samp{#f}.
25104 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
25105 Host UUID. UUID must not have all digits be the same.
25107 Defaults to @samp{""}.
25111 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
25112 Source to read host UUID.
25116 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
25119 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
25123 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
25126 Defaults to @samp{"smbios"}.
25130 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
25131 A keepalive message is sent to a client after @code{keepalive_interval}
25132 seconds of inactivity to check if the client is still responding. If
25133 set to -1, libvirtd will never send keepalive requests; however clients
25134 can still send them and the daemon will send responses.
25136 Defaults to @samp{5}.
25140 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
25141 Maximum number of keepalive messages that are allowed to be sent to the
25142 client without getting any response before the connection is considered
25145 In other words, the connection is automatically closed approximately
25146 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
25147 the last message received from the client. When @code{keepalive-count}
25148 is set to 0, connections will be automatically closed after
25149 @code{keepalive-interval} seconds of inactivity without sending any
25150 keepalive messages.
25152 Defaults to @samp{5}.
25156 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
25157 Same as above but for admin interface.
25159 Defaults to @samp{5}.
25163 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
25164 Same as above but for admin interface.
25166 Defaults to @samp{5}.
25170 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
25171 Timeout for Open vSwitch calls.
25173 The @code{ovs-vsctl} utility is used for the configuration and its
25174 timeout option is set by default to 5 seconds to avoid potential
25175 infinite waits blocking libvirt.
25177 Defaults to @samp{5}.
25181 @c %end of autogenerated docs
25183 @subsubheading Virtlog daemon
25184 The virtlogd service is a server side daemon component of libvirt that is
25185 used to manage logs from virtual machine consoles.
25187 This daemon is not used directly by libvirt client applications, rather it
25188 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
25189 standalone daemon, the main @code{libvirtd} daemon can be restarted without
25190 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
25191 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
25193 @deffn {Scheme Variable} virtlog-service-type
25194 This is the type of the virtlog daemon.
25195 Its value must be a @code{virtlog-configuration}.
25198 (service virtlog-service-type
25199 (virtlog-configuration
25200 (max-clients 1000)))
25204 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
25205 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
25207 Defaults to @samp{3}.
25211 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
25214 A filter allows to select a different logging level for a given category
25215 of logs The format for a filter is one of:
25226 where @code{name} is a string which is matched against the category
25227 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
25228 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
25229 be a substring of the full category name, in order to match multiple
25230 similar categories), the optional "+" prefix tells libvirt to log stack
25231 trace for each message matching name, and @code{x} is the minimal level
25232 where matching messages should be logged:
25249 Multiple filters can be defined in a single filters statement, they just
25250 need to be separated by spaces.
25252 Defaults to @samp{"3:remote 4:event"}.
25256 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
25259 An output is one of the places to save logging information The format
25260 for an output can be:
25264 output goes to stderr
25266 @item x:syslog:name
25267 use syslog for the output and use the given name as the ident
25269 @item x:file:file_path
25270 output to a file, with the given filepath
25273 output to journald logging system
25277 In all case the x prefix is the minimal level, acting as a filter
25294 Multiple outputs can be defined, they just need to be separated by
25297 Defaults to @samp{"3:stderr"}.
25301 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
25302 Maximum number of concurrent client connections to allow over all
25305 Defaults to @samp{1024}.
25309 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
25310 Maximum file size before rolling over.
25312 Defaults to @samp{2MB}
25316 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
25317 Maximum number of backup files to keep.
25319 Defaults to @samp{3}
25322 @node Transparent Emulation with QEMU
25323 @subsubheading Transparent Emulation with QEMU
25326 @cindex @code{binfmt_misc}
25327 @code{qemu-binfmt-service-type} provides support for transparent
25328 emulation of program binaries built for different architectures---e.g.,
25329 it allows you to transparently execute an ARMv7 program on an x86_64
25330 machine. It achieves this by combining the @uref{https://www.qemu.org,
25331 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
25333 @defvr {Scheme Variable} qemu-binfmt-service-type
25334 This is the type of the QEMU/binfmt service for transparent emulation.
25335 Its value must be a @code{qemu-binfmt-configuration} object, which
25336 specifies the QEMU package to use as well as the architecture we want to
25340 (service qemu-binfmt-service-type
25341 (qemu-binfmt-configuration
25342 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
25345 In this example, we enable transparent emulation for the ARM and aarch64
25346 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
25347 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
25348 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
25351 @deftp {Data Type} qemu-binfmt-configuration
25352 This is the configuration for the @code{qemu-binfmt} service.
25355 @item @code{platforms} (default: @code{'()})
25356 The list of emulated QEMU platforms. Each item must be a @dfn{platform
25357 object} as returned by @code{lookup-qemu-platforms} (see below).
25359 @item @code{guix-support?} (default: @code{#f})
25360 When it is true, QEMU and all its dependencies are added to the build
25361 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
25362 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
25363 handlers to be used within the build environment, which in turn means
25364 that you can transparently build programs for another architecture.
25366 For example, let's suppose you're on an x86_64 machine and you have this
25370 (service qemu-binfmt-service-type
25371 (qemu-binfmt-configuration
25372 (platforms (lookup-qemu-platforms "arm"))
25373 (guix-support? #t)))
25379 guix build -s armhf-linux inkscape
25383 and it will build Inkscape for ARMv7 @emph{as if it were a native
25384 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
25385 if you'd like to test a package build for an architecture you don't have
25388 @item @code{qemu} (default: @code{qemu})
25389 The QEMU package to use.
25393 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
25394 Return the list of QEMU platform objects corresponding to
25395 @var{platforms}@dots{}. @var{platforms} must be a list of strings
25396 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
25397 @code{"mips64el"}, and so on.
25400 @deffn {Scheme Procedure} qemu-platform? @var{obj}
25401 Return true if @var{obj} is a platform object.
25404 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
25405 Return the name of @var{platform}---a string such as @code{"arm"}.
25409 @subsubheading The Hurd in a Virtual Machine
25411 @cindex @code{hurd}
25415 Service @code{hurd-vm} provides support for running GNU/Hurd in a
25416 virtual machine (VM), a so-called ``Childhurd''. The virtual machine is
25417 a Shepherd service that can be referred to by the names @code{hurd-vm}
25418 and @code{childhurd} and be controlled with commands such as:
25422 herd stop childhurd
25425 The given GNU/Hurd operating system configuration is cross-compiled.
25427 @defvr {Scheme Variable} hurd-vm-service-type
25428 This is the type of the Hurd in a Virtual Machine service. Its value
25429 must be a @code{hurd-vm-configuration} object, which specifies the
25430 operating system (@pxref{operating-system Reference}) and the disk size
25431 for the Hurd Virtual Machine, the QEMU package to use as well as the
25432 options for running it.
25437 (service hurd-vm-service-type
25438 (hurd-vm-configuration
25439 (disk-size (* 5000 (expt 2 20))) ;5G
25440 (memory-size 1024))) ;1024MiB
25443 would create a disk image big enough to build GNU@tie{}Hello, with some
25447 @deftp {Data Type} hurd-vm-configuration
25448 The data type representing the configuration for
25449 @code{hurd-vm-service-type}.
25452 @item @code{os} (default: @var{%hurd-vm-operating-system})
25453 The operating system to instantiate. This default is bare-bones with a
25454 permissive OpenSSH secure shell daemon listening on port 2222
25455 (@pxref{Networking Services, @code{openssh-service-type}}).
25457 @item @code{qemu} (default: @code{qemu-minimal})
25458 The QEMU package to use.
25460 @item @code{image} (default: @var{hurd-vm-disk-image})
25461 The procedure used to build the disk-image built from this
25464 @item @code{disk-size} (default: @code{'guess})
25465 The size of the disk image.
25467 @item @code{memory-size} (default: @code{512})
25468 The memory size of the Virtual Machine in mebibytes.
25470 @item @code{options} (default: @code{'("--snapshot")})
25471 The extra options for running QEMU.
25473 @item @code{id} (default: @code{#f})
25474 If set, a non-zero positive integer used to parameterize Childhurd
25475 instances. It is appended to the service's name,
25476 e.g. @code{childhurd1}.
25478 @item @code{net-options} (default: @var{hurd-vm-net-options})
25479 The procedure used to produce the list of QEMU networking options.
25481 By default, it produces
25484 '("--device" "rtl8139,netdev=net0"
25485 "--netdev" "user,id=net0\
25486 ,hostfwd=tcp:127.0.0.1:<secrets-port>-:1004\
25487 ,hostfwd=tcp:127.0.0.1:<ssh-port>-:2222\
25488 ,hostfwd=tcp:127.0.0.1:<vnc-port>-:5900")
25490 with forwarded ports
25492 <ssh-port>: @code{(+ 11004 (* 1000 @var{ID}))}
25493 <ssh-port>: @code{(+ 10022 (* 1000 @var{ID}))}
25494 <vnc-port>: @code{(+ 15900 (* 1000 @var{ID}))}
25497 @item @code{secret-root} (default: @file{/etc/childhurd})
25498 The root directory with out-of-band secrets to be installed into the
25499 childhurd once it runs. Childhurds are volatile which means that on
25500 every startup, secrets such as the SSH host keys and Guix signing key
25503 If the @file{/etc/childhurd} directory does not exist, the
25504 @code{secret-service} running in the Childhurd will be sent an empty
25507 Typical use to populate @file{"/etc/childhurd"} with a tree of
25508 non-volatile secrets, like so
25511 /etc/childhurd/etc/guix/signing-key.pub
25512 /etc/childhurd/etc/guix/signing-key.sec
25513 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
25514 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
25515 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
25516 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
25519 to be sent to the Childhurd, including permissions.
25524 Note that by default the VM image is volatile, i.e., once stopped the
25525 contents are lost. If you want a stateful image instead, override the
25526 configuration's @code{image} and @code{options} without
25527 the @code{--snapshot} flag using something along these lines:
25530 (service hurd-vm-service-type
25531 (hurd-vm-configuration
25532 (image (const "/out/of/store/writable/hurd.img"))
25533 (options '("--hda"))))
25536 @subsubheading Ganeti
25541 This service is considered experimental. Configuration options may be changed
25542 in a backwards-incompatible manner, and not all features have been thorougly
25543 tested. Users of this service are encouraged to share their experience at
25544 @email{guix-devel@@gnu.org}.
25547 Ganeti is a virtual machine management system. It is designed to keep virtual
25548 machines running on a cluster of servers even in the event of hardware failures,
25549 and to make maintenance and recovery tasks easy. It consists of multiple
25550 services which are described later in this section. In addition to the Ganeti
25551 service, you will need the OpenSSH service (@pxref{Networking Services,
25552 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
25553 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
25554 and address (or use a DNS server).
25556 All nodes participating in a Ganeti cluster should have the same Ganeti and
25557 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
25558 cluster node that supports multiple storage backends, and installs the
25559 @code{debootstrap} and @code{guix} @dfn{OS providers}:
25562 (use-package-modules virtualization)
25563 (use-service-modules base ganeti networking ssh)
25566 (host-name "node1")
25567 (hosts-file (plain-file "hosts" (format #f "
25568 127.0.0.1 localhost
25571 192.168.1.200 ganeti.example.com
25572 192.168.1.201 node1.example.com node1
25573 192.168.1.202 node2.example.com node2
25576 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
25577 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
25578 (packages (append (map specification->package
25579 '("qemu" "lvm2" "drbd-utils" "ceph"
25580 ;; Add the debootstrap and guix OS providers.
25581 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
25584 (append (list (static-networking-service "eth0" "192.168.1.201"
25585 #:netmask "255.255.255.0"
25586 #:gateway "192.168.1.254"
25587 #:name-servers '("192.168.1.252"
25590 ;; Ganeti uses SSH to communicate between nodes.
25591 (service openssh-service-type
25592 (openssh-configuration
25593 (permit-root-login 'without-password)))
25595 (service ganeti-service-type
25596 (ganeti-configuration
25597 ;; This list specifies allowed file system paths
25598 ;; for storing virtual machine images.
25599 (file-storage-paths '("/srv/ganeti/file-storage"))
25600 ;; This variable configures a single "variant" for
25601 ;; both Debootstrap and Guix that works with KVM.
25602 (os %default-ganeti-os))))
25606 Users are advised to read the
25607 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
25608 administrators guide} to learn about the various cluster options and
25609 day-to-day operations. There is also a
25610 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
25611 describing how to configure and initialize a small cluster.
25613 @defvr {Scheme Variable} ganeti-service-type
25614 This is a service type that includes all the various services that Ganeti
25617 Its value is a @code{ganeti-configuration} object that defines the package
25618 to use for CLI operations, as well as configuration for the various daemons.
25619 Allowed file storage paths and available guest operating systems are also
25620 configured through this data type.
25623 @deftp {Data Type} ganeti-configuration
25624 The @code{ganeti} service takes the following configuration options:
25627 @item @code{ganeti} (default: @code{ganeti})
25628 The @code{ganeti} package to use. It will be installed to the system profile
25629 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
25630 that the value specified here does not affect the other services as each refer
25631 to a specific @code{ganeti} package (see below).
25633 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
25634 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
25635 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
25636 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
25637 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
25638 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
25639 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
25640 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
25641 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
25642 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
25644 These options control the various daemons and cron jobs that are distributed
25645 with Ganeti. The possible values for these are described in detail below.
25646 To override a setting, you must use the configuration type for that service:
25649 (service ganeti-service-type
25650 (ganeti-configuration
25651 (rapi-configuration
25652 (ganeti-rapi-configuration
25653 (interface "eth1"))))
25654 (watcher-configuration
25655 (ganeti-watcher-configuration
25656 (rapi-ip "10.0.0.1"))))
25659 @item @code{file-storage-paths} (default: @code{'()})
25660 List of allowed directories for file storage backend.
25662 @item @code{os} (default: @code{%default-ganeti-os})
25663 List of @code{<ganeti-os>} records.
25666 In essence @code{ganeti-service-type} is shorthand for declaring each service
25670 (service ganeti-noded-service-type)
25671 (service ganeti-confd-service-type)
25672 (service ganeti-wconfd-service-type)
25673 (service ganeti-luxid-service-type)
25674 (service ganeti-kvmd-service-type)
25675 (service ganeti-mond-service-type)
25676 (service ganeti-metad-service-type)
25677 (service ganeti-watcher-service-type)
25678 (service ganeti-cleaner-service-type)
25681 Plus a service extension for @code{etc-service-type} that configures the file
25682 storage backend and OS variants.
25686 @deftp {Data Type} ganeti-os
25687 This data type is suitable for passing to the @code{os} parameter of
25688 @code{ganeti-configuration}. It takes the following parameters:
25692 The name for this OS provider. It is only used to specify where the
25693 configuration ends up. Setting it to ``debootstrap'' will create
25694 @file{/etc/ganeti/instance-debootstrap}.
25696 @item @code{extension}
25697 The file extension for variants of this OS type. For example
25698 @file{.conf} or @file{.scm}.
25700 @item @code{variants} (default: @code{'()})
25701 List of @code{ganeti-os-variant} objects for this OS.
25706 @deftp {Data Type} ganeti-os-variant
25707 This is the data type for a Ganeti OS variant. It takes the following
25712 The name of this variant.
25714 @item @code{configuration}
25715 A configuration file for this variant.
25719 @defvr {Scheme Variable} %default-debootstrap-hooks
25720 This variable contains hooks to configure networking and the GRUB bootloader.
25723 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
25724 This variable contains a list of packages suitable for a fully-virtualized guest.
25727 @deftp {Data Type} debootstrap-configuration
25729 This data type creates configuration files suitable for the debootstrap OS provider.
25732 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
25733 When not @code{#f}, this must be a G-expression that specifies a directory with
25734 scripts that will run when the OS is installed. It can also be a list of
25735 @code{(name . file-like)} pairs. For example:
25738 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
25741 That will create a directory with one executable named @code{99-hello-world}
25742 and run it every time this variant is installed. If set to @code{#f}, hooks
25743 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
25744 @item @code{proxy} (default: @code{#f})
25745 Optional HTTP proxy to use.
25746 @item @code{mirror} (default: @code{#f})
25747 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
25748 The default varies depending on the distribution.
25749 @item @code{arch} (default: @code{#f})
25750 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
25751 on an AArch64 host. Default is to use the current system architecture.
25752 @item @code{suite} (default: @code{"stable"})
25753 When set, this must be a Debian distribution ``suite'' such as @code{buster}
25754 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
25755 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
25756 List of extra packages that will get installed by dpkg in addition
25757 to the minimal system.
25758 @item @code{components} (default: @code{#f})
25759 When set, must be a list of Debian repository ``components''. For example
25760 @code{'("main" "contrib")}.
25761 @item @code{generate-cache?} (default: @code{#t})
25762 Whether to automatically cache the generated debootstrap archive.
25763 @item @code{clean-cache} (default: @code{14})
25764 Discard the cache after this amount of days. Use @code{#f} to never
25766 @item @code{partition-style} (default: @code{'msdos})
25767 The type of partition to create. When set, it must be one of
25768 @code{'msdos}, @code{'none} or a string.
25769 @item @code{partition-alignment} (default: @code{2048})
25770 Alignment of the partition in sectors.
25774 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
25775 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
25776 takes two parameters: a name and a @code{debootstrap-configuration} object.
25779 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
25780 This is a helper procedure that creates a @code{ganeti-os} record. It takes
25781 a list of variants created with @code{debootstrap-variant}.
25784 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
25785 This is a helper procedure that creates a @code{ganeti-os-variant} record for
25786 use with the Guix OS provider. It takes a name and a G-expression that returns
25787 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
25788 Guix System configuration.
25791 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
25792 This is a helper procedure that creates a @code{ganeti-os} record. It
25793 takes a list of variants produced by @code{guix-variant}.
25796 @defvr {Scheme Variable} %default-debootstrap-variants
25797 This is a convenience variable to make the debootstrap provider work
25798 ``out of the box'' without users having to declare variants manually. It
25799 contains a single debootstrap variant with the default configuration:
25802 (list (debootstrap-variant
25804 (debootstrap-configuration)))
25808 @defvr {Scheme Variable} %default-guix-variants
25809 This is a convenience variable to make the Guix OS provider work without
25810 additional configuration. It creates a virtual machine that has an SSH
25811 server, a serial console, and authorizes the Ganeti hosts SSH keys.
25814 (list (guix-variant
25816 (file-append ganeti-instance-guix
25817 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
25821 Users can implement support for OS providers unbeknownst to Guix by extending
25822 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
25828 (extension ".conf")
25830 (list (ganeti-os-variant
25832 (configuration (plain-file "bar" "this is fine"))))))
25835 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
25836 to a file in the store with contents @code{this is fine}. It also creates
25837 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
25839 Obviously this may not work for all OS providers out there. If you find the
25840 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
25842 The rest of this section documents the various services that are included by
25843 @code{ganeti-service-type}.
25845 @defvr {Scheme Variable} ganeti-noded-service-type
25846 @command{ganeti-noded} is the daemon responsible for node-specific functions
25847 within the Ganeti system. The value of this service must be a
25848 @code{ganeti-noded-configuration} object.
25851 @deftp {Data Type} ganeti-noded-configuration
25852 This is the configuration for the @code{ganeti-noded} service.
25855 @item @code{ganeti} (default: @code{ganeti})
25856 The @code{ganeti} package to use for this service.
25858 @item @code{port} (default: @code{1811})
25859 The TCP port on which the node daemon listens for network requests.
25861 @item @code{address} (default: @code{"0.0.0.0"})
25862 The network address that the daemon will bind to. The default address means
25863 bind to all available addresses.
25865 @item @code{interface} (default: @code{#f})
25866 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
25867 that the daemon will bind to.
25869 @item @code{max-clients} (default: @code{20})
25870 This sets a limit on the maximum number of simultaneous client connections
25871 that the daemon will handle. Connections above this count are accepted, but
25872 no responses will be sent until enough connections have closed.
25874 @item @code{ssl?} (default: @code{#t})
25875 Whether to use SSL/TLS to encrypt network communications. The certificate
25876 is automatically provisioned by the cluster and can be rotated with
25877 @command{gnt-cluster renew-crypto}.
25879 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
25880 This can be used to provide a specific encryption key for TLS communications.
25882 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
25883 This can be used to provide a specific certificate for TLS communications.
25885 @item @code{debug?} (default: @code{#f})
25886 When true, the daemon performs additional logging for debugging purposes.
25887 Note that this will leak encryption details to the log files, use with caution.
25892 @defvr {Scheme Variable} ganeti-confd-service-type
25893 @command{ganeti-confd} answers queries related to the configuration of a
25894 Ganeti cluster. The purpose of this daemon is to have a highly available
25895 and fast way to query cluster configuration values. It is automatically
25896 active on all @dfn{master candidates}. The value of this service must be a
25897 @code{ganeti-confd-configuration} object.
25901 @deftp {Data Type} ganeti-confd-configuration
25902 This is the configuration for the @code{ganeti-confd} service.
25905 @item @code{ganeti} (default: @code{ganeti})
25906 The @code{ganeti} package to use for this service.
25908 @item @code{port} (default: @code{1814})
25909 The UDP port on which to listen for network requests.
25911 @item @code{address} (default: @code{"0.0.0.0"})
25912 Network address that the daemon will bind to.
25914 @item @code{debug?} (default: @code{#f})
25915 When true, the daemon performs additional logging for debugging purposes.
25920 @defvr {Scheme Variable} ganeti-wconfd-service-type
25921 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
25922 about the cluster configuration and is the only entity that can accept
25923 changes to it. All jobs that need to modify the configuration will do so
25924 by sending appropriate requests to this daemon. It only runs on the
25925 @dfn{master node} and will automatically disable itself on other nodes.
25927 The value of this service must be a
25928 @code{ganeti-wconfd-configuration} object.
25931 @deftp {Data Type} ganeti-wconfd-configuration
25932 This is the configuration for the @code{ganeti-wconfd} service.
25935 @item @code{ganeti} (default: @code{ganeti})
25936 The @code{ganeti} package to use for this service.
25938 @item @code{no-voting?} (default: @code{#f})
25939 The daemon will refuse to start if the majority of cluster nodes does not
25940 agree that it is running on the master node. Set to @code{#t} to start
25941 even if a quorum can not be reached (dangerous, use with caution).
25943 @item @code{debug?} (default: @code{#f})
25944 When true, the daemon performs additional logging for debugging purposes.
25949 @defvr {Scheme Variable} ganeti-luxid-service-type
25950 @command{ganeti-luxid} is a daemon used to answer queries related to the
25951 configuration and the current live state of a Ganeti cluster. Additionally,
25952 it is the authoritative daemon for the Ganeti job queue. Jobs can be
25953 submitted via this daemon and it schedules and starts them.
25955 It takes a @code{ganeti-luxid-configuration} object.
25958 @deftp {Data Type} ganeti-luxid-configuration
25959 This is the configuration for the @code{ganeti-wconfd} service.
25962 @item @code{ganeti} (default: @code{ganeti})
25963 The @code{ganeti} package to use for this service.
25965 @item @code{no-voting?} (default: @code{#f})
25966 The daemon will refuse to start if it cannot verify that the majority of
25967 cluster nodes believes that it is running on the master node. Set to
25968 @code{#t} to ignore such checks and start anyway (this can be dangerous).
25970 @item @code{debug?} (default: @code{#f})
25971 When true, the daemon performs additional logging for debugging purposes.
25976 @defvr {Scheme Variable} ganeti-rapi-service-type
25977 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
25978 the master node and can be used to perform cluster actions programmatically
25979 via a JSON-based RPC protocol.
25981 Most query operations are allowed without authentication (unless
25982 @var{require-authentication?} is set), whereas write operations require
25983 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
25984 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
25985 API documentation} for more information.
25987 The value of this service must be a @code{ganeti-rapi-configuration} object.
25990 @deftp {Data Type} ganeti-rapi-configuration
25991 This is the configuration for the @code{ganeti-rapi} service.
25994 @item @code{ganeti} (default: @code{ganeti})
25995 The @code{ganeti} package to use for this service.
25997 @item @code{require-authentication?} (default: @code{#f})
25998 Whether to require authentication even for read-only operations.
26000 @item @code{port} (default: @code{5080})
26001 The TCP port on which to listen to API requests.
26003 @item @code{address} (default: @code{"0.0.0.0"})
26004 The network address that the service will bind to. By default it listens
26005 on all configured addresses.
26007 @item @code{interface} (default: @code{#f})
26008 When set, it must specify a specific network interface such as @code{eth0}
26009 that the daemon will bind to.
26011 @item @code{max-clients} (default: @code{20})
26012 The maximum number of simultaneous client requests to handle. Further
26013 connections are allowed, but no responses are sent until enough connections
26016 @item @code{ssl?} (default: @code{#t})
26017 Whether to use SSL/TLS encryption on the RAPI port.
26019 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
26020 This can be used to provide a specific encryption key for TLS communications.
26022 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
26023 This can be used to provide a specific certificate for TLS communications.
26025 @item @code{debug?} (default: @code{#f})
26026 When true, the daemon performs additional logging for debugging purposes.
26027 Note that this will leak encryption details to the log files, use with caution.
26032 @defvr {Scheme Variable} ganeti-kvmd-service-type
26033 @command{ganeti-kvmd} is responsible for determining whether a given KVM
26034 instance was shut down by an administrator or a user. Normally Ganeti will
26035 restart an instance that was not stopped through Ganeti itself. If the
26036 cluster option @code{user_shutdown} is true, this daemon monitors the
26037 @code{QMP} socket provided by QEMU and listens for shutdown events, and
26038 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
26039 it shuts down gracefully by itself.
26041 It takes a @code{ganeti-kvmd-configuration} object.
26044 @deftp {Data Type} ganeti-kvmd-configuration
26047 @item @code{ganeti} (default: @code{ganeti})
26048 The @code{ganeti} package to use for this service.
26050 @item @code{debug?} (default: @code{#f})
26051 When true, the daemon performs additional logging for debugging purposes.
26056 @defvr {Scheme Variable} ganeti-mond-service-type
26057 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
26058 functionality. It is responsible for running data collectors and publish the
26059 collected information through a HTTP interface.
26061 It takes a @code{ganeti-mond-configuration} object.
26064 @deftp {Data Type} ganeti-mond-configuration
26067 @item @code{ganeti} (default: @code{ganeti})
26068 The @code{ganeti} package to use for this service.
26070 @item @code{port} (default: @code{1815})
26071 The port on which the daemon will listen.
26073 @item @code{address} (default: @code{"0.0.0.0"})
26074 The network address that the daemon will bind to. By default it binds to all
26075 available interfaces.
26077 @item @code{debug?} (default: @code{#f})
26078 When true, the daemon performs additional logging for debugging purposes.
26083 @defvr {Scheme Variable} ganeti-metad-service-type
26084 @command{ganeti-metad} is an optional daemon that can be used to provide
26085 information about the cluster to instances or OS install scripts.
26087 It takes a @code{ganeti-metad-configuration} object.
26090 @deftp {Data Type} ganeti-metad-configuration
26093 @item @code{ganeti} (default: @code{ganeti})
26094 The @code{ganeti} package to use for this service.
26096 @item @code{port} (default: @code{80})
26097 The port on which the daemon will listen.
26099 @item @code{address} (default: @code{#f})
26100 If set, the daemon will bind to this address only. If left unset, the behavior
26101 depends on the cluster configuration.
26103 @item @code{debug?} (default: @code{#f})
26104 When true, the daemon performs additional logging for debugging purposes.
26109 @defvr {Scheme Variable} ganeti-watcher-service-type
26110 @command{ganeti-watcher} is a script designed to run periodically and ensure
26111 the health of a cluster. It will automatically restart instances that have
26112 stopped without Ganetis consent, and repairs DRBD links in case a node has
26113 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
26114 that are not running. If the cluster parameter @code{ensure_node_health}
26115 is set, the watcher will also shutdown instances and DRBD devices if the
26116 node it is running on is declared offline by known master candidates.
26118 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
26120 The service takes a @code{ganeti-watcher-configuration} object.
26123 @deftp {Data Type} ganeti-watcher-configuration
26126 @item @code{ganeti} (default: @code{ganeti})
26127 The @code{ganeti} package to use for this service.
26129 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
26130 How often to run the script. The default is every five minutes.
26132 @item @code{rapi-ip} (default: @code{#f})
26133 This option needs to be specified only if the RAPI daemon is configured to use
26134 a particular interface or address. By default the cluster address is used.
26136 @item @code{job-age} (default: @code{(* 6 3600)})
26137 Archive cluster jobs older than this age, specified in seconds. The default
26138 is 6 hours. This keeps @command{gnt-job list} manageable.
26140 @item @code{verify-disks?} (default: @code{#t})
26141 If this is @code{#f}, the watcher will not try to repair broken DRBD links
26142 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
26145 @item @code{debug?} (default: @code{#f})
26146 When @code{#t}, the script performs additional logging for debugging purposes.
26151 @defvr {Scheme Variable} ganeti-cleaner-service-type
26152 @command{ganeti-cleaner} is a script designed to run periodically and remove
26153 old files from the cluster. This service type controls two @dfn{cron jobs}:
26154 one intended for the master node that permanently purges old cluster jobs,
26155 and one intended for every node that removes expired X509 certificates, keys,
26156 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
26157 it is safe to include even on non-master nodes as it will disable itself as
26160 It takes a @code{ganeti-cleaner-configuration} object.
26163 @deftp {Data Type} ganeti-cleaner-configuration
26166 @item @code{ganeti} (default: @code{ganeti})
26167 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
26169 @item @code{master-schedule} (default: @code{"45 1 * * *"})
26170 How often to run the master cleaning job. The default is once per day, at
26173 @item @code{node-schedule} (default: @code{"45 2 * * *"})
26174 How often to run the node cleaning job. The default is once per day, at
26180 @node Version Control Services
26181 @subsection Version Control Services
26183 The @code{(gnu services version-control)} module provides a service to
26184 allow remote access to local Git repositories. There are three options:
26185 the @code{git-daemon-service}, which provides access to repositories via
26186 the @code{git://} unsecured TCP-based protocol, extending the
26187 @code{nginx} web server to proxy some requests to
26188 @code{git-http-backend}, or providing a web interface with
26189 @code{cgit-service-type}.
26191 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
26193 Return a service that runs @command{git daemon}, a simple TCP server to
26194 expose repositories over the Git protocol for anonymous access.
26196 The optional @var{config} argument should be a
26197 @code{<git-daemon-configuration>} object, by default it allows read-only
26198 access to exported@footnote{By creating the magic file
26199 @file{git-daemon-export-ok} in the repository directory.} repositories under
26204 @deftp {Data Type} git-daemon-configuration
26205 Data type representing the configuration for @code{git-daemon-service}.
26208 @item @code{package} (default: @code{git})
26209 Package object of the Git distributed version control system.
26211 @item @code{export-all?} (default: @code{#f})
26212 Whether to allow access for all Git repositories, even if they do not
26213 have the @file{git-daemon-export-ok} file.
26215 @item @code{base-path} (default: @file{/srv/git})
26216 Whether to remap all the path requests as relative to the given path.
26217 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
26218 @samp{example.com}, then if you later try to pull
26219 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
26220 path as @file{/srv/git/hello.git}.
26222 @item @code{user-path} (default: @code{#f})
26223 Whether to allow @code{~user} notation to be used in requests. When
26224 specified with empty string, requests to
26225 @indicateurl{git://host/~alice/foo} is taken as a request to access
26226 @code{foo} repository in the home directory of user @code{alice}. If
26227 @code{(user-path "@var{path}")} is specified, the same request is taken
26228 as a request to access @file{@var{path}/foo} repository in the home
26229 directory of user @code{alice}.
26231 @item @code{listen} (default: @code{'()})
26232 Whether to listen on specific IP addresses or hostnames, defaults to
26235 @item @code{port} (default: @code{#f})
26236 Whether to listen on an alternative port, which defaults to 9418.
26238 @item @code{whitelist} (default: @code{'()})
26239 If not empty, only allow access to this list of directories.
26241 @item @code{extra-options} (default: @code{'()})
26242 Extra options will be passed to @command{git daemon}, please run
26243 @command{man git-daemon} for more information.
26248 The @code{git://} protocol lacks authentication. When you pull from a
26249 repository fetched via @code{git://}, you don't know whether the data you
26250 receive was modified or is even coming from the specified host, and your
26251 connection is subject to eavesdropping. It's better to use an authenticated
26252 and encrypted transport, such as @code{https}. Although Git allows you
26253 to serve repositories using unsophisticated file-based web servers,
26254 there is a faster protocol implemented by the @code{git-http-backend}
26255 program. This program is the back-end of a proper Git web service. It
26256 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
26257 on running the necessary @code{fcgiwrap} daemon.
26259 Guix has a separate configuration data type for serving Git repositories
26262 @deftp {Data Type} git-http-configuration
26263 Data type representing the configuration for a future
26264 @code{git-http-service-type}; can currently be used to configure Nginx
26265 trough @code{git-http-nginx-location-configuration}.
26268 @item @code{package} (default: @var{git})
26269 Package object of the Git distributed version control system.
26271 @item @code{git-root} (default: @file{/srv/git})
26272 Directory containing the Git repositories to expose to the world.
26274 @item @code{export-all?} (default: @code{#f})
26275 Whether to expose access for all Git repositories in @var{git-root},
26276 even if they do not have the @file{git-daemon-export-ok} file.
26278 @item @code{uri-path} (default: @samp{/git/})
26279 Path prefix for Git access. With the default @samp{/git/} prefix, this
26280 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
26281 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
26282 with this prefix are not passed on to this Git instance.
26284 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
26285 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
26290 There is no @code{git-http-service-type}, currently; instead you can
26291 create an @code{nginx-location-configuration} from a
26292 @code{git-http-configuration} and then add that location to a web
26295 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
26296 [config=(git-http-configuration)]
26297 Compute an @code{nginx-location-configuration} that corresponds to the
26298 given Git http configuration. An example nginx service definition to
26299 serve the default @file{/srv/git} over HTTPS might be:
26302 (service nginx-service-type
26303 (nginx-configuration
26306 (nginx-server-configuration
26307 (listen '("443 ssl"))
26308 (server-name "git.my-host.org")
26310 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
26311 (ssl-certificate-key
26312 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
26315 (git-http-nginx-location-configuration
26316 (git-http-configuration (uri-path "/"))))))))))
26319 This example assumes that you are using Let's Encrypt to get your TLS
26320 certificate. @xref{Certificate Services}. The default @code{certbot}
26321 service will redirect all HTTP traffic on @code{git.my-host.org} to
26322 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
26323 system services. @xref{Web Services}.
26326 @subsubheading Cgit Service
26328 @cindex Cgit service
26329 @cindex Git, web interface
26330 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
26331 repositories written in C.
26333 The following example will configure the service with default values.
26334 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
26337 (service cgit-service-type)
26340 The @code{file-object} type designates either a file-like object
26341 (@pxref{G-Expressions, file-like objects}) or a string.
26343 @c %start of fragment
26345 Available @code{cgit-configuration} fields are:
26347 @deftypevr {@code{cgit-configuration} parameter} package package
26352 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
26353 NGINX configuration.
26357 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
26358 Specifies a command which will be invoked to format the content of about
26359 pages (both top-level and for each repository).
26361 Defaults to @samp{""}.
26365 @deftypevr {@code{cgit-configuration} parameter} string agefile
26366 Specifies a path, relative to each repository path, which can be used to
26367 specify the date and time of the youngest commit in the repository.
26369 Defaults to @samp{""}.
26373 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
26374 Specifies a command that will be invoked for authenticating repository
26377 Defaults to @samp{""}.
26381 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
26382 Flag which, when set to @samp{age}, enables date ordering in the branch
26383 ref list, and when set @samp{name} enables ordering by branch name.
26385 Defaults to @samp{"name"}.
26389 @deftypevr {@code{cgit-configuration} parameter} string cache-root
26390 Path used to store the cgit cache entries.
26392 Defaults to @samp{"/var/cache/cgit"}.
26396 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
26397 Number which specifies the time-to-live, in minutes, for the cached
26398 version of repository pages accessed with a fixed SHA1.
26400 Defaults to @samp{-1}.
26404 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
26405 Number which specifies the time-to-live, in minutes, for the cached
26406 version of repository pages accessed without a fixed SHA1.
26408 Defaults to @samp{5}.
26412 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
26413 Number which specifies the time-to-live, in minutes, for the cached
26414 version of the repository summary page.
26416 Defaults to @samp{5}.
26420 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
26421 Number which specifies the time-to-live, in minutes, for the cached
26422 version of the repository index page.
26424 Defaults to @samp{5}.
26428 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
26429 Number which specifies the time-to-live, in minutes, for the result of
26430 scanning a path for Git repositories.
26432 Defaults to @samp{15}.
26436 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
26437 Number which specifies the time-to-live, in minutes, for the cached
26438 version of the repository about page.
26440 Defaults to @samp{15}.
26444 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
26445 Number which specifies the time-to-live, in minutes, for the cached
26446 version of snapshots.
26448 Defaults to @samp{5}.
26452 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
26453 The maximum number of entries in the cgit cache. When set to @samp{0},
26454 caching is disabled.
26456 Defaults to @samp{0}.
26460 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
26461 Sort items in the repo list case sensitively.
26463 Defaults to @samp{#t}.
26467 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
26468 List of common prefixes which, when combined with a repository URL,
26469 generates valid clone URLs for the repository.
26471 Defaults to @samp{()}.
26475 @deftypevr {@code{cgit-configuration} parameter} list clone-url
26476 List of @code{clone-url} templates.
26478 Defaults to @samp{()}.
26482 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
26483 Command which will be invoked to format commit messages.
26485 Defaults to @samp{""}.
26489 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
26490 Flag which, when set to @samp{date}, enables strict date ordering in the
26491 commit log, and when set to @samp{topo} enables strict topological
26494 Defaults to @samp{"git log"}.
26498 @deftypevr {@code{cgit-configuration} parameter} file-object css
26499 URL which specifies the css document to include in all cgit pages.
26501 Defaults to @samp{"/share/cgit/cgit.css"}.
26505 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
26506 Specifies a command which will be invoked to format names and email
26507 address of committers, authors, and taggers, as represented in various
26508 places throughout the cgit interface.
26510 Defaults to @samp{""}.
26514 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
26515 Flag which, when set to @samp{#t}, will make cgit generate a HTML
26516 fragment suitable for embedding in other HTML pages.
26518 Defaults to @samp{#f}.
26522 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
26523 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
26524 commit history graph to the left of the commit messages in the
26525 repository log page.
26527 Defaults to @samp{#f}.
26531 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
26532 Flag which, when set to @samp{#t}, allows all filter settings to be
26533 overridden in repository-specific cgitrc files.
26535 Defaults to @samp{#f}.
26539 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
26540 Flag which, when set to @samp{#t}, allows users to follow a file in the
26543 Defaults to @samp{#f}.
26547 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
26548 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
26551 Defaults to @samp{#t}.
26555 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
26556 Flag which, when set to @samp{#t}, will make cgit generate extra links
26557 "summary", "commit", "tree" for each repo in the repository index.
26559 Defaults to @samp{#f}.
26563 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
26564 Flag which, when set to @samp{#t}, will make cgit display the owner of
26565 each repo in the repository index.
26567 Defaults to @samp{#t}.
26571 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
26572 Flag which, when set to @samp{#t}, will make cgit print the number of
26573 modified files for each commit on the repository log page.
26575 Defaults to @samp{#f}.
26579 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
26580 Flag which, when set to @samp{#t}, will make cgit print the number of
26581 added and removed lines for each commit on the repository log page.
26583 Defaults to @samp{#f}.
26587 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
26588 Flag which, when set to @code{#t}, will make cgit display remote
26589 branches in the summary and refs views.
26591 Defaults to @samp{#f}.
26595 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
26596 Flag which, when set to @code{1}, will make cgit use the subject of the
26597 parent commit as link text when generating links to parent commits in
26600 Defaults to @samp{#f}.
26604 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
26605 Flag which, when set to @samp{#t}, will make cgit use the subject of the
26606 parent commit as link text when generating links to parent commits in
26609 Defaults to @samp{#f}.
26613 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
26614 Flag which, when set to @samp{#t}, will make cgit generate linenumber
26615 links for plaintext blobs printed in the tree view.
26617 Defaults to @samp{#t}.
26621 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
26622 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
26623 set any repo specific settings.
26625 Defaults to @samp{#f}.
26629 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
26630 URL used as link to a shortcut icon for cgit.
26632 Defaults to @samp{"/favicon.ico"}.
26636 @deftypevr {@code{cgit-configuration} parameter} string footer
26637 The content of the file specified with this option will be included
26638 verbatim at the bottom of all pages (i.e.@: it replaces the standard
26639 "generated by..."@: message).
26641 Defaults to @samp{""}.
26645 @deftypevr {@code{cgit-configuration} parameter} string head-include
26646 The content of the file specified with this option will be included
26647 verbatim in the HTML HEAD section on all pages.
26649 Defaults to @samp{""}.
26653 @deftypevr {@code{cgit-configuration} parameter} string header
26654 The content of the file specified with this option will be included
26655 verbatim at the top of all pages.
26657 Defaults to @samp{""}.
26661 @deftypevr {@code{cgit-configuration} parameter} file-object include
26662 Name of a configfile to include before the rest of the current config-
26665 Defaults to @samp{""}.
26669 @deftypevr {@code{cgit-configuration} parameter} string index-header
26670 The content of the file specified with this option will be included
26671 verbatim above the repository index.
26673 Defaults to @samp{""}.
26677 @deftypevr {@code{cgit-configuration} parameter} string index-info
26678 The content of the file specified with this option will be included
26679 verbatim below the heading on the repository index page.
26681 Defaults to @samp{""}.
26685 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
26686 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
26687 in the servers timezone.
26689 Defaults to @samp{#f}.
26693 @deftypevr {@code{cgit-configuration} parameter} file-object logo
26694 URL which specifies the source of an image which will be used as a logo
26697 Defaults to @samp{"/share/cgit/cgit.png"}.
26701 @deftypevr {@code{cgit-configuration} parameter} string logo-link
26702 URL loaded when clicking on the cgit logo image.
26704 Defaults to @samp{""}.
26708 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
26709 Command which will be invoked to format the Owner column of the main
26712 Defaults to @samp{""}.
26716 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
26717 Number of items to display in atom feeds view.
26719 Defaults to @samp{10}.
26723 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
26724 Number of entries to list per page in "log" view.
26726 Defaults to @samp{50}.
26730 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
26731 Number of commit message characters to display in "log" view.
26733 Defaults to @samp{80}.
26737 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
26738 Specifies the number of entries to list per page on the repository index
26741 Defaults to @samp{50}.
26745 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
26746 Specifies the maximum number of repo description characters to display
26747 on the repository index page.
26749 Defaults to @samp{80}.
26753 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
26754 Specifies the maximum size of a blob to display HTML for in KBytes.
26756 Defaults to @samp{0}.
26760 @deftypevr {@code{cgit-configuration} parameter} string max-stats
26761 Maximum statistics period. Valid values are @samp{week},@samp{month},
26762 @samp{quarter} and @samp{year}.
26764 Defaults to @samp{""}.
26768 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
26769 Mimetype for the specified filename extension.
26771 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
26772 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
26773 "image/png") (svg "image/svg+xml"))}.
26777 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
26778 Specifies the file to use for automatic mimetype lookup.
26780 Defaults to @samp{""}.
26784 @deftypevr {@code{cgit-configuration} parameter} string module-link
26785 Text which will be used as the formatstring for a hyperlink when a
26786 submodule is printed in a directory listing.
26788 Defaults to @samp{""}.
26792 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
26793 If set to the value @samp{#t} caching will be disabled.
26795 Defaults to @samp{#f}.
26799 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
26800 If set to @samp{#t} showing full author email addresses will be
26803 Defaults to @samp{#f}.
26807 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
26808 Flag which, when set to @samp{#t}, will make cgit omit the standard
26809 header on all pages.
26811 Defaults to @samp{#f}.
26815 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
26816 A list of subdirectories inside of @code{repository-directory}, relative
26817 to it, that should loaded as Git repositories. An empty list means that
26818 all subdirectories will be loaded.
26820 Defaults to @samp{()}.
26824 @deftypevr {@code{cgit-configuration} parameter} file-object readme
26825 Text which will be used as default value for @code{cgit-repo-readme}.
26827 Defaults to @samp{""}.
26831 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
26832 If set to @code{#t} and @code{repository-directory} is enabled, if any
26833 repositories are found with a suffix of @code{.git}, this suffix will be
26834 removed for the URL and name.
26836 Defaults to @samp{#f}.
26840 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
26841 Maximum number of files to consider when detecting renames.
26843 Defaults to @samp{-1}.
26847 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
26848 The way in which repositories in each section are sorted.
26850 Defaults to @samp{""}.
26854 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
26855 Text used as content for the @code{robots} meta-tag.
26857 Defaults to @samp{("noindex" "nofollow")}.
26861 @deftypevr {@code{cgit-configuration} parameter} string root-desc
26862 Text printed below the heading on the repository index page.
26864 Defaults to @samp{"a fast webinterface for the git dscm"}.
26868 @deftypevr {@code{cgit-configuration} parameter} string root-readme
26869 The content of the file specified with this option will be included
26870 verbatim below the ``about'' link on the repository index page.
26872 Defaults to @samp{""}.
26876 @deftypevr {@code{cgit-configuration} parameter} string root-title
26877 Text printed as heading on the repository index page.
26879 Defaults to @samp{""}.
26883 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
26884 If set to @samp{#t} and repository-directory is enabled,
26885 repository-directory will recurse into directories whose name starts
26886 with a period. Otherwise, repository-directory will stay away from such
26887 directories, considered as ``hidden''. Note that this does not apply to
26888 the @file{.git} directory in non-bare repos.
26890 Defaults to @samp{#f}.
26894 @deftypevr {@code{cgit-configuration} parameter} list snapshots
26895 Text which specifies the default set of snapshot formats that cgit
26896 generates links for.
26898 Defaults to @samp{()}.
26902 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
26903 Name of the directory to scan for repositories (represents
26906 Defaults to @samp{"/srv/git"}.
26910 @deftypevr {@code{cgit-configuration} parameter} string section
26911 The name of the current repository section - all repositories defined
26912 after this option will inherit the current section name.
26914 Defaults to @samp{""}.
26918 @deftypevr {@code{cgit-configuration} parameter} string section-sort
26919 Flag which, when set to @samp{1}, will sort the sections on the
26920 repository listing by name.
26922 Defaults to @samp{""}.
26926 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
26927 A number which, if defined prior to repository-directory, specifies how
26928 many path elements from each repo path to use as a default section name.
26930 Defaults to @samp{0}.
26934 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
26935 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
26938 Defaults to @samp{#f}.
26942 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
26943 Specifies a command which will be invoked to format plaintext blobs in
26946 Defaults to @samp{""}.
26950 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
26951 Specifies the number of branches to display in the repository ``summary''
26954 Defaults to @samp{10}.
26958 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
26959 Specifies the number of log entries to display in the repository
26962 Defaults to @samp{10}.
26966 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
26967 Specifies the number of tags to display in the repository ``summary''
26970 Defaults to @samp{10}.
26974 @deftypevr {@code{cgit-configuration} parameter} string strict-export
26975 Filename which, if specified, needs to be present within the repository
26976 for cgit to allow access to that repository.
26978 Defaults to @samp{""}.
26982 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
26983 URL which, if specified, will be used as root for all cgit links.
26985 Defaults to @samp{"/"}.
26989 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
26990 A list of @dfn{cgit-repo} records to use with config.
26992 Defaults to @samp{()}.
26994 Available @code{repository-cgit-configuration} fields are:
26996 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
26997 A mask of snapshot formats for this repo that cgit generates links for,
26998 restricted by the global @code{snapshots} setting.
27000 Defaults to @samp{()}.
27004 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
27005 Override the default @code{source-filter}.
27007 Defaults to @samp{""}.
27011 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
27012 The relative URL used to access the repository.
27014 Defaults to @samp{""}.
27018 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
27019 Override the default @code{about-filter}.
27021 Defaults to @samp{""}.
27025 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
27026 Flag which, when set to @samp{age}, enables date ordering in the branch
27027 ref list, and when set to @samp{name} enables ordering by branch name.
27029 Defaults to @samp{""}.
27033 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
27034 A list of URLs which can be used to clone repo.
27036 Defaults to @samp{()}.
27040 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
27041 Override the default @code{commit-filter}.
27043 Defaults to @samp{""}.
27047 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
27048 Flag which, when set to @samp{date}, enables strict date ordering in the
27049 commit log, and when set to @samp{topo} enables strict topological
27052 Defaults to @samp{""}.
27056 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
27057 The name of the default branch for this repository. If no such branch
27058 exists in the repository, the first branch name (when sorted) is used as
27059 default instead. By default branch pointed to by HEAD, or ``master'' if
27060 there is no suitable HEAD.
27062 Defaults to @samp{""}.
27066 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
27067 The value to show as repository description.
27069 Defaults to @samp{""}.
27073 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
27074 The value to show as repository homepage.
27076 Defaults to @samp{""}.
27080 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
27081 Override the default @code{email-filter}.
27083 Defaults to @samp{""}.
27087 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
27088 A flag which can be used to disable the global setting
27089 @code{enable-commit-graph?}.
27091 Defaults to @samp{disabled}.
27095 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
27096 A flag which can be used to disable the global setting
27097 @code{enable-log-filecount?}.
27099 Defaults to @samp{disabled}.
27103 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
27104 A flag which can be used to disable the global setting
27105 @code{enable-log-linecount?}.
27107 Defaults to @samp{disabled}.
27111 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
27112 Flag which, when set to @code{#t}, will make cgit display remote
27113 branches in the summary and refs views.
27115 Defaults to @samp{disabled}.
27119 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
27120 A flag which can be used to override the global setting
27121 @code{enable-subject-links?}.
27123 Defaults to @samp{disabled}.
27127 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
27128 A flag which can be used to override the global setting
27129 @code{enable-html-serving?}.
27131 Defaults to @samp{disabled}.
27135 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
27136 Flag which, when set to @code{#t}, hides the repository from the
27139 Defaults to @samp{#f}.
27143 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
27144 Flag which, when set to @samp{#t}, ignores the repository.
27146 Defaults to @samp{#f}.
27150 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
27151 URL which specifies the source of an image which will be used as a logo
27152 on this repo’s pages.
27154 Defaults to @samp{""}.
27158 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
27159 URL loaded when clicking on the cgit logo image.
27161 Defaults to @samp{""}.
27165 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
27166 Override the default @code{owner-filter}.
27168 Defaults to @samp{""}.
27172 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
27173 Text which will be used as the formatstring for a hyperlink when a
27174 submodule is printed in a directory listing. The arguments for the
27175 formatstring are the path and SHA1 of the submodule commit.
27177 Defaults to @samp{""}.
27181 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
27182 Text which will be used as the formatstring for a hyperlink when a
27183 submodule with the specified subdirectory path is printed in a directory
27186 Defaults to @samp{()}.
27190 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
27191 Override the default maximum statistics period.
27193 Defaults to @samp{""}.
27197 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
27198 The value to show as repository name.
27200 Defaults to @samp{""}.
27204 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
27205 A value used to identify the owner of the repository.
27207 Defaults to @samp{""}.
27211 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
27212 An absolute path to the repository directory.
27214 Defaults to @samp{""}.
27218 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
27219 A path (relative to repo) which specifies a file to include verbatim as
27220 the ``About'' page for this repo.
27222 Defaults to @samp{""}.
27226 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
27227 The name of the current repository section - all repositories defined
27228 after this option will inherit the current section name.
27230 Defaults to @samp{""}.
27234 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
27235 Extra options will be appended to cgitrc file.
27237 Defaults to @samp{()}.
27243 @deftypevr {@code{cgit-configuration} parameter} list extra-options
27244 Extra options will be appended to cgitrc file.
27246 Defaults to @samp{()}.
27251 @c %end of fragment
27253 However, it could be that you just want to get a @code{cgitrc} up and
27254 running. In that case, you can pass an @code{opaque-cgit-configuration}
27255 as a record to @code{cgit-service-type}. As its name indicates, an
27256 opaque configuration does not have easy reflective capabilities.
27258 Available @code{opaque-cgit-configuration} fields are:
27260 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
27264 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
27265 The contents of the @code{cgitrc}, as a string.
27268 For example, if your @code{cgitrc} is just the empty string, you
27269 could instantiate a cgit service like this:
27272 (service cgit-service-type
27273 (opaque-cgit-configuration
27277 @subsubheading Gitolite Service
27279 @cindex Gitolite service
27280 @cindex Git, hosting
27281 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
27282 repositories on a central server.
27284 Gitolite can handle multiple repositories and users, and supports flexible
27285 configuration of the permissions for the users on the repositories.
27287 The following example will configure Gitolite using the default @code{git}
27288 user, and the provided SSH public key.
27291 (service gitolite-service-type
27292 (gitolite-configuration
27293 (admin-pubkey (plain-file
27295 "ssh-rsa AAAA... guix@@example.com"))))
27298 Gitolite is configured through a special admin repository which you can clone,
27299 for example, if you setup Gitolite on @code{example.com}, you would run the
27300 following command to clone the admin repository.
27303 git clone git@@example.com:gitolite-admin
27306 When the Gitolite service is activated, the provided @code{admin-pubkey} will
27307 be inserted in to the @file{keydir} directory in the gitolite-admin
27308 repository. If this results in a change in the repository, it will be
27309 committed using the message ``gitolite setup by GNU Guix''.
27311 @deftp {Data Type} gitolite-configuration
27312 Data type representing the configuration for @code{gitolite-service-type}.
27315 @item @code{package} (default: @var{gitolite})
27316 Gitolite package to use.
27318 @item @code{user} (default: @var{git})
27319 User to use for Gitolite. This will be user that you use when accessing
27322 @item @code{group} (default: @var{git})
27323 Group to use for Gitolite.
27325 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
27326 Directory in which to store the Gitolite configuration and repositories.
27328 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
27329 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
27330 representing the configuration for Gitolite.
27332 @item @code{admin-pubkey} (default: @var{#f})
27333 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
27334 setup Gitolite. This will be inserted in to the @file{keydir} directory
27335 within the gitolite-admin repository.
27337 To specify the SSH key as a string, use the @code{plain-file} function.
27340 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
27346 @deftp {Data Type} gitolite-rc-file
27347 Data type representing the Gitolite RC file.
27350 @item @code{umask} (default: @code{#o0077})
27351 This controls the permissions Gitolite sets on the repositories and their
27354 A value like @code{#o0027} will give read access to the group used by Gitolite
27355 (by default: @code{git}). This is necessary when using Gitolite with software
27356 like cgit or gitweb.
27358 @item @code{git-config-keys} (default: @code{""})
27359 Gitolite allows you to set git config values using the @samp{config} keyword. This
27360 setting allows control over the config keys to accept.
27362 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
27363 Set the role names allowed to be used by users running the perms command.
27365 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
27366 This setting controls the commands and features to enable within Gitolite.
27372 @node Game Services
27373 @subsection Game Services
27375 @subsubheading The Battle for Wesnoth Service
27377 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
27378 based tactical strategy game, with several single player campaigns, and
27379 multiplayer games (both networked and local).
27381 @defvar {Scheme Variable} wesnothd-service-type
27382 Service type for the wesnothd service. Its value must be a
27383 @code{wesnothd-configuration} object. To run wesnothd in the default
27384 configuration, instantiate it as:
27387 (service wesnothd-service-type)
27391 @deftp {Data Type} wesnothd-configuration
27392 Data type representing the configuration of @command{wesnothd}.
27395 @item @code{package} (default: @code{wesnoth-server})
27396 The wesnoth server package to use.
27398 @item @code{port} (default: @code{15000})
27399 The port to bind the server to.
27404 @node PAM Mount Service
27405 @subsection PAM Mount Service
27408 The @code{(gnu services pam-mount)} module provides a service allowing
27409 users to mount volumes when they log in. It should be able to mount any
27410 volume format supported by the system.
27412 @defvar {Scheme Variable} pam-mount-service-type
27413 Service type for PAM Mount support.
27416 @deftp {Data Type} pam-mount-configuration
27417 Data type representing the configuration of PAM Mount.
27419 It takes the following parameters:
27423 The configuration rules that will be used to generate
27424 @file{/etc/security/pam_mount.conf.xml}.
27426 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
27427 Guile Reference Manual}), and the the default ones don't mount anything
27428 for anyone at login:
27431 `((debug (@@ (enable "0")))
27432 (mntoptions (@@ (allow ,(string-join
27433 '("nosuid" "nodev" "loop"
27434 "encryption" "fsck" "nonempty"
27435 "allow_root" "allow_other")
27437 (mntoptions (@@ (require "nosuid,nodev")))
27438 (logout (@@ (wait "0")
27442 (mkmountpoint (@@ (enable "1")
27446 Some @code{volume} elements must be added to automatically mount volumes
27447 at login. Here's an example allowing the user @code{alice} to mount her
27448 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
27449 the partition where he stores his data:
27452 (define pam-mount-rules
27453 `((debug (@@ (enable "0")))
27454 (volume (@@ (user "alice")
27457 (mountpoint "/home/alice")))
27458 (volume (@@ (user "bob")
27461 (mountpoint "/home/bob/data")
27462 (options "defaults,autodefrag,compress")))
27463 (mntoptions (@@ (allow ,(string-join
27464 '("nosuid" "nodev" "loop"
27465 "encryption" "fsck" "nonempty"
27466 "allow_root" "allow_other")
27468 (mntoptions (@@ (require "nosuid,nodev")))
27469 (logout (@@ (wait "0")
27473 (mkmountpoint (@@ (enable "1")
27474 (remove "true")))))
27476 (service pam-mount-service-type
27477 (pam-mount-configuration
27478 (rules pam-mount-rules)))
27481 The complete list of possible options can be found in the man page for
27482 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
27487 @node Guix Services
27488 @subsection Guix Services
27490 @subsubheading Guix Data Service
27491 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
27492 and provides data about GNU Guix. This includes information about
27493 packages, derivations and lint warnings.
27495 The data is stored in a PostgreSQL database, and available through a web
27498 @defvar {Scheme Variable} guix-data-service-type
27499 Service type for the Guix Data Service. Its value must be a
27500 @code{guix-data-service-configuration} object. The service optionally
27501 extends the getmail service, as the guix-commits mailing list is used to
27502 find out about changes in the Guix git repository.
27505 @deftp {Data Type} guix-data-service-configuration
27506 Data type representing the configuration of the Guix Data Service.
27509 @item @code{package} (default: @code{guix-data-service})
27510 The Guix Data Service package to use.
27512 @item @code{user} (default: @code{"guix-data-service"})
27513 The system user to run the service as.
27515 @item @code{group} (default: @code{"guix-data-service"})
27516 The system group to run the service as.
27518 @item @code{port} (default: @code{8765})
27519 The port to bind the web service to.
27521 @item @code{host} (default: @code{"127.0.0.1"})
27522 The host to bind the web service to.
27524 @item @code{getmail-idle-mailboxes} (default: @code{#f})
27525 If set, this is the list of mailboxes that the getmail service will be
27526 configured to listen to.
27528 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
27529 If set, this is the @code{getmail-retriever-configuration} object with
27530 which to configure getmail to fetch mail from the guix-commits mailing
27533 @item @code{extra-options} (default: @var{'()})
27534 Extra command line options for @code{guix-data-service}.
27536 @item @code{extra-process-jobs-options} (default: @var{'()})
27537 Extra command line options for @code{guix-data-service-process-jobs}.
27542 @node Linux Services
27543 @subsection Linux Services
27546 @cindex out of memory killer
27548 @cindex early out of memory daemon
27549 @subsubheading Early OOM Service
27551 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
27552 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
27553 space and provides a more responsive and configurable alternative to the
27554 in-kernel OOM killer. It is useful to prevent the system from becoming
27555 unresponsive when it runs out of memory.
27557 @deffn {Scheme Variable} earlyoom-service-type
27558 The service type for running @command{earlyoom}, the Early OOM daemon.
27559 Its value must be a @code{earlyoom-configuration} object, described
27560 below. The service can be instantiated in its default configuration
27564 (service earlyoom-service-type)
27568 @deftp {Data Type} earlyoom-configuration
27569 This is the configuration record for the @code{earlyoom-service-type}.
27572 @item @code{earlyoom} (default: @var{earlyoom})
27573 The Earlyoom package to use.
27575 @item @code{minimum-available-memory} (default: @code{10})
27576 The threshold for the minimum @emph{available} memory, in percentages.
27578 @item @code{minimum-free-swap} (default: @code{10})
27579 The threshold for the minimum free swap memory, in percentages.
27581 @item @code{prefer-regexp} (default: @code{#f})
27582 A regular expression (as a string) to match the names of the processes
27583 that should be preferably killed.
27585 @item @code{avoid-regexp} (default: @code{#f})
27586 A regular expression (as a string) to match the names of the processes
27587 that should @emph{not} be killed.
27589 @item @code{memory-report-interval} (default: @code{0})
27590 The interval in seconds at which a memory report is printed. It is
27591 disabled by default.
27593 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
27594 A boolean indicating whether the positive adjustments set in
27595 @file{/proc/*/oom_score_adj}.
27597 @item @code{show-debug-messages?} (default: @code{#f})
27598 A boolean indicating whether debug messages should be printed. The logs
27599 are saved at @file{/var/log/earlyoom.log}.
27601 @item @code{send-notification-command} (default: @code{#f})
27602 This can be used to provide a custom command used for sending
27608 @cindex kernel module loader
27609 @subsubheading Kernel Module Loader Service
27611 The kernel module loader service allows one to load loadable kernel
27612 modules at boot. This is especially useful for modules that don't
27613 autoload and need to be manually loaded, as it's the case with
27616 @deffn {Scheme Variable} kernel-module-loader-service-type
27617 The service type for loading loadable kernel modules at boot with
27618 @command{modprobe}. Its value must be a list of strings representing
27619 module names. For example loading the drivers provided by
27620 @code{ddcci-driver-linux}, in debugging mode by passing some module
27621 parameters, can be done as follow:
27624 (use-modules (gnu) (gnu services))
27625 (use-package-modules linux)
27626 (use-service-modules linux)
27628 (define ddcci-config
27629 (plain-file "ddcci.conf"
27630 "options ddcci dyndbg delay=120"))
27634 (services (cons* (service kernel-module-loader-service-type
27635 '("ddcci" "ddcci_backlight"))
27636 (simple-service 'ddcci-config etc-service-type
27637 (list `("modprobe.d/ddcci.conf"
27640 (kernel-loadable-modules (list ddcci-driver-linux)))
27645 @cindex compressed swap
27646 @cindex Compressed RAM-based block devices
27647 @subsubheading Zram Device Service
27649 The Zram device service provides a compressed swap device in system
27650 memory. The Linux Kernel documentation has more information about
27651 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
27654 @deffn {Scheme Variable} zram-device-service-type
27655 This service creates the zram block device, formats it as swap and
27656 enables it as a swap device. The service's value is a
27657 @code{zram-device-configuration} record.
27659 @deftp {Data Type} zram-device-configuration
27660 This is the data type representing the configuration for the zram-device
27664 @item @code{size} (default @var{"1G"})
27665 This is the amount of space you wish to provide for the zram device. It
27666 accepts a string and can be a number of bytes or use a suffix, eg.:
27667 @var{"512M"} or @var{1024000}.
27668 @item @code{compression-algorithm} (default @var{'lzo})
27669 This is the compression algorithm you wish to use. It is difficult to
27670 list all the possible compression options, but common ones supported by
27671 Guix's Linux Libre Kernel include @var{'lzo}, @var{'lz4} and @var{'zstd}.
27672 @item @code{memory-limit} (default @var{0})
27673 This is the maximum amount of memory which the zram device can use.
27674 Setting it to '0' disables the limit. While it is generally expected
27675 that compression will be 2:1, it is possible that uncompressable data
27676 can be written to swap and this is a method to limit how much memory can
27677 be used. It accepts a string and can be a number of bytes or use a
27678 suffix, eg.: @var{"2G"}.
27679 @item @code{priority} (default @var{-1})
27680 This is the priority of the swap device created from the zram device.
27681 @code{swapon} accepts values between -1 and 32767, with higher values
27682 indicating higher priority. Higher priority swap will generally be used
27689 @node Hurd Services
27690 @subsection Hurd Services
27692 @defvr {Scheme Variable} hurd-console-service-type
27693 This service starts the fancy @code{VGA} console client on the Hurd.
27695 The service's value is a @code{hurd-console-configuration} record.
27698 @deftp {Data Type} hurd-console-configuration
27699 This is the data type representing the configuration for the
27700 hurd-console-service.
27703 @item @code{hurd} (default: @var{hurd})
27704 The Hurd package to use.
27708 @defvr {Scheme Variable} hurd-getty-service-type
27709 This service starts a tty using the Hurd @code{getty} program.
27711 The service's value is a @code{hurd-getty-configuration} record.
27714 @deftp {Data Type} hurd-getty-configuration
27715 This is the data type representing the configuration for the
27716 hurd-getty-service.
27719 @item @code{hurd} (default: @var{hurd})
27720 The Hurd package to use.
27723 The name of the console this Getty runs on---e.g., @code{"tty1"}.
27725 @item @code{baud-rate} (default: @code{38400})
27726 An integer specifying the baud rate of the tty.
27731 @node Miscellaneous Services
27732 @subsection Miscellaneous Services
27734 @cindex fingerprint
27735 @subsubheading Fingerprint Service
27737 The @code{(gnu services authentication)} module provides a DBus service to
27738 read and identify fingerprints via a fingerprint sensor.
27740 @defvr {Scheme Variable} fprintd-service-type
27741 The service type for @command{fprintd}, which provides the fingerprint
27742 reading capability.
27745 (service fprintd-service-type)
27750 @subsubheading System Control Service
27752 The @code{(gnu services sysctl)} provides a service to configure kernel
27753 parameters at boot.
27755 @defvr {Scheme Variable} sysctl-service-type
27756 The service type for @command{sysctl}, which modifies kernel parameters
27757 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
27761 (service sysctl-service-type
27762 (sysctl-configuration
27763 (settings '(("net.ipv4.ip_forward" . "1")))))
27767 @deftp {Data Type} sysctl-configuration
27768 The data type representing the configuration of @command{sysctl}.
27771 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
27772 The @command{sysctl} executable to use.
27774 @item @code{settings} (default: @code{'()})
27775 An association list specifies kernel parameters and their values.
27780 @subsubheading PC/SC Smart Card Daemon Service
27782 The @code{(gnu services security-token)} module provides the following service
27783 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
27784 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
27785 manager that coordinates communications with smart card readers, smart cards
27786 and cryptographic tokens that are connected to the system.
27788 @defvr {Scheme Variable} pcscd-service-type
27789 Service type for the @command{pcscd} service. Its value must be a
27790 @code{pcscd-configuration} object. To run pcscd in the default
27791 configuration, instantiate it as:
27794 (service pcscd-service-type)
27798 @deftp {Data Type} pcscd-configuration
27799 The data type representing the configuration of @command{pcscd}.
27802 @item @code{pcsc-lite} (default: @code{pcsc-lite})
27803 The pcsc-lite package that provides pcscd.
27804 @item @code{usb-drivers} (default: @code{(list ccid)})
27805 List of packages that provide USB drivers to pcscd. Drivers are expected to be
27806 under @file{pcsc/drivers} in the store directory of the package.
27811 @subsubheading Lirc Service
27813 The @code{(gnu services lirc)} module provides the following service.
27815 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
27816 [#:device #f] [#:driver #f] [#:config-file #f] @
27817 [#:extra-options '()]
27818 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
27819 decodes infrared signals from remote controls.
27821 Optionally, @var{device}, @var{driver} and @var{config-file}
27822 (configuration file name) may be specified. See @command{lircd} manual
27825 Finally, @var{extra-options} is a list of additional command-line options
27826 passed to @command{lircd}.
27830 @subsubheading Spice Service
27832 The @code{(gnu services spice)} module provides the following service.
27834 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
27835 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
27836 that enables sharing the clipboard with a vm and setting the guest display
27837 resolution when the graphical console window resizes.
27840 @cindex inputattach
27841 @subsubheading inputattach Service
27843 @cindex tablet input, for Xorg
27844 @cindex touchscreen input, for Xorg
27845 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
27846 use input devices such as Wacom tablets, touchscreens, or joysticks with the
27847 Xorg display server.
27849 @deffn {Scheme Variable} inputattach-service-type
27850 Type of a service that runs @command{inputattach} on a device and
27851 dispatches events from it.
27854 @deftp {Data Type} inputattach-configuration
27856 @item @code{device-type} (default: @code{"wacom"})
27857 The type of device to connect to. Run @command{inputattach --help}, from the
27858 @code{inputattach} package, to see the list of supported device types.
27860 @item @code{device} (default: @code{"/dev/ttyS0"})
27861 The device file to connect to the device.
27863 @item @code{baud-rate} (default: @code{#f})
27864 Baud rate to use for the serial connection.
27865 Should be a number or @code{#f}.
27867 @item @code{log-file} (default: @code{#f})
27868 If true, this must be the name of a file to log messages to.
27872 @subsubheading Dictionary Service
27874 The @code{(gnu services dict)} module provides the following service:
27876 @defvr {Scheme Variable} dicod-service-type
27877 This is the type of the service that runs the @command{dicod} daemon, an
27878 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27881 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
27882 Return a service that runs the @command{dicod} daemon, an implementation
27883 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
27885 The optional @var{config} argument specifies the configuration for
27886 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
27887 default it serves the GNU Collaborative International Dictionary of English.
27889 You can add @command{open localhost} to your @file{~/.dico} file to make
27890 @code{localhost} the default server for @command{dico} client
27891 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
27894 @deftp {Data Type} dicod-configuration
27895 Data type representing the configuration of dicod.
27898 @item @code{dico} (default: @var{dico})
27899 Package object of the GNU Dico dictionary server.
27901 @item @code{interfaces} (default: @var{'("localhost")})
27902 This is the list of IP addresses and ports and possibly socket file
27903 names to listen to (@pxref{Server Settings, @code{listen} directive,,
27904 dico, GNU Dico Manual}).
27906 @item @code{handlers} (default: @var{'()})
27907 List of @code{<dicod-handler>} objects denoting handlers (module instances).
27909 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
27910 List of @code{<dicod-database>} objects denoting dictionaries to be served.
27914 @deftp {Data Type} dicod-handler
27915 Data type representing a dictionary handler (module instance).
27919 Name of the handler (module instance).
27921 @item @code{module} (default: @var{#f})
27922 Name of the dicod module of the handler (instance). If it is @code{#f},
27923 the module has the same name as the handler.
27924 (@pxref{Modules,,, dico, GNU Dico Manual}).
27926 @item @code{options}
27927 List of strings or gexps representing the arguments for the module handler
27931 @deftp {Data Type} dicod-database
27932 Data type representing a dictionary database.
27936 Name of the database, will be used in DICT commands.
27938 @item @code{handler}
27939 Name of the dicod handler (module instance) used by this database
27940 (@pxref{Handlers,,, dico, GNU Dico Manual}).
27942 @item @code{complex?} (default: @var{#f})
27943 Whether the database configuration complex. The complex configuration
27944 will need a corresponding @code{<dicod-handler>} object, otherwise not.
27946 @item @code{options}
27947 List of strings or gexps representing the arguments for the database
27948 (@pxref{Databases,,, dico, GNU Dico Manual}).
27952 @defvr {Scheme Variable} %dicod-database:gcide
27953 A @code{<dicod-database>} object serving the GNU Collaborative International
27954 Dictionary of English using the @code{gcide} package.
27957 The following is an example @code{dicod-service} configuration.
27960 (dicod-service #:config
27961 (dicod-configuration
27962 (handlers (list (dicod-handler
27966 (list #~(string-append "dbdir=" #$wordnet))))))
27967 (databases (list (dicod-database
27970 (handler "wordnet")
27971 (options '("database=wn")))
27972 %dicod-database:gcide))))
27976 @subsubheading Docker Service
27978 The @code{(gnu services docker)} module provides the following services.
27980 @defvr {Scheme Variable} docker-service-type
27982 This is the type of the service that runs @url{https://www.docker.com,Docker},
27983 a daemon that can execute application bundles (sometimes referred to as
27984 ``containers'') in isolated environments.
27988 @deftp {Data Type} docker-configuration
27989 This is the data type representing the configuration of Docker and Containerd.
27993 @item @code{package} (default: @code{docker})
27994 The Docker daemon package to use.
27996 @item @code{package} (default: @code{docker-cli})
27997 The Docker client package to use.
27999 @item @code{containerd} (default: @var{containerd})
28000 The Containerd package to use.
28002 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
28003 The Docker user-land networking proxy package to use.
28005 @item @code{enable-proxy?} (default @code{#t})
28006 Enable or disable the use of the Docker user-land networking proxy.
28008 @item @code{debug?} (default @code{#f})
28009 Enable or disable debug output.
28011 @item @code{enable-iptables?} (default @code{#t})
28012 Enable or disable the addition of iptables rules.
28018 @subsubheading Auditd Service
28020 The @code{(gnu services auditd)} module provides the following service.
28022 @defvr {Scheme Variable} auditd-service-type
28024 This is the type of the service that runs
28025 @url{https://people.redhat.com/sgrubb/audit/,auditd},
28026 a daemon that tracks security-relevant information on your system.
28028 Examples of things that can be tracked:
28038 Failed login attempts
28045 @command{auditctl} from the @code{audit} package can be used in order
28046 to add or remove events to be tracked (until the next reboot).
28047 In order to permanently track events, put the command line arguments
28048 of auditctl into a file called @code{audit.rules} in the configuration
28049 directory (see below).
28050 @command{aureport} from the @code{audit} package can be used in order
28051 to view a report of all recorded events.
28052 The audit daemon by default logs into the file
28053 @file{/var/log/audit.log}.
28057 @deftp {Data Type} auditd-configuration
28058 This is the data type representing the configuration of auditd.
28062 @item @code{audit} (default: @code{audit})
28063 The audit package to use.
28065 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
28066 The directory containing the configuration file for the audit package, which
28067 must be named @code{auditd.conf}, and optionally some audit rules to
28068 instantiate on startup.
28073 @defvr {Scheme Variable} singularity-service-type
28074 This is the type of the service that allows you to run
28075 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
28076 create and run application bundles (aka. ``containers''). The value for this
28077 service is the Singularity package to use.
28079 The service does not install a daemon; instead, it installs helper programs as
28080 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
28081 @command{singularity run} and similar commands.
28085 @subsubheading R-Shiny service
28087 The @code{(gnu services science)} module provides the following service.
28089 @defvr {Scheme Variable} rshiny-service-type
28091 This is a type of service which is used to run a webapp created with
28092 @code{r-shiny}. This service sets the @code{R_LIBS_USER} environment
28093 variable and runs the provided script to call @code{runApp}.
28095 @deftp {Data Type} rshiny-configuration
28096 This is the data type representing the configuration of rshiny.
28100 @item @code{package} (default: @code{r-shiny})
28101 The package to use.
28103 @item @code{binary} (defaunlt @code{"rshiny"})
28104 The name of the binary or shell script located at @code{package/bin/} to
28105 run when the service is run.
28107 The common way to create this file is as follows:
28111 (let* ((out (assoc-ref %outputs "out"))
28112 (targetdir (string-append out "/share/" ,name))
28113 (app (string-append out "/bin/" ,name))
28114 (Rbin (string-append (assoc-ref %build-inputs "r-min")
28117 (mkdir-p (string-append out "/bin"))
28118 (call-with-output-file app
28124 runApp(launch.browser=0, port=4202)~%\n"
28133 @subsubheading Nix service
28135 The @code{(gnu services nix)} module provides the following service.
28137 @defvr {Scheme Variable} nix-service-type
28139 This is the type of the service that runs build daemon of the
28140 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
28144 (use-modules (gnu))
28145 (use-service-modules nix)
28146 (use-package-modules package-management)
28150 (packages (append (list nix)
28153 (services (append (list (service nix-service-type))
28157 After @command{guix system reconfigure} configure Nix for your user:
28160 @item Add a Nix channel and update it. See
28161 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
28163 @item Create a symlink to your profile and activate Nix profile:
28167 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
28168 $ source /run/current-system/profile/etc/profile.d/nix.sh
28173 @deftp {Data Type} nix-configuration
28174 This data type represents the configuration of the Nix daemon.
28177 @item @code{nix} (default: @code{nix})
28178 The Nix package to use.
28180 @item @code{sandbox} (default: @code{#t})
28181 Specifies whether builds are sandboxed by default.
28183 @item @code{build-sandbox-items} (default: @code{'()})
28184 This is a list of strings or objects appended to the
28185 @code{build-sandbox-items} field of the configuration file.
28187 @item @code{extra-config} (default: @code{'()})
28188 This is a list of strings or objects appended to the configuration file.
28189 It is used to pass extra text to be added verbatim to the configuration
28192 @item @code{extra-options} (default: @code{'()})
28193 Extra command line options for @code{nix-service-type}.
28197 @node Setuid Programs
28198 @section Setuid Programs
28200 @cindex setuid programs
28201 Some programs need to run with ``root'' privileges, even when they are
28202 launched by unprivileged users. A notorious example is the
28203 @command{passwd} program, which users can run to change their
28204 password, and which needs to access the @file{/etc/passwd} and
28205 @file{/etc/shadow} files---something normally restricted to root, for
28206 obvious security reasons. To address that, these executables are
28207 @dfn{setuid-root}, meaning that they always run with root privileges
28208 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
28209 for more info about the setuid mechanism).
28211 The store itself @emph{cannot} contain setuid programs: that would be a
28212 security issue since any user on the system can write derivations that
28213 populate the store (@pxref{The Store}). Thus, a different mechanism is
28214 used: instead of changing the setuid bit directly on files that are in
28215 the store, we let the system administrator @emph{declare} which programs
28216 should be setuid root.
28218 The @code{setuid-programs} field of an @code{operating-system}
28219 declaration contains a list of G-expressions denoting the names of
28220 programs to be setuid-root (@pxref{Using the Configuration System}).
28221 For instance, the @command{passwd} program, which is part of the Shadow
28222 package, can be designated by this G-expression (@pxref{G-Expressions}):
28225 #~(string-append #$shadow "/bin/passwd")
28228 A default set of setuid programs is defined by the
28229 @code{%setuid-programs} variable of the @code{(gnu system)} module.
28231 @defvr {Scheme Variable} %setuid-programs
28232 A list of G-expressions denoting common programs that are setuid-root.
28234 The list includes commands such as @command{passwd}, @command{ping},
28235 @command{su}, and @command{sudo}.
28238 Under the hood, the actual setuid programs are created in the
28239 @file{/run/setuid-programs} directory at system activation time. The
28240 files in this directory refer to the ``real'' binaries, which are in the
28243 @node X.509 Certificates
28244 @section X.509 Certificates
28246 @cindex HTTPS, certificates
28247 @cindex X.509 certificates
28249 Web servers available over HTTPS (that is, HTTP over the transport-layer
28250 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
28251 that the client can then use to @emph{authenticate} the server. To do
28252 that, clients verify that the server's certificate is signed by a
28253 so-called @dfn{certificate authority} (CA). But to verify the CA's
28254 signature, clients must have first acquired the CA's certificate.
28256 Web browsers such as GNU@tie{}IceCat include their own set of CA
28257 certificates, such that they are able to verify CA signatures
28260 However, most other programs that can talk HTTPS---@command{wget},
28261 @command{git}, @command{w3m}, etc.---need to be told where CA
28262 certificates can be found.
28264 @cindex @code{nss-certs}
28265 In Guix, this is done by adding a package that provides certificates
28266 to the @code{packages} field of the @code{operating-system} declaration
28267 (@pxref{operating-system Reference}). Guix includes one such package,
28268 @code{nss-certs}, which is a set of CA certificates provided as part of
28269 Mozilla's Network Security Services.
28271 Note that it is @emph{not} part of @code{%base-packages}, so you need to
28272 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
28273 most applications and libraries look for certificates by default, points
28274 to the certificates installed globally.
28276 Unprivileged users, including users of Guix on a foreign distro,
28277 can also install their own certificate package in
28278 their profile. A number of environment variables need to be defined so
28279 that applications and libraries know where to find them. Namely, the
28280 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
28281 variables. Some applications add their own environment variables; for
28282 instance, the Git version control system honors the certificate bundle
28283 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
28284 would typically run something like:
28287 guix install nss-certs
28288 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
28289 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28290 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
28293 As another example, R requires the @env{CURL_CA_BUNDLE} environment
28294 variable to point to a certificate bundle, so you would have to run
28295 something like this:
28298 guix install nss-certs
28299 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
28302 For other applications you may want to look up the required environment
28303 variable in the relevant documentation.
28306 @node Name Service Switch
28307 @section Name Service Switch
28309 @cindex name service switch
28311 The @code{(gnu system nss)} module provides bindings to the
28312 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
28313 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
28314 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
28315 extended with new ``name'' lookup methods for system databases, which
28316 includes host names, service names, user accounts, and more (@pxref{Name
28317 Service Switch, System Databases and Name Service Switch,, libc, The GNU
28318 C Library Reference Manual}).
28320 The NSS configuration specifies, for each system database, which lookup
28321 method is to be used, and how the various methods are chained
28322 together---for instance, under which circumstances NSS should try the
28323 next method in the list. The NSS configuration is given in the
28324 @code{name-service-switch} field of @code{operating-system} declarations
28325 (@pxref{operating-system Reference, @code{name-service-switch}}).
28328 @cindex .local, host name lookup
28329 As an example, the declaration below configures the NSS to use the
28330 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
28331 back-end}, which supports host name lookups over multicast DNS (mDNS)
28332 for host names ending in @code{.local}:
28335 (name-service-switch
28336 (hosts (list %files ;first, check /etc/hosts
28338 ;; If the above did not succeed, try
28339 ;; with 'mdns_minimal'.
28341 (name "mdns_minimal")
28343 ;; 'mdns_minimal' is authoritative for
28344 ;; '.local'. When it returns "not found",
28345 ;; no need to try the next methods.
28346 (reaction (lookup-specification
28347 (not-found => return))))
28349 ;; Then fall back to DNS.
28353 ;; Finally, try with the "full" 'mdns'.
28358 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
28359 contains this configuration, so you will not have to type it if all you
28360 want is to have @code{.local} host lookup working.
28362 Note that, in this case, in addition to setting the
28363 @code{name-service-switch} of the @code{operating-system} declaration,
28364 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
28365 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
28366 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
28367 to the name service cache daemon (@pxref{Base Services,
28368 @code{nscd-service}}).
28370 For convenience, the following variables provide typical NSS
28373 @defvr {Scheme Variable} %default-nss
28374 This is the default name service switch configuration, a
28375 @code{name-service-switch} object.
28378 @defvr {Scheme Variable} %mdns-host-lookup-nss
28379 This is the name service switch configuration with support for host name
28380 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
28383 The reference for name service switch configuration is given below. It
28384 is a direct mapping of the configuration file format of the C library , so
28385 please refer to the C library manual for more information (@pxref{NSS
28386 Configuration File,,, libc, The GNU C Library Reference Manual}).
28387 Compared to the configuration file format of libc NSS, it has the advantage
28388 not only of adding this warm parenthetic feel that we like, but also
28389 static checks: you will know about syntax errors and typos as soon as you
28390 run @command{guix system}.
28392 @deftp {Data Type} name-service-switch
28394 This is the data type representation the configuration of libc's name
28395 service switch (NSS). Each field below represents one of the supported
28412 The system databases handled by the NSS. Each of these fields must be a
28413 list of @code{<name-service>} objects (see below).
28417 @deftp {Data Type} name-service
28419 This is the data type representing an actual name service and the
28420 associated lookup action.
28424 A string denoting the name service (@pxref{Services in the NSS
28425 configuration,,, libc, The GNU C Library Reference Manual}).
28427 Note that name services listed here must be visible to nscd. This is
28428 achieved by passing the @code{#:name-services} argument to
28429 @code{nscd-service} the list of packages providing the needed name
28430 services (@pxref{Base Services, @code{nscd-service}}).
28433 An action specified using the @code{lookup-specification} macro
28434 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
28435 Reference Manual}). For example:
28438 (lookup-specification (unavailable => continue)
28439 (success => return))
28444 @node Initial RAM Disk
28445 @section Initial RAM Disk
28448 @cindex initial RAM disk
28449 For bootstrapping purposes, the Linux-Libre kernel is passed an
28450 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
28451 root file system as well as an initialization script. The latter is
28452 responsible for mounting the real root file system, and for loading any
28453 kernel modules that may be needed to achieve that.
28455 The @code{initrd-modules} field of an @code{operating-system}
28456 declaration allows you to specify Linux-libre kernel modules that must
28457 be available in the initrd. In particular, this is where you would list
28458 modules needed to actually drive the hard disk where your root partition
28459 is---although the default value of @code{initrd-modules} should cover
28460 most use cases. For example, assuming you need the @code{megaraid_sas}
28461 module in addition to the default modules to be able to access your root
28462 file system, you would write:
28467 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
28470 @defvr {Scheme Variable} %base-initrd-modules
28471 This is the list of kernel modules included in the initrd by default.
28474 Furthermore, if you need lower-level customization, the @code{initrd}
28475 field of an @code{operating-system} declaration allows
28476 you to specify which initrd you would like to use. The @code{(gnu
28477 system linux-initrd)} module provides three ways to build an initrd: the
28478 high-level @code{base-initrd} procedure and the low-level
28479 @code{raw-initrd} and @code{expression->initrd} procedures.
28481 The @code{base-initrd} procedure is intended to cover most common uses.
28482 For example, if you want to add a bunch of kernel modules to be loaded
28483 at boot time, you can define the @code{initrd} field of the operating
28484 system declaration like this:
28487 (initrd (lambda (file-systems . rest)
28488 ;; Create a standard initrd but set up networking
28489 ;; with the parameters QEMU expects by default.
28490 (apply base-initrd file-systems
28491 #:qemu-networking? #t
28495 The @code{base-initrd} procedure also handles common use cases that
28496 involves using the system as a QEMU guest, or as a ``live'' system with
28497 volatile root file system.
28499 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
28500 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
28501 such as trying to guess which kernel modules and packages should be included
28502 to the initrd. An example use of @code{raw-initrd} is when a user has
28503 a custom Linux kernel configuration and default kernel modules included by
28504 @code{base-initrd} are not available.
28506 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
28507 honors several options passed on the Linux kernel command line
28508 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
28509 @code{-append} option of QEMU), notably:
28512 @item --load=@var{boot}
28513 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
28514 program, once it has mounted the root file system.
28516 Guix uses this option to yield control to a boot program that runs the
28517 service activation programs and then spawns the GNU@tie{}Shepherd, the
28518 initialization system.
28520 @item --root=@var{root}
28521 Mount @var{root} as the root file system. @var{root} can be a device
28522 name like @code{/dev/sda1}, a file system label, or a file system UUID.
28523 When unspecified, the device name from the root file system of the
28524 operating system declaration is used.
28526 @item --system=@var{system}
28527 Have @file{/run/booted-system} and @file{/run/current-system} point to
28530 @item modprobe.blacklist=@var{modules}@dots{}
28531 @cindex module, black-listing
28532 @cindex black list, of kernel modules
28533 Instruct the initial RAM disk as well as the @command{modprobe} command
28534 (from the kmod package) to refuse to load @var{modules}. @var{modules}
28535 must be a comma-separated list of module names---e.g.,
28536 @code{usbkbd,9pnet}.
28539 Start a read-eval-print loop (REPL) from the initial RAM disk before it
28540 tries to load kernel modules and to mount the root file system. Our
28541 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
28542 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
28543 Manual}, for more information on Guile's REPL.
28547 Now that you know all the features that initial RAM disks produced by
28548 @code{base-initrd} and @code{raw-initrd} provide,
28549 here is how to use it and customize it further.
28552 @cindex initial RAM disk
28553 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
28554 [#:linux-modules '()] [#:mapped-devices '()] @
28555 [#:keyboard-layout #f] @
28556 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
28557 Return a derivation that builds a raw initrd. @var{file-systems} is
28558 a list of file systems to be mounted by the initrd, possibly in addition to
28559 the root file system specified on the kernel command line via @option{--root}.
28560 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
28561 @var{mapped-devices} is a list of device mappings to realize before
28562 @var{file-systems} are mounted (@pxref{Mapped Devices}).
28563 @var{helper-packages} is a list of packages to be copied in the initrd. It may
28564 include @code{e2fsck/static} or other packages needed by the initrd to check
28565 the root file system.
28567 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28568 the desired console keyboard layout. This is done before @var{mapped-devices}
28569 are set up and before @var{file-systems} are mounted such that, should the
28570 user need to enter a passphrase or use the REPL, this happens using the
28571 intended keyboard layout.
28573 When @var{qemu-networking?} is true, set up networking with the standard QEMU
28574 parameters. When @var{virtio?} is true, load additional modules so that the
28575 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
28577 When @var{volatile-root?} is true, the root file system is writable but any changes
28581 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
28582 [#:mapped-devices '()] [#:keyboard-layout #f] @
28583 [#:qemu-networking? #f] [#:volatile-root? #f] @
28584 [#:linux-modules '()]
28585 Return as a file-like object a generic initrd, with kernel
28586 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
28587 mounted by the initrd, possibly in addition to the root file system specified
28588 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
28589 mappings to realize before @var{file-systems} are mounted.
28591 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
28592 the desired console keyboard layout. This is done before @var{mapped-devices}
28593 are set up and before @var{file-systems} are mounted such that, should the
28594 user need to enter a passphrase or use the REPL, this happens using the
28595 intended keyboard layout.
28597 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
28599 The initrd is automatically populated with all the kernel modules necessary
28600 for @var{file-systems} and for the given options. Additional kernel
28601 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
28602 loaded at boot time in the order in which they appear.
28605 Needless to say, the initrds we produce and use embed a
28606 statically-linked Guile, and the initialization program is a Guile
28607 program. That gives a lot of flexibility. The
28608 @code{expression->initrd} procedure builds such an initrd, given the
28609 program to run in that initrd.
28611 @deffn {Scheme Procedure} expression->initrd @var{exp} @
28612 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
28613 Return as a file-like object a Linux initrd (a gzipped cpio archive)
28614 containing @var{guile} and that evaluates @var{exp}, a G-expression,
28615 upon booting. All the derivations referenced by @var{exp} are
28616 automatically copied to the initrd.
28619 @node Bootloader Configuration
28620 @section Bootloader Configuration
28623 @cindex boot loader
28625 The operating system supports multiple bootloaders. The bootloader is
28626 configured using @code{bootloader-configuration} declaration. All the
28627 fields of this structure are bootloader agnostic except for one field,
28628 @code{bootloader} that indicates the bootloader to be configured and
28631 Some of the bootloaders do not honor every field of
28632 @code{bootloader-configuration}. For instance, the extlinux
28633 bootloader does not support themes and thus ignores the @code{theme}
28636 @deftp {Data Type} bootloader-configuration
28637 The type of a bootloader configuration declaration.
28641 @item @code{bootloader}
28642 @cindex EFI, bootloader
28643 @cindex UEFI, bootloader
28644 @cindex BIOS, bootloader
28645 The bootloader to use, as a @code{bootloader} object. For now
28646 @code{grub-bootloader}, @code{grub-efi-bootloader},
28647 @code{extlinux-bootloader} and @code{u-boot-bootloader} are supported.
28649 @vindex grub-efi-bootloader
28650 @code{grub-efi-bootloader} allows to boot on modern systems using the
28651 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
28652 use if the installation image contains a @file{/sys/firmware/efi} directory
28653 when you boot it on your system.
28655 @vindex grub-bootloader
28656 @code{grub-bootloader} allows you to boot in particular Intel-based machines
28657 in ``legacy'' BIOS mode.
28659 @cindex ARM, bootloaders
28660 @cindex AArch64, bootloaders
28661 Available bootloaders are described in @code{(gnu bootloader @dots{})}
28662 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
28663 of bootloaders for a wide range of ARM and AArch64 systems, using the
28664 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
28666 @item @code{target}
28667 This is a string denoting the target onto which to install the
28670 The interpretation depends on the bootloader in question. For
28671 @code{grub-bootloader}, for example, it should be a device name understood by
28672 the bootloader @command{installer} command, such as @code{/dev/sda} or
28673 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
28674 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
28675 system, usually @file{/boot/efi}.
28677 @item @code{menu-entries} (default: @code{()})
28678 A possibly empty list of @code{menu-entry} objects (see below), denoting
28679 entries to appear in the bootloader menu, in addition to the current
28680 system entry and the entry pointing to previous system generations.
28682 @item @code{default-entry} (default: @code{0})
28683 The index of the default boot menu entry. Index 0 is for the entry of the
28686 @item @code{timeout} (default: @code{5})
28687 The number of seconds to wait for keyboard input before booting. Set to
28688 0 to boot immediately, and to -1 to wait indefinitely.
28690 @cindex keyboard layout, for the bootloader
28691 @item @code{keyboard-layout} (default: @code{#f})
28692 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
28693 layout, usually US@tie{}English (``qwerty'').
28695 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
28699 This option is currently ignored by bootloaders other than @code{grub} and
28703 @item @code{theme} (default: @var{#f})
28704 The bootloader theme object describing the theme to use. If no theme
28705 is provided, some bootloaders might use a default theme, that's true
28708 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
28709 The output terminals used for the bootloader boot menu, as a list of
28710 symbols. GRUB accepts the values: @code{console}, @code{serial},
28711 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
28712 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
28713 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
28714 configuration,,, grub,GNU GRUB manual}).
28716 @item @code{terminal-inputs} (default: @code{'()})
28717 The input terminals used for the bootloader boot menu, as a list of
28718 symbols. For GRUB, the default is the native platform terminal as
28719 determined at run-time. GRUB accepts the values: @code{console},
28720 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
28721 @code{usb_keyboard}. This field corresponds to the GRUB variable
28722 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
28725 @item @code{serial-unit} (default: @code{#f})
28726 The serial unit used by the bootloader, as an integer from 0 to 3.
28727 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
28728 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28730 @item @code{serial-speed} (default: @code{#f})
28731 The speed of the serial interface, as an integer. For GRUB, the
28732 default value is chosen at run-time; currently GRUB chooses
28733 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
28740 Should you want to list additional boot menu entries @i{via} the
28741 @code{menu-entries} field above, you will need to create them with the
28742 @code{menu-entry} form. For example, imagine you want to be able to
28743 boot another distro (hard to imagine!), you can define a menu entry
28748 (label "The Other Distro")
28749 (linux "/boot/old/vmlinux-2.6.32")
28750 (linux-arguments '("root=/dev/sda2"))
28751 (initrd "/boot/old/initrd"))
28756 @deftp {Data Type} menu-entry
28757 The type of an entry in the bootloader menu.
28762 The label to show in the menu---e.g., @code{"GNU"}.
28764 @item @code{linux} (default: @code{#f})
28765 The Linux kernel image to boot, for example:
28768 (file-append linux-libre "/bzImage")
28771 For GRUB, it is also possible to specify a device explicitly in the
28772 file path using GRUB's device naming convention (@pxref{Naming
28773 convention,,, grub, GNU GRUB manual}), for example:
28776 "(hd0,msdos1)/boot/vmlinuz"
28779 If the device is specified explicitly as above, then the @code{device}
28780 field is ignored entirely.
28782 @item @code{linux-arguments} (default: @code{()})
28783 The list of extra Linux kernel command-line arguments---e.g.,
28784 @code{("console=ttyS0")}.
28786 @item @code{initrd} (default: @code{#f})
28787 A G-Expression or string denoting the file name of the initial RAM disk
28788 to use (@pxref{G-Expressions}).
28790 @item @code{device} (default: @code{#f})
28791 The device where the kernel and initrd are to be found---i.e., for GRUB,
28792 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
28794 This may be a file system label (a string), a file system UUID (a
28795 bytevector, @pxref{File Systems}), or @code{#f}, in which case
28796 the bootloader will search the device containing the file specified by
28797 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
28798 must @emph{not} be an OS device name such as @file{/dev/sda1}.
28800 @item @code{multiboot-kernel} (default: @code{#f})
28801 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
28802 manual}). When this field is set, a Multiboot menu-entry is generated.
28806 (file-append mach "/boot/gnumach")
28809 @item @code{multiboot-arguments} (default: @code{()})
28810 The list of extra command-line arguments for the multiboot-kernel.
28812 @item @code{multiboot-modules} (default: @code{()})
28813 The list of commands for loading Multiboot modules. For example:
28816 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
28818 (list (file-append libc "/lib/ld.so.1") "exec"
28828 @c FIXME: Write documentation once it's stable.
28829 For now only GRUB has theme support. GRUB themes are created using
28830 the @code{grub-theme} form, which is not fully documented yet.
28832 @deftp {Data Type} grub-theme
28833 Data type representing the configuration of the GRUB theme.
28836 @item @code{gfxmode} (default: @code{'("auto")})
28837 The GRUB @code{gfxmode} to set (a list of screen resolution strings, see
28838 @pxref{gfxmode,,, grub, GNU GRUB manual}).
28842 @deffn {Scheme Procedure} grub-theme
28843 Return the default GRUB theme used by the operating system if no
28844 @code{theme} field is specified in @code{bootloader-configuration}
28847 It comes with a fancy background image displaying the GNU and Guix
28851 For example, to override the default resolution, you may use something
28856 (bootloader-configuration
28859 (inherit (grub-theme))
28860 (gfxmode '("1024x786x32" "auto"))))))
28863 @node Invoking guix system
28864 @section Invoking @code{guix system}
28866 Once you have written an operating system declaration as seen in the
28867 previous section, it can be @dfn{instantiated} using the @command{guix
28868 system} command. The synopsis is:
28871 guix system @var{options}@dots{} @var{action} @var{file}
28874 @var{file} must be the name of a file containing an
28875 @code{operating-system} declaration. @var{action} specifies how the
28876 operating system is instantiated. Currently the following values are
28881 Display available service type definitions that match the given regular
28882 expressions, sorted by relevance:
28888 $ guix system search console
28889 name: console-fonts
28890 location: gnu/services/base.scm:806:2
28891 extends: shepherd-root
28892 description: Install the given fonts on the specified ttys (fonts are per
28893 + virtual console on GNU/Linux). The value of this service is a list of
28894 + tty/font pairs. The font can be the name of a font provided by the `kbd'
28895 + package or any valid argument to `setfont', as in this example:
28897 + '(("tty1" . "LatGrkCyr-8x16")
28898 + ("tty2" . (file-append
28900 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
28901 + ("tty3" . (file-append
28903 + "/share/consolefonts/ter-132n"))) ; for HDPI
28907 location: gnu/services/base.scm:1190:2
28908 extends: shepherd-root
28909 description: Provide console login using the `mingetty' program.
28913 location: gnu/services/base.scm:860:2
28915 description: Provide a console log-in service as specified by its
28916 + configuration value, a `login-configuration' object.
28922 As for @command{guix package --search}, the result is written in
28923 @code{recutils} format, which makes it easy to filter the output
28924 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
28927 Build the operating system described in @var{file}, activate it, and
28928 switch to it@footnote{This action (and the related actions
28929 @code{switch-generation} and @code{roll-back}) are usable only on
28930 systems already running Guix System.}.
28933 @c The paragraph below refers to the problem discussed at
28934 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
28935 It is highly recommended to run @command{guix pull} once before you run
28936 @command{guix system reconfigure} for the first time (@pxref{Invoking
28937 guix pull}). Failing to do that you would see an older version of Guix
28938 once @command{reconfigure} has completed.
28941 This effects all the configuration specified in @var{file}: user
28942 accounts, system services, global package list, setuid programs, etc.
28943 The command starts system services specified in @var{file} that are not
28944 currently running; if a service is currently running this command will
28945 arrange for it to be upgraded the next time it is stopped (e.g.@: by
28946 @code{herd stop X} or @code{herd restart X}).
28948 This command creates a new generation whose number is one greater than
28949 the current generation (as reported by @command{guix system
28950 list-generations}). If that generation already exists, it will be
28951 overwritten. This behavior mirrors that of @command{guix package}
28952 (@pxref{Invoking guix package}).
28954 It also adds a bootloader menu entry for the new OS configuration,
28955 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
28956 entries for older configurations to a submenu, allowing you to choose
28957 an older system generation at boot time should you need it.
28959 @cindex provenance tracking, of the operating system
28960 Upon completion, the new system is deployed under
28961 @file{/run/current-system}. This directory contains @dfn{provenance
28962 meta-data}: the list of channels in use (@pxref{Channels}) and
28963 @var{file} itself, when available. You can view it by running:
28966 guix system describe
28969 This information is useful should you later want to inspect how this
28970 particular generation was built. In fact, assuming @var{file} is
28971 self-contained, you can later rebuild generation @var{n} of your
28972 operating system with:
28975 guix time-machine \
28976 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
28977 system reconfigure \
28978 /var/guix/profiles/system-@var{n}-link/configuration.scm
28981 You can think of it as some sort of built-in version control! Your
28982 system is not just a binary artifact: @emph{it carries its own source}.
28983 @xref{Service Reference, @code{provenance-service-type}}, for more
28984 information on provenance tracking.
28986 By default, @command{reconfigure} @emph{prevents you from downgrading
28987 your system}, which could (re)introduce security vulnerabilities and
28988 also cause problems with ``stateful'' services such as database
28989 management systems. You can override that behavior by passing
28990 @option{--allow-downgrades}.
28992 @item switch-generation
28993 @cindex generations
28994 Switch to an existing system generation. This action atomically
28995 switches the system profile to the specified system generation. It
28996 also rearranges the system's existing bootloader menu entries. It
28997 makes the menu entry for the specified system generation the default,
28998 and it moves the entries for the other generations to a submenu, if
28999 supported by the bootloader being used. The next time the system
29000 boots, it will use the specified system generation.
29002 The bootloader itself is not being reinstalled when using this
29003 command. Thus, the installed bootloader is used with an updated
29004 configuration file.
29006 The target generation can be specified explicitly by its generation
29007 number. For example, the following invocation would switch to system
29011 guix system switch-generation 7
29014 The target generation can also be specified relative to the current
29015 generation with the form @code{+N} or @code{-N}, where @code{+3} means
29016 ``3 generations ahead of the current generation,'' and @code{-1} means
29017 ``1 generation prior to the current generation.'' When specifying a
29018 negative value such as @code{-1}, you must precede it with @code{--} to
29019 prevent it from being parsed as an option. For example:
29022 guix system switch-generation -- -1
29025 Currently, the effect of invoking this action is @emph{only} to switch
29026 the system profile to an existing generation and rearrange the
29027 bootloader menu entries. To actually start using the target system
29028 generation, you must reboot after running this action. In the future,
29029 it will be updated to do the same things as @command{reconfigure},
29030 like activating and deactivating services.
29032 This action will fail if the specified generation does not exist.
29035 @cindex rolling back
29036 Switch to the preceding system generation. The next time the system
29037 boots, it will use the preceding system generation. This is the inverse
29038 of @command{reconfigure}, and it is exactly the same as invoking
29039 @command{switch-generation} with an argument of @code{-1}.
29041 Currently, as with @command{switch-generation}, you must reboot after
29042 running this action to actually start using the preceding system
29045 @item delete-generations
29046 @cindex deleting system generations
29047 @cindex saving space
29048 Delete system generations, making them candidates for garbage collection
29049 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
29052 This works in the same way as @samp{guix package --delete-generations}
29053 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
29054 arguments, all system generations but the current one are deleted:
29057 guix system delete-generations
29060 You can also select the generations you want to delete. The example below
29061 deletes all the system generations that are more than two month old:
29064 guix system delete-generations 2m
29067 Running this command automatically reinstalls the bootloader with an updated
29068 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
29069 longer lists the generations that have been deleted.
29072 Build the derivation of the operating system, which includes all the
29073 configuration files and programs needed to boot and run the system.
29074 This action does not actually install anything.
29077 Populate the given directory with all the files necessary to run the
29078 operating system specified in @var{file}. This is useful for first-time
29079 installations of Guix System. For instance:
29082 guix system init my-os-config.scm /mnt
29085 copies to @file{/mnt} all the store items required by the configuration
29086 specified in @file{my-os-config.scm}. This includes configuration
29087 files, packages, and so on. It also creates other essential files
29088 needed for the system to operate correctly---e.g., the @file{/etc},
29089 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
29091 This command also installs bootloader on the target specified in
29092 @file{my-os-config}, unless the @option{--no-bootloader} option was
29096 @cindex virtual machine
29098 @anchor{guix system vm}
29099 Build a virtual machine that contains the operating system declared in
29100 @var{file}, and return a script to run that virtual machine (VM).
29103 The @code{vm} action and others below
29104 can use KVM support in the Linux-libre kernel. Specifically, if the
29105 machine has hardware virtualization support, the corresponding
29106 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
29107 must exist and be readable and writable by the user and by the
29108 build users of the daemon (@pxref{Build Environment Setup}).
29111 Arguments given to the script are passed to QEMU as in the example
29112 below, which enables networking and requests 1@tie{}GiB of RAM for the
29116 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
29119 The VM shares its store with the host system.
29121 Additional file systems can be shared between the host and the VM using
29122 the @option{--share} and @option{--expose} command-line options: the former
29123 specifies a directory to be shared with write access, while the latter
29124 provides read-only access to the shared directory.
29126 The example below creates a VM in which the user's home directory is
29127 accessible read-only, and where the @file{/exchange} directory is a
29128 read-write mapping of @file{$HOME/tmp} on the host:
29131 guix system vm my-config.scm \
29132 --expose=$HOME --share=$HOME/tmp=/exchange
29135 On GNU/Linux, the default is to boot directly to the kernel; this has
29136 the advantage of requiring only a very tiny root disk image since the
29137 store of the host can then be mounted.
29139 The @option{--full-boot} option forces a complete boot sequence, starting
29140 with the bootloader. This requires more disk space since a root image
29141 containing at least the kernel, initrd, and bootloader data files must
29142 be created. The @option{--image-size} option can be used to specify the
29145 @cindex System images, creation in various formats
29146 @cindex Creating system images in various formats
29149 @itemx docker-image
29150 Return a virtual machine, disk image, or Docker image of the operating
29151 system declared in @var{file} that stands alone. By default,
29152 @command{guix system} estimates the size of the image needed to store
29153 the system, but you can use the @option{--image-size} option to specify
29154 a value. Docker images are built to contain exactly what they need, so
29155 the @option{--image-size} option is ignored in the case of
29156 @code{docker-image}.
29158 You can specify the root file system type by using the
29159 @option{--file-system-type} option. It defaults to @code{ext4}. When its
29160 value is @code{iso9660}, the @option{--label} option can be used to specify
29161 a volume ID with @code{disk-image}.
29163 When using @code{vm-image}, the returned image is in qcow2 format, which
29164 the QEMU emulator can efficiently use. @xref{Running Guix in a VM},
29165 for more information on how to run the image in a virtual machine.
29167 When using @code{disk-image}, a raw disk image is produced; it can be
29168 copied as is to a USB stick, for instance. Assuming @code{/dev/sdc} is
29169 the device corresponding to a USB stick, one can copy the image to it
29170 using the following command:
29173 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
29176 When using @code{docker-image}, a Docker image is produced. Guix builds
29177 the image from scratch, not from a pre-existing Docker base image. As a
29178 result, it contains @emph{exactly} what you define in the operating
29179 system configuration file. You can then load the image and launch a
29180 Docker container using commands like the following:
29183 image_id="`docker load < guix-system-docker-image.tar.gz`"
29184 container_id="`docker create $image_id`"
29185 docker start $container_id
29188 This command starts a new Docker container from the specified image. It
29189 will boot the Guix system in the usual manner, which means it will
29190 start any services you have defined in the operating system
29191 configuration. You can get an interactive shell running in the container
29192 using @command{docker exec}:
29195 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
29198 Depending on what you run in the Docker container, it
29199 may be necessary to give the container additional permissions. For
29200 example, if you intend to build software using Guix inside of the Docker
29201 container, you may need to pass the @option{--privileged} option to
29202 @code{docker create}.
29204 Last, the @option{--network} option applies to @command{guix system
29205 docker-image}: it produces an image where network is supposedly shared
29206 with the host, and thus without services like nscd or NetworkManager.
29209 Return a script to run the operating system declared in @var{file}
29210 within a container. Containers are a set of lightweight isolation
29211 mechanisms provided by the kernel Linux-libre. Containers are
29212 substantially less resource-demanding than full virtual machines since
29213 the kernel, shared objects, and other resources can be shared with the
29214 host system; this also means they provide thinner isolation.
29216 Currently, the script must be run as root in order to support more than
29217 a single user and group. The container shares its store with the host
29220 As with the @code{vm} action (@pxref{guix system vm}), additional file
29221 systems to be shared between the host and container can be specified
29222 using the @option{--share} and @option{--expose} options:
29225 guix system container my-config.scm \
29226 --expose=$HOME --share=$HOME/tmp=/exchange
29230 This option requires Linux-libre 3.19 or newer.
29235 @var{options} can contain any of the common build options (@pxref{Common
29236 Build Options}). In addition, @var{options} can contain one of the
29240 @item --expression=@var{expr}
29241 @itemx -e @var{expr}
29242 Consider the operating-system @var{expr} evaluates to.
29243 This is an alternative to specifying a file which evaluates to an
29245 This is used to generate the Guix system installer @pxref{Building the
29246 Installation Image}).
29248 @item --system=@var{system}
29249 @itemx -s @var{system}
29250 Attempt to build for @var{system} instead of the host system type.
29251 This works as per @command{guix build} (@pxref{Invoking guix build}).
29255 Return the derivation file name of the given operating system without
29258 @cindex provenance tracking, of the operating system
29259 @item --save-provenance
29260 As discussed above, @command{guix system init} and @command{guix system
29261 reconfigure} always save provenance information @i{via} a dedicated
29262 service (@pxref{Service Reference, @code{provenance-service-type}}).
29263 However, other commands don't do that by default. If you wish to, say,
29264 create a virtual machine image that contains provenance information, you
29268 guix system vm-image --save-provenance config.scm
29271 That way, the resulting image will effectively ``embed its own source''
29272 in the form of meta-data in @file{/run/current-system}. With that
29273 information, one can rebuild the image to make sure it really contains
29274 what it pretends to contain; or they could use that to derive a variant
29277 @item --file-system-type=@var{type}
29278 @itemx -t @var{type}
29279 For the @code{disk-image} action, create a file system of the given
29280 @var{type} on the image.
29282 When this option is omitted, @command{guix system} uses @code{ext4}.
29284 @cindex ISO-9660 format
29285 @cindex CD image format
29286 @cindex DVD image format
29287 @option{--file-system-type=iso9660} produces an ISO-9660 image, suitable
29288 for burning on CDs and DVDs.
29290 @item --image-size=@var{size}
29291 For the @code{vm-image} and @code{disk-image} actions, create an image
29292 of the given @var{size}. @var{size} may be a number of bytes, or it may
29293 include a unit as a suffix (@pxref{Block size, size specifications,,
29294 coreutils, GNU Coreutils}).
29296 When this option is omitted, @command{guix system} computes an estimate
29297 of the image size as a function of the size of the system declared in
29302 For the @code{container} action, allow containers to access the host network,
29303 that is, do not create a network namespace.
29305 @item --root=@var{file}
29306 @itemx -r @var{file}
29307 Make @var{file} a symlink to the result, and register it as a garbage
29310 @item --skip-checks
29311 Skip pre-installation safety checks.
29313 By default, @command{guix system init} and @command{guix system
29314 reconfigure} perform safety checks: they make sure the file systems that
29315 appear in the @code{operating-system} declaration actually exist
29316 (@pxref{File Systems}), and that any Linux kernel modules that may be
29317 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
29318 RAM Disk}). Passing this option skips these tests altogether.
29320 @item --allow-downgrades
29321 Instruct @command{guix system reconfigure} to allow system downgrades.
29323 By default, @command{reconfigure} prevents you from downgrading your
29324 system. It achieves that by comparing the provenance info of your
29325 system (shown by @command{guix system describe}) with that of your
29326 @command{guix} command (shown by @command{guix describe}). If the
29327 commits for @command{guix} are not descendants of those used for your
29328 system, @command{guix system reconfigure} errors out. Passing
29329 @option{--allow-downgrades} allows you to bypass these checks.
29332 Make sure you understand its security implications before using
29333 @option{--allow-downgrades}.
29337 @cindex on-error strategy
29338 @cindex error strategy
29339 @item --on-error=@var{strategy}
29340 Apply @var{strategy} when an error occurs when reading @var{file}.
29341 @var{strategy} may be one of the following:
29344 @item nothing-special
29345 Report the error concisely and exit. This is the default strategy.
29348 Likewise, but also display a backtrace.
29351 Report the error and enter Guile's debugger. From there, you can run
29352 commands such as @code{,bt} to get a backtrace, @code{,locals} to
29353 display local variable values, and more generally inspect the state of the
29354 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
29355 a list of available debugging commands.
29359 Once you have built, configured, re-configured, and re-re-configured
29360 your Guix installation, you may find it useful to list the operating
29361 system generations available on disk---and that you can choose from the
29362 bootloader boot menu:
29367 Describe the current system generation: its file name, the kernel and
29368 bootloader used, etc., as well as provenance information when available.
29370 @item list-generations
29371 List a summary of each generation of the operating system available on
29372 disk, in a human-readable way. This is similar to the
29373 @option{--list-generations} option of @command{guix package}
29374 (@pxref{Invoking guix package}).
29376 Optionally, one can specify a pattern, with the same syntax that is used
29377 in @command{guix package --list-generations}, to restrict the list of
29378 generations displayed. For instance, the following command displays
29379 generations that are up to 10 days old:
29382 $ guix system list-generations 10d
29387 The @command{guix system} command has even more to offer! The following
29388 sub-commands allow you to visualize how your system services relate to
29391 @anchor{system-extension-graph}
29394 @item extension-graph
29395 Emit in Dot/Graphviz format to standard output the @dfn{service
29396 extension graph} of the operating system defined in @var{file}
29397 (@pxref{Service Composition}, for more information on service
29403 $ guix system extension-graph @var{file} | xdot -
29406 shows the extension relations among services.
29408 @anchor{system-shepherd-graph}
29409 @item shepherd-graph
29410 Emit in Dot/Graphviz format to standard output the @dfn{dependency
29411 graph} of shepherd services of the operating system defined in
29412 @var{file}. @xref{Shepherd Services}, for more information and for an
29417 @node Invoking guix deploy
29418 @section Invoking @code{guix deploy}
29420 We've already seen @code{operating-system} declarations used to manage a
29421 machine's configuration locally. Suppose you need to configure multiple
29422 machines, though---perhaps you're managing a service on the web that's
29423 comprised of several servers. @command{guix deploy} enables you to use those
29424 same @code{operating-system} declarations to manage multiple remote hosts at
29425 once as a logical ``deployment''.
29428 The functionality described in this section is still under development
29429 and is subject to change. Get in touch with us on
29430 @email{guix-devel@@gnu.org}!
29434 guix deploy @var{file}
29437 Such an invocation will deploy the machines that the code within @var{file}
29438 evaluates to. As an example, @var{file} might contain a definition like this:
29441 ;; This is a Guix deployment of a "bare bones" setup, with
29442 ;; no X11 display server, to a machine with an SSH daemon
29443 ;; listening on localhost:2222. A configuration such as this
29444 ;; may be appropriate for virtual machine with ports
29445 ;; forwarded to the host's loopback interface.
29447 (use-service-modules networking ssh)
29448 (use-package-modules bootloaders)
29452 (host-name "gnu-deployed")
29453 (timezone "Etc/UTC")
29454 (bootloader (bootloader-configuration
29455 (bootloader grub-bootloader)
29456 (target "/dev/vda")
29457 (terminal-outputs '(console))))
29458 (file-systems (cons (file-system
29460 (device "/dev/vda1")
29462 %base-file-systems))
29464 (append (list (service dhcp-client-service-type)
29465 (service openssh-service-type
29466 (openssh-configuration
29467 (permit-root-login #t)
29468 (allow-empty-passwords? #t))))
29472 (operating-system %system)
29473 (environment managed-host-environment-type)
29474 (configuration (machine-ssh-configuration
29475 (host-name "localhost")
29476 (system "x86_64-linux")
29478 (identity "./id_rsa")
29482 The file should evaluate to a list of @var{machine} objects. This example,
29483 upon being deployed, will create a new generation on the remote system
29484 realizing the @code{operating-system} declaration @code{%system}.
29485 @code{environment} and @code{configuration} specify how the machine should be
29486 provisioned---that is, how the computing resources should be created and
29487 managed. The above example does not create any resources, as a
29488 @code{'managed-host} is a machine that is already running the Guix system and
29489 available over the network. This is a particularly simple case; a more
29490 complex deployment may involve, for example, starting virtual machines through
29491 a Virtual Private Server (VPS) provider. In such a case, a different
29492 @var{environment} type would be used.
29494 Do note that you first need to generate a key pair on the coordinator machine
29495 to allow the daemon to export signed archives of files from the store
29496 (@pxref{Invoking guix archive}).
29499 # guix archive --generate-key
29503 Each target machine must authorize the key of the master machine so that it
29504 accepts store items it receives from the coordinator:
29507 # guix archive --authorize < coordinator-public-key.txt
29510 @code{user}, in this example, specifies the name of the user account to log in
29511 as to perform the deployment. Its default value is @code{root}, but root
29512 login over SSH may be forbidden in some cases. To work around this,
29513 @command{guix deploy} can log in as an unprivileged user and employ
29514 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
29515 currently installed on the remote and can be invoked non-interactively as
29516 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
29517 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
29518 be accomplished with the following operating system configuration snippet:
29522 (gnu system)) ;for %sudoers-specification
29524 (define %user "username")
29529 (plain-file "sudoers"
29530 (string-append (plain-file-content %sudoers-specification)
29531 (format #f "~a ALL = NOPASSWD: ALL~%"
29536 For more information regarding the format of the @file{sudoers} file,
29537 consult @command{man sudoers}.
29539 @deftp {Data Type} machine
29540 This is the data type representing a single machine in a heterogeneous Guix
29544 @item @code{operating-system}
29545 The object of the operating system configuration to deploy.
29547 @item @code{environment}
29548 An @code{environment-type} describing how the machine should be provisioned.
29550 @item @code{configuration} (default: @code{#f})
29551 An object describing the configuration for the machine's @code{environment}.
29552 If the @code{environment} has a default configuration, @code{#f} may be used.
29553 If @code{#f} is used for an environment with no default configuration,
29554 however, an error will be thrown.
29558 @deftp {Data Type} machine-ssh-configuration
29559 This is the data type representing the SSH client parameters for a machine
29560 with an @code{environment} of @code{managed-host-environment-type}.
29563 @item @code{host-name}
29564 @item @code{build-locally?} (default: @code{#t})
29565 If false, system derivations will be built on the machine being deployed to.
29566 @item @code{system}
29567 The system type describing the architecture of the machine being deployed
29568 to---e.g., @code{"x86_64-linux"}.
29569 @item @code{authorize?} (default: @code{#t})
29570 If true, the coordinator's signing key will be added to the remote's ACL
29572 @item @code{port} (default: @code{22})
29573 @item @code{user} (default: @code{"root"})
29574 @item @code{identity} (default: @code{#f})
29575 If specified, the path to the SSH private key to use to authenticate with the
29578 @item @code{host-key} (default: @code{#f})
29579 This should be the SSH host key of the machine, which looks like this:
29582 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
29585 When @code{host-key} is @code{#f}, the server is authenticated against
29586 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
29589 @item @code{allow-downgrades?} (default: @code{#f})
29590 Whether to allow potential downgrades.
29592 Like @command{guix system reconfigure}, @command{guix deploy} compares
29593 the channel commits currently deployed on the remote host (as returned
29594 by @command{guix system describe}) to those currently in use (as
29595 returned by @command{guix describe}) to determine whether commits
29596 currently in use are descendants of those deployed. When this is not
29597 the case and @code{allow-downgrades?} is false, it raises an error.
29598 This ensures you do not accidentally downgrade remote machines.
29602 @deftp {Data Type} digital-ocean-configuration
29603 This is the data type describing the Droplet that should be created for a
29604 machine with an @code{environment} of @code{digital-ocean-environment-type}.
29607 @item @code{ssh-key}
29608 The path to the SSH private key to use to authenticate with the remote
29609 host. In the future, this field may not exist.
29611 A list of string ``tags'' that uniquely identify the machine. Must be given
29612 such that no two machines in the deployment have the same set of tags.
29613 @item @code{region}
29614 A Digital Ocean region slug, such as @code{"nyc3"}.
29616 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
29617 @item @code{enable-ipv6?}
29618 Whether or not the droplet should be created with IPv6 networking.
29622 @node Running Guix in a VM
29623 @section Running Guix in a Virtual Machine
29625 @cindex virtual machine
29626 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
29628 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
29629 This image is a compressed image in QCOW format. You will first need to
29630 decompress with @command{xz -d}, and then you can pass it to an emulator such
29631 as QEMU (see below for details).
29633 This image boots the Xfce graphical environment and it contains some
29634 commonly-used tools. You can install more software in the image by running
29635 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
29636 also reconfigure the system based on its initial configuration file available
29637 as @file{/run/current-system/configuration.scm} (@pxref{Using the
29638 Configuration System}).
29640 Instead of using this pre-built image, one can also build their own virtual
29641 machine image using @command{guix system vm-image} (@pxref{Invoking guix
29642 system}). The returned image is in qcow2 format, which the
29643 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
29646 If you built your own image, you must copy it out of the store
29647 (@pxref{The Store}) and give yourself permission to write to the copy
29648 before you can use it. When invoking QEMU, you must choose a system
29649 emulator that is suitable for your hardware platform. Here is a minimal
29650 QEMU invocation that will boot the result of @command{guix system
29651 vm-image} on x86_64 hardware:
29654 $ qemu-system-x86_64 \
29655 -nic user,model=virtio-net-pci \
29656 -enable-kvm -m 1024 \
29657 -device virtio-blk,drive=myhd \
29658 -drive if=none,file=/tmp/qemu-image,id=myhd
29661 Here is what each of these options means:
29664 @item qemu-system-x86_64
29665 This specifies the hardware platform to emulate. This should match the
29668 @item -nic user,model=virtio-net-pci
29669 Enable the unprivileged user-mode network stack. The guest OS can
29670 access the host but not vice versa. This is the simplest way to get the
29671 guest OS online. @code{model} specifies which network device to emulate:
29672 @code{virtio-net-pci} is a special device made for virtualized operating
29673 systems and recommended for most uses. Assuming your hardware platform is
29674 x86_64, you can get a list of available NIC models by running
29675 @command{qemu-system-x86_64 -nic model=help}.
29678 If your system has hardware virtualization extensions, enabling the
29679 virtual machine support (KVM) of the Linux kernel will make things run
29682 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
29684 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
29685 which may be insufficient for some operations.
29687 @item -device virtio-blk,drive=myhd
29688 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
29689 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
29690 better performance than if it were emulating a complete disk drive. See the
29691 QEMU and KVM documentation for more info.
29693 @item -drive if=none,file=/tmp/qemu-image,id=myhd
29694 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing store the
29695 the ``myhd'' drive.
29698 The default @command{run-vm.sh} script that is returned by an invocation of
29699 @command{guix system vm} does not add a @command{-nic user} flag by default.
29700 To get network access from within the vm add the @code{(dhcp-client-service)}
29701 to your system definition and start the VM using
29702 @command{`guix system vm config.scm` -nic user}. An important caveat of using
29703 @command{-nic user} for networking is that @command{ping} will not work, because
29704 it uses the ICMP protocol. You'll have to use a different command to check for
29705 network connectivity, for example @command{guix download}.
29707 @subsection Connecting Through SSH
29711 To enable SSH inside a VM you need to add an SSH server like
29712 @code{openssh-service-type} to your VM (@pxref{Networking Services,
29713 @code{openssh-service-type}}). In addition you need to forward the SSH port,
29714 22 by default, to the host. You can do this with
29717 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
29720 To connect to the VM you can run
29723 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
29726 The @command{-p} tells @command{ssh} the port you want to connect to.
29727 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
29728 every time you modify your @command{config.scm} file and the
29729 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
29730 connection to an unknown host every time you connect.
29732 @subsection Using @command{virt-viewer} with Spice
29734 As an alternative to the default @command{qemu} graphical client you can
29735 use the @command{remote-viewer} from the @command{virt-viewer} package. To
29736 connect pass the @command{-spice port=5930,disable-ticketing} flag to
29737 @command{qemu}. See previous section for further information on how to do this.
29739 Spice also allows you to do some nice stuff like share your clipboard with your
29740 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
29743 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
29744 -chardev spicevmc,name=vdagent,id=vdagent
29745 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
29746 name=com.redhat.spice.0
29749 You'll also need to add the @code{(spice-vdagent-service)} to your
29750 system definition (@pxref{Miscellaneous Services, Spice service}).
29752 @node Defining Services
29753 @section Defining Services
29755 The previous sections show the available services and how one can combine
29756 them in an @code{operating-system} declaration. But how do we define
29757 them in the first place? And what is a service anyway?
29760 * Service Composition:: The model for composing services.
29761 * Service Types and Services:: Types and services.
29762 * Service Reference:: API reference.
29763 * Shepherd Services:: A particular type of service.
29766 @node Service Composition
29767 @subsection Service Composition
29771 Here we define a @dfn{service} as, broadly, something that extends the
29772 functionality of the operating system. Often a service is a process---a
29773 @dfn{daemon}---started when the system boots: a secure shell server, a
29774 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
29775 whose execution can be triggered by another daemon---e.g., an FTP server
29776 started by @command{inetd} or a D-Bus service activated by
29777 @command{dbus-daemon}. Occasionally, a service does not map to a
29778 daemon. For instance, the ``account'' service collects user accounts
29779 and makes sure they exist when the system runs; the ``udev'' service
29780 collects device management rules and makes them available to the eudev
29781 daemon; the @file{/etc} service populates the @file{/etc} directory
29784 @cindex service extensions
29785 Guix system services are connected by @dfn{extensions}. For instance, the
29786 secure shell service @emph{extends} the Shepherd---the
29787 initialization system, running as PID@tie{}1---by giving it the command
29788 lines to start and stop the secure shell daemon (@pxref{Networking
29789 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
29790 service by passing it its @file{.service} specification, and extends the
29791 udev service by passing it device management rules (@pxref{Desktop
29792 Services, @code{upower-service}}); the Guix daemon service extends the
29793 Shepherd by passing it the command lines to start and stop the daemon,
29794 and extends the account service by passing it a list of required build
29795 user accounts (@pxref{Base Services}).
29797 All in all, services and their ``extends'' relations form a directed
29798 acyclic graph (DAG). If we represent services as boxes and extensions
29799 as arrows, a typical system might provide something like this:
29801 @image{images/service-graph,,5in,Typical service extension graph.}
29803 @cindex system service
29804 At the bottom, we see the @dfn{system service}, which produces the
29805 directory containing everything to run and boot the system, as returned
29806 by the @command{guix system build} command. @xref{Service Reference},
29807 to learn about the other service types shown here.
29808 @xref{system-extension-graph, the @command{guix system extension-graph}
29809 command}, for information on how to generate this representation for a
29810 particular operating system definition.
29812 @cindex service types
29813 Technically, developers can define @dfn{service types} to express these
29814 relations. There can be any number of services of a given type on the
29815 system---for instance, a system running two instances of the GNU secure
29816 shell server (lsh) has two instances of @code{lsh-service-type}, with
29817 different parameters.
29819 The following section describes the programming interface for service
29820 types and services.
29822 @node Service Types and Services
29823 @subsection Service Types and Services
29825 A @dfn{service type} is a node in the DAG described above. Let us start
29826 with a simple example, the service type for the Guix build daemon
29827 (@pxref{Invoking guix-daemon}):
29830 (define guix-service-type
29834 (list (service-extension shepherd-root-service-type guix-shepherd-service)
29835 (service-extension account-service-type guix-accounts)
29836 (service-extension activation-service-type guix-activation)))
29837 (default-value (guix-configuration))))
29841 It defines three things:
29845 A name, whose sole purpose is to make inspection and debugging easier.
29848 A list of @dfn{service extensions}, where each extension designates the
29849 target service type and a procedure that, given the parameters of the
29850 service, returns a list of objects to extend the service of that type.
29852 Every service type has at least one service extension. The only
29853 exception is the @dfn{boot service type}, which is the ultimate service.
29856 Optionally, a default value for instances of this type.
29859 In this example, @code{guix-service-type} extends three services:
29862 @item shepherd-root-service-type
29863 The @code{guix-shepherd-service} procedure defines how the Shepherd
29864 service is extended. Namely, it returns a @code{<shepherd-service>}
29865 object that defines how @command{guix-daemon} is started and stopped
29866 (@pxref{Shepherd Services}).
29868 @item account-service-type
29869 This extension for this service is computed by @code{guix-accounts},
29870 which returns a list of @code{user-group} and @code{user-account}
29871 objects representing the build user accounts (@pxref{Invoking
29874 @item activation-service-type
29875 Here @code{guix-activation} is a procedure that returns a gexp, which is
29876 a code snippet to run at ``activation time''---e.g., when the service is
29880 A service of this type is instantiated like this:
29883 (service guix-service-type
29884 (guix-configuration
29886 (use-substitutes? #f)))
29889 The second argument to the @code{service} form is a value representing
29890 the parameters of this specific service instance.
29891 @xref{guix-configuration-type, @code{guix-configuration}}, for
29892 information about the @code{guix-configuration} data type. When the
29893 value is omitted, the default value specified by
29894 @code{guix-service-type} is used:
29897 (service guix-service-type)
29900 @code{guix-service-type} is quite simple because it extends other
29901 services but is not extensible itself.
29903 @c @subsubsubsection Extensible Service Types
29905 The service type for an @emph{extensible} service looks like this:
29908 (define udev-service-type
29909 (service-type (name 'udev)
29911 (list (service-extension shepherd-root-service-type
29912 udev-shepherd-service)))
29914 (compose concatenate) ;concatenate the list of rules
29915 (extend (lambda (config rules)
29917 (($ <udev-configuration> udev initial-rules)
29918 (udev-configuration
29919 (udev udev) ;the udev package to use
29920 (rules (append initial-rules rules)))))))))
29923 This is the service type for the
29924 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
29925 management daemon}. Compared to the previous example, in addition to an
29926 extension of @code{shepherd-root-service-type}, we see two new fields:
29930 This is the procedure to @dfn{compose} the list of extensions to
29931 services of this type.
29933 Services can extend the udev service by passing it lists of rules; we
29934 compose those extensions simply by concatenating them.
29937 This procedure defines how the value of the service is @dfn{extended} with
29938 the composition of the extensions.
29940 Udev extensions are composed into a list of rules, but the udev service
29941 value is itself a @code{<udev-configuration>} record. So here, we
29942 extend that record by appending the list of rules it contains to the
29943 list of contributed rules.
29946 This is a string giving an overview of the service type. The string can
29947 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
29948 @command{guix system search} command searches these strings and displays
29949 them (@pxref{Invoking guix system}).
29952 There can be only one instance of an extensible service type such as
29953 @code{udev-service-type}. If there were more, the
29954 @code{service-extension} specifications would be ambiguous.
29956 Still here? The next section provides a reference of the programming
29957 interface for services.
29959 @node Service Reference
29960 @subsection Service Reference
29962 We have seen an overview of service types (@pxref{Service Types and
29963 Services}). This section provides a reference on how to manipulate
29964 services and service types. This interface is provided by the
29965 @code{(gnu services)} module.
29967 @deffn {Scheme Procedure} service @var{type} [@var{value}]
29968 Return a new service of @var{type}, a @code{<service-type>} object (see
29969 below). @var{value} can be any object; it represents the parameters of
29970 this particular service instance.
29972 When @var{value} is omitted, the default value specified by @var{type}
29973 is used; if @var{type} does not specify a default value, an error is
29976 For instance, this:
29979 (service openssh-service-type)
29983 is equivalent to this:
29986 (service openssh-service-type
29987 (openssh-configuration))
29990 In both cases the result is an instance of @code{openssh-service-type}
29991 with the default configuration.
29994 @deffn {Scheme Procedure} service? @var{obj}
29995 Return true if @var{obj} is a service.
29998 @deffn {Scheme Procedure} service-kind @var{service}
29999 Return the type of @var{service}---i.e., a @code{<service-type>} object.
30002 @deffn {Scheme Procedure} service-value @var{service}
30003 Return the value associated with @var{service}. It represents its
30007 Here is an example of how a service is created and manipulated:
30011 (service nginx-service-type
30012 (nginx-configuration
30014 (log-directory log-directory)
30015 (run-directory run-directory)
30016 (file config-file))))
30021 (eq? (service-kind s) nginx-service-type)
30025 The @code{modify-services} form provides a handy way to change the
30026 parameters of some of the services of a list such as
30027 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
30028 evaluates to a list of services. Of course, you could always use
30029 standard list combinators such as @code{map} and @code{fold} to do that
30030 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
30031 @code{modify-services} simply provides a more concise form for this
30034 @deffn {Scheme Syntax} modify-services @var{services} @
30035 (@var{type} @var{variable} => @var{body}) @dots{}
30037 Modify the services listed in @var{services} according to the given
30038 clauses. Each clause has the form:
30041 (@var{type} @var{variable} => @var{body})
30044 where @var{type} is a service type---e.g.,
30045 @code{guix-service-type}---and @var{variable} is an identifier that is
30046 bound within the @var{body} to the service parameters---e.g., a
30047 @code{guix-configuration} instance---of the original service of that
30050 The @var{body} should evaluate to the new service parameters, which will
30051 be used to configure the new service. This new service will replace the
30052 original in the resulting list. Because a service's service parameters
30053 are created using @code{define-record-type*}, you can write a succinct
30054 @var{body} that evaluates to the new service parameters by using the
30055 @code{inherit} feature that @code{define-record-type*} provides.
30057 @xref{Using the Configuration System}, for example usage.
30061 Next comes the programming interface for service types. This is
30062 something you want to know when writing new service definitions, but not
30063 necessarily when simply looking for ways to customize your
30064 @code{operating-system} declaration.
30066 @deftp {Data Type} service-type
30067 @cindex service type
30068 This is the representation of a @dfn{service type} (@pxref{Service Types
30073 This is a symbol, used only to simplify inspection and debugging.
30075 @item @code{extensions}
30076 A non-empty list of @code{<service-extension>} objects (see below).
30078 @item @code{compose} (default: @code{#f})
30079 If this is @code{#f}, then the service type denotes services that cannot
30080 be extended---i.e., services that do not receive ``values'' from other
30083 Otherwise, it must be a one-argument procedure. The procedure is called
30084 by @code{fold-services} and is passed a list of values collected from
30085 extensions. It may return any single value.
30087 @item @code{extend} (default: @code{#f})
30088 If this is @code{#f}, services of this type cannot be extended.
30090 Otherwise, it must be a two-argument procedure: @code{fold-services}
30091 calls it, passing it the initial value of the service as the first
30092 argument and the result of applying @code{compose} to the extension
30093 values as the second argument. It must return a value that is a valid
30094 parameter value for the service instance.
30096 @item @code{description}
30097 This is a string, possibly using Texinfo markup, describing in a couple
30098 of sentences what the service is about. This string allows users to
30099 find about the service through @command{guix system search}
30100 (@pxref{Invoking guix system}).
30102 @item @code{default-value} (default: @code{&no-default-value})
30103 The default value associated for instances of this service type. This
30104 allows users to use the @code{service} form without its second argument:
30107 (service @var{type})
30110 The returned service in this case has the default value specified by
30114 @xref{Service Types and Services}, for examples.
30117 @deffn {Scheme Procedure} service-extension @var{target-type} @
30119 Return a new extension for services of type @var{target-type}.
30120 @var{compute} must be a one-argument procedure: @code{fold-services}
30121 calls it, passing it the value associated with the service that provides
30122 the extension; it must return a valid value for the target service.
30125 @deffn {Scheme Procedure} service-extension? @var{obj}
30126 Return true if @var{obj} is a service extension.
30129 Occasionally, you might want to simply extend an existing service. This
30130 involves creating a new service type and specifying the extension of
30131 interest, which can be verbose; the @code{simple-service} procedure
30132 provides a shorthand for this.
30134 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
30135 Return a service that extends @var{target} with @var{value}. This works
30136 by creating a singleton service type @var{name}, of which the returned
30137 service is an instance.
30139 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
30143 (simple-service 'my-mcron-job mcron-service-type
30144 #~(job '(next-hour (3)) "guix gc -F 2G"))
30148 At the core of the service abstraction lies the @code{fold-services}
30149 procedure, which is responsible for ``compiling'' a list of services
30150 down to a single directory that contains everything needed to boot and
30151 run the system---the directory shown by the @command{guix system build}
30152 command (@pxref{Invoking guix system}). In essence, it propagates
30153 service extensions down the service graph, updating each node parameters
30154 on the way, until it reaches the root node.
30156 @deffn {Scheme Procedure} fold-services @var{services} @
30157 [#:target-type @var{system-service-type}]
30158 Fold @var{services} by propagating their extensions down to the root of
30159 type @var{target-type}; return the root service adjusted accordingly.
30162 Lastly, the @code{(gnu services)} module also defines several essential
30163 service types, some of which are listed below.
30165 @defvr {Scheme Variable} system-service-type
30166 This is the root of the service graph. It produces the system directory
30167 as returned by the @command{guix system build} command.
30170 @defvr {Scheme Variable} boot-service-type
30171 The type of the ``boot service'', which produces the @dfn{boot script}.
30172 The boot script is what the initial RAM disk runs when booting.
30175 @defvr {Scheme Variable} etc-service-type
30176 The type of the @file{/etc} service. This service is used to create
30177 files under @file{/etc} and can be extended by
30178 passing it name/file tuples such as:
30181 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
30184 In this example, the effect would be to add an @file{/etc/issue} file
30185 pointing to the given file.
30188 @defvr {Scheme Variable} setuid-program-service-type
30189 Type for the ``setuid-program service''. This service collects lists of
30190 executable file names, passed as gexps, and adds them to the set of
30191 setuid-root programs on the system (@pxref{Setuid Programs}).
30194 @defvr {Scheme Variable} profile-service-type
30195 Type of the service that populates the @dfn{system profile}---i.e., the
30196 programs under @file{/run/current-system/profile}. Other services can
30197 extend it by passing it lists of packages to add to the system profile.
30200 @cindex provenance tracking, of the operating system
30201 @anchor{provenance-service-type}
30202 @defvr {Scheme Variable} provenance-service-type
30203 This is the type of the service that records @dfn{provenance meta-data}
30204 in the system itself. It creates several files under
30205 @file{/run/current-system}:
30209 This is a ``channel file'' that can be passed to @command{guix pull -C}
30210 or @command{guix time-machine -C}, and which describes the channels used
30211 to build the system, if that information was available
30212 (@pxref{Channels}).
30214 @item configuration.scm
30215 This is the file that was passed as the value for this
30216 @code{provenance-service-type} service. By default, @command{guix
30217 system reconfigure} automatically passes the OS configuration file it
30218 received on the command line.
30221 This contains the same information as the two other files but in a
30222 format that is more readily processable.
30225 In general, these two pieces of information (channels and configuration
30226 file) are enough to reproduce the operating system ``from source''.
30229 This information is necessary to rebuild your operating system, but it
30230 is not always sufficient. In particular, @file{configuration.scm}
30231 itself is insufficient if it is not self-contained---if it refers to
30232 external Guile modules or to extra files. If you want
30233 @file{configuration.scm} to be self-contained, we recommend that modules
30234 or files it refers to be part of a channel.
30236 Besides, provenance meta-data is ``silent'' in the sense that it does
30237 not change the bits contained in your system, @emph{except for the
30238 meta-data bits themselves}. Two different OS configurations or sets of
30239 channels can lead to the same system, bit-for-bit; when
30240 @code{provenance-service-type} is used, these two systems will have
30241 different meta-data and thus different store file names, which makes
30242 comparison less trivial.
30245 This service is automatically added to your operating system
30246 configuration when you use @command{guix system reconfigure},
30247 @command{guix system init}, or @command{guix deploy}.
30250 @node Shepherd Services
30251 @subsection Shepherd Services
30253 @cindex shepherd services
30255 @cindex init system
30256 The @code{(gnu services shepherd)} module provides a way to define
30257 services managed by the GNU@tie{}Shepherd, which is the
30258 initialization system---the first process that is started when the
30259 system boots, also known as PID@tie{}1
30260 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
30262 Services in the Shepherd can depend on each other. For instance, the
30263 SSH daemon may need to be started after the syslog daemon has been
30264 started, which in turn can only happen once all the file systems have
30265 been mounted. The simple operating system defined earlier (@pxref{Using
30266 the Configuration System}) results in a service graph like this:
30268 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
30270 You can actually generate such a graph for any operating system
30271 definition using the @command{guix system shepherd-graph} command
30272 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
30274 The @code{%shepherd-root-service} is a service object representing
30275 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
30276 by passing it lists of @code{<shepherd-service>} objects.
30278 @deftp {Data Type} shepherd-service
30279 The data type representing a service managed by the Shepherd.
30282 @item @code{provision}
30283 This is a list of symbols denoting what the service provides.
30285 These are the names that may be passed to @command{herd start},
30286 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
30287 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
30288 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
30290 @item @code{requirement} (default: @code{'()})
30291 List of symbols denoting the Shepherd services this one depends on.
30293 @cindex one-shot services, for the Shepherd
30294 @item @code{one-shot?} (default: @code{#f})
30295 Whether this service is @dfn{one-shot}. One-shot services stop immediately
30296 after their @code{start} action has completed. @xref{Slots of services,,,
30297 shepherd, The GNU Shepherd Manual}, for more info.
30299 @item @code{respawn?} (default: @code{#t})
30300 Whether to restart the service when it stops, for instance when the
30301 underlying process dies.
30304 @itemx @code{stop} (default: @code{#~(const #f)})
30305 The @code{start} and @code{stop} fields refer to the Shepherd's
30306 facilities to start and stop processes (@pxref{Service De- and
30307 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
30308 G-expressions that get expanded in the Shepherd configuration file
30309 (@pxref{G-Expressions}).
30311 @item @code{actions} (default: @code{'()})
30312 @cindex actions, of Shepherd services
30313 This is a list of @code{shepherd-action} objects (see below) defining
30314 @dfn{actions} supported by the service, in addition to the standard
30315 @code{start} and @code{stop} actions. Actions listed here become available as
30316 @command{herd} sub-commands:
30319 herd @var{action} @var{service} [@var{arguments}@dots{}]
30322 @item @code{auto-start?} (default: @code{#t})
30323 Whether this service should be started automatically by the Shepherd. If it
30324 is @code{#f} the service has to be started manually with @code{herd start}.
30326 @item @code{documentation}
30327 A documentation string, as shown when running:
30330 herd doc @var{service-name}
30333 where @var{service-name} is one of the symbols in @code{provision}
30334 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
30336 @item @code{modules} (default: @code{%default-modules})
30337 This is the list of modules that must be in scope when @code{start} and
30338 @code{stop} are evaluated.
30343 @deftp {Data Type} shepherd-action
30344 This is the data type that defines additional actions implemented by a
30345 Shepherd service (see above).
30349 Symbol naming the action.
30351 @item documentation
30352 This is a documentation string for the action. It can be viewed by running:
30355 herd doc @var{service} action @var{action}
30359 This should be a gexp that evaluates to a procedure of at least one argument,
30360 which is the ``running value'' of the service (@pxref{Slots of services,,,
30361 shepherd, The GNU Shepherd Manual}).
30364 The following example defines an action called @code{say-hello} that kindly
30370 (documentation "Say hi!")
30371 (procedure #~(lambda (running . args)
30372 (format #t "Hello, friend! arguments: ~s\n"
30377 Assuming this action is added to the @code{example} service, then you can do:
30380 # herd say-hello example
30381 Hello, friend! arguments: ()
30382 # herd say-hello example a b c
30383 Hello, friend! arguments: ("a" "b" "c")
30386 This, as you can see, is a fairly sophisticated way to say hello.
30387 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
30391 @defvr {Scheme Variable} shepherd-root-service-type
30392 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
30394 This is the service type that extensions target when they want to create
30395 shepherd services (@pxref{Service Types and Services}, for an example).
30396 Each extension must pass a list of @code{<shepherd-service>}.
30399 @defvr {Scheme Variable} %shepherd-root-service
30400 This service represents PID@tie{}1.
30404 @node Documentation
30405 @chapter Documentation
30407 @cindex documentation, searching for
30408 @cindex searching for documentation
30409 @cindex Info, documentation format
30411 @cindex manual pages
30412 In most cases packages installed with Guix come with documentation.
30413 There are two main documentation formats: ``Info'', a browseable
30414 hypertext format used for GNU software, and ``manual pages'' (or ``man
30415 pages''), the linear documentation format traditionally found on Unix.
30416 Info manuals are accessed with the @command{info} command or with Emacs,
30417 and man pages are accessed using @command{man}.
30419 You can look for documentation of software installed on your system by
30420 keyword. For example, the following command searches for information
30421 about ``TLS'' in Info manuals:
30425 "(emacs)Network Security" -- STARTTLS
30426 "(emacs)Network Security" -- TLS
30427 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
30428 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
30433 The command below searches for the same keyword in man pages:
30437 SSL (7) - OpenSSL SSL/TLS library
30438 certtool (1) - GnuTLS certificate tool
30442 These searches are purely local to your computer so you have the
30443 guarantee that documentation you find corresponds to what you have
30444 actually installed, you can access it off-line, and your privacy is
30447 Once you have these results, you can view the relevant documentation by
30451 $ info "(gnutls)Core TLS API"
30461 Info manuals contain sections and indices as well as hyperlinks like
30462 those found in Web pages. The @command{info} reader (@pxref{Top, Info
30463 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
30464 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
30465 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
30466 Introduction}, for an introduction to Info navigation.
30468 @node Installing Debugging Files
30469 @chapter Installing Debugging Files
30471 @cindex debugging files
30472 Program binaries, as produced by the GCC compilers for instance, are
30473 typically written in the ELF format, with a section containing
30474 @dfn{debugging information}. Debugging information is what allows the
30475 debugger, GDB, to map binary code to source code; it is required to
30476 debug a compiled program in good conditions.
30478 The problem with debugging information is that is takes up a fair amount
30479 of disk space. For example, debugging information for the GNU C Library
30480 weighs in at more than 60 MiB. Thus, as a user, keeping all the
30481 debugging info of all the installed programs is usually not an option.
30482 Yet, space savings should not come at the cost of an impediment to
30483 debugging---especially in the GNU system, which should make it easier
30484 for users to exert their computing freedom (@pxref{GNU Distribution}).
30486 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
30487 mechanism that allows users to get the best of both worlds: debugging
30488 information can be stripped from the binaries and stored in separate
30489 files. GDB is then able to load debugging information from those files,
30490 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
30493 The GNU distribution takes advantage of this by storing debugging
30494 information in the @code{lib/debug} sub-directory of a separate package
30495 output unimaginatively called @code{debug} (@pxref{Packages with
30496 Multiple Outputs}). Users can choose to install the @code{debug} output
30497 of a package when they need it. For instance, the following command
30498 installs the debugging information for the GNU C Library and for GNU
30502 guix install glibc:debug guile:debug
30505 GDB must then be told to look for debug files in the user's profile, by
30506 setting the @code{debug-file-directory} variable (consider setting it
30507 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
30511 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
30514 From there on, GDB will pick up debugging information from the
30515 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
30517 In addition, you will most likely want GDB to be able to show the source
30518 code being debugged. To do that, you will have to unpack the source
30519 code of the package of interest (obtained with @code{guix build
30520 --source}, @pxref{Invoking guix build}), and to point GDB to that source
30521 directory using the @code{directory} command (@pxref{Source Path,
30522 @code{directory},, gdb, Debugging with GDB}).
30524 @c XXX: keep me up-to-date
30525 The @code{debug} output mechanism in Guix is implemented by the
30526 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
30527 opt-in---debugging information is available only for the packages
30528 with definitions explicitly declaring a @code{debug} output. This may be
30529 changed to opt-out in the future if our build farm servers can handle
30530 the load. To check whether a package has a @code{debug} output, use
30531 @command{guix package --list-available} (@pxref{Invoking guix package}).
30534 @node Security Updates
30535 @chapter Security Updates
30537 @cindex security updates
30538 @cindex security vulnerabilities
30539 Occasionally, important security vulnerabilities are discovered in software
30540 packages and must be patched. Guix developers try hard to keep track of
30541 known vulnerabilities and to apply fixes as soon as possible in the
30542 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
30543 containing only security updates). The @command{guix lint} tool helps
30544 developers find out about vulnerable versions of software packages in the
30549 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
30550 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
30551 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
30555 @xref{Invoking guix lint}, for more information.
30557 Guix follows a functional
30558 package management discipline (@pxref{Introduction}), which implies
30559 that, when a package is changed, @emph{every package that depends on it}
30560 must be rebuilt. This can significantly slow down the deployment of
30561 fixes in core packages such as libc or Bash, since basically the whole
30562 distribution would need to be rebuilt. Using pre-built binaries helps
30563 (@pxref{Substitutes}), but deployment may still take more time than
30567 To address this, Guix implements @dfn{grafts}, a mechanism that allows
30568 for fast deployment of critical updates without the costs associated
30569 with a whole-distribution rebuild. The idea is to rebuild only the
30570 package that needs to be patched, and then to ``graft'' it onto packages
30571 explicitly installed by the user and that were previously referring to
30572 the original package. The cost of grafting is typically very low, and
30573 order of magnitudes lower than a full rebuild of the dependency chain.
30575 @cindex replacements of packages, for grafts
30576 For instance, suppose a security update needs to be applied to Bash.
30577 Guix developers will provide a package definition for the ``fixed''
30578 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
30579 Packages}). Then, the original package definition is augmented with a
30580 @code{replacement} field pointing to the package containing the bug fix:
30587 (replacement bash-fixed)))
30590 From there on, any package depending directly or indirectly on Bash---as
30591 reported by @command{guix gc --requisites} (@pxref{Invoking guix
30592 gc})---that is installed is automatically ``rewritten'' to refer to
30593 @code{bash-fixed} instead of @code{bash}. This grafting process takes
30594 time proportional to the size of the package, usually less than a
30595 minute for an ``average'' package on a recent machine. Grafting is
30596 recursive: when an indirect dependency requires grafting, then grafting
30597 ``propagates'' up to the package that the user is installing.
30599 Currently, the length of the name and version of the graft and that of
30600 the package it replaces (@code{bash-fixed} and @code{bash} in the example
30601 above) must be equal. This restriction mostly comes from the fact that
30602 grafting works by patching files, including binary files, directly.
30603 Other restrictions may apply: for instance, when adding a graft to a
30604 package providing a shared library, the original shared library and its
30605 replacement must have the same @code{SONAME} and be binary-compatible.
30607 The @option{--no-grafts} command-line option allows you to forcefully
30608 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
30612 guix build bash --no-grafts
30616 returns the store file name of the original Bash, whereas:
30623 returns the store file name of the ``fixed'', replacement Bash. This
30624 allows you to distinguish between the two variants of Bash.
30626 To verify which Bash your whole profile refers to, you can run
30627 (@pxref{Invoking guix gc}):
30630 guix gc -R `readlink -f ~/.guix-profile` | grep bash
30634 @dots{} and compare the store file names that you get with those above.
30635 Likewise for a complete Guix system generation:
30638 guix gc -R `guix system build my-config.scm` | grep bash
30641 Lastly, to check which Bash running processes are using, you can use the
30642 @command{lsof} command:
30645 lsof | grep /gnu/store/.*bash
30649 @node Bootstrapping
30650 @chapter Bootstrapping
30652 @c Adapted from the ELS 2013 paper.
30654 @cindex bootstrapping
30656 Bootstrapping in our context refers to how the distribution gets built
30657 ``from nothing''. Remember that the build environment of a derivation
30658 contains nothing but its declared inputs (@pxref{Introduction}). So
30659 there's an obvious chicken-and-egg problem: how does the first package
30660 get built? How does the first compiler get compiled? Note that this is
30661 a question of interest only to the curious hacker, not to the regular
30662 user, so you can shamelessly skip this section if you consider yourself
30663 a ``regular user''.
30665 @cindex bootstrap binaries
30666 The GNU system is primarily made of C code, with libc at its core. The
30667 GNU build system itself assumes the availability of a Bourne shell and
30668 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
30669 `grep'. Furthermore, build programs---programs that run
30670 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
30671 (@pxref{Derivations}). Consequently, to be able to build anything at
30672 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
30673 Binutils, libc, and the other packages mentioned above---the
30674 @dfn{bootstrap binaries}.
30676 These bootstrap binaries are ``taken for granted'', though we can also
30677 re-create them if needed (@pxref{Preparing to Use the Bootstrap
30681 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
30682 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
30685 @node Reduced Binary Seed Bootstrap
30686 @section The Reduced Binary Seed Bootstrap
30688 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
30689 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
30690 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
30691 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
30692 ``taken for granted.''
30694 Taking the bootstrap binaries for granted means that we consider them to
30695 be a correct and trustworthy ``seed'' for building the complete system.
30696 Therein lies a problem: the combined size of these bootstrap binaries is
30697 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
30698 or even inspecting these is next to impossible.
30700 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
30701 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
30702 Source Bootstrap'' and while we are working towards that goal it would
30703 be hyperbole to use that term for what we do now.}.
30705 The Reduced Binary Seed bootstrap removes the most critical tools---from a
30706 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
30707 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
30708 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
30709 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
30711 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
30712 C Library are built from source. From here on the more traditional
30713 bootstrap process resumes. This approach has reduced the bootstrap
30714 binaries in size to about 145MB in Guix v1.1.
30716 The next step that Guix has taken is to replace the shell and all its
30717 utilities with implementations in Guile Scheme, the @emph{Scheme-only
30718 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
30719 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
30720 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
30721 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
30722 removed are now built from source.
30724 Building the GNU System from source is currently only possibly by adding
30725 some historical GNU packages as intermediate steps@footnote{Packages
30726 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
30727 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
30728 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
30729 and GNU packages become more bootstrappable again (e.g., new releases of
30730 GNU Sed will also ship as gzipped tarballs again, as alternative to the
30731 hard to bootstrap @code{xz}-compression), this set of added packages can
30732 hopefully be reduced again.
30734 The graph below shows the resulting dependency graph for
30735 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
30736 traditional bootstrap of the rest of the Guix System.
30738 @c ./pre-inst-env guix graph -e '(@@ (gnu packages commencement) gcc-core-mesboot0)' | sed -re 's,((bootstrap-mescc-tools|bootstrap-mes|guile-bootstrap).*shape =) box,\1 ellipse,' > doc/images/gcc-core-mesboot0-graph.dot
30739 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
30741 The only significant binary bootstrap seeds that remain@footnote{
30742 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
30743 together with @code{mes}.} are a Scheme intepreter and a Scheme
30744 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
30745 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
30746 to get Guile running.}.
30748 This further reduction has brought down the size of the binary seed to
30749 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
30751 Work is ongoing to remove all binary blobs from our free software
30752 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
30753 is work to bring these bootstraps to the @code{arm-linux} and
30754 @code{aarch64-linux} architectures and to the Hurd.
30756 If you are interested, join us on @samp{#bootstrappable} on the Freenode
30757 IRC network or discuss on @email{bug-mes@@gnu.org} or
30758 @email{gash-devel@@nongnu.org}.
30760 @node Preparing to Use the Bootstrap Binaries
30761 @section Preparing to Use the Bootstrap Binaries
30763 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
30764 @c large image, it's hard to scroll. Oh well.
30765 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
30767 The figure above shows the very beginning of the dependency graph of the
30768 distribution, corresponding to the package definitions of the @code{(gnu
30769 packages bootstrap)} module. A similar figure can be generated with
30770 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
30773 guix graph -t derivation \
30774 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
30775 | dot -Tps > gcc.ps
30778 or, for the further Reduced Binary Seed bootstrap
30781 guix graph -t derivation \
30782 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
30783 | dot -Tps > mes.ps
30786 At this level of detail, things are
30787 slightly complex. First, Guile itself consists of an ELF executable,
30788 along with many source and compiled Scheme files that are dynamically
30789 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
30790 tarball shown in this graph. This tarball is part of Guix's ``source''
30791 distribution, and gets inserted into the store with @code{add-to-store}
30792 (@pxref{The Store}).
30794 But how do we write a derivation that unpacks this tarball and adds it
30795 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
30796 derivation---the first one that gets built---uses @code{bash} as its
30797 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
30798 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
30799 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
30800 the Guix source distribution, whose sole purpose is to allow the Guile
30801 tarball to be unpacked.
30803 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
30804 Guile that can be used to run subsequent build programs. Its first task
30805 is to download tarballs containing the other pre-built binaries---this
30806 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
30807 @code{ftp-client.scm} are used for this purpose. The
30808 @code{module-import.drv} derivations import those modules in a directory
30809 in the store, using the original layout. The
30810 @code{module-import-compiled.drv} derivations compile those modules, and
30811 write them in an output directory with the right layout. This
30812 corresponds to the @code{#:modules} argument of
30813 @code{build-expression->derivation} (@pxref{Derivations}).
30815 Finally, the various tarballs are unpacked by the derivations
30816 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
30817 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
30818 point we have a working C tool chain.
30820 @unnumberedsec Building the Build Tools
30822 Bootstrapping is complete when we have a full tool chain that does not
30823 depend on the pre-built bootstrap tools discussed above. This
30824 no-dependency requirement is verified by checking whether the files of
30825 the final tool chain contain references to the @file{/gnu/store}
30826 directories of the bootstrap inputs. The process that leads to this
30827 ``final'' tool chain is described by the package definitions found in
30828 the @code{(gnu packages commencement)} module.
30830 The @command{guix graph} command allows us to ``zoom out'' compared to
30831 the graph above, by looking at the level of package objects instead of
30832 individual derivations---remember that a package may translate to
30833 several derivations, typically one derivation to download its source,
30834 one to build the Guile modules it needs, and one to actually build the
30835 package from source. The command:
30838 guix graph -t bag \
30839 -e '(@@@@ (gnu packages commencement)
30840 glibc-final-with-bootstrap-bash)' | xdot -
30844 displays the dependency graph leading to the ``final'' C
30845 library@footnote{You may notice the @code{glibc-intermediate} label,
30846 suggesting that it is not @emph{quite} final, but as a good
30847 approximation, we will consider it final.}, depicted below.
30849 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
30851 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
30852 The first tool that gets built with the bootstrap binaries is
30853 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
30854 for all the following packages. From there Findutils and Diffutils get
30857 Then come the first-stage Binutils and GCC, built as pseudo cross
30858 tools---i.e., with @option{--target} equal to @option{--host}. They are
30859 used to build libc. Thanks to this cross-build trick, this libc is
30860 guaranteed not to hold any reference to the initial tool chain.
30862 From there the final Binutils and GCC (not shown above) are built. GCC
30863 uses @command{ld} from the final Binutils, and links programs against
30864 the just-built libc. This tool chain is used to build the other
30865 packages used by Guix and by the GNU Build System: Guile, Bash,
30868 And voilà! At this point we have the complete set of build tools that
30869 the GNU Build System expects. These are in the @code{%final-inputs}
30870 variable of the @code{(gnu packages commencement)} module, and are
30871 implicitly used by any package that uses @code{gnu-build-system}
30872 (@pxref{Build Systems, @code{gnu-build-system}}).
30875 @unnumberedsec Building the Bootstrap Binaries
30877 @cindex bootstrap binaries
30878 Because the final tool chain does not depend on the bootstrap binaries,
30879 those rarely need to be updated. Nevertheless, it is useful to have an
30880 automated way to produce them, should an update occur, and this is what
30881 the @code{(gnu packages make-bootstrap)} module provides.
30883 The following command builds the tarballs containing the bootstrap binaries
30884 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
30885 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
30886 and Guile, and a tarball containing a mixture of Coreutils and other basic
30887 command-line tools):
30890 guix build bootstrap-tarballs
30893 The generated tarballs are those that should be referred to in the
30894 @code{(gnu packages bootstrap)} module mentioned at the beginning of
30897 Still here? Then perhaps by now you've started to wonder: when do we
30898 reach a fixed point? That is an interesting question! The answer is
30899 unknown, but if you would like to investigate further (and have
30900 significant computational and storage resources to do so), then let us
30903 @unnumberedsec Reducing the Set of Bootstrap Binaries
30905 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
30906 binary code! Why is that a problem? It's a problem because these big chunks
30907 of binary code are practically non-auditable, which makes it hard to establish
30908 what source code produced them. Every unauditable binary also leaves us
30909 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
30910 paper @emph{Reflections on Trusting Trust}.
30912 This is mitigated by the fact that our bootstrap binaries were generated
30913 from an earlier Guix revision. Nevertheless it lacks the level of
30914 transparency that we get in the rest of the package dependency graph,
30915 where Guix always gives us a source-to-binary mapping. Thus, our goal
30916 is to reduce the set of bootstrap binaries to the bare minimum.
30918 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
30919 on-going projects to do that. One of these is about replacing the
30920 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
30921 of increasing complexity, which could be built from source starting from
30922 a simple and auditable assembler.
30924 Our first major achievement is the replacement of of GCC, the GNU C Library
30925 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
30926 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
30927 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
30928 bootstrapped yet and thus we inject them as binary seeds. We call this the
30929 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
30930 binaries! Also, it has eliminated the C compiler binary; i686-linux and
30931 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
30933 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
30934 also looking at any other bootstrap binaries. Your help is welcome!
30937 @chapter Porting to a New Platform
30939 As discussed above, the GNU distribution is self-contained, and
30940 self-containment is achieved by relying on pre-built ``bootstrap
30941 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
30942 operating system kernel, CPU architecture, and application binary
30943 interface (ABI). Thus, to port the distribution to a platform that is
30944 not yet supported, one must build those bootstrap binaries, and update
30945 the @code{(gnu packages bootstrap)} module to use them on that platform.
30947 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
30948 When everything goes well, and assuming the GNU tool chain supports the
30949 target platform, this can be as simple as running a command like this
30953 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
30956 For this to work, the @code{glibc-dynamic-linker} procedure in
30957 @code{(gnu packages bootstrap)} must be augmented to return the right
30958 file name for libc's dynamic linker on that platform; likewise,
30959 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
30960 taught about the new platform.
30962 Once these are built, the @code{(gnu packages bootstrap)} module needs
30963 to be updated to refer to these binaries on the target platform. That
30964 is, the hashes and URLs of the bootstrap tarballs for the new platform
30965 must be added alongside those of the currently supported platforms. The
30966 bootstrap Guile tarball is treated specially: it is expected to be
30967 available locally, and @file{gnu/local.mk} has rules to download it for
30968 the supported architectures; a rule for the new platform must be added
30971 In practice, there may be some complications. First, it may be that the
30972 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
30973 above) is not recognized by all the GNU tools. Typically, glibc
30974 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
30975 configure flag (see @code{gcc.scm} for examples of how to handle this).
30976 Second, some of the required packages could fail to build for that
30977 platform. Lastly, the generated binaries could be broken for some
30980 @c *********************************************************************
30981 @include contributing.texi
30983 @c *********************************************************************
30984 @node Acknowledgments
30985 @chapter Acknowledgments
30987 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
30988 which was designed and
30989 implemented by Eelco Dolstra, with contributions from other people (see
30990 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
30991 management, and promoted unprecedented features, such as transactional
30992 package upgrades and rollbacks, per-user profiles, and referentially
30993 transparent build processes. Without this work, Guix would not exist.
30995 The Nix-based software distributions, Nixpkgs and NixOS, have also been
30996 an inspiration for Guix.
30998 GNU@tie{}Guix itself is a collective work with contributions from a
30999 number of people. See the @file{AUTHORS} file in Guix for more
31000 information on these fine people. The @file{THANKS} file lists people
31001 who have helped by reporting bugs, taking care of the infrastructure,
31002 providing artwork and themes, making suggestions, and more---thank you!
31005 @c *********************************************************************
31006 @node GNU Free Documentation License
31007 @appendix GNU Free Documentation License
31008 @cindex license, GNU Free Documentation License
31009 @include fdl-1.3.texi
31011 @c *********************************************************************
31012 @node Concept Index
31013 @unnumbered Concept Index
31016 @node Programming Index
31017 @unnumbered Programming Index
31018 @syncodeindex tp fn
31019 @syncodeindex vr fn
31024 @c Local Variables:
31025 @c ispell-local-dictionary: "american";